Neurology I Flashcards
most common location for canine glioma?
frontal (inclusive of olfactory) 34%
What immunohistochemical marker is a reliable marker of glial differentiation in biopsy or necropsy samples
olig2
*oligos tend to have strong diffuse immunoreactivity, astros have variable reactivity
Koehler 2018
what lesions are hyperintense on T1?
3 F’s and 4 M’s
F: fat ; slow flow, proteinaceous fluid
M:melanin, methemoglobin, mineralisation,
Magnevist (gadolinium contrast)
20% of dogs with CSM have lesions present at which 2 sites?
C5/6, C6/7
Sharp
What are the primary indications for distraction and stabilization for CSM?
- presence of a traction-responsive lesion
- to relieve nerve root compression
How does long-term clorazepate treatment alter phenobarbital level?
increases phenobarbital level
Adverse effects associated with lomustine treatment for MUO?
leukopenia
severe thrombocytopenia
hemorrhagic gastroenteritis
flegel 2011
GABA binding to GABA-B receptor results in…
opens K+ channels and closes Ca2+ channels –> hyperpolarization
Blades Golubovic 2017
How do inotropic glutamate receptors function? What are examples of inotropic glutamate receptors? (3)
Inotropic - influx of sodium and efflux of potassium through inotropic channel –> depolarization –> AP generation
- AMPA - kainate - NMDA - has a Ca channel that becomes permeable to calcium during local membrane depolarization
Blades Golubovic 2017
what special stain will demonstrate chromatolysis better than H&E?
cresyl violet
T/F: in general, the closer to the cell body the axonal lesion, the more likely is the cell to die
true
What type of chromatolysis is induced in motor neuron degenerations described in various species?
central chromatolysis
_____ ______ is loss of cytoplasmic bulk and reduction in size. When might it be expected?
neuronal atrophy might be expected in situations of permanent loss of synaptic connections (as when axons undergo wallerian degeneration but fail to regenerate)
What is the predominant intermediate filament type expressed in meningiomas?
vimentin
an immunohistochemical panel consisting of _____, ______, and _____ has been proposed for the characterization of canine and feline meningiomas from other neoplasias
- vimentin
- CD34
- E-cadherin
Three external landmarks used to locate the tympanic bulla?
- mandibular symphysis
- caudal border of the mandible
- larynx
3 proposed mechanisms of action of phenobarbital
- increasing neuronal responsiveness to GABA
- antiglutamate effects
- decreasing calcium flow into neurons
Fecal incontinence was ____ times more likely in dogs presented with clinical signs compatible with spinal shock
2x
Mari 2019
What characteristics can be used to differentiate ishcemic myelopathy from ANNPE?
- length and directional pattern of intramedullary hyperintensity of the spinal cord on T2W images - ischemic myelopathy - hyperintense intramedullary lesion is long and ill-defined and has a longitudinal pattern - ANNPE - lesion is short and well-defined with caudoventral to craniodorsal oblique directional pattern originated from the affected intervertebral disc, corresponding NP has normal signal intensity but decreased volume
- finding of meningeal and epidural fat enhancement on T1W FS sequences –> ANNPE
(Specchi 2016)
What is seen on histopathology of extruded material in dogs with ANNPE?
cartilaginous material with areas of variable degeneration consistent with a final diagnosis of extrusion of partially degenerated nucleus pulposus
Falzone, 2016
Mari 2017 (157 dogs with ANNPE, 44 dogs with FCEM) - T/F a significant difference was found between groups for the development of urinary incontinence, presence of persistent motor deficits and time to recovery f
False - no significant difference was found for these variables
T/F: no significant difference between CSF lactate concentrations was found between: dogs with clinical signs and MRI evidence of structural intracranial disease -AND - dogs with clinical signs of intracranial disease and normal MRI
true
Beedicenti 2018
How does CSF TNCC influence survival time in dogs with MUO? relapse rate?
lower CSF TNCC significantly associated with improved survival in dogs with MUO (Oliphant 2017)
Niether CSF TNCC nor protein concentration had an effect on survival time in 148 dogs with MUO (Cornelis 2019)
Lowrie et al 2013 identified an association between abnormal CSF analysis and relapse or poor outcome in 29 dogs with MUO
Studies suggest that ___% of dogs with GME die before being treated
15%
Cornelis 2019
Binding of GABA to GABA-A receptors causes……
what drugs are GABA-A agonists?
binding of GABA to GABA-A receptors causes influx of Cl –> hyperpolarization
benzodiazepines and barbituates work through this manner
MOA of metatropic glutamate receptors?
second messenger system to increase inward currents of Na and Ca2+ –> leads to depolarization
Blades Golubovic 2017
How does increase vs. decrease in MAP alter vascular tone?
increase MAP –> vascular constriction
Decrease MAP –> vascular dilation
What two conditions are associated with atherosclerosis?
Hypothyroidism
primary hyperlipidemia
Which 3 processes are important in primary injury of ischemic cerebrovascular disease
- Failure of Na/K ATPase –> cytotoxic edema
- Failure of aerobic metabolism –> lactic acidosis -> cytotoxicity
- Loss of ionic gradients –> depolarization of resting potential and increased Ca2+ release –> activation of proteases and phospholipases –> membrane damage and
free radical formation
Boudreau 2018
What two processes are key in secondary injury in ischemic cerebrovascular disease?
- Damage to BBB –> vasogenic edema and inflammatory cell infiltrate
- severe endothelial injury “hemorrhagic conversion” occurs = extravasation of all blood components through compromised capillaries
Boudreae 2018
When is contrast enhancement secondary to ischemic cerebrovascular disease most evident?
7-10 days after clinical onset
Boudreae 2018
In dogs with multiple nontraumatic ICH > 5mm, outcome was poor in ___%
70%
What is neurologic claudication?
Lameness/weakness that worsens with exercise and resolves to some degree with rest
Neurologic claudication is due to failure of arterial wall vasodilation in affected nerve roots during exercise
Sharp and Wheeler
What surgery is recommended to surgically address LS telescoping?
Dorsal fixation-fusion
Sharp and wheeler
2 mechanisms by which proteins/toxins leave the CNS parenchyma?
- perivascular spaces
- diffusion through the pia mater into the subarachnoid space
(Di Terlizzi 2006)
Where is the area postrema located? What is it’s function?
Located on the dorsal surface of the medulla oblongata at the caudal end of the 4th ventricle -chemoreceptor trigger zone for emesis
positioned to detect emetic toxins, changes in plasma osmolality, glucose, and electrolytes
(Di Terlizzi 2006)
What enzyme is increased in lymphoma of the CNS?
LDH
(Di Terlizzi 2006)
what proteins are found in CSF and synthesized intrathecally? (4)
beta/gamma globulins
tau protei
glial fibrillary acidic protein
myelin basic protein
(Di Terlizzi 2006)
What dye is considered the most specific technique for CSF total protein determination? How is this different for dogs?
Pyrogallol red
underestimates CSF total protein in dogs due to 20% lower affinity for globulins than for albumins
(Di Terlizzi 2006)
Name the 4 ligaments involving C1 and 2
- transverse ligament of the atlas
- apical ligaments of the dens (dens to foramen magnum)
- alar ligaments (dens to occipital bones)
- dorsal atlantoaxial ligament (dorsal arch of C1 - spinous processes of C2)
Which area of the brain has the richest blood supply?
Hypothalamus
Kings
the cranial and caudal vertebral body growth plates close at about ___ mos in dogs
11 mos
Sharp
What are the three branches of the vertebral artery associated with the vertebral column?
- dorsal muscular branch (located caudal to the articular processes and can be harmed during cervical hemi)
- ventral muscular branch
- spinal branch
(Sharp)
Blood from the dorsal surface of the forebrain drains into the _____ dorsal deep part of the forebrain drains to _____ ventral surface of the forebrain_____
- Dorsal surface of the forebrain –> dorsal saggital sinus
- Dorsal deep part of the forebrain –> great cerebral vein
- Ventral surface of the forebrain –> dorsal petrosal sinus
Kings
Where is the origin and insertion of the longus colli muscles?
Origin: transverse process (ventral border) of C3 - C6 Insert: Ventral spine of the next preceding vertebrae
The most cranial segment ends on the ventral tubercle of the atlas
Action: flex the neck
What is the main product of retrograde axonal transport?
Lysosomes
(Kings)
What are the 4 “dorsal root ganglia” that primary afferent neurons of the cranial nerves pass through when forming reflex arcs?
1) trigeminal ganglion
2) geniculate ganglion of the facial nerve
3) proximal and distal ganglion of the glossopharyngeal nerve
4) proximal or distal ganglion of the vagus nerve
Kings
What tract is thought to play the role of the spinothalamic tract in domestic animals?
Spinocervical tract = spinocervicothalamic tract
(Kings)
How does the spinothalamic tract vary in domestic mammals from man?
1) poorly defined
2) Multisynaptic
3) tends to be bilateral rather than unilateral
4) the modalities it transmits are uncertain
(king’s)
What histologic lesions are seen in the temporal cortex, hippocampus and piriform one after seizures?
edema
neovascularization
reactive astrocytosis
acute neuronal necrosis
Volk et al
Characteristics of epilepsy in the English Springer Spaniel? (seizure characteristics, age of onset, genetic basis and sex influence)
Partial and generalized seizures
age of onset < 6y old
partially penetrant autosomal recessive or polygenic inheritance No bias
Ekenstedt et al
Characteristics of IE in Petit basset Griffon Vendeen? (seizure characteristics, age of onset, genetic basis and sex influence)
Mostly focal onset, some with secondary generalization
Mean of 2.2y
Likely hereditary basis owing to clustering within litters
no sex bias
ekenstedt et al
Characteristics of epilepsy in Labrador retrievers? (seizure characteristics, age of onset, genetic basis and sex influence)
partial and generalized seizures
onset 1 - 3y, under 4y
polygenic autosomal recessive no sex bias
ekenstedt et al
What are the 2 most common causes for reactive seizures?
Intoxications
Hypoglycemia
brauer et al
What is the MOA of pregabalin?
binds to the α2δ subunit of voltage-gated Ca channel (GABA receptor)
Dewey 2009
What is the half life of pregabalin in dogs?
7h
(Dewey 2009)
Adverse effects of pregabalin in dogs?
ataxia
sedation
elevated liver enzymes
(Dewey 2009)
How does KBr alter thyroid function?
it doesn’t
“therapeutic administration of KBr in dogs was not found to affect thyroid weight or serum TT4/FT4, TT3 or TSH or to cause histologic changes/thyroid gland weight changes”
(Baird-Heinz et al, 2012)
The _____ is buried deeply in the piriform lobe, consists of a complex of nuclei, and is part of the limbic system
Amygdaloid body
(king’s)
Describe the parasympathetic innervation of the mandibular salivary gland
1) Parasympathetic nucleus CN 7 = salvatory nucleus –> CN VII –> chorda tympani -> lingual nerve (Br of V3)
2) Mandibular ganglion
3) Mandibular gland
CN 7 –> CN 5 RG
What afferent pathways are NOT transmitted through the ascending reticular formation?
muscle proprioception
joint proprioception
King’s
_____% of dogs improved postoperatively after FMD w/ cranioplasty
81%
Dewey et al 2007
It is recommended that hypothyroid dogs with vWF and prolonged bleeding times be given thyroid hormone supplementation for _____h prior to surgery
48h
DeRisio et al 2001
What imaging findings are associated with phantom scratching in the CKCS?
mid-cervical syrinx with a transverse width greater than 4mm
-and/or-
syrinx extension to the region of the superficial dorsal horn
Knowler et al 2018
What clinical signs can be observed in dogs that develop spinal cord damage from syrinx?
scoliosis, weakness, proprioceptive deficits
Knowler et al 2018
T/F: There was a mismatch or rearrangement of neural parenchyma with SM-affected dogs?
True
Knowler et al 2018
How does head position alter imaging findings in dogs with CM/SM?
- no difference in volumetric measurement of the neural parenchyma with changes in head position during MRI
- The CSF space between the cerebellum and brainstem was larger in the flexed position
Knowler et al 2018
Both pain and syrinx size are positively correlated with….
Syrinxes located in the dorsal half of the spinal cord
Knowler et al 2018
The presence of a CSF flow void in the mesencephalic aqueduct associated with ventricular enlargement and SM in dogs suggests….
CSF turbulence and possibly reduced intracranial compliance
Knowler et al 2018
What is different about the development of the spheno-occipital synchondrosis in CKCS and brachycephelic breeds?
Early closure (even earlier in CKCS) \*suspected to be result in basicranium
The ______________ ____________ ____________ cells which delaminate from the dorsal neural tube, contribute not only to the peripheral nervous system, but also to the ectomesenchymal precursors that underpins the cranial skeleton and thus the potential to influence irregularities associated with CM
The multipotent neural crest cells which delaminate from the dorsal neural tube, contribute not only to the peripheral nervous system, but also to the ectomesenchymal precursors that underpins the cranial skeleton and thus the potential to influence irregularities associated with CM
Knowler et al 2018
What is the definition of atlanto-occipital overlapping?
ingavination of the odontoid process into the foramen magnum with ventral brainstem compression
Knowler et al 2018
Is medullary kinking, or dorsal spinal cord compression more strongly associated with CM/SM-related clinical signs?
Medullary kinking significantly higher in dogs with CM/SM related clinical signs
No statistical difference was detected in dorsal spinal cord compression between the 2 groups
Kiviranta et al 2017
drawback to ultrasonic aspirators for resection of intra-axial masses?
- heat and vibration generated during use may damage adjacent normal parenchyma or cranial nerves
- neoplastic cells may be aerosolized and seeded to other areas of the brain
Packer and McGrath 2020
What is the histopathologic finding associated with meningeal fibrosis in pugs?
circumferential meningeal fibrosis with concomitant focal, malacic destruction of the neuroparenchyma in the thoracolumbar spinal cord in 24/30 pugs
vertebra lesions accompanied the focal spinal cord lesion, and lympho-histiocytic inflammation associated or not to the parenchymal lesion in 43% of the pugs
Rohdin et al 2020
MRI vs. CT for detecting CM and SM - which has best agreement between evaluators. Which is more sensitive? Which is more specific?
MRI - most agreement
MRI - most sensitivity for cerebellar herniation and SM
MRI and CT have equal specificity for identifying cerebellar herniation
CT - more specific for identifying SM
Weber et al 2020
What % of patients improved after C-LOX distraction/stabilization for CCSM?
10/11 (90%)
King et al 2020
What are the signs and progression seen in Cocker Spaniels with neuronal abiotrophy?
Onset of signs at 1 year old, disease progresses slowly over several months
Dewey
What neurochemical changes occur in the aging brain and are thought to contribute to cognitive impairment?
decline in: acetylcholine, dopamine, norepinephrine, serotonin, and GABA
increase in: acetylcholinesterase, MOA B
CSF: elevated lactate, pyruvate, and potassium
Dewey
Potential causes for Congenital hydrocephalus? (5)
1) intraventricular hemorrhage (dystocia related)
2) viral infections (parainfluenza in digs, coronavirus in cats)
3) Teratogen exposure
4) Nutritional deficiencies (vitamin A)
5) heritable malformations
Dewey
What is convection-enhanced delivery of chemo for brain tumors?
infusion catheter inserted into the region to be treated
the chemotherapeutic agent is infused via the catheter through the interstitial spaces under a pressure gradient
(Dewey)
MRI findings associated with clinically relevant hydrocephalus? (7)
Elevation of the corpus callosum
Dorsoventral flattening of the interthalamic adhesion
Periventricular edema
Dilation of the olfactory recesses
Thinning of the cortical sulci and/or subarachnoid space
Disruption of the internal capsule adjacent to the caudate nucleus
Ventricle/brain-index - significantly higher in dogs with relevant hydrocephalus
(Laubner 2015)
What is the “hydrodynamic theory” of congenital hydrocephalus?
Hydrocephalus develops due to abnormal (reduced) intracranial compliance
Hydrocephalic patients are believed to have poor intracranial compliance –> increased capillary pulse pressure –> pulsatile transmantle pressure gradient directed from the cerebral tissue toward the lateral ventricles –> rebound pressure from recurring gradient as well as hyperdynamic CSF flow in the mesencephalic aqueduct leads to progressive ventricular enlargement.
Dewey
*abnormal capillary pulsations occur within normal mean ICP
The ______________ ____________ ____________ cells which delaminate from the dorsal neural tube, contribute not only to the peripheral nervous system, but also to the ectomesenchymal precursors that underpins the cranial skeleton and thus the potential to influence irregularities associated with CM
The multipotent neural crest cells which delaminate from the dorsal neural tube, contribute not only to the peripheral nervous system, but also to the ectomesenchymal precursors that underpins the cranial skeleton and thus the potential to influence irregularities associated with CM
Knowler et al 2018
Name 5 anomalous/developmental encephalopathies?
- Congenital hydrocephalus
- Caudal occipital malformation syndrome
- Intracranial arachnoid “cyst”
- Neuronal migration disorders Dandy-walker syndrome
- Miscellaneous malformations
Dewey
in globoid cell leukodystrophy, the deficient enzyme leads to the accumulation of ______ which is toxic to which cells?
in globoid cell leukodystrophy, the deficient enzyme leads to the accumulation of psychosine (splingolipid) which is toxic to
oligodendrocytes and Schwann cells
White matter in the CNS and PNS are affected
(Dewey)
The natural course of paroxysmal dyskinesia is self-limiting in which two breeds of dogs?
labrador retrievers
JRT
32% of dogs undergoing spontaneous remission
75% of dogs showing marked improvement
T/F: study on chihuahuas with CM/SM found that the width of syrinx is associated with clinical signs?
False
Kiviranta et al 2017
Causes of thiamine deficiency in cats? Dogs?
Cats - feeding all fish diet (high in thiaminase)
Dogs - overcooking canned food or meat (heat destruction of thiamine), meat preserved with sulfur dioxide, possibly amprolium induced?
(Dewey)
What are the second and third most common feline brain tumors?
1) meningioma 2) multicentric lymphoma 3) Pituitary tumor
(Dewey)
What two CCJ abnormalities are thought to play an important role in the pathogenesis of SM and neuropathic pain in chihuahuas
medullary elevation dorsal spinal cord compression
What are the two forms of gliomatosis cerebri?
Type I (more common) - diffusely infiltrative form. No mass effect Type II - mass lesion in addition to diffuse neoplastic infiltration Dewey
Underlying cause for organic acidurias?
inherited (usually autosomal recessive) deficiencies of mitochrondrial respiratory chain enzymes (some involve cytosolic enzymes) - enzyme deficiency leads to accumulation of 1+ organic acids - organic acids accumulate in serum, CSF or urine - differ from mitochondrial encephalopathy in the presence of accumulation of organic acids in the urine and other body fludis
(Dewey)
T/F: The brain has glycogen stores
FALSE
(Dewey)
Experimental studies have shown that ______ of the ventricles dilate first in dogs with internal hydrocephalus
temporal horns
(Laubner et al 2018)
What is the prognosis for cats with acquired MG that do NOT have a cranial mediastinal mass?
Excellent!
retrospective case series n=8 - all cats achieved immune remission within 6 mos. 4 cats received no treatment
Megnan et al 2020
Does mean F-wave duration correlate with clinical grade of IVDH in dachshunds?
Yes - mean F-wave duration is well correlated with clinical grade of IVDH
Okuno 2020
how can ketamine have anticonvulsant properties? dexmedetomidine?
Ketamine - decreases excitatory glutamate activity. Also neuroprotective
Dex - decreases sympathetic stimulation and attenuates noradrenaline release. Cerebral vasoconstriction - reduce cerebral edema?
Gioeni et al
Stress and exercise have been identified as a trigger for paroxysmal dyskinesia in which two breeds of dogs? Which breed tends to have episodes at rest?
Norwich Terriers and Maltese - stress/exercise
Border terriers - episodes occur mainly at rest
How does occipital bone volume vary between CKCS w/ and w/o SM and French Bulldogs?
No difference in volume –> does not support theory of occipital bone hypoplasia
Rusbridge et al 2018
in Rohdin et al paper RE 30 pugs with TL myelopathy, what region were most meningeal fibrosis lesions found in?
T5-L1
Leakage of ________has been shown in clinically normal pugs, and is suggested to be the result of a breed-specific astrocyte fragility
GFAP
Rohdin et al 2020
How is neuropathic pain evaluated objectively?
measure mechanical sensory threshold
What two breeds are reported to suffer from cervical IVDH at multiple sites?
Shih tzus and Yorkshire Terriers
Guo et al 2020
Which micro RNAs can *potentially* be used to differentiate glioma and other brain diseases?
miR-15b and miR-342-3p
micro RNA = small noncoding molecules that regulate gene expression following transcription
Narita et al 2020
what is “an epileptic seizure that is objectively and consistently evoked by a specific afferent stimulus or by activity of the patient?”
Reflex epilepsy
Does mean F-wave duration correlate with clinical grade of IVDH in dachshunds?
Yes - mean F-wave duration is well correlated with clinical grade of IVDH
Okuno 2020
How does duration of surgery affect outcome in dogs with absent pain perception treated surgically for TL IVDH?
- Median anesthesia duration in dogs that regained ambulation within 1 year of surgery was significantly shorter than those that did not
- significant negative association between both duration of surgery and total anesthesia time and ambulation at one year, when controlling for body weight and number of disc spaces operated on
Fenn, 2020
What craniocervical junction abnormalities are risk factors for SM?(5)
atlanto-occipital overlapping
atlantoaxial subluxation
dorsal angulation of the dens
occipital dysplasia
atlantoaxial axial “banding”
in globoid cell leukodystrophy, the deficient enzyme leads to the accumulation of ______ which is toxic to which cells?
in globoid cell leukodystrophy, the deficient enzyme leads to the accumulation of psychosine (splingolipid) which is toxic to
oligodendrocytes and Schwann cells
White matter in the CNS and PNS are affected
(Dewey)
Name 5 anomalous/developmental encephalopathies?
- Congenital hydrocephalus 2. Caudal occipital malformation syndrome 3. Intracranial arachnoid “cyst” 4. Neuronal migration disorders Dandy-walker syndrome 5. Miscellaneous malformations
Dewey
2 mechanisms that result in leukodystrophy?
Abnormal synthesis of myelin in the CNS Abnormal maintenance of myelin in the CNS
Rare, poorly understood, heritable, progressive diseases
Dewey
what physiologic processes are thought to contribute to CDS?
increased oxygen free radical mediated cellular damage decreased endogeneous antioxidant edfenses inflammation decreased mitochondrial function
DNA damage
altered gene expression
vascular compromise
decreased capacity for neurogenesis
synaptic dysfunction
neurotransmitter imbalance
Dewey
An interthalamic adhesion diameter of less than ____ mm was found to be consistent with a diagnosis of CDS in dogs
5mm
Dewey
What is thought to be the underlying cause for the development of intracranial arachnoid fluid accumulation?
split of the arachnoid membrane during embryogenesis - aberration of CSF flow from the choroid plexuses during development forces a separation within the forming arachnoid layer - fills w. fluid (identical to CSF)
Dewey
What is the average ate of onset of clinical signs in dogs with IAC?
4y
2m - 10y reported - prosencephalic signs - central vestibular signs - neck pain
Dewey
T/F: notrosourea chemotherapy drugs easily cross the BBB?
True high lipid soluble alkylating agents that cross BBB readily
(Dewey)
In one large study, it was found that ___% of canine intracranial meningiomas had aggressive histologic grade tumors
43% (Dewey)
An ____ CSF level of uric acid and glutamate have been demonstrated in dogs with primary brain tumors
increased
uric acid is an indicator of oxidative injury and potential glutamate excitotoxicity
(Dewey)
In animals that die due to thiamine deficiency, characteristic bilaterally symmetric lesions (petechial hemorrhages) are appreciable throughout the brain at necropsy, especially in the _____
IIn animals that die due to thiamine deficiency, characteristic bilaterally symmetric lesions (petechial hemorrhages) are appreciable throughout the brain at necropsy, especially in the caudal colliculi of the midbrain
(Dewey)
What breed of dog and breed of cat appear predisposed to developing CNS cryptococcosis?
American Cocker Spaniels Siamese cat
(Dewey)
Recent study of 34 cats undergoing surgery for PSS - what percentage experienced post-operative seizures?
23%
Valiente 2020
T/F: study on chihuahuas with CM/SM found that the width of syrinx is associated with clinical signs?
False
Kiviranta et al 2017
Proposed mechanism for clinical signs caused by CCJ abnormalities?
compression of the spinal nucleus and tract of CN V
- receives sensory input related to nociception and temp from the skin/mm of the head
- continues as the substantial gelatinosa and dorsolateral fasiculus in the spinal cord
Kiviranta et al 2017
CM and SM have a _____ mode of inheritance with ______ penetrance in CKCS
polygenic mode of inheritance with variable penetrance
Kiviranta et al 2017
drawback to ultrasonic aspirators for resection of intra-axial masses?
- heat and vibration generated during use may damage adjacent normal parenchyma or cranial nerves - neoplastic cells may be aerosolized and seeded to other areas of the brain
Packer and McGrath 2020
What factors contribute to brain shift (concerning neuronavigation systems)
release of pressure created by presence of a space-occupying mass effects of gravity volume loss of CSF or blood during the procedure differences in animal positioning from imaging to surgery administration of mannitol size of craniotomy defect tumor size tumor type
Packer and McGrath 2020
What percent of cerebrovascular accidents were misinterpreted as gliomas?
10 - 47%
Gutmann 2020
in Rohdin et al paper RE 30 pugs with TL myelopathy, what region were most meningeal fibrosis lesions found in?
T5-L1
MRI vs. CT for detecting CM and SM - which has best agreement between evaluators. Which is more sensitive? Which is more specific?
MRI - most agreement MRI - most sensitivity for cerebellar herniation and SM MRI and CT have equal specificity for identifying cerebellar herniation CT - more specific for identifying SM
Weber et al 2020
how can ketamine have anticonvulsant properties? dexmedetomidine?
Ketamine - decreases excitatory glutamate activity. Also neuroprotective
Dex - decreases sympathetic stimulation and attenuates noradrenaline release. Cerebral vasoconstriction - reduce cerebral edema?
Gioeni et al
What do F-waves represent?
muscle action potentials resulting from excitation of the alpha-motor neurons after antidromic stimulation of a peripheral motor nerve
Okuno 2020
What noninvasive measures can be used to estimate ICP?
MRI
Transcranial doppler ultrasonography
Optic nerve sheath diameter
Giannasi 2020
What atypical MRI features for glioma should raise concern for a granuloma? (4)
- Mixed intra and extra-axial features
- T2W hypointensity without apparent hemorrhage
- Concomitant meningeal enhancement - Minor contralateral lesions
Diangelo et al 2020
What pattern of PET imaging is seen in the normal spinal cord?
Increased SUVmax values at the spinal cord intumescences
SUVmax = standardized uptake values
French 2019
Name 5 anomalous/developmental encephalopathies?
- Congenital hydrocephalus
- Caudal occipital malformation syndrome
- Intracranial arachnoid “cyst”
- Neuronal migration disorders Dandy-walker syndrome
- Miscellaneous malformations
Dewey
MRI findings associated with clinically relevant hydrocephalus? (7)
Elevation of the corpus callosum
Dorsoventral flattening of the interthalamic adhesion
Periventricular edema
Dilation of the olfactory recesses
Thinning of the cortical sulci and/or subarachnoid space
Disruption of the internal capsule adjacent to the caudate nucleus
Ventricle/brain-index - significantly higher in dogs with relevant hydrocephalus
(Laubner 2015)
Enlargement of the ____ nerves is often palpable in dogs with fucosidosis
ulnar nerves (due to edema and infiltration with lipid-filled phagocytes and Schwann cells)
Dewey
clinical signs of neuronal vacuolation and spinocerebellar degeneration in Rottweilers and Boxer Dogs?
-generalized weakness, cerebellar ataxia inspiratory stridor due to laryngeal nerve dysfunction -congenital ocular abnormalities (cataracts, persistent pupillary membrane, microophtlamia, retinal dysplasia) - signs worsen over weeks, end stage - behavior changes
Dewey
What is the “hydrodynamic theory” of congenital hydrocephalus?
Hydrocephalus develops due to abnormal (reduced) intracranial compliance
Hydrocephalic patients are believed to have poor intracranial compliance –> increased capillary pulse pressure –> pulsatile transmantle pressure gradient directed from the cerebral tissue toward the lateral ventricles –> rebound pressure from recurring gradient as well as hyperdynamic CSF flow in the mesencephalic aqueduct leads to progressive ventricular enlargement.
Dewey
*abnormal capillary pulsations occur within normal mean ICP
epidermoid and dermoid cysts are thought to be due to a failure of complete separation of _____ from _____ during embryogenesis
epidermoid and dermoid cysts are thought to be due to a failure of complete separation of neuroectoderm from non-neural (epithelial) ectoderm
if the epithelial ectoderm has adnexal structures, the structure is called a dermoid cyst. If the epithelial ectoderm does NOT have adnexal structures, the structure is called a epidermoid cyst
(Dewey)
What is the average ate of onset of clinical signs in dogs with IAC?
4y
2m - 10y reported - prosencephalic signs - central vestibular signs - neck pain
Dewey
How does hypernatremia affect brain parenchymal cells?
HyperNa –> shrinkage of brain parenchymal cells –> stretching/tearing of small intracranial blood vessels –> hemorrhage Chronic hyperNa (increased osmolality) –> brain parenchymal cells produce idiogenic osmoles
(Dewey)
How can CSF be used to differentiate choroid plexus papilloma from choroid plexus carcinoma?
carcinoma more likely to have CSF > 80mg/dL
Dewey
Dogs with supratentorial masses had a median survival of ____ days whereas those with infratentorial masses had a median survival of ____ days
Dogs with supratentorial masses had a median survival of 178 days whereas those with infratentorial masses had a median survival of 28 days
(Dewey)
There is a ____ association with proliferative cell nuclear antigen (PCNA) level and the likelihood of canine brain tumor reoccurrence, and a ___ association with PCNA level and level of tumor progesterone receptors.
There is a positive association with proliferative cell nuclear antigen (PCNA) level and the likelihood of canine brain tumor reoccurrence, and a negative association with PCNA level and level of tumor progesterone receptors
(Dewey)
What species of aspergillus is most frequently associated with systemic aspergillosis in dogs?
A.terreus
A. fumigatus and A. flavus usually cause localized disease in the nasal cavity A. deflectus and A. niger are reported to cause disease in dogs
Schultz 2008
Causes of false positive Aspergillus Galactolamman ELISA? Causes of false negative?
False-positive - plasmalyte administration, other systemic mycoses False-negative - localized pulmonary involvement
Garcia 2012
The EEG signal is modified by 4 factors
- electrical conductive properties of the tissues
- distance between the electrical source and recording electrode on the scalp
- conductive properties of the electrode
- the orientation of the cortical generator to the recording electrode
Brain Camp Lecture
Indications for running EEG? (4)
- Seizure disorder
- Sleep disorder
- evaluate cerebral function in comatose or obtunded patients
- distinguish seizures from syncopal episodes or paroxysmal dyskinesias
- sheets/streams of neoplastic w/ fibrillary stroma 2. abundant polygonal or elongate eosinophilic cytoplasm w/ indistinct cell margins, finely stippled chromatin, 1 - 2 nucleoli typical features or?
astrocytoma
how to differentiate high-grade from low-grade oligodendroglioma and astrocytoma?
- microvascular proliferation
- necrosis
Koehler 2018
T/F: severe articular process changes or vertebral body malformations raise the index of suspicion for CSM?
True
Sharp
oligodendrogliomas are primarily in gray or white matter?
gray matter. Typically compact, focally infiltrative
koehler 2018
T/F, the degree of infiltration does not determine low vs. high grade astrocytoma
false
- sheets of neoplastic cells w/ basophilic fibrovascular stroma 2. neoplastic cells w/ eosinophilic cytoplasm w/ artifactual perinuclear clear halo 3. oval nuclei w/ dense/coarse chromatin typical of what neoplasm?
oligodendroglioma
What is CNPase?
myelinating enzyme specific to oligodendrocytes and schwann cells, can be used to differentiate oligo vs. astro in BIOPSY samples
Koehler 2018
What is a rathke’s cleft cyst?
Benign cystic lesions
Derived from the remnants of the epithelium embryologically lining Rathke’ s cleft (craniopharyngeal duct
Only ____ _____ with necrotizing meningoencephalitis (NME) showed elevated serum GFAP concentrations (<0.01 to 1.14 ng/ml ), while other breeds of dogs with NME did not
Only Pug dogs with necrotizing meningoencephalitis (NME) showed elevated serum GFAP concentrations (<0.01 to 1.14 ng/ml ), while other breeds of dogs with NME did not
MIYAKE, J-STAGE, 2013
traction-responsive CSM lesions are most likely to respond to which surgical procedures?
distraction-stabilization
traction response suggests compression by anulus fibrosus or ligamentous tissue
traction non-responsive CSM lesions are most likely to respond to which surgical procedures?
ventral slot or dorsal decompression
usually caused by new bone formation or extrusion of nucleus pulposus
___% of dobermans in the US have a bleeding tendency related to VW diesase
16%
Sharp
Mean BMBT for dog is _____
2.62 minutes w range of 1.7 - 4.2 min
surgically treated CSM with associated disc protrusion found an ____% short-term success rate with ___% having significant reocurrence after long-term follow up
surgically treated CSM with associated disc protrusion found an
80% short-term success rate with 20% having significant reocurrence after long-term follow upon
About ___% of dogs undergoing single level decompression (ventral slot) for CSM suffer a second episode of neurological signs within 2 - 3 years.
30%
Sharp
What are the choices of prophylactic procedure for adjacent disc spaces after ventral slot in patient w/ CSM?
- cancellous bone graft at the adjacent space combined w/ forage of ventral cortical bone (aim is to promote fusion)
- place a cement plug at the adjacent space (may increase collapse at slotted space causing foraminal narrowing)
T/F: fenestration is a suitable treatment for any dog w/ CSM
false - it hastens intervertebral collapse and anular buckling - causes spinal cord compression
Sharp
transport of 25nm vesicles in the anterograde direction by a “fast” transport system is fueled by which enzyme?
kinesin - ATPase - moves @ 20 - 30mm/h - enzyme is intricately associated w/ neurotubules
T/F: mitochondria are transported within a neuron via slow transport?
false - moved by a fast transport system
what three locations in the brain are known to have continuous postnatal generation of neurons?
- olfactory bulb “rostral migratory stream”
- hypothalamic-hypophyseal connections (median eminence)
______ canine maningioma have thin-walled capillary and sinusoidal vascular spaces and is rich in reticulin. Can also have small capillary vessels, and interstitial cells which are vacuolated and swollen with lipid
angioblastic meningioma
Type of meningioma?
Microcystic meningioma, with clear and vacuolated tumour cell cytoplasm
Montoliu et al 2006
a significant elevation in _____ acid in the CSF of dogs with confirmed intracranial meningioma
uric acid - significance unknown
Platt et all 2006
______ _____ is a bone erosion caused by pressure atrophy with subsequent thickening due to invasion of the haversian canals by tumor cells
Tumor-related hyperostosis
uncommon phenobarbital associated side effects reported in cats? (5)
facial pruritus
generalized pruritis
distal limb edema
thrombocytopenia
leukopenia
Paraplegic dogs with ANNPE are ____ more times likely to develop urinary incontinence and ____ more times likely to develop fecal incontinence (compared to nonparaplegic dogs)
Paraplegic dogs with ANNPE are 3x more times likely to develop urinary incontinence and 4x more times likely to develop fecal incontinence (compared to nonparaplegic dogs)
Mari 2019
What subgroup of dogs are predisposed to GME? NE?
middle-aged toy and terrier breeds are predisposed to GME
NE predominantly affects younger toy and small breed dogs
___% of dogs diagnosed with GME presented with neurological deficits suggestive of a myelopathy
8%
Granger 2010
4 diagnostic criteria for MUO proposed by Granger et al
- older than 6m
- multiple, single or diffuse intra-axial hyperintensities on T2W MRI images
- pleocytosis on CSF analysis with > 50% monocytes/lymphocytes
4) rule out infectious diseases commonly occurring in the specific geographic area
Most common MRI abnormalities reported in dogs with NME?
- asymmetrical, multifocal
- located in the forebrain
- hyperintense on T2W and FLAIR images
- affect the cortical grey and subcortical white matter (loss of grey/white matter demarcation)
- variable degrees of contrast enhancement of the parenchymal lesions on T2W post-contrast images
(Cornelis 2019)
how does time from onset of signs to presentation alter survival time in dogs with MUO?
significantly longer MST was recorded in 25 dogs that were presented within 7 days of onset of clinical signs, compared to those presented after more than 7 days
Barnoon 2016
what findings on MRI in dogs with MUO are significantly associated with increased risk of mortality? (3)
Mass effect
loss of identifiable cerebral sulci
foramen magnum herniation
Lowrie 2013, 2016
Despite the initiation of appropriate and aggressive immunosuppressive treatment, ___% of dogs in one study died or were euthanized because of MUO, and ___% of these dogs did so within 3d after diagnosis
Despite the initiation of appropriate and aggressive immunosuppressive treatment, 56% of dogs in one study died or were euthanized because of MUO, and
33% of these dogs did so within 3d after diagnosis
Status epilepticus can shorten a dog’s lifespan by about ___ years due to the increased likelihood for euthanasia
2 years
Saito et al
a ____ (positive/negative) correlation between CSF GLU:GABA ratio and seizure frequency difference was found in dogs with idiopathic epilepsy
negative
Podell 1999
where is an eccentric nerve nucleus normal?
large cells of the periventricular gray matter (mesencephalic nucleus of the trigeminal nerve and the olives)
*these cells tend to have a “chromatolytic appearance”
A (higher/lower) risk for development of epileptic seizures and SE has been found in spayed females compared to intact females
higher
Blades Golubovic 2017
In a study of ischemic stroke in dogs, approximately ____ % of patients died within the first 30 days
25% died within 1st 30 days
those that survived first 30 days had MST of 505 days
Gredal 2013
What is the significance of nuclear margination and loss of staining affinity within the nerve cell body?
nonspecific degeneration
*neuronal nucleus is usually single and centrally located
If a neuron dies, surviving neurons with which it has synaptic connections may regress due to lack of activation, undergo atrophy and eventually die - this process is called ___________ __________
transynaptic degeneration
________ is a change in appearance of the soma, brought about by dispersal of the rER
chromatolysis
______ _______ is often seen bulbo-spinal motor neurons and sensory neurons whose peripherally projecting axons are injured and especially when the injury occurs close to the cell body
central chromatolysis
______ ______ has been termed the axon reaction and represents an anabolic adaptive response to axonal injury
central chromatolysis
- represents a shift in metabolic activity towards synthesis of structural cellular proteins and decline in synthesis of transmitters
______ _______ indicates clearing of the periphery of the soma with Nissl granules persisting around the nucleus
peripheral chromatolysis
_____ necrosis involves liquefaction of the nucleus without phagocytosis
ischemic
- may be seen in the ecerebral cortex in hypoxia, hypoglycemia, thiamine deficiency encephalopathy, intoxications (organomercurialism, salt)
- may be seen in the dentate gyrus of the hippocampus and cerebellar purkinje neurons following seizures
excessive stimulus by an excitatory neurotransmitter leading to neuronal degeneration and death is called ________
excitotoxicity
canine meningiomas are derived from _____ ____ cells
arachnoid cap cells (arachnoid granulations)
*particularly where arachonid cells project into dural sinus
ventricular meningiomas are presumed to arise from the _____ _____
tela choroidea (pia mater of the choroid plexus)
_____ subtype of canine meningioma contains nests and lobules of neoplastic meningothelial cells delineated by fine collagenous fibers.
meningothelial (AKA syncytial) types
_____ canine meningioma have interlacing bundles of slender fibroblastic cells
fibroblastic meningioma
______ canine meningiomas have concentric whorls of cells
transitional form (admixture of syncytial and fibroblastic meningioma)
a _____ canine meningioma has small whorls of neoplastic cells and blood vessels that become hyalinized and encrusted with calcium salts - forms _____ body
psammomatous meningioma - forms psammoma body
in ______ canine meningiomas individual lobules of a meningioma undergo a spongy vacuolar change producing a cribiform appearance
microcystic
T/F: metastasis of intracranial meningioma has never been reported in the dog?
False - metastasis to the lungs has been reported in 3 dogs
T/F: labelling for S100 is common in meningiomas?
True 90% (n=30) in Montoliu et al (2006)
type of meningioma?
Angiomatous meningioma. Note the presence of thin-walled vascular spaces and haemorrhages
Montoliu et al 2006
Type of meningioma?
Papillary meningioma. Meningothelial cells grow perpendicularly to the surface of fibrovascular strands
Montoliu et al 2006
Type of meningioma?
Anaplastic meningioma, with scattered mitoses and moderate pleomorphism
Montoliu et al 2006
Type of meningioma?
Optic nerve meningioma with areas of cartilaginous and myxoid metaplasia
Montoliu et al 2006
Type of meningioma?
Transitional meningioma located in the spinal cord. Note the presence of cartilaginous metaplasia
Montoliu et al 2006
How strongly do canine meningiomas stain with NSE (neuron specific enolase)?
variable
Montoliu et al 2006
Do canine meningiomas commlnly show CK expression or GFAP expression?
no
Montoliu et al 2006
meningiomas exhibit differentiation of what two embryonic cell lines?
mesenchymal and epithelial differentiation
T/F: MMP-2 and MMP-9 expression by tumor cells is not predictive of the formation of peritumoral edema in canine rostrotentorial meningiomas?
T
Beltran et al 2013
Which type of meningioma is most likely to act malignant?
anaplastic
what two feline diseases can mimic the appearance of a meningioma?
Toxoplasmosis, cryptococcosis
T/F: > 40% of canine meningiomas are atypical (grade II)
True
(a mitotic index > 4/10HPF and brain invasion are sufficient criteria to identify grade II meningiomas)
T/F: more aggressive and atypical meningiomas are more likely to express progesterone receptors in dogs
False - more aggressive/atypical meningiomas are LESS likely to express PR
What is the MOA of hydroxyurea?
- antimetabolite that specifically affects the S stage of the cell cycle
- Inhibits the growth of slow growing tumors
What are the two superficial muscles encountered during approach to VBO?
platysma and sphincter colli
what vascular/nervous/salivary structures are encountered during approach to VBO?
- mandibular salivary gland
- lingofacial and maxillary veins
- hypoglossal nerve
- lingual artery
what are the deep muscles that are dissected during approach to VBO?
- digastricus
- mylohyoid
- hyoglossus
- styloglossus
What structure is housed within the promontory?
The cochlea
Where in the middle ear of the cat are sympathetic fibers most vulnerable to surgical trauma?
promontory
What is the elimination half life of phenobarbital in dogs? cats?
40 - 90h in dogs 40 - 50h in cats (after PO administration)
How does phenobarbital alter TT4, FT4 and TSH?
decreases TT4
decreases FT4
increases TSH WITHOUT inducing clinical signs of hypothyroidism
how does phenobarbital alter adrenal function tests in dogs?
it doesnt
What is the MOA of bromide?
hyperpolarizes neuronal membranes after traversing neuronal chloride channels
What is the elimination half life of KBr in dogs?
24 days
High chloride intake _____ bromide elimination
High chloride intake INCREASES bromide elimination
How should KBr dosing be altered in patient with kidney insufficiency?
renal insufficiency DECREASES KBr elimination dog w/ kidney dz –> LOWER dose of KBr should be used
What are adverse effects of KBr in dogs (besides sedation/ataxia, PU/PD, polyphagia)
hyperactivity
megaesophagus
pruritic skin rash
vomiting
pancreatitis
coughing - rare
What is the elimination half life of clorazepate?
3-6 hrs in dogs
What is the MOA of zonisamide? (2)
blockage of T-type calcium and voltage-gated Na channels binding to the chloride channel associated w/ GABA
How is zonisamide metabolized? what is the half life in dogs?
metabolized by hepatic microsomal enzymes half life in dogs is 15 hrs
MOA of levetiracetam?
binds to SV2A (synaptic vesicle protein) –> altera neuronal calcium flow. exact MOA unknown
What is the elimination half life of levetiracetam in dogs? cats?
4h in dogs, 3h in cats
How is LEV metabolism altered in dogs concurrently receiving phenobarbital?
metabolism is accelerated over time in dogs concurrently receiving phenobarbital
How does taurine deficiency cause blindness?
retinal degeneration
a hyperreflective focal lesion in the area centralis of a cat: likely cause?
taurine deficiency
what vitamin abnormality in the cat can cause muscle soreness and hyperesthesia along the neck and forelimbs?
Vitamin A toxicity
How can FeLV affect the spinal cord?
suspected to cause degenerative myelopathy
T/F: There were significant differences in circulating melatonin, serotonin or dopamine concentrations between dogs with SARDS, PDH and normal dogs
False
Oh. JVIM 2019
T/F fear and anxiety behaviors were significantly reduced under impetoin treatment compared to placebo
true - clinical trial, owners started treatment 2d before the anticipated noisy event
Engel 2019
MOA of imepitoin?
partial agonist of the benzodiazepine-binding site of the GABA-receptor with low affinity –> potentiates neuronal inhibition
Dogs with ANNPE and an intramedullary hyperintensity > _____% of the cross-sectional area of the spinal cord at the same level on transverse images were ____ times more likely to develop urinary incontinence
Dogs with ANNPE and an intramedullary hyperintensity > 40% of the cross-sectional area of the spinal cord at the same level on transverse images were 4x times more likely to develop urinary incontinence
Mari 2019
4 MRI features of ANNPE
- narrowed IVD space + reduced volume of nucleus pulposus located below a focal T2w hyperintense intramedullary spinal cord lesion
- presence of extradural material compatible with hydrated nucleus pulposus at the same level causing minimal or NO spinal cord compression
- the presence of a cleft in the dorsal part of the annulus fibrosis
- the presence of meningeal or epidural contrast enhancement in post-contrast T1W fat-suppressed images
DiRisio 2009 - what % of dogs with ANNPE had a successful outcome?
67%
T/F: detection of intramedullary hypointensity is associated with outcome in dogs with ANNPE?
True
DiRisio - results of multivariate analysis of dogs with ANNPE suggested that _______ was the best predictor of outcome
maximal cross-sectional area of the intramedullary hyperintensity on transverse T2 weighted MR images
Traumatic IVD extrusion with concurrent spinal cord compression is positively associated with what two factors
age and chondrodystrophic breeds
(Henke 2013)
Ros 2017 on ANNPE: 1. Accuracy of myelography to detect site of herniation was ___% and to identify extradural compression was ___% 2. All dogs had an _____ pattern, but an ____ pattern was detected in 57% of cases 3. Based on myelography, reviewers would not have performed surgical decompression in _____% of dogs
- Accuracy of myelography to detect site of herniation was
- 9% and to identify extradural compression was 57% in study by Ros 2017
- All dogs had an intramedullary pattern, but an extramedullary pattern was detected in 57% of cases
- Based on myelography, reviewers would not have performed surgical decompression in 71% of dogs
causes of ischemic myelopathy? (6)
- infectious emboli (bacterial, parasitic)
- neoplastic emboli
- fat emboli
- thrombi
- atherosclerosis
- fibrocartilage emboli
What is the “vaccum phenomenon” as it relates to ANNPE?
gas accumulation within the disc space after herniation of hydrated material
Manunta et al 2015 - 5 dogs tetraparetic/tetraplegic dogs with ANNPE treated conservatively regained ambulatory status within _____
1 month
ANNPE vs. ischemic myelopathy - which feature is characteristic of each 1. older age at disease onset 2. history of vocalization 3. spinal hyperesthesia 4. L4-S3 localization 5. C1-5 localization 6. ambulatory at hospital discharge 7. long-term quality of life/outcome 8. long-term fecal incontinence
- older age at disease onset (ANNPE)
- history of vocalization (ANNPE)
- spinal hyperesthesia (ANNPE)
- L4-S3 localization (IM)
- C1-5 localization (ANNPE)
- ambulatory at hospital discharge (ANNPE)
- long-term quality of life/outcome (good in both provided intact nociception)
- long-term fecal incontinence (IM)
Fenn 2016
Mari 2017 (ANNPE vs. FCE) - fecal incontinence was ____x more likely in dogs with presumptive ANNPE compared with presumptive FCEM
5x more likely with ANNE
ANNPE 23%, FCEM 7.5%
Is CSF lactate concentration associated with… diagnosis NCC protein RBC count survival
no correlation between CSF lactate concentration and diagnosis, RBC count or survival
weak correlations were noted between CSF lactate concentration and:
NCC (absolute large mononuclear cell count, absolute small mononuclear cell count, absolute neutrophil count)
Protein
What is the reference interval for L-lactate in canine CSF?
1-2.5 mmol/L
Nye 2018
How is CSF lactate affected in dogs with age-related cognitive dysfunction?
CSF lactate was significantly higher in dogs with severe cognitive dysfunction than in unaffected and mildly affected dogs
What % of dogs diagnosed with MUO were large breeds?
25%
Cornelis 2016
T/F: recent studies have found females are statistically significantly more likely to develop GME?
false - no statistical significance in female:male ratio in more recent studies
Cornelis 2019
In one study of GME, ___% of dogs had no abnormalities on T2W MRI
7%
Talarico and Schatzberg 2010, Granger 2010
Typical MRI findings in patients with NLE?
- multiple asymmetrical cerebral white matter and brainstem abnormalities
- hyperintensity on T2W and FLAIR images (often with regions of cystic necrosis)
- mimimal contrast enhancement of parenchymal abnormalities
Cornelis 2019
Typical MRI findings in dogs with meningomyelitis of unknown origin?
Multifocal or focal poorly demarcated intramedullary T2W hyperintensities with variable contrast enhancement
Cornelis 2019
Adverse effects associated with procarbazine treatment for MUO?
myelosuppression
hemorrhagic enteritis
Coates 2007
adverse effects reported from treatment with mycophenolate for MUO?
hemorrhagic diarrhea in the first 2 weeks
adverse effects associated with treatment with vincristine and cyclophosphamide for MUO? (3)
myelsuppression hemorrhagic cystitis pyometra
unacceptable to authors, excluded from further investigation
Smith 2009
How is age associated with prognosis in dogs diagnosed with MUO?
younger age at time of diagnosis was significantly associated with improved survival in 52 dogs (Oliphant 2017)
Relapse was recorded in ___% of dogs (n=39) within a median of ____ days after diagnosis (Lowrie 2013)
Relapse was recorded in 65% of dogs (n=39) within a median of 210 days after diagnosis (Lowrie 2013)
Abnormal CSF @ 3m was associated with higher risk of relapse combination of MRI and CSF analysis provided greater sensitivity for predicting relapse than one modality alone discontinuation of treatment before resolution of MRI abnormalities always resulted in relapse
How does intranasal midazolam compare to IV midazolam in treating status epilepticus?
IN route demonstrated superiority when the time needed to place an IV catheter was taken into account
seizure cessation time for IN compared to IV was not significantly different (without IVC placement time)
Charalambous 2019
What is the estimated case fatality rate of dogs that experience status epilepticus?
25.3 - 38.5%
Charalambous 2017
How is CSF GABA concentration correlated with seizure frequency in dogs dogs
lower CSF GABA concentration reduced response to phenobarbital administration
(Podell 1999)
Approximately _____% of dogs with primary epilepsy are refractory to antiepileptic drug therapy
30 - 40%
Podell 1999
What is the MOA of phenobarbital?
binds the GABA-A receptor to:
- directly activate GABA receptor-gated chloride channels
- potentiate GABA-mediated Cl conductance
end result is enhanced hyperpolarization of neuronal membranes
Podell 1999
_____ concentrations of GABA and _____ concentrations of glutamate were present in the CSF of untreated epileptic dogs
Lower concentrations of GABA and higher concentrations of glutamate were present in the CSF of untreated epileptic dogs
Secondary adverse effects of increased autonomic stimulation associated with SE? (7)
- cardiac arrhythmias
- acidosis
- rhabdomyolysis
- hypotension
- shock
- noncardiogenic pulmonary edema
7 acute tubular necrosis
Blades Golubovic 2017
A hereditary basis for epilepsy has been proven in which 9 breeds
- Labrador Retrievers
- German Shepherd dogs
- Golden Retrievers
- Bernese Mountain Dogs
- Belgian Tervurens
- Vizslas
- Keeshonds
- English Springer Spaniel
- Border Collies
approximately ___% of dogs diagnosed with ischemic strokes have concurrent underlying diseases - the 4 most common are?
50% of dogs have underlying systemic disease
- HAC
- CKD
- Hypothyroidism
- Systemic hypertension
Garosi 2005
T/F: There is an association between region of the brain involved in a stroke, type of infarction, and outcome
False
Garosi 2005
Dogs w/ acute ischemic stroke commonly have ___ (elevated/decreased/normal cardiac troponin I
elevated cTn1
level was not different between dogs experiencing good and poor outcomes (small study)
cardiac disease is not considered to be a common underlying cause for ischemic stroke in dogs
Goncalves 2019
Canine arterial cerebrovascular blood supply arises from the ____ and ______ arteries which feed into the cerebral arterial circle. In the cat. Blood flow through the _____ artery is predominantly directed craniocaudally and the ______ artery supplies most of the blood to the cerebral arterial circle.
Canine arterial cerebrovascular blood supply arises from the basilar and internal carotid arteries which feed into the cerebral arterial circle. In the cat. Blood flow through the basilar artery is predominantly directed craniocaudally and the external carotid artery (via maxillary artery) supplies most of the blood to the cerebral arterial circle
Boudreau 2018
total cerebral blood flow should be constant for mean arterial pressures between ____ and ____ mmHg
50 - 150mmHg systolic
CPP < ___mmHg systolic results in ischemia and loss of autoregulation
cerebral perfusion pressure < 40mmHg systolic
Boudreau 2018
What is primary vs. secondary injury related to ischemic cerebrovascular dz
primary injury
-due to energy failure
secondary injury
- due to compromise of local vascular endothelium and supporting cells. Develops ~ 4-6 hrs after onset of hypoperfusion, progresses for 24 - 48h
Boudreau 2018
What is the difference between ischemia and infarction?
ischemia - perfusion reduction sufficient to induce dysfunction in the affected tissue
infarction - perfusion reduction that causes irreversible injury and eventually necrosis
Boudreau 2018
How does PaCO2 alter cerebral vascular tone?
Increased PaCO2 –> cerebral vasodilation
Decreased PaCO2 –> cerebral vasoconstriction
How does cerebral PaO2 alter cerebral vascular tone?
Increased PaO2 –> cerebral vasoconstriction
Decreased PaO2 –> cerebral vasodilation
What regions of the brain are most susceptible to ischemia? (4)
- cerebral cortex (esp. gray matter of the hippocampus)
- cerebellar cortex
- Basal nuclei
- Thalamic nuclei
Boudreau 2018
Which two dog breeds are predisposed to ischemic CVD?
CKCS
Greyhound
Boudreau 2018
3 causes of subdural hemorrhage?
- Trauma
- Chronic hydrocephalus
- Chronic storage disease
Boudreau 2018
What does cerebrovascular ishcemic change look like on CT scan?
mild focal edema
mild mass effect
minimal contrast enhancement
- subtle and nonspecific changes
What does acute cerebrovascular hemorrhage look like on CT scan?
- hyperattenuation relative to gray and white matter (due to globin) - increases for 72h after onset –> then gradually decreases to isoattenuation ~1m post hemorrhage (beginning from periphery and extending inward)
- peripheral contrast enhancement from 6d - 6w post event (d/t neovascularization?)
Boudreau 2018
MRI changes associated with global ischemia?
mild diffuse T2 hyperintensity in the gray matter of the cerebrum, thalamus and cerebellum with mild contrast enhancement of the same regions
Boudreau 2018
T/F: DWI showed ischemic change earlier than conventional MRI sequences in an experimental feline model?
true
Boudreau 2018
The technique of T2* exploits the sensitivity of the GRE sequences to _________
small magnetic field inhomogeneities (like those produced by paramagnetic intracellular deoxyhemoglobin or methemoglobin)
superparamagnetic blood breakdown products may produce GRE artifacts for months to years
Boudreau 2018
CSF in cases of hemorrhagic CVD?
often nonspecific, may be normal
mild increases in protein content or increases in neutrophilic and mononuclear populations
Boudreau 2018
What CSF biomarker is increases in canine models and clinical cases of ischemic stroke?
interleukin 6
Boudreau 2018
In dogs with single nontraumatic intracerebral hemorrhage > 5mm, long term outcome was good in ____%
60%
Boudreau 2018
How does cardiac troponin I concentration change in dogs with recent seizures
serum concentrations of cardiac troponin I were higher in dogs that had recent seizures compared to controls.
The predictors most clearly associated with cardiac troponin I concentration were:
- number of seizures
- age * both positively associated with increasing concentrations of troponin I
Dutton 2017
Garosi et al 2005 - small breed dogs were significantly more likely to have _______ infarcts and large breed dogs were significantly more likely to have _____ infarcts
small breed dogs were significantly more likely to have cerebellar territorial infarcts and large breed dogs were significantly more likely to have lacunar thalamic or midbrain infarcts
How does the presence of a concurrent medical condition in patient diagnosed with brain infarction associated with survival time?
Dogs with concurrent medical conditions had significantly shorter survival times than those with no identifiable medical condition
Dogs with concurrent medical conditions were more likely to suffer from recurrent neurologic signs because of subsequent infarcts
Garosi 2005
How does the sided-ness of an ischemic CVA influence survival time?
right-sided lesions posed a significantly increased risk of mortality with MST in dogs with right-sided lesions of 24 days vs. 602 days in dogs with left-sided lesions
Gredal 2013
What risk factors for repeated stroke has been identified in dogs?
none reported thus far
Gredal 2013
Compressive radiculopathy of the L7 nerve root reportedly occurs in ___% of dogs with DLSS and is associated with clinical signs in ____%
Compressive radiculopathy of the L7 nerve root reportedly occurs in 68% of dogs with DLSS and is associated with clinical signs in 50%
Godde and Steffen 2007
what two factors control rate of CSF formation?
- Weight of the choroid plexi
2) rate of sodium and bicarbonate ion exchange
(Di Terlizzi 2006)
What are the 8 possible components of “lumbosacral disease”
- Stenosis of the vertebral canal
- Hansen type II disc herniation at L7/S1
- subluxation, osteophytosis or thickening of the articular processes
- Epidural fibrosis
- Soft tissue proliferation of the joint capsule or ligamentous structures
- Vascular compromise of the spinal nerves
- Osteochondrosis of the sacrum
- Instability and misalignment of L7/S1
Sharp and Wheeler
EMG of patient with LS disease may show?
LMN disruption –> spontaneous activity
EMG is useful to reduce the number of false + diagnoses associated with MRI evidence of nerve root disorders
Sharp and Wheeler
The subarachnoid space extends beyond the LS junction in about ___% of dogs
80%
Sharp and Wheeler
Indications for surgery in dogs with LS disease?
Nonsurgical treatment has failed
Working dogs
pain or neurological deficits
CT or MRI findings of increased soft tissue suggestive of epidural fibrosis (especially if it enhances with contrast)
T/F: Lateral foraminotomy does not have a good short term and long-term outcome
False
Gomes et al 2018
According to Di Risio et al (2001) what clinical sign of DLSS is most significantly associated with outcome?
Urinary or fecal incontinence
- pre-operative duration of urinary incontinence was the sole temporal variable significantly associated with that outcome - authors concluded that prognosis is guarded in those cases where incontinence (particularly urinary incontinence) exceeds 1 month
what are the names of the 3 foraminal zones?
a) entrance zone b) middle zone c) exit zone
The lateral foraminotomy described by Godde and Steffen was developed to address compressive lesions in which region?
Developed to address compressive lesions within the foramen and at its exit
T/F: Compression of the soft-tissue structures within the vertebral canal at the LS space is associated with severity of clinical signs
false
Mayhew et al 2002
Epidural steroid injection for DLSS - ____% of treated dogs were reported to improve clinically and ____% were considered cured by their owners
79% of treated dogs were reported to improve clinically and 53% were considered cured by their owners
Jeffery 2014
What is the risk of performing an L7/S1 dorsal laminectomy with a foraminotomy?
articular process fracture
Jeffery 2014
What are the goals of fixation-fusion surgery for DLSS?
reduce pain and cauda equina dysfunction by:
- eliminating the dynamic components of nerve compression within the vertebral canal or foramina (fix the bones to prevent motion)
- slightly flex the LS joint –> opens the foramina and decreases annular protrusion
jeffery 2014
How does disc degeneration alter the stability of the lumbosacral region in dogs?
reduced ROM
jeffery 2014
How does CSF pressure change during inspiration and expiration?
Inspiration - CSF pressure rises
Expiration - CSF pressure falls
In pathological ICP elevations, the fluctuations in CSF pressure become very marked
(Di Terlizzi 2006)
IF there is a sudden increase in intracranial blood volume, CSF can be momentarily accommodated into the _____ _______ space because of the elasticity of the dura mater
cervical subarachnoid space
(Di Terlizzi 2006)
Sites of CSF draining/absorption?
- Arachnoid villi –> cerebral veins
- Veins/lymphatic vessels around the spinal nerve roots and spinal nerves
- Veins/lymphatic vessels around CN I and II where they leave the skull
(Di Terlizzi 2006)
3 regions of the brain that lack BBB
- Hypothalamus
- Pituitary gland
- Area postrema
(Di Terlizzi 2006)
what type of cells make up the BBB and blood spinal cord barrier?
non-fenestrated endothelial cells with interendothelial tight junctions
(Di Terlizzi 2006)
What 2 kinds of cells make up the blood-CSF barrier?
1) fenestrated vascular endothelial layer
2) ciliated columnar epithelial choroidal cells w/ basolateral infoldings and apical tight junctions
(Di Terlizzi 2006)
What type of cells make up arachnoid villi? How are toxic substances prevented from entering the CSF from the blood?
- arachnoid cap cells = endothelial cells with tight junctions - valve-like channels collapse when pressure is applied from the venous side and open when CSF pressure increases - creates a SEMIPERMEABLE membrane
(Di Terlizzi 2006)
Experimental studies in dogs have demonstrated that ___% of CSF is derived from the third and lateral ventricles,___% from the fourth ventricle, and ___% from the subarachnoid space
Experimental studies in dogs have demonstrated that 35% of CSF is derived from the third and lateral ventricles, 23% from the fourth ventricle, and 42% from the subarachnoid space
(Di Terlizzi 2006)
The secretion of CSF depends primarily on what process?
Active transport of Na+ ions into the ventricles
(Di Terlizzi 2006)
What process allows absorption through arachnoid villi?
micropinocytotic vesicles
(Di Terlizzi 2006)
What is the typical reference range for protein content in CSF? what is the main protein in CSF?
10 - 40mg/dL for cisternal sample
albumin is the main protein in the CSF, globulins are normally very low
(Di Terlizzi 2006)
What factors determine glucose concentration in CNS?
- blood glucose
- rate of glucose transport into the CSF
- metabolic rate of the CNS
(Di Terlizzi 2006)
T/F: Changes in plasma potassium concentration will significantly alter CSF K+ content
false
CSF K+ concentration remains within normal range across wide range of plasma K+
(Di Terlizzi 2006)
What two enzymes may increase in the CSF when extensive myelin degeneration has occured?
AST and CK (nervous isoenzyme)
(Di Terlizzi 2006)
4 disease processes that can result in blockage of CSF absorption at arachnoid villi
- space occupying lesions - compression of the venous sinuses
- cerebral edema
- meningoencephalitis
- vitamin A deficiency –> arachnoid villi atrophy
(Di Terlizzi 2006)
In which order to cells deteriorate in CSF stored at 4C?
small mononuclear cells
large mononuclear cells
neutrophils
eosinophils
(Di Terlizzi 2006)
What products can be added to CSF to aid stability? (4)
fetal calf serum
hetastarch
foramlin
fresh or frozen autologous clear plasma/serum
(Di Terlizzi 2006)
A CSF NCC of > ___ cells/uL is associated with an increase of turbidity
500
(Di Terlizzi 2006)
What proteins are synthesized in the choroid plexus and found in CSF? (3)
transthyretin retinol-binding protein
transferrin
What is a screening test for the presence of globulins in CSF?
Pandy test
few drops of CSF to 1mL of pandy reagent (10% carboxylic acid). Turbidity indicates the presence of globulin and has a sensitivity of approximately 50mg/dL
(Di Terlizzi 2006)
Which immunoglobulin is not normally found in CSF?
IgM - its presence in serum and/or CSF is considered more specific than IgG or total immunoglobulin levels for detection of active infectious diseases
(Di Terlizzi 2006)
How does CSF MBP vary in dogs with degenerative myelopathy?
increase in CSF MBP concentration in dogs with DM (lumbar cistern)
the same study confirmed a correlation between MBP and the severity of demyelination
What cell type is most abundant in normal CSF in dogs? cats?
dogs - small lymphocyte
cats - macrophages
(Di Terlizzi)
At L6/7 and L7/S1 in the dog, the spinal nerve and main arterial vessel pass through the ____ sub-compartment of the intervertebral foramen and the intervertebral vein passed through the ______ sub-compartment
At L6/7 and L7/S1 in the dog, the spinal nerve and main arterial vessel pass through the cranial sub-compartment of the intervertebral foramen and the intervertebral vein passed through the caudal sub-compartment
The intervertebral foramen contains a fibrous septum dividing it into 2 subcompartments by connecting the fibrous capsule of the articular process joints with the intervertebral disc and the adjoining vertebral body
(Breit et al, 2013)
Surgical options for treating L7/S1 foraminal compression? (4)
- dorsal laminectomy and partial discectomy +/- facetectomy
- unilateral foraminotomy
- distraction/fusion techniques (insertion of an intervertebral cage, insertion of a titanium intervertebral distraction bolt)
- Pedicle screw-rod fixation (+/- flexion)
Smolders et al (2020)
In cadaver study by Smolders et al, did foraminotomy or distraction/stabilization of L7/S1 result in greater volume of the foramen
foraminotomy was more effective in increasing the foraminal volume and especially the cranial subcompartment (where the L7 nerve root traverses the foramen)
The lumbar internal vertebral venous plexus drains into the _____ veins
major veins of the abdomen
- mainly the azygous vein and the caudal vena cava
(Sharp)
What is the difference between myelin figures and myelin fragments when analyzing CSF cytology?
Myelin figures - originate from a nonspecific lipid source. Originate from cell-membrane phospholipids
Myelin fragments - collection of myelin found extracellularly, more indicative of demyelination
foraminal stenosis and compressive radiculopathy of the L7 nerve root has been reported in ____% of dogs affected by DLSS
68% (Mayhew 2014)
Where are the mamillary processes of the thoracic vertebrae located in the thoracic spine? lumbar vertebrae?
thoracic vertebrae - short, knob-like dorsal projections from transverse processes
lumbar vertebrae - dorsal projections of the cranial articular processes
Sharp
Where does a change in orientation of the cranial/caudal articular processes occur in the thoracic vertebrae?
The articular processes from T1 - 10 are in an oblique horizontal plane as in the cervical vertebrae
In the caudal thoracic vertebrae (around the anticlinal) they adopt a more vertical orientation (as in the lumbar vertebrae)
(Sharp)
Right to left: C5, 6, 7
Note the transverse foramen in C5 and C6. The transverse process of C have no foramina and have a characteristic horizontal orientation
(Sharp)
T/F: the ligamentum flavum is continuous with the joint capsule of the articular processes
True
(Sharp)
T/F: The fibers of the annulus fibrosis carries pain fibers, but the dorsal longitudinal ligament does not
False - both carry pain fibers, the dorsal longitudinal ligament merges with the dorsal annulus
which IVD spaces contain an intercapital ligament?
T2 - T10
(Sharp)
the arterial supply to the cervical vertebrae is from the ______ artery which originates from the ______ artery. The arteries run through the _____ foramina of the vertebrae
the arterial supply to the cervical vertebrae is from the paired vertebral artery which originates from the paired subclavian arteries
The arteries run through the transverse foramina
of the vertebrae (except C7)
At each segment, there are dorsal and ventral muscular branches
** a significant vessel runs near the caudal edge of the articular processes!! - likes to bleed in sx
(Sharp)
The internal vertebral venous plexus drains into the ______ vein
drains into the major veins of the dorsal thorax mainly the AZYGOUS vein
(Sharp)
what are two ways that the vertebral artery contributes to intracranial blood flow
- connects to the internal carotid artery
- supplies the ventral spinal artery –> basilar artery
(King’s)
How does arterial supply to the brain vary in dog vs. cat?
Dog - supplied by internal carotid artery and vertebral artery (vertebral artery)
Cat - maxillary blood supplies to all of the brain except the caudal part of the medulla oblongata which is supplied by vertebral blood - the basilar artery carries blood away from the arterial circle
Ox - a mixture of maxillary and vertebral blood reaches all parts of the brain
(KINGS)
Which arterial branches supply the inner zone of the spinal cord? Which branches supply the outer zone?
inner zone - Vertical arteries
Outer zone - radial artery
Kings
Midway between successive spinal roots, the pia mater and arachnoid are firmly attached to the dura mater forming the _____ ______
denticulate ligament
(Kings)
The meningeal “sheath” of dorsal and ventral spinal nerve roots extends to the _____, then fuses with the _____.
The meningeal “sheath” of dorsal and ventral spinal nerve roots extends to the intervertebral foramen, then fuses with the epineurium
*the tubular sheaths of CN I and II extend to their peripheral ends
(Kings)
The bony tentorium cerebelli projects ventrally from the _____ bone
parietal
Kings
What are the 2 main mechanisms for forming spinal fluid?
- dialysis
- active secretion
Kings
3 main functions of CSF?
- Protection of the brain and spinal cord against impact
- nutrition
- permit variations in the volume of blood inside the cranial cavity
2 criteria for Dandy Walker syndrome?
- cystic dilation of the 4th ventricle
- absence of the cerebellar vermis
Kings
Blood from the face/orbit/nasal cavity, and upper teeth drains to the _____
cavernous sinus
Name the 3 sinuses that comprise the dorsal system of sinuses?
- Dorsal saggital sinus
- Straight sinus
- Transverse sinus
(King)
Name the three main sinuses that comprise the ventral system of intracranial sinuses?
- Cavernous sinus
- Dorsal petrosal sinus
- Ventral petrosal sinus
(Kings)
The cranial system of venous sinuses drains mainly via the ____ sinus into the _____ vein
The cranial system of venous sinuses drains mainly via the
connecting sinus into the maxillary vein
Kings
What are the three main veins that drain the cranium?
- maxillary vein
- internal jugular vein
- occipital vein
Kings
How are veins of the brain different than the rest of the body? (3)
- No valves
- No smooth muscle (and therefore very thin walled)
- Frequent anastamoses
Kings
Describe the two categories of veins that drain the cerebrum
- Superficial: superficial cerebral veins –> dorsal cerebral veins –> dorsal system of cranial venous sinuses -OR superficial cerebral veins –> ventral cerebral veins –> ventral system of cranial venous sinuses
- Deep: deep cerebral vein –> great cerebral vein –> straight sinus
Venous blood from which structures drains into the internal vertebral plexus?
- Spinal cord (via ventral spinal vein) - roots of the spinal nerves - vertebral bodies
(King)
The internal vertebral plexus drains into the ______ veins. Where do these veins ultimately drain?
Internal vertebral plexus drains into the intervertebral veins –> VERTEBRAL VEINS (neck), AZYGOS VEIN (thorax), CAUDAL VENA CAVA (abdomen)
King
Neurologic deficits are more common with cervical disc herniations at which sites? Neck pain is more common for cervical disc herniations at which sites?
C4/5 - C6/7 –> more likely to have neurologic deficits
C2/3, C3/4 –> more likely to have just neck pain
Sharp
What small breed dog is known for having cervical disc herniation at C6/7?
Peekignese
Sharp
What are the CT characteristics of a mineralized disc herniation?
heterogeneous, hyperattenuating extradural mass with loss of epidural fat
(Sharp)
How does the location of a cervical disc herniation/ventral slot alter the outcome?
the outcome after ventral slot decompression in small-breed dogs appears to be better for dogs with cranial cervical lesions (C2/3 or C3/4) than for those with caudal cervical lesions (C4/5 - C6/7)
* Significant improvement in clinical results was seen in caudal disk protrusions when additional surgical distraction and stabilization were provided following ventral slot decompression
Sharp
ROM increases in cadaver spines by ______% after fenestration and by _____% after ventral slot, even if the slot is only 1/3 of the vertebral width
How long after surgery are these signs typically observed?
ROM increases in cadaver spines by 30 - 40% after fenestration and by 66% after ventral slot, even if the slot is only 1/3 of the vertebral width
Typically occur within a week of surgery, can be delayed for up to 3 mos
(Sharp)
Prognosis for dog that cannot walk due to disc herniation, after ventral slot?
1) Complete recovery in 55 - 60%
2) Recovery with residual deficit in 15 - 20%
Sharp
How is collagen chemonucleolysis used in dogs with IVDD?
injection into the intervertebral disc –> results in dissolution of the NP and portions of the AF
Atilola et al
About what percent of dogs require ventilatory assistance after cervical spinal surgery?
13/263 (4.9%)
Beal (JAVMA) 2001
What factors are associated with a higher risk of perioperative hypoventilation in patients undergoing cervical spinal surgery?
Lesions between the 2nd and 4th cervical vertebrae
Treatment by means of a dorsal decompressive laminectomy
bilaterally symmetrical, periventricular T2, and FLAIR hyperintensities in brains of elderly dogs can be termed?
leukoaraios
(Scarpante 2017)
What is this called? What cohort of dogs develops it?
leukoaraios
Does bilateral hemilaminectomy alter outcome? Does it alter ROM or cause instability?
Does bilateral hemilaminectomy alter outcome? Does it alter ROM or cause instability?
In which cohort of dogs does fatty infiltration of the end plates most commonly occur? Which site is the most common location for end plate lesions (except fatty deposits)
Small breed dogs
L7/S1
(Gendron 2012)
What do reactive endplate changes look like on MRI?
T2W and STIR hyperintensity
T1W hypointensity +/- endplate enhancement
(2012GENDRON)
What are imaging criteria for endplate sclerosis?
T1W and T2W hypointense signal
(2012GENDRON)
Imaging criteria of fatty infiltration of endplates?
T1W and T2W hyperintensities that are nulled in STIR sequence
(2012GENDRON)
What are the imaging criteria for endplate osteochondrosis?
Defect observed on the dorsal edge of an endplate with or without a matching bone fragment, with disc-isointense material filling the gap
(2012GENDRON)
What are the imaging criteria for Schmorl’s nodes?
well marginated focal endplate defect contiguous with the disc that is filled with disc-isointense material.
Schmorl’s nodes should not involve the periphery of the end-plates, should be localized centrally
(2012GENDRON)
Endplate osteochondrosis
(GENDRON 2012)
Intravertebral disc herniation (Schmorl’s nodes)
(Gendron 2012)
Fatty replacement at the endplate
STIR should null signal
(Gendron 2012)
Two types of anterograde transport?
1) Slow - axonal cytoskeleton, proteins/enzymes
* function is to RENEW the axoplasm continuously or supply new axoplasm in a regenerating axon
2) Fast - carries new membrane material and membrane-bound organelles
(King)
The visceral (autonomic afferent pathways from the head and trunk project to a single long nucleus called the ________
nucleus of the solitary tract
* receives projections from three cranial nerves (facial, glossopharyngeal, and vagus nerves)
Kings
The modalites of touch, pressure and joint proprioception are transmitted in the ______ and ______ fasicles . Their receptor endings are ________receptors
The modalites of touch, pressure and joint proprioception are transmitted in the cuneate and gracile fasicles . Their receptor endings are mechanoreceptors.
Kings
3 neurons of the spinal cord spinothalamic tract (of man)
Neuron 1 w/ cell body in DRG –> short branches > interneurons, ARAS short branches > synapse in dorsal horn (DH)
Neuron 2 w/ cell body DH –> decussates and ascends in contralateral spinothalamic tract –> joins medial lemniscus at the pons
Neuron 3 Cell body in the ventral group of thalamic nuclei
(Kings)
Neuron 2 of the visual system forms the afferent component of which 4 visual reflexes?
(Neuron 2 = bipolar cells of the retina –> LGN)
1) eye movements
2) pupil constriction
3) turning of head/neck
4) ARAS
(King)
Which 3 dog breeds have a known genetic defect leading to epilepsy?
Lagotto Romagnolo
Belgian shepherd
Boerboels
Volk et al
What is the difference between genetic epilepsy, idiopathic suspected genetic epilepsy, and idiopathic epilepsy?
genetic epilepsy - a causative gene for epilepsy has been identified or there is confirmed genetic background
suspected genetic epilepsy - a genetic influence is supported by a high breed prevalence/genealogical analysis or familial accumulation of epileptic individuals
Idiopathic epilepsy - epilepsy in which the nature of the underlying cause is unknown with no indication of structural epilepsy
Volk et al
What is the most common seizure type observed in the dog?
focal epileptic seizures evolving into generalized epileptic seizures
Volk et al
What are the two types of tonic movements seen during a seizure?
tonic = sustained increase in muscle contraction lasting a few seconds to minutes
versive = a sustained forced conjugate ocular, cephalic and/or truncal rotation or lateral deviation from the midline
dystonic = sustained contractions of both agonist and antagonist muscles producing athetoid (writhing) or twisting movements which when prolonged may produce abnormal postures
Volk et al
Infective material that enters the veins of the face, nasal cavity, orbit, and upper teeth can drain directly into the _______
ventral system of venous sinuses
* bacterial infection of the endothelium of the sinuses may cause a thrombus –> can lead to a sudden obstruction of venous drainage in the sinus system –> serious/fatal results
(King)
What is a paradoxical embolism?
Unexpected movements of tumor cells or infections
Microorganisms from an infected kidney can reach the head, neck, or thorax via abdominal straining (creates enough of a pressure difference to overcome venous valves, then gains access to the valveless sinuses)
(King)
Four membrane-bound organelles that are found in the axon?
1) vesicles containing neurotransmitters
2) smooth ER (for storing and transporting substances)
3) lysosomes
4) mitochondria
RIBOSOMES = ABSENT - no synthesis of protein from amino acids can occur in the axon
(King)
Describe the perineurium, epineurium and endoneurium
How to cholinergic vesicles and noradrenergic/adrenergic vesicles appear differently under EM?
Cholinergic vesicles appear empty
Noradrenergic and adrenergic vesicles contain a dense core –> called small granular vesicles or small dense-cored vesicles
Both are spherical and 30 - 60nm in diameter
(King)
What happens to acetylcholine that is released at a synapse? What happens to noradrenaline that is released
acetylcholine that is release is rapidly inactivated by acetylcholenesterase. Choline is reabsorbed and recycled
Noradrenaline is largely reabsorbed and recycled within the synaptic end bulb
(Kings)
How does magnesium alter neurotransmitter release?
Blocks the release of neurotransmitters by exocytosis (opposite effect of calcium)
(Kings)
How does the shape and position of the central canal vary between the brainstem and spinal cord?
brainstem cent canal = 4th vent. Tends to be DORSAL and WIDER than the central canal of the spinal cord
The columns of the grey matter become V-shaped when seen transversely. They lie obliquely on either side of the 4th ventricle
(Kings)
How does the anatomy of the grey matter of the brainstem vary from the spinal cord?
How does the anatomy of the grey matter of the brainstem vary from the spinal cord?
What is the special visceral efferent system? Where are these nuclei located
efferent nerves that supply innervation to the muscles of the pharyngeal arches
Nuclei are located ventrolateral to the central canal/4th ventricle
(Kings)
What three cranial nerve nuclei contain a special visceral efferent component?
1) motor nucleus of the TG nerve (supplies masticatory m)
2) motor nucleus of the facial nerve (supplies facial m)
3) nucleus ambiguus (supplies pharyngeal and laryngeal muscles)
(Kings)
Which 4 cranial nerves possess somatic afferent fibers?
CN 5 - largest
CN 7
CN IX
CN X
Kings
What is the somatic afferent nucleus called in the brainstem? What are the three divisions of this nucleus? What is the responsibility of each division?
Sensory nucleus of the trigeminal nerve
1) Nucleus of the spinal tract of CN V
2) Principal (pontine) sensory trigeminal nucleus 3) Nucleus of the mesencephalic tract of the trigeminal nerve
Kings
What is the function of each division of the sensory nucleus of the trigeminal nerve? What are the homologous structures of the spinal cord?
- Pain/temp from face –> nucleus of the spinal tract of the trigeminal nerve = spinothalamic tract
- Touch and pressure from face –> pontine sensory nucleus = cuneate and gracile nuclei
- Proprioceptive information –> nucleus of the mesencephalic tract of the TG nerve = DRG
Kings
What are the four visceral efferent nuclei of the cranial nerves? What is their homologous structure in the spinal cord?
Parasympathetic nuclei of CN 3, 7, 9, and 10
Homologous to the lateral horn of the spinal cord
Kings
What are the 4 somatic efferent nuclei of the cranial nerves?
Motor nucleus of CN 3
Motor nucleus of CN IV
Motor nucleus of CN VI
Motor nucleus of CN XII
Kings
Name the three neurons of the medial lemniscal system
1) Neuron 1 primary afferent neuron w/ cell body in DRG –> a) short branch > interneuron > reflex arc. b) short branch > ARAS. c) long branch > gracile nucleus or med. cuneate nucleus (in medulla)
2) Neuron 2 cell body in the gracile nucleus or medial cuneate nucleus –> decussates in the deep arcuate fibers –> medial lemniscus –> thalamic nucleus
3) Neuron 3 cell body in the ventral group of thalamic nuclei –> primary somatic sensory area of the cerebral cortex
(Kings)
Why is it that experimental destruction of the dorsal funiculi in the cervical region results in severe ataxia of the forelimbs, but less pronounced ataxia of the hindlimbs?
NUCLEUS Z the majority of the proprioceptive fibers from the hindlimb leave the gracile fascicle in the 1st lumbar segment –> synapse in the dorsal horn in the thoracic nucleus with neurons that ascend in the dorsal spinocerebellar tract
–> end in nucleus Z –> travel in deep arcuate fibers to join medial lemniscus –> cerebral cortex
** nucleus Z may be a displaced fragment of the gracile nucleus? ** in contrast, the proprioceptive fibers from the forelimb are ONLY in the cuneate fasicle
(Kings)
What is the equivalent of the dorsal horn when referring to somatic pain pathways from the head? visceral pain afferents of the head?
somatic pain - nucleus of the spinal tract of the trigeminal nerve
visceral pain afferents of the head? nucleus of the solitary tract or the nucleus of the spinal tract of the trigeminal nerve
(Kings)
Explain the 4 neurons of the spinocervical tract
1) cutaneous receptors of touch, pressure and superficial pain –> DRG
2) Cell body in DORSAL HORN –> axon ascends in ipsilateral spinocervical tract of the lateral funiculus
3) cell body in LATERAL CERVICAL NUCLEUS at C1 and C2 –> decussates and joint the medial lemniscus
4) Cell body in ventral group of thalamic nuclei
** The spinocervical tract is different from the rest of the medial lemniscal system because it has FOUR neurons instead of three
(King’s)
Name the 3 neurons of the visual pathway
1) bipolar cell of the retina (receives inpulses from the neuroepithelial cells of the retina)
2) Ganglion cell of the retina –> optic nerve –> optic canal –> optic chiasm –> optic tract –> LGN
3) LGN –> occipitl cortex
King’s
Name the 3 neurons of the auditory pathway
1) neuroepithelial cells in the spiral organ of corti –> neuron w/ cell body in the spiral ganglion of the cochlear nerve (located in the MODIOLUS in the cochlea) –> CN 8 –> cochlear nuclei
2) cochlear nuclei –> decussate in the trapezoid body (and synapse w/ nucleus of the trapezoid body)–> contralateral lateral lemniscus –> caudal colliculus –> medial geniculate nucleus ** some axons project from cochlear nucleus –> ipsilateral lateral lemniscus –> medial geniculate nucleus
3) Medial geniculate nucleus –> auditory radiation in the internal capsule to the auditory area of the temporal cerebral cortex
** medial geniculate nucleus belongs to the ventral group of thalamic nuclei
(King’s)
What neuronal pathways are able to regulate sound wave frequency?
neuronal connections between the:
1) Cochlear nuclei – > the efferent motor neurons of the trigeminal nerve –> tensor tympani m.
2) Cochlear nuclei –> efferent motor neurons f the facial nerves –> stapedius muscles
* these muscles control the degree of mobility of the ear ossicles
(King’s)
What is the prevalence of canine epilepsy (estimated?)
0.6 - 0.75%
Volk et al
What are focal epileptic seizures?
- lateralized and/r regional signs of motor, autonomic or behavioral signs
- the abnormal electrical activity arises in a localized group of neurons or network within one hemisphere –> the clinical signs reflect the functions of the area involved
Volk et al
what is the definition of clonic?
myoclonus which is regularly repetitive, involves the same muscle groups, at a frequency of about 2 - 3 seconds, and is prolonged
Volk et al
Define automatism
a coordinated, repetitive, motor activity usually occurring when cognition is impaired, and for which the subject is usually amnesic afterwards
ex/ lip smacking, chewing, swallowing, teeth grinding (oroalimentary) or pedal (running movement)
Volk et al
How can a paroxysmal movement disorder be differentiated from a focal motor epileptic seizure?
movement disorder - normal between episodes, no autonomic signs, no behavioral changes, no EEE abnormalities
Volk et al
A study identified that inter-ictal EEG recordings in epileptic dogs under GA (propofol and rocuronium) was able to detect interictal paroxysmal epileptiform activity in ___% of IE dogs
25% of IE dogs
Volk et al
What gene abnormality is associated with paroxysmal exercise-induced dyskinesia in CKCS?
BCAN gene deletion
AKA “episodic falling.”
Volk et al
Dogs with poisoning had a ____x higher risk of presenting in status epilepticus at seizure onset than dogs with IE or structural epilepsy
2.7x
Volk et al
What factors are associated with a worse prognosis in border collies w/ seizures?
T/F - there is a strong genetic component to IE in border collies
early seizure onset and high initial seizure frequency - both associated with a worse prognosis
T - there is a strong genetic component to IE in border collies
IE with a severe clinical course and frequent drug resistance frequently occurs in German border collies
Huesmeyer et al
T/F: epileptic dogs that require 2 AEDs can expect a lower life expectancy
False
Fredso et al
What is the gene mutation that has been identified in the Lagotto Romagnolo associated with epilepsy?
truncating mutation in LGI2
results in alteration of protein that is critical in synaptic function
Ekenstedt et al
What is the genetic mutation responsible for Lafora disease and myoclonic epilepsy in miniature wirehaired dachshunds?
biallelic expansion of a dodecamer repeat in the EPM2B gene
AUTOSOMAL RECESSIVE
Ekenstedt et al
How is MDR1 (AKA ACBC1) gene mutation associated with seizure control in collies with epilepsy?
Collies homozygous for the mutation had significantly improved seizure outcome compared with the heterozygous dogs or dogs that were homozygous for the wild-type allele
** there is no association between the mutation and diagnosis of IE
Ekenstedt et al
Which two breeds are known to have a genetic abnormality leading to 2-hydroxyglutaric aciduria (2-HGA)?
Staffordshire bull terrier - 2 base pair substitution in exon 10 of the L2HGDH gene
Yorkshire terrier - single nucleotide substitution in the initiation codon for methionine in the L2HGDH gene
Ekenstedt et al
______ is a group of metabolic disorders that progressively damages brain tissue resulting in a clinical presentation that resembles epilepsy, including seizures
2-hydroxyglutaric aciduria (2-HGA)
urinary organic acid profile study is abnormal
Ekenstedt et al
Characteristics of epilepsy in Australian Shepherds? (seizure characteristics, age of onset, genetic basis and sex influence)
generalized seizures (some with focal onset)
under 5y onset
hereditary basis
bias towards MALES
ekenstedt et al
Characteristics of epilepsy in Beagles?(seizure characteristics, age of onset, genetic basis and sex influence)
partial and generalized seizures
1y minimum at onset
significant sire effect bias towards males
Ekenstedt et al
Epilepsy characteristics in Belgian Shepherds? (seizure characteristics, age of onset, genetic basis and sex influence)
focal seizures or generalized
mean onset 3.3y - 4y simple mendelian, likely autosomal mode of inheritance (1 study) polygenic inheritence in another study No sex bias
Ekenstedt
T/F: epilepsy is inherited in the Belgian Terveren
Yes
Characteristics of epilepsy in the Bernese Mountain Dog? (seizure characteristics, age of onset, genetic basis and sex influence)
mostly generalized seizures
onset 1 - 3y old polygenic autosomal recessive, sex modified inheritance
Bias towards males
ekenstedt et al
T/F: Dalmantions with seizures are known to have a bias towards males
False - slight bias towards females
Mostly partial onset seizures with secondary generalization
Ekenstedt et al
T/F: There is a sire effect noted in GSD with epilepsy?
True - sire effect and affected dogs are more inbred
Bias towards males
Age of onset 1 - 2y
ekenstedt et al
Characteristics of IE in Standard Poodles? (seizure characteristics, age of onset, genetic basis and sex influence)
Partial onset with secondary generalization
age of onset 3y, < 7.5y
simple autosomal recessive with complete or nearly complete penetrance
Characteristics of IE in Schipperke?
partial and generalized seizures with mean age of onset 4.4y.
hereditary correlation and sex predilection not reported
ekenstedt et al
Characteristics of IE in Golden Retrievers? (seizure characteristics, age of onset, genetic basis and sex influence)
Mostly generalized seizures
Age of onset 1 - 3y old
Polygenic autosomal recessive
Bias towards males
Ekenstedt et al
Characteristics of epilepsy in Irish Wolfhounds? (seizure characteristics, age of onset, genetic basis and sex influence)
Generalized seizures
Age of onset < 3y
Incompletely penetrant recessive with sex predilection
Bias towards males
Ekenstedt et al
Characteristics of epilepsy in keeshonds? (seizure characteristics, age of onset, genetic basis and sex influence)
1y minimum at age of onset
hereditary basis in one study, single autosomal recessive in another study
bias towards males in one study, no bias in another study
ekenstedt et al
Characterstics of IE in Lagotto Romgnolo? (seizure characteristics, age of onset, genetic basis and sex influence)
seizures vary - some simple focal, others complex focal, or secondarily generalized
onset 5-9 weeks, remitting by 4m of age autosomal recessive inheritance with possible incomplete penetrance and ~ 7% diseased with heterozygosity
No sex bias
ekenstedt et al
Characteristics of epilepsy in the Vizsla? (seizure characteristics, age of onset, genetic basis and sex influence)
partial and generalized seizures
1-3y autosomal recessive, possibly polygenic
no sex bias
ekenstedt et al
7 breeds that have been identified to have NCL?
English setter
Border Collie
American Bulldog
Dachshund
American Staffordshire Terrier
Australian Shepherd
Tibetan Terrier
ekenstdt et al
T/F: episodic head tremor syndrome is inherited in Doberman Pinscher dogs
True
Wolf et al
T/F: Interpretation of paroxysmal events by multiple veterinarians was found to have good agreement regarding the presence of an epileptic seizure
False - moderate agreement with focal seizures having lowest agreement
Packer et al
What is the most common electrolyte abnormality leading to seizures?
Hypocalcemia
Brauer et al
What test is used to diagnose organophosphate or carbamate intoxication?
blood cholinesterase
Brauer et al
What toxins are the most common causes of reactive seizures in dogs?
metaldehyde organophosphate/carbamate poisoning
Brauer et al
What is the elimination half-life of gabapentin in dogs?
3-4h
(Dewey 2009)
The owners of epileptic dogs consider 1 seizure every ____ months to be acceptable
1 seizure every 3 mos
(Dewey 2009)
______ is located on the floor of the 4th ventricle, with the rostral end directly continuous with the piriform lobe
hippocampus
King’s
What sensations are transmitted through the medial lemniscal system?
Touch/pressure
Joint proprioception
Superficial pain
Heat and cold
(King’s)
Approximately what % of dogs that undergo FMD require reoperation because of excessive scar tissue formation?
25%
Dewey et al
How is gabapentin excreted by dogs?
kidneys, 30 - 40% hepatic metabolism
(Dewey 2009)
What anticonvulsant can cause renal tubular acidosis? What is the proposed mechanism of action?
Zonisamide
Weak carbonic anhydrase inhibitor
(Cook 2011)
How does zonisamide alter thyroid hormone levels?
reduction in thyroxine and increased TSH
(Boothe/Perkins 2008)
Clinical signs of bromide toxicosis are typically seen in the range of…?
2.4 - 4mg/mL
Also found that dogs were successfully treated without signs of toxicosis at serum concentrations as high as 4 - 4.8 mg/dL
(Baird-Heinz et al, 2012)
What skin lesions have been rarely reported associated with KBr administration?
nonsuppurative white macules with scales or as pustular dermatitis
Pruritic skin lesions (anecdotally)
(Baird-Heinz et al, 2012)
Three neurons involved in hearing
1) impulses from spiral organ of corti –> cochlear neuron w/ cell body in SPIRAL GANGLION –> 8th CN –> internal acoustic meatus –> cochlear nuclei
2) neuron w/ cell body in cochlear nuc. –> decussate at the TRAPEZOID BODY –> lateral lemniscus –> caudal colliculus/medial geniculate nucleus
3) cell body located in medial geniculate nucleus –> internal capsule (specifically the auditory radiation) –> auditory area of the TEMPORAL cortex
King’s
Where is the spiral ganglion located?
modiolus of the cochlea
King’s
Describe the 3 neurons involved in the vestibular system?
1) impulses from: 3 semicircular ducts, saccule, and utricle –> vestibular neuron (cell body in vestib. ganglion) –> CN8 –> internal acoustic meatus –> vestibular ganglion
2) vestibular nuclei (4) –> prosencephalon; MLF to CN 3, 4, 8; vestibulospinal tract; cerebellum; ascending/descending reticular formations
(King’s)
Describe the 2 neurons involved in taste
1) taste buds on the rostral 2/3 of the tongue –> geniculate ganglion (of CN7) –> CN VII -or- 1) taste buds on the caudal 1/3 of the tongue –> distal ganglion (of CN IX) –> CN IX -or- 1) taste buds of the mucosa of the caudal pharynx/larynx –> distal ganglion (of CN X) –> CN X
2) nucleus of the solitary tract –> solitarothalamic pathway –> contralateral ventral caudal medial nucleus of the thalamus –> sensory cortex
(King’s)
What are the three neurons involved in smell
1) olfactory neuroepithelial cell (axon is the central process of the neuroepithelial cell) –> pass through the fribriform plate of the ethmoid bone –> olfactory bulb *The cell lies in the olfactory epithelium on the ethmoturbinate bones 2) olfactory bulb –> olfactory peduncle –> medial/lateral olfactory tracts –> olfactory tubercle
2) olfactory bulb –> septal nuclei and subcallosal area –> medial forebrain bundle –> hypothalamus -or- medial forebrain bundle –> reticular formation of the brainstem
3) olfactory tubercle –> olfactory region of the cerebral cortex (piriform lobe)
(king’s)
What are the two divisions of the rhinencephalon?
1) Olfactory (olfactory bulb/pedubcle/tracts/tubercle and piriform lobe) 2) Limbic (hippocampus, amygdaloid body, septal nuclei, habenular nuclei)
the ______ is involved in: 1) motor expression of emotion and rage 2) process of learning and memory 3) instinct
hippocampus
King’s
A large group of efferent fibers that fibers that passes from the amygdala to the rostral hypothalamus and septal area is called?
stria terminalis
King’s
The _____ nuclei lie in the roof of the 3rd ventricle and are part of the limbic system
habenular nuclei
King’s
What is the mean relapse time for cavaliers treated surgically with FMD?
16 months
Dewey et al
Describe the parasympathetic innervation to the zygomatic salivary gland
1) parasympathetic nucleus of CN IX –> tympanic nerve/plexus –> minor petrosal nerve
2) Otic ganglion –> buccal n. (branch of CN V mandibular)
3) zygomatic salivary gland
CN IX –> CN V RG
Describe the parasympathetic innervation to the sublingual salivary gland
1) parasympathetic nucleus of CN 7 (rostral salvatory nucleus) –> CN 7 –> chorda tympani –> lingual nerve (br of V3)
2) Sublingual ganglion n
3) Sublingual salivary gland
CN 7 –> CN 5 RG
Approximate “long-term” success rate of ventral slot for disc-associated CCSM?
~ 72%
Jeffery et al 2001
Rusbridge et al 2007: what % of dogs deteriorated after cranial cervical decompression? What was the mean time for deterioration?
80% improved and 20% were unchanged immediately after surgery
47% of dogs deteriorated after surgery (mean 16 months)
T/F: Cranial cervical decompression results in syrinx collapse or the resolution of the syrinx
False
Rusbridge et al
Study by Cerda-Gonzalez et al found that what % of Cavaliers had crebellar crowding at the foramen magnum?
51/59 = 86%
T/F: There is a significant difference in the caudal fossa volume between CKCS with and without syringomyelia?
False
Cerda-Gonzalez
Describe the pathway for parasympathetic innervation of the parotid salivary gland?
1) Parasympathetic nucleus of CN IX –> CN IX –> tympanic nerve/tympanic plexus –> minor petrosal nerve
2) Otic ganglion –> auriculotemporal nerve (br of mandiblar n of CN V)
3) Parotid gland
CN IX –> CN V RG
Describe the sympathetic innervation of the salivary glands
Cranial cervical ganglion –> vasculature to the gland
RG
ventral slot vs. vertebral distraction and stabilization as tx for disc associated CCSM - which one is more likely to result in neurologic deterioration post-operative? Which one is more likely to be associated with recurrence of clinical signs?
neurologic deterioration more likely w/ ventral slot
Recurrence of signs - vertebral distraction/stabilization
Rusbridge 1998
What is the success rate for ventral slot or distraction/stabilization for disc-associated CCSM?
both approximately 80%
Rusbridge 1998
What is the approximate rate of recurrence after surgery for disc associated CCSM?
20%
Jeffery 2001
Does ambulatory status prior to surgery for disc-associated CCSM influence the outcome?
no
Jeffery et al 2001
7 categories of surgery that can be performed for disc-associated CCSM?
1) ventral slot
2) fenestration
3) Interbody screw
4) PMMA/metal
5) Lubra/spacer
6) Screw/distractor
7) PMMA plug
Jeffery et al 2001
unique post-operative complication of long dorsal laminectomy for CCSM?
laminectomy membrane formation
DiRisio et al 2001
How does dorsal cervical laminectomy for CCSM compare to other surgical methods RE post-operative complication and recurrence rates?
comparable
Complication rate - 30%
Recurrence rate - 30%
DiRisio et al 2001
Why does intervertebral “spacer” and screw surgery tend to fail for disc-associated CSSM?
Fracture to the caudoventral aspect of the cranial vertebrae
Is there a sex predilection for CCSM?
Some studies say no
Other studies say older male doberman pinschers
DiRisio et al 2002
When should dorsal laminectomy for CCSM be considered?
- substantial dorsal or dorsolateral compression of the spinal cord
- dorsal component to the compression that does not improve with traction - Multiple sites are involved
DiRisio et al 2002
What was the early postoperative morbidity associated with dorsal laminectomy for CCSM?
high (70%) 14/20
Defined as worsened neurologic status 2 days after surgery
DiRisio et al 2002
Characterizations of the morphogenesis of CM/SM? (6)
1) Rostral flattening
2) Olfactory bulb rotation
3) increased height of the cranium/occipital lobe
4) reduction in cranial base with spheno-occipital synchondrosis angulation
5) reduced supraoccipital and interparietal crest
6) rostral displacement of the axis and atlas with increased odontoid angulation
Knowler et al 2018
When dogs are affected with SM as young dogs, how does this predict their clinical signs over time?
SM-affected young dogs develop more severe clinical signs and syrinxes that enlarge over time
Knowler et al 2018
How does venous sinus volume (in the caudal cranial fossa), skull base, and jugular foramen size compare in CKCS with CM/SM and CM?
Venous sinus volume in the caudal cranial fossa is REDUCED, skull base is REDUCED, jugular foramen are NARROWED in CKCS with CM/SM as compared to CKCS with CM
*narrowing of the jugular foramen could potentially increase intracranial venous pressure and impair CSF absorption?
Knowler et al 2018
What are the three grades of CM defined by BVA KC?
CM 0 - cerebellum has rounded shape w/ high signal intensity on weighted images consistent with CSF between the caudal cerebellar vermis and the foramen magnum
CM1 the cerebellum does not have a rounded shape, i.e., there is indentation by the supraoccipital bone, but there is a signal consistent with CSF between the caudal vermis and the foramen magnum
CM2 the cerebellar vermis is impacted into or herniated through the foramen magnum
Knowler et al 2018
Brachycephalic breeds have facial skeleton foreshortening due to _______ hypogenesis
Maxillary hypogenesis
What two morphologic characteristics are associated with CM pain?
Rostral forebrain flattening
short basioccipital bone
Rusbridge et al 2018
What was the conclusion of DaCosta’s study RE outcome of medical vs. surgical treatment in dogs with CCSM?
Outcome was not significantly different between dogs treated medically and surgically
- Outcome = survival time - 81% of dogs were improved after surgical treatment
- 54% of dogs were improved after medical treatment (no significant difference from surgery)
DaCosta 2008
Morphologic abnormalities associated with CM/SM?
How does cerebellar volume compare in dogs/CKCS with CM/SM and normal dogs?
Cerebellar volume was greater in CKCS with CM/SM and abnormal in in dogs with CM/SM compared to normal controls
Knowler et al 2018
T/F: there is a correlation between severity of cerebellar herniation and neurologic signs in dogs with CM/SM?
False
What is the strongest predictor of pain, phantom scratching, and scoliosis in dogs with SM?
Maximum syrinx width
Knowler et al 2018
Toy breeds that have been reported with SM secondary to CM include (15)
CKCS
Cross breeds
Griffon Bruxellois
Bichon
Affenpinschers
Shih tzu
Yorkshire Terrier
Miniature Dachshund
French Bulldog
Papillions
Havanese
Maltese
Chihuahua
Boston terrier
Pomeranian
Knowler et al 2018
T/F: Craniocervical junction abnormalities can predict development of worsening of clinical signs of SM?
False - CCJA did not predict development or worsening clinical signs, but may contribute to them (atlaotooccipital overlapping, atlantoaxial bands, medullary elevation)
Knowler et al 2018
What is the definition of atlanto-occipital overlapping?
invagination of the odoitoid process into the foramen magnum with ventral brainstem compression
Knowler et al
T/F: Canine CM is known to have a strong heritable component?
True
* breeding away from SM has shown to be effective
Knowler et al 2018
How is symptomatic SM diagnosed?
Signs of myelopathy and presence of a large syrinx that is consistent with the neurolocalization
Rusbridge et al 2018
Griffon bruxellois with CM have shortened basicranium and ________ bone with a compensatory lengthening of the ______ _____ ______, especially the _______ bone
Griffon Bruxellois with CM have shortened basicranium and supraoccipital bone, with compensatory lengthening of the
dorsal cranial vault, especially the parietal bone
Rusbridge et al 2018
T/F: There is no an association between acute angulation at the spheno-occipital synchrondrosis (spheroid flexure) and SM
True
Rusbridge et al 2018
How does the morphology of the occipital crest relate to development of SM?
There is an association between a reduced occipital crest and SM in the CKCS
Rusbridge et al 2018
How does the morphology of the frontal sinus relate to development of SM
There is an assocation between small frontal sinuses and SM in small breed dogs
Rusbridge et al 2018
How does occipital bone volume vary between CKCS w/ and w/o SM and French Bulldogs?
No difference in volume –> does not support theory of occipital bone hypoplasia
Rusbridge et al 2018
How does the size of the jugular foramen compare in CKCS with CM and CM/SM
narrowed jugular foramen in CKCS with CM and SM as compared to CKCS with CM only
What craniocervical junction abnormalities are risk factors for SM?(5)
atlanto-occipital overlapping
atlantoaxial subluxation
dorsal angulation of the dens
occipital dysplasia
atlantoaxial axial “banding”
What is the most common CM/SM related clinical sign in Chihuahuas? What was the most common neurologic deficit related to CM/SM?
Scratching was the most common CM/SM-related clinical sign (73%)
Decreased postural reaction the most common neurologic deficit (87%)
Kiviranta et al 2017
How is atlantooccipital overalapping diagnosed on CT?
How is atlantooccipital overalapping diagnosed on CT?
What two CCJ abnormalities are thought to play an important role in the pathogenesis of SM and neuropathic pain in chihuahuas
medullary elevation dorsal spinal cord compression
T/F: study on chihuahuas with CM/SM found that the width of syrinx is associated with clinical signs?
False
Kiviranta et al 2017
Proposed mechanism for clinical signs caused by CCJ abnormalities?
compression of the spinal nucleus and tract of CN V
- receives sensory input related to nociception and temp from the skin/mm of the head
- continues as the substantial gelatinosa and dorsolateral fasiculus in the spinal cord
Kiviranta et al 2017
T/F: Atlantooccipital overlapping is rare in chihuahuas
False - detected in 70% of dogs in one study
Kiviranta et al 2017
T/F: Atlantooccipital overlapping was NOT associated with the presence of CM/SM-related clinical signs. SM, or severity of CM
true
Kiviranta et al 2017
CM and SM have a _____ mode of inheritance with ______ penetrance in CKCS
polygenic mode of inheritance with variable penetrance
Kiviranta et al 2017
What two CCJ abnormalities are thought to play an important role in the pathogenesis of SM and neuropathic pain in chihuahuas
medullary elevation dorsal spinal cord compression
What was the most prominent weakness to neuronavigation-guided resection of brain masses w/ NICO myriad?
significant reliance on preoperative navigation images and inability to correct for brain shift
Packer and McGrath 2020
How does occipital bone volume vary between CKCS w/ and w/o SM and French Bulldogs?
No difference in volume –> does not support theory of occipital bone hypoplasia
Rusbridge et al 2018
What factors contribute to brain shift (concerning neuronavigation systems)
release of pressure created by presence of a space-occupying mass
effects of gravity
volume loss of CSF or blood during the procedure
differences in animal positioning from imaging to surgery
administration of mannitol
size of craniotomy defect
tumor size
tumor type
Packer and McGrath 2020
T/F: The neuronavigation-guided resection of brain masses w/ NICO myriad was feasible?
True
McGrath, Packer 2020
What percent of gliomas are diagnosed as infarctions?
12%
Gutmann 2020
The MRI-based personalized 3D printed stereotactic brain biopsy device achieved ___________ precision in targeting predefined intracranial points in the caudate nucleus and piriform lobes of cadavers
The MRI-based personalized 3D printed stereotactic brain biopsy device achieved excellent precision in targeting predefined intracranial points in the caudate nucleus and piriform lobes of cadavers
Gutmann et al 2020
T/F: study on chihuahuas with CM/SM found that the width of syrinx is associated with clinical signs?
False
Kiviranta et al 2017
in Rohdin et al paper RE 30 pugs with TL myelopathy, what region were most meningeal fibrosis lesions found in?
T5-L1
RE pugs with meningeal fibrosis - the finding of meningeal fibrosis unrelated to the thoracolumbar spinal cord lesion more likely suggests a predisposition to ______ ______
meningeal proliferation
the profound meningeal fibrosis could interfere with vascular supply to the spinal cord, as well as cause obstruction of CSF flow with subsequent parenchymal spinal cord destruction
Rohdin et al 2020
Leakage of ________has been shown in clinically normal pugs, and is suggested to be the result of a breed-specific astrocyte fragility
GFAP
Rohdin et al 2020
When comparing dogs with brain-tumor associated seizures treated medically or with RT, how did seizure freedom and survival time compare?
RT: mean duration of seizure freedom 24 mos, mean survival time 34.6 mos (significantly greater than…)
medical: mean duration of seizure freedom 1.7 mos, mean survival time 6.2 mos
Monforte Monteiro et al
Is medullary kinking, or dorsal spinal cord compression more strongly associated with CM/SM-related clinical signs?
Medullary kinking significantly higher in dogs with CM/SM related clinical signs No statistical difference was detected in dorsal spinal cord compression between the 2 groups
Kiviranta et al 2017
Is cell-free DNA useful as a diagnostic marker in CSF of dogs?
No
Start et al 2020 - There were no substantial differences in cell-free DNA concentrations identified between dogs with or without neurologic disease.
Cell free DNA did not correlate with CSF RBC, NCC, or protein
How is neuropathic pain evaluated objectively?
measure mechanical sensory threshold
What are the most common extraneural abnormalities associated with mannosidosis/MPS and mucolipidosis?
skeletal abnormalities - craniofacial malformation, joint immobility
PL paresis often develops in cases of mucopolysaccharidoses and mucolipidosis (bony vertebral growths that cause spinal cord compression)
A group of related _____ (breed) was described with suspected neuronal abiotrophy
red-haired cocker spaniels
Proposed mechanism for clinical signs caused by CCJ abnormalities?
compression of the spinal nucleus and tract of CN V
- receives sensory input related to nociception and temp from the skin/mm of the head
- continues as the substantial gelatinosa and dorsolateral fasiculus in the spinal cord
Kiviranta et al 2017
how does chronic bony compression at the cervicomedullary junction, turbulent CSF flow and pressure changes in this region alter the composition of the meninges?
Meninges become hypertrophied with time
Pathological evidence of dural fibrosis in the region of the malformation
Dewey
_____ is caused by an an overly-rapid hemodialysis causing osmotic gradient between the brain and ECF
Dialysis disequilibrium syndrome (DDS)
(Dewey)
T/F: Atlantooccipital overlapping is rare in chihuahuas
False - detected in 70% of dogs in one study
Kiviranta et al 2017
What two breeds are reported to suffer from cervical IVDH at multiple sites?
Shih tzus and Yorkshire Terriers
Guo et al 2020
How does the size of the jugular foramen compare in CKCS with CM and CM/SM
narrowed jugular foramen in CKCS with CM and SM as compared to CKCS with CM only
T/F: Atlantooccipital overlapping was NOT associated with the presence of CM/SM-related clinical signs. SM, or severity of CM
true
Kiviranta et al 2017
Which micro RNAs can *potentially* be used to differentiate glioma and other brain diseases?
miR-15b and miR-342-3p
micro RNA = small noncoding molecules that regulate gene expression following transcription
Narita et al 2020
What do epidermoid cysts look like on CT? MRI? How does this vary from DERMOID cyst??
Epidermoid: hypoattenuating on CT images hypointense on T1WI with RING enhancement hyperintense on T2WI
Dermoid: hyperintense on T1WI and T2WI (due to fat content)
(Dewey)
epidermoid and dermoid cysts are thought to be due to a failure of complete separation of _____ from _____ during embryogenesis
epidermoid and dermoid cysts are thought to be due to a failure of complete separation of neuroectoderm from non-neural (epithelial) ectoderm
if the epithelial ectoderm has adnexal structures, the structure is called a dermoid cyst. If the epithelial ectoderm does NOT have adnexal structures, the structure is called a epidermoid cyst
(Dewey)
Main changes seen in the brain of dogs with cognitive dysfunction syndrome? (6)
- Cerebral vascular changes (blood vessel wall fibrosis, microhemorrhages and infarcts)
- meningeal thickening
- gliosis, axonal degeneration
- ventricular dilation
- accumulation of beta-amyloid in and around neurons
- intraneuronal accumulation of tau protein, lipofuscin, polyglucosan bodies, ubiquitin
- cerebral atrophy
Dewey
clinical signs of neuronal vacuolation and spinocerebellar degeneration in Rottweilers and Boxer Dogs?
- generalized weakness, cerebellar ataxia inspiratory stridor due to laryngeal nerve dysfunction
- congenital ocular abnormalities (cataracts, persistent pupillary membrane, microophtlamia, retinal dysplasia)
- signs worsen over weeks, end stage - behavior changes
Dewey
Neuronal vacuolation and spinocerebellar degeneration of Rottweilers/Boxers - histopathologic findings
- intraneuronal vacuoles primarily in the brainstem, cerbellum, and spinal cord grey matter.
*reminiscent of scrapie-associated spongiform change
- axonal necrosis dorsolateral and ventromedial funiculi of the cervical and thoracic spinal cord
- Selective distal neuropathy of the recurrent laryngeal nerves
Dewey
Histologic findings associated with leukodystrophy/spongy degeneration?
CNS white matter loss with vacuolation of the brain tissue (spongiform change)
ROSENTHAL fibers = astrocytic inclusion bodie
Dewey
2 mechanisms that result in leukodystrophy?
Abnormal synthesis of myelin in the CNS Abnormal maintenance of myelin in the CNS
Rare, poorly understood, heritable, progressive diseases
Dewey
Name the 3 lysosomal storage diseases where prosencephalic dysfunction predominates
- Neuronal glycoproteinosis (Lafora’s disease)
- ceroid lipofuscinosis (Batten’s disease)
- Fucosidosis
Dewey
Name the 5 lysosomal storage disorders that have cerebellar dysfunction as an early sign of disease
- Mannosidosis
- Gangliosidoses (GM1, GM2)
- Globoid cell leukodystrophy (Krabbe’s disease)
- Glucocerebridosis (Gaucher’s disease)
- Sphingomyelinosis (Niemann-Pick disease)
Dewey
Name 5 degenerative encephalopathies
- Lysosomal storage disease
- Leukodystrophy/spongy degeneration
- Neuronal vacuolation of Rottweilers and Boxer dogs
- Multisystem neuronal degeneration/abiotrophy of Cocker Spaniels
- Canine cognitive dysfunction syndrome (CCDS)
Dewey
English springer and cocker spaniel paradoxical pseudomyotonia:
- Age at onset? - Appearance of episodes?
- Trigger? - Diagnostics?
- Disease course?
- Age at onset? < 24 mos
- Appearance of episodes? myotonic-like generalized muscle stiffness, spontaneously resolve with rest in < 45 seconds (in all but 1 dog)
- Trigger? exercise, extreme outside temperatures seemed to worsen episode frequency and severity - why this is PARADOXICAL PSEUDOMYOTONIA
- Diagnostics? bloodwork, MRI, CSF, electrodiagnostics, echocardiogram normal in all dogs
- Disease course? episodes remained stable or decreased in severity and frequency in 6/7 dogs
Stee 2020
What is the definition of a movement disorder?
episode of abnormal involuntary hyperkinetic movement without altered consciousness
- no autonomic dysfunction
- no postictal behavior
Causes of false positive Aspergillus Galactolamman ELISA? Causes of false negative?
False-positive - plasmalyte administration, other systemic mycoses False-negative - localized pulmonary involvement
Garcia 2012
What species of aspergillus is most frequently associated with systemic aspergillosis in dogs?
A.terreus
A. fumigatus and A. flavus usually cause localized disease in the nasal cavity A. deflectus and A. niger are reported to cause disease in dogs
Schultz 2008
What cohort of dogs are predisposed to systemic aspergillosis?
Middle age female german shepherd dogs
Schultz 2008
T/F: Cats that undergo surgery for PSS - of the cats that had postoperative seizures, most also had preoperative seizures
FALSE - of the cats that developed seizures postoperatively, 5 of 8 (62%) did NOT have seizures before surgery
* all the cats that developed seizures after surgery had received antiepileptic drugs before surgery *most seizures occurred within 5 days of surgery
Valiente et al 2020
Cat with PSS and HE undergoing surgery - does preoperative plasma ammonia concentration, pre/post feeding bile acid concentration alter survival to discharge?
no
Valiente 2020
Cat with PSS and HE - was there a significant association between preoperative seizures, postoperative seizures, and survival to discharge?
no
Valiente 2020
What breed of dog and breed of cat appear predisposed to developing CNS cryptococcosis?
American Cocker Spaniels Siamese cat
(Dewey)
T/F: TMS crosses the BBB even when not inflammed
True
(Dewey)
In animals that die due to thiamine deficiency, characteristic bilaterally symmetric lesions (petechial hemorrhages) are appreciable throughout the brain at necropsy, especially in the _____
In animals that die due to thiamine deficiency, characteristic bilaterally symmetric lesions (petechial hemorrhages) are appreciable throughout the brain at necropsy, especially in the caudal colliculi of the midbrain
(Dewey)
Elevated blood pyruvate and lactate levels, and decreased erythrocyte transketolase activity are supportive of a diagnosis of what nutritional encephalopathy?
thiamine deficiency
(Dewey)
What are the top 5 most common secondary brain tumors?
1) hemangiosarcoma (29%) 2) pituitary tumor (25%) 3) lymphosarcoma (12%) 4) metastatic carcinoma (11%) 5) invasive nasal tumors (6%)
(Dewey)
An ____ CSF level of uric acid and glutamate have been demonstrated in dogs with primary brain tumors
increased
uric acid is an indicator of oxidative injury and potential glutamate excitotoxicity
(Dewey)
There is a documented association with the degree of malignancy and an _____ expression of VEGF and nuclear protein (MIB-1) in canine brain tumors
increased
(Dewey)
There is a ____ association with proliferative cell nuclear antigen (PCNA) level and the likelihood of canine brain tumor reoccurrence, and a ___ association with PCNA level and level of tumor progesterone receptors.
There is a positive association with proliferative cell nuclear antigen (PCNA) level and the likelihood of canine brain tumor reoccurrence, and a negative association with PCNA level and level of tumor progesterone receptors
(Dewey)
In one large study, it was found that ___% of canine intracranial meningiomas had aggressive histologic grade tumors
43% (Dewey)
Tumor recurrence for feline meningioma has been estimated to be around ___%?
20 - 25%
(Dewey)
Dogs with supratentorial masses had a median survival of ____ days whereas those with infratentorial masses had a median survival of ____ days
Dogs with supratentorial masses had a median survival of 178 days whereas those with infratentorial masses had a median survival of 28 days
(Dewey)
Average survival time for dogs with intracranial meningiomas treated with prednisone alone?
4 mos
(Dewey)
Delayed dose-related hepatotoxicity has been reported to occur in approximately ___% of patients receiving lomustine
6% (Dewey)
How can lomustine administration affect the metabolism of phenobarbital?
p450 enzymes are responsible for generating anti-neoplastic metabolites from lomustine AND metabolism of phenobarbital
Being on phenobarbital can REDUCE the drug efficacy of lomustine
(Dewey)
T/F: notrosourea chemotherapy drugs easily cross the BBB?
True high lipid soluble alkylating agents that cross BBB readily
(Dewey)
What is N-TIRE treatment for brain tumor?
place electrodes within the target and induce a regional electric field with low energy impulses that disrupts cell membranes
(Dewey)
What is brachytherapy for brain tumor?
local application of radiation via a catheter inserted into the lesion
(Dewey)
How is atlantooccipital overalapping diagnosed on CT?
CCJ was considered overlapped when the dorsocranial border of the lamina of the atlas was at the level of the purple line
Kiviranta et al 2017
How are organic acidurias treated?
Manipulating diet (high carb, low fat, low protein)
vitamin supplementation (L-carnitine supplementation, B-vicamins)
anticonvulsant therapy PRN
Dewey
How can CSF be used to differentiate choroid plexus papilloma from choroid plexus carcinoma?
carcinoma more likely to have CSF > 80mg/dL
Dewey
What is the frequency of finding multiple meningiomas in the cat?
17%
Dewey
What are MRI findings associated with organic aciduria?
bilaterally symmetric lesions of white or gray matter structures that are hyperintense on T2W images Slightly hypointense on T1W images Noncontrast enhancing
How does organic aciduria lead to carnitine deficiency?
carnitine serves as a buffer for accumulated organic acids –> binds with excess organic acids (typically fatty acids) –> excreted in the urine –> secondary carnitine deficiency develops
(Dewey)
Causes of acquired organic aciduria?
B12 deficiency Malabsorption (EPI) Toxin (Proplyene glycol toxicity)
What three dogs are most notable for having mitochondrial encephalopathy?
Alaskan Huskies Australian Cattle Dogs Shetland Sheepdogs
(Dewey)
How does the brain cope with chronic hyponatremia?
Hyponatremia –> swelling of brain parenchymal cells –> brain edema
Brain parenchymal cells compensate by extruding osmotically active intracellular components (K and amino acids)
(Dewey)
How does hypernatremia affect brain parenchymal cells?
HyperNa –> shrinkage of brain parenchymal cells –> stretching/tearing of small intracranial blood vessels –> hemorrhage Chronic hyperNa (increased osmolality) –> brain parenchymal cells produce idiogenic osmoles
(Dewey)
What is the most common CM/SM related clinical sign in Chihuahuas? What was the most common neurologic deficit related to CM/SM?
Scratching was the most common CM/SM-related clinical sign (73%)
Decreased postural reaction the most common neurologic deficit (87%)
Kiviranta et al 2017
What is the MOA of dialysis disequilibrium syndrome?
uremic state –> production of idiogenic osmoles –> brain becomes hyoerosmotic
rapid dialysis –> brain remains hyperosmotic to the blood –> gradient causes neurons to “imbibe” water –> cerebral edema
(Dewey)
Proposed MOA of uremic encephalopathy (7)
1) Elevated PTH –> directly toxic and causes elevated Ca –> neuronal mineralization 2) Hyperosmolality –> cerebral neuronal dehydration 3) Hypertension –> changes in cerebral vasculature 4) Uremic vasculitis 5) Acid-base imbalance (acidosis depresses cerebral function) 6) uremia-induced neurotransmitter imbalance 7) anemia
(Dewey)
What is the role of “false neurotransmitters” in dogs with HE?
increased circulating levels of aromatic amino acids and benzodiazepine-like substances –> act on brain GABA receptors –> HE signs
(Dewey)
What is the average ate of onset of clinical signs in dogs with IAC?
4y
2m - 10y reported - prosencephalic signs - central vestibular signs - neck pain
Dewey
What is thought to be the underlying cause for the development of intracranial arachnoid fluid accumulation?
split of the arachnoid membrane during embryogenesis - aberration of CSF flow from the choroid plexuses during development forces a separation within the forming arachnoid layer - fills w. fluid (identical to CSF)
Dewey
T/F: The occipital bone, C1 and C2 develop together
True
Dewey
An interthalamic adhesion diameter of less than ____ mm was found to be consistent with a diagnosis of CDS in dogs
5mm
Dewey
In what parts of the brain are neuritic plaques most prominent?
frontal cortex and hippocampus
neuritic plaques = accumulations of beta-amyloid
Dewey
What is the definition of atlanto-occipital overlapping?
ingavination of the odontoid process into the foramen magnum with ventral brainstem compression
Knowler et al 2018
Enlargement of the ____ nerves is often palpable in dogs with fucosidosis
ulnar nerves (due to edema and infiltration with lipid-filled phagocytes and Schwann cells)
Dewey
Name 8 metabolic encephalopathies
- hepatic encephalopathy 2. Renal associated encephalopathy 3. hypoglycemic encephalopathy 4. electrolyte-associated encephalopathy 5. Miscellaneous endocrine-related encephalopathies 6. acid-base disturbance encephalopathy 7. mitochondrial encephalopathy 8. organic acidurias
Dewey
What atypical MRI features for glioma should raise concern for a granuloma? (4)
- Mixed intra and extra-axial features -T2W hypointensity without apparent hemorrhage
- Concomitant meningeal enhancement - Minor contralateral lesions
Diangelo et al 2020
How does imepitoin compare with phenobarbital as a monotherapy for dogs with IE?
“AME-naive dogs receiving imepitoin-monotherapy developed cluster seizures significantly more frequently and earlier in the course of disease, developed aggression, and required earlier discontinuation of monotherapy than AEM-naive dogs receiving phenobarbital monotherapy”
Stabile et al 2019
What pattern of PET imaging is seen in the normal spinal cord?
Increased SUVmax values at the spinal cord intumescences
SUVmax = standardized uptake values
French 2019
What is the definition of intracranial hypertension when measuring via direct ICP?
Does not exist in dogs yet!
Giannasi 2020
What are the disadvantages of fiberoptic ICP monitoring systems?
high profile cranial bolt
fragile fiberoptic monitoring cable
Giannasi 2020
How does duration of surgery affect outcome in dogs with absent pain perception treated surgically for TL IVDH?
- Median anesthesia duration in dogs that regained ambulation within 1 year of surgery was significantly shorter than those that did not
- significant negative association between both duration of surgery and total anesthesia time and ambulation at one year, when controlling for body weight and number of disc spaces operated on
Fenn, 2020
How does F-wave amplitude differ between normal dogs and dogs w/ experimentally induced TL myelopathy?
F-wave amplitude and persistence increased in dogs with experimentally induced myelopathy
What mutation is associated with paroxysmal dyskinesia in Wheaten Terriers?
PIGN gene
CM and SM have a _____ mode of inheritance with ______ penetrance in CKCS
polygenic mode of inheritance with variable penetrance
Kiviranta et al 2017
drawback to ultrasonic aspirators for resection of intra-axial masses?
- heat and vibration generated during use may damage adjacent normal parenchyma or cranial nerves - neoplastic cells may be aerosolized and seeded to other areas of the brain
Packer and McGrath 2020
What was the most prominent weakness to neuronavigation-guided resection of brain masses w/ NICO myriad?
significant reliance on preoperative navigation images and inability to correct for brain shift
Packer and McGrath 2020
What factors contribute to brain shift (concerning neuronavigation systems)
release of pressure created by presence of a space-occupying mass effects of gravity volume loss of CSF or blood during the procedure differences in animal positioning from imaging to surgery administration of mannitol size of craniotomy defect tumor size tumor type
Packer and McGrath 2020
T/F: The neuronavigation-guided resection of brain masses w/ NICO myriad was feasible?
True
McGrath, Packer 2020
What percent of cerebrovascular accidents were misinterpreted as gliomas?
10 - 47%
Gutmann 2020
What percent of gliomas are diagnosed as infarctions?
12%
Gutmann 2020
The MRI-based personalized 3D printed stereotactic brain biopsy device achieved ___________ precision in targeting predefined intracranial points in the caudate nucleus and piriform lobes of cadavers
The MRI-based personalized 3D printed stereotactic brain biopsy device achieved excellent precision in targeting predefined intracranial points in the caudate nucleus and piriform lobes of cadavers
Gutmann et al 2020
What is the histopathologic finding associated with meningeal fibrosis in pugs?
circumferential meningeal fibrosis with concomitant focal, malacic destruction of the neuroparenchyma in the thoracolumbar spinal cord in 24/30 pugs
vertebra lesions accompanied the focal spinal cord lesion, and lympho-histiocytic inflammation associated or not to the parenchymal lesion in 43% of the pugs
Rohdin et al 2020
RE pugs with meningeal fibrosis - the finding of meningeal fibrosis unrelated to the thoracolumbar spinal cord lesion more likely suggests a predisposition to ______ ______
meningeal proliferation
the profound meningeal fibrosis could interfere with vascular supply to the spinal cord, as well as cause obstruction of CSF flow with subsequent parenchymal spinal cord destruction
Rohdin et al 2020
What concomitant conditions are suspected to be related to meningeal fibrosis in pugs?
CNS inflammation and neighboring vertebral column pathology
High prevalence suggests they are part of the underlying etiology
Rohdin et al 2020
MRI vs. CT for detecting CM and SM - which has best agreement between evaluators. Which is more sensitive? Which is more specific?
MRI - most agreement MRI - most sensitivity for cerebellar herniation and SM
MRI and CT have equal specificity for identifying cerebellar herniation
CT - more specific for identifying SM
Weber et al 2020
What % of patients improved after C-LOX distraction/stabilization for CCSM?
10/11 (90%)
King et al 2020
When comparing dogs with brain-tumor associated seizures treated medically or with RT, how did seizure freedom and survival time compare?
RT: mean duration of seizure freedom 24 mos, mean survival time 34.6 mos (significantly greater than…)
medical: mean duration of seizure freedom 1.7 mos, mean survival time 6.2 mos
Monforte Monteiro et al
What complications are associated with C-LOX distraction/stabilization for CCSM?
screw loosening (40%) cage subsidence (50%)
King et al 2020
Does single site vs. multiple site IVDH ventral slot decompression alter postoperative outcome?
no
There was no difference in the TIME TO REACH AMBULATION and the PRESENCE OF NEUROLOGIC DEFICITS after surgery between dogs that underwent single and multiple VSD.
Guo et al 2020
Is cell-free DNA useful as a diagnostic marker in CSF of dogs?
No
Start et al 2020 - There were no substantial differences in cell-free DNA concentrations identified between dogs with or without neurologic disease. Cell free DNA did not correlate with CSF RBC, NCC, or protein
What 5 drugs are reported to be successful in the treatment of dogs with PD?
acetazolamide
fluoxetine
clonazepam
diazepam
phenobarbital
What are the most common extraneural abnormalities associated with mannosidosis/MPS and mucolipidosis?
skeletal abnormalities - craniofacial malformation, joint immobility
PL paresis often develops in cases of mucopolysaccharidoses and mucolipidosis (bony vertebral growths that cause spinal cord compression)
A group of related _____ (breed) was described with suspected neuronal abiotrophy
red-haired cocker spaniels
What are the signs and progression seen in Cocker Spaniels with neuronal abiotrophy?
Onset of signs at 1 year old, disease progresses slowly over several months
Dewey
What neurochemical changes occur in the aging brain and are thought to contribute to cognitive impairment?
decline in: acetylcholine, dopamine, norepinephrine, serotonin, and GABA
increase in: acetylcholinesterase, MOA B
CSF: elevated lactate, pyruvate, and potassium
Dewey
Potential causes for Congenital hydrocephalus? (5)
1) intraventricular hemorrhage (dystocia related)
2) viral infections (parainfluenza in digs, coronavirus in cats)
3) Teratogen exposure
4) Nutritional deficiencies (vitamin A)
5) heritable malformations
Dewey
how does chronic bony compression at the cervicomedullary junction, turbulent CSF flow and pressure changes in this region alter the composition of the meninges?
Meninges become hypertrophied with time
Pathological evidence of dural fibrosis in the region of the malformation
Dewey
_____ is caused by an an overly-rapid hemodialysis causing osmotic gradient between the brain and ECF
Dialysis disequilibrium syndrome (DDS)
(Dewey)
What is convection-enhanced delivery of chemo for brain tumors?
infusion catheter inserted into the region to be treated
the chemotherapeutic agent is infused via the catheter through the interstitial spaces under a pressure gradient
(Dewey)
How does the size of the jugular foramen compare in CKCS with CM and CM/SM
narrowed jugular foramen in CKCS with CM and SM as compared to CKCS with CM only
What is the definition of a movement disorder?
episode of abnormal involuntary hyperkinetic movement without altered consciousness - no autonomic dysfunction - no postictal behavior
What mutation is associated with paroxysmal dyskinesia in Wheaten Terriers?
PIGN gene
The natural course of paroxysmal dyskinesia is self-limiting in which two breeds of dogs?
labrador retrievers JRT 32% of dogs undergoing spontaneous remission 75% of dogs showing marked improvement
Stress and exercise have been identified as a trigger for paroxysmal dyskinesia in which two breeds of dogs? Which breed tends to have episodes at rest?
Norwich Terriers and Maltese - stress/exercise
Border terriers - episodes occur mainly at rest
how can ketamine have anticonvulsant properties? dexmedetomidine?
Ketamine - decreases excitatory glutamate activity. Also neuroprotective
Dex - decreases sympathetic stimulation and attenuates noradrenaline release. Cerebral vasoconstriction - reduce cerebral edema?
Gioeni et al
What do F-waves represent?
muscle action potentials resulting from excitation of the alpha-motor neurons after antidromic stimulation of a peripheral motor nerve
Okuno 2020
How does F-wave amplitude differ between normal dogs and dogs w/ experimentally induced TL myelopathy?
F-wave amplitude and persistence increased in dogs with experimentally induced myelopathy
What is the incidence of post-operate paraspinal SCI-associated neuropathic pain?
~ 15%
Zidan 2020
What are the disadvantages of fiberoptic ICP monitoring systems?
high profile cranial bolt
fragile fiberoptic monitoring cable
Giannasi 2020
What noninvasive measures can be used to estimate ICP?
MRI
Transcranial doppler ultrasonography
Optic nerve sheath diameter
Giannasi 2020
What is the definition of intracranial hypertension when measuring via direct ICP?
Does not exist in dogs yet!
Giannasi 2020
What pattern of PET imaging is seen in the normal spinal cord?
Increased SUVmax values at the spinal cord intumescences
SUVmax = standardized uptake values
French 2019
which two lysosomal storage diseases tend to have a relatively late onset of clinical signs?
ceroid lipofuscinosis
fucosidosis
Dewey
How are cord dorsum potential onset latency, F-wave onset latency, and F-ratio affected in dogs with lumbosacral foraminal stenosis?
All were increased in dogs with LS foraminal stenosis
- Consistent with decreased conduction velocity in the proximal segment of the nerve and affecting both motor and sensory axons
Harcourt-Brown et al 2020
What is the prognosis for cats with acquired MG that do NOT have a cranial mediastinal mass?
Excellent!
retrospective case series n=8 - all cats achieved immune remission within 6 mos. 4 cats received no treatment
Megnan et al 2020
How does imepitoin compare with phenobarbital as a monotherapy for dogs with IE?
“AME-naive dogs receiving imepitoin-monotherapy developed cluster seizures significantly more frequently and earlier in the course of disease, developed aggression, and required earlier discontinuation of monotherapy than AEM-naive dogs receiving phenobarbital monotherapy”
Stabile et al 2019
English springer and cocker spaniel paradoxical pseudomyotonia:
- Age at onset? - Appearance of episodes?
- Trigger? - Diagnostics?
- Disease course?
- Age at onset? < 24 mos - Appearance of episodes? myotonic-like generalized muscle stiffness, spontaneously resolve with rest in < 45 seconds (in all but 1 dog) - Trigger? exercise, extreme outside temperatures seemed to worsen episode frequency and severity - why this is PARADOXICAL PSEUDOMYOTONIA - Diagnostics? bloodwork, MRI, CSF, electrodiagnostics, echocardiogram normal in all dogs - Disease course? episodes remained stable or decreased in severity and frequency in 6/7 dogs
Stee 2020
What atypical MRI features for glioma should raise concern for a granuloma? (4)
- Mixed intra and extra-axial features -T2W hypointensity without apparent hemorrhage
- Concomitant meningeal enhancement - Minor contralateral lesions
Diangelo et al 2020
Name 5 degenerative encephalopathies
- Lysosomal storage disease 2. Leukodystrophy/spongy degeneration 3. Neuronal vacuolation of Rottweilers and Boxer dogs 4. Multisystem neuronal degeneration/abiotrophy of Cocker Spaniels 5. Canine cognitive dysfunction syndrome (CCDS)
Dewey
Name 8 metabolic encephalopathies
- hepatic encephalopathy 2. Renal associated encephalopathy 3. hypoglycemic encephalopathy 4. electrolyte-associated encephalopathy 5. Miscellaneous endocrine-related encephalopathies 6. acid-base disturbance encephalopathy 7. mitochondrial encephalopathy 8. organic acidurias
Dewey
Name the 5 lysosomal storage disorders that have cerebellar dysfunction as an early sign of disease
- Mannosidosis 2. Gangliosidoses (GM1, GM2) 3. Globoid cell leukodystrophy (Krabbe’s disease) 4. Glucocerebridosis (Gaucher’s disease) 5. Sphingomyelinosis (Niemann-Pick disease)
Dewey
Name the 3 lysosomal storage diseases where prosencephalic dysfunction predominates
- Neuronal glycoproteinosis (Lafora’s disease) 2. ceroid lipofuscinosis (Batten’s disease) 3. Fucosidosis
Dewey
Enlargement of the ____ nerves is often palpable in dogs with fucosidosis
ulnar nerves (due to edema and infiltration with lipid-filled phagocytes and Schwann cells)
Dewey
What is the definition of atlanto-occipital overlapping?
ingavination of the odontoid process into the foramen magnum with ventral brainstem compression
Knowler et al 2018
Histologic findings associated with leukodystrophy/spongy degeneration?
CNS white matter loss with vacuolation of the brain tissue (spongiform change) ROSENTHAL fibers = astrocytic inclusion bodie
Dewey
Neuronal vacuolation and spinocerebellar degeneration of Rottweilers/Boxers - histopathologic findings
- intraneuronal vacuoles primarily in the brainstem, cerbellum, and spinal cord grey matter. *reminiscent of scrapie-associated spongiform change - axonal necrosis dorsolateral and ventromedial funiculi of the cervical and thoracic spinal cord
- Selective distal neuropathy of the recurrent laryngeal nerves
Dewey
clinical signs of neuronal vacuolation and spinocerebellar degeneration in Rottweilers and Boxer Dogs?
-generalized weakness, cerebellar ataxia inspiratory stridor due to laryngeal nerve dysfunction -congenital ocular abnormalities (cataracts, persistent pupillary membrane, microophtlamia, retinal dysplasia) - signs worsen over weeks, end stage - behavior changes
Dewey
Cocker spaniels with neuronal abiotrophy were reported to develop clinical signs at approximately _____ years old
1 year old - signs of forebrain and cerebellar dysfunction
Dewey
MOA of selegiline?
irreversible inhibitor of monoamine oxidase B
* MAO B catalyzes the breakdown of dopamine with a subsequent formation of free radicals
Dewey
Main changes seen in the brain of dogs with cognitive dysfunction syndrome? (6)
- Cerebral vascular changes (blood vessel wall fibrosis, microhemorrhages and infarcts) 2. meningeal thickening 3. gliosis, axonal degeneration 4. ventricular dilation 5. accumulation of beta-amyloid in and around neurons 6. intraneuronal accumulation of tau protein, lipofuscin, polyglucosan bodies, ubiquitin 7. cerebral atrophy
Dewey
In what parts of the brain are neuritic plaques most prominent?
frontal cortex and hippocampus
neuritic plaques = accumulations of beta-amyloid
Dewey
The acetylcholinesterase inhibitor ______ has exhibited efficacy in improving function in dogs with CDS in clinical trials
phenserine
* not commercially available for dogs
Dewey
What is the “bulk flow” concept of CSF accumulation in congenital hydrocephalus?
Excessive fluid accumulation results from:
1) obstruction of CSF flow within the ventricular system - and/or
2) insufficient absorption of CSF into the venous system at the arachnoid villi level
Dewey
How do ventricular to brain brain ratio and basilar artery resistive index (via doppler ultrasonography) vary between dogs with clinical hydrocephalus and dogs with ventriculomegaly and no neurologic dysfunction?
basilar artery resistive index (RI) and ventricular to brain ratio (VB) were both significantly higher in clinically hydrocephalic dogs
- combining these measurements provided a sensitivity of 77% and specificity of 84% for identifying clinical hydrocephalic dogs - RI changed with changes in neurologic status (but not VB ratio)
Dewey
epidermoid and dermoid cysts are thought to be due to a failure of complete separation of _____ from _____ during embryogenesis
epidermoid and dermoid cysts are thought to be due to a failure of complete separation of neuroectoderm from non-neural (epithelial) ectoderm
if the epithelial ectoderm has adnexal structures, the structure is called a dermoid cyst. If the epithelial ectoderm does NOT have adnexal structures, the structure is called a epidermoid cyst
(Dewey)
What 3 conditions compose Dandy Walker Syndrome?
Lack of a cerebellar vermis
Cystic dilation of the 4th ventricle
Hydrocephalus
The ______________ ____________ ____________ cells which delaminate from the dorsal neural tube, contribute not only to the peripheral nervous system, but also to the ectomesenchymal precursors that underpins the cranial skeleton and thus the potential to influence irregularities associated with CM
The multipotent neural crest cells which delaminate from the dorsal neural tube, contribute not only to the peripheral nervous system, but also to the ectomesenchymal precursors that underpins the cranial skeleton and thus the potential to influence irregularities associated with CM
Knowler et al 2018
What is the “hydrodynamic theory” of congenital hydrocephalus?
Hydrocephalus develops due to abnormal (reduced) intracranial compliance
Hydrocephalic patients are believed to have poor intracranial compliance –> increased capillary pulse pressure –> pulsatile transmantle pressure gradient directed from the cerebral tissue toward the lateral ventricles –> rebound pressure from recurring gradient as well as hyperdynamic CSF flow in the mesencephalic aqueduct leads to progressive ventricular enlargement.
Dewey
*abnormal capillary pulsations occur within normal mean ICP
T/F: The occipital bone, C1 and C2 develop together
True
Dewey
MRI findings associated with clinically relevant hydrocephalus? (7)
Elevation of the corpus callosum Dorsoventral flattening of the interthalamic adhesion Periventricular edema Dilation of the olfactory recesses Thinning of the cortical sulci and/or subarachnoid space Disruption of the internal capsule adjacent to the caudate nucleus Ventricle/brain-index - significantly higher in dogs with relevant hydrocephalus
(Laubner 2015)
Experimental studies have shown that ______ of the ventricles dilate first in dogs with internal hydrocephalus
temporal horns
(Laubner et al 2018)
What do epidermoid cysts look like on CT? MRI? How does this vary from DERMOID cyst??
Epidermoid:hypoattenuating on CT images hypointense on T1WI with RING enhancement hyperintense on T2WI
Dermoid: hyperintense on T1WI and T2WI (due to fat content)
(Dewey)
What is the role of “false neurotransmitters” in dogs with HE?
increased circulating levels of aromatic amino acids and benzodiazepine-like substances –> act on brain GABA receptors –> HE signs
(Dewey)
Proposed MOA of uremic encephalopathy (7)
1) Elevated PTH –> directly toxic and causes elevated Ca –> neuronal mineralization 2) Hyperosmolality –> cerebral neuronal dehydration 3) Hypertension –> changes in cerebral vasculature 4) Uremic vasculitis 5) Acid-base imbalance (acidosis depresses cerebral function) 6) uremia-induced neurotransmitter imbalance 7) anemia
(Dewey)
What is the MOA of dialysis disequilibrium syndrome?
uremic state –> production of idiogenic osmoles –> brain becomes hyoerosmotic
rapid dialysis –> brain remains hyperosmotic to the blood –> gradient causes neurons to “imbibe” water –> cerebral edema
(Dewey)
What is the most common CM/SM related clinical sign in Chihuahuas? What was the most common neurologic deficit related to CM/SM?
Scratching was the most common CM/SM-related clinical sign (73%)
Decreased postural reaction the most common neurologic deficit (87%)
Kiviranta et al 2017
Glucose enters the brain via a ____ _____ ____ mechanism
noninsulin-dependent facilitated transport mechanism *Requires a minimum BG to operate effectively
(Dewey)
T/F: The brain has glycogen stores
FALSE
(Dewey)
How does hypernatremia affect brain parenchymal cells?
HyperNa –> shrinkage of brain parenchymal cells –> stretching/tearing of small intracranial blood vessels –> hemorrhage Chronic hyperNa (increased osmolality) –> brain parenchymal cells produce idiogenic osmoles
(Dewey)
How does the brain cope with chronic hyponatremia?
Hyponatremia –> swelling of brain parenchymal cells –> brain edema
Brain parenchymal cells compensate by extruding osmotically active intracellular components (K and amino acids)
(Dewey)
What occurs ic hyponatremia is too rapidly corrected?
brain parenchymal cells compensate for chronic hyponatremia by actively extruding osmotically active components
Correction of hypoNa –> axonal shrinkage –> demyelination in the brainstem (similar to central pontine myelinolysis)
How does respiratory acidosis cause encephalopathy?
Hypercapnia –> CO2 diffuses across BBB readily –> alters brain neurotransmitter balance and increases blood brain volume –> increased ICP
Hypoxia –> exacerbates the effects of hypercapnia on the brain Metabolic acidosis may lead to mild encephalopathic signs
(Dewey)
What three dogs are most notable for having mitochondrial encephalopathy?
Alaskan Huskies Australian Cattle Dogs Shetland Sheepdogs
(Dewey)
Underlying cause for organic acidurias?
inherited (usually autosomal recessive) deficiencies of mitochrondrial respiratory chain enzymes (some involve cytosolic enzymes) - enzyme deficiency leads to accumulation of 1+ organic acids - organic acids accumulate in serum, CSF or urine - differ from mitochondrial encephalopathy in the presence of accumulation of organic acids in the urine and other body fludis
(Dewey)
Causes of acquired organic aciduria?
B12 deficiency Malabsorption (EPI) Toxin (Proplyene glycol toxicity)
How does organic aciduria lead to carnitine deficiency?
carnitine serves as a buffer for accumulated organic acids –> binds with excess organic acids (typically fatty acids) –> excreted in the urine –> secondary carnitine deficiency develops
(Dewey)
How is organic aciduria diagnosed? (what sample and testing method)
Demonstrate abnormally high levels of specific organic acids in urine, serum, and/or CSF using gas chromatography-mass spectroscopy
Dewey
What is the current standard protocol for definitive megavoltage radiation therapy of brain tumors in dogs and cats?
fractionated daily doses of 2.5 - 4 Gy on a Monday through Friday schedule for 4 weeks
Total cumulative dose of 40 - 50 Gy
(Dewey)
What are MRI findings associated with organic aciduria?
bilaterally symmetric lesions of white or gray matter structures that are hyperintense on T2W images Slightly hypointense on T1W images Noncontrast enhancing
How are organic acidurias treated?
Manipulating diet (high carb, low fat, low protein) vitamin supplementation (L-carnitine supplementation, B-vicamins) anticonvulsant therapy PRN Dewey
What are the two forms of gliomatosis cerebri?
Type I (more common) - diffusely infiltrative form. No mass effect Type II - mass lesion in addition to diffuse neoplastic infiltration Dewey
What is the frequency of finding multiple meningiomas in the cat?
17%
Dewey
How can CSF be used to differentiate choroid plexus papilloma from choroid plexus carcinoma?
carcinoma more likely to have CSF > 80mg/dL
Dewey
How is atlantooccipital overalapping diagnosed on CT?
CCJ was considered overlapped when the dorsocranial border of the lamina of the atlas was at the level of the purple line
Kiviranta et al 2017
What is brachytherapy for brain tumor?
local application of radiation via a catheter inserted into the lesion
(Dewey)
What is N-TIRE treatment for brain tumor?
place electrodes within the target and induce a regional electric field with low energy impulses that disrupts cell membranes
(Dewey)
How can lomustine administration affect the metabolism of phenobarbital?
p450 enzymes are responsible for generating anti-neoplastic metabolites from lomustine AND metabolism of phenobarbital
Being on phenobarbital can REDUCE the drug efficacy of lomustine
(Dewey)
Delayed dose-related hepatotoxicity has been reported to occur in approximately ___% of patients receiving lomustine
6% (Dewey)
There is a ____ association with proliferative cell nuclear antigen (PCNA) level and the likelihood of canine brain tumor reoccurrence, and a ___ association with PCNA level and level of tumor progesterone receptors.
There is a positive association with proliferative cell nuclear antigen (PCNA) level and the likelihood of canine brain tumor reoccurrence, and a negative association with PCNA level and level of tumor progesterone receptors
(Dewey)
Average survival time for dogs with intracranial meningiomas treated with prednisone alone?
4 mos
(Dewey)
Dogs with supratentorial masses had a median survival of ____ days whereas those with infratentorial masses had a median survival of ____ days
Dogs with supratentorial masses had a median survival of 178 days whereas those with infratentorial masses had a median survival of 28 days
(Dewey)
in a recent report of 121 cases of feline meningioma treated surgically, median postoperative survival time was ____ mos
58 mos
(Dewey)
Cats with what two subtypes of meningioma had significantly shorter survival times?
anaplastic and meningothelial subtypes – significantly shorter survival times
(Dewey)
Tumor recurrence for feline meningioma has been estimated to be around ___%?
20 - 25%
(Dewey)
There is a documented association with the degree of malignancy and an _____ expression of VEGF and nuclear protein (MIB-1) in canine brain tumors
increased
(Dewey)
What two CCJ abnormalities are thought to play an important role in the pathogenesis of SM and neuropathic pain in chihuahuas
medullary elevation dorsal spinal cord compression
What are the top 5 most common secondary brain tumors?
1) hemangiosarcoma (29%) 2) pituitary tumor (25%) 3) lymphosarcoma (12%) 4) metastatic carcinoma (11%) 5) invasive nasal tumors (6%)
(Dewey)
What are the second and third most common feline brain tumors?
1) meningioma 2) multicentric lymphoma 3) Pituitary tumor
(Dewey)
T/F: dogs and cats can produce endogenous thiamine
False - must be provided in the diet
(Dewey)
Causes of thiamine deficiency in cats? Dogs?
Cats - feeding all fish diet (high in thiaminase)
Dogs - overcooking canned food or meat (heat destruction of thiamine), meat preserved with sulfur dioxide, possibly amprolium induced?
(Dewey)
Elevated blood pyruvate and lactate levels, and decreased erythrocyte transketolase activity are supportive of a diagnosis of what nutritional encephalopathy?
thiamine deficiency
(Dewey)
CBC abnormalities such as leukocytosis, leukopenia, and thrombocytopenia have been reported to occur in approximately ___% of cases of canine bacterial meningoencephalitis
57% (Dewey)
What two antifungal drugs readily cross the BBB?
Flucytosine and fluconazole
(Dewey)
T/F: TMS crosses the BBB even when not inflammed
True
(Dewey)
Cat with PSS and HE - was there a significant association between preoperative seizures, postoperative seizures, and survival to discharge?
no
Valiente 2020
Cat with PSS and HE undergoing surgery - does preoperative plasma ammonia concentration, pre/post feeding bile acid concentration alter survival to discharge?
no
Valiente 2020
T/F: Male cats are overrepresented to have a portosystemic shunt
true
* also domestic shorthair
Valiente 2020
T/F: Cats that undergo surgery for PSS - of the cats that had postoperative seizures, most also had preoperative seizures
FALSE - of the cats that developed seizures postoperatively, 5 of 8 (62%) did NOT have seizures before surgery
* all the cats that developed seizures after surgery had received antiepileptic drugs before surgery *most seizures occurred within 5 days of surgery
Valiente et al 2020
Ptyalism is a common sign of what condition in cats?
PSS
Is medullary kinking, or dorsal spinal cord compression more strongly associated with CM/SM-related clinical signs?
Medullary kinking significantly higher in dogs with CM/SM related clinical signs
No statistical difference was detected in dorsal spinal cord compression between the 2 groups
Kiviranta et al 2017
What cohort of dogs are predisposed to systemic aspergillosis?
Middle age female german shepherd dogs
Schultz 2008
What species of aspergillus is most frequently associated with systemic aspergillosis in dogs?
A.terreus
A. fumigatus and A. flavus usually cause localized disease in the nasal cavity A. deflectus and A. niger are reported to cause disease in dogs
Schultz 2008
Causes of false positive Aspergillus Galactolamman ELISA? Causes of false negative?
False-positive - plasmalyte administration, other systemic mycoses False-negative - localized pulmonary involvement
Garcia 2012
Dogs with vertebral OSA and FSA - what is the median survival time? does radiation or chemotherapy improve survival?
Median survival time is 135 days
Overall poor survival not impacted by various treatments employed (curative intent radiation, palliative radiation, cisplatin)
Dernell 2000
Dernell et al - how does post-treatment neurologic status influence the outcome of patients with vertebral tumors?
Post-treatment neurological status had a significant influence on outcome
Dernell 2000
______ bone destruction appears to be a late event in the sequence of spinal cord invasion by metastatic cells (in humans)
cortical bone destruction
Dernell 2000
T/F: Atlantooccipital overlapping is rare in chihuahuas
False - detected in 70% of dogs in one study
Kiviranta et al 2017
T/F: Atlantooccipital overlapping was NOT associated with the presence of CM/SM-related clinical signs. SM, or severity of CM
true
Kiviranta et al 2017
What was the most prominent weakness to neuronavigation-guided resection of brain masses w/ NICO myriad?
significant reliance on preoperative navigation images and inability to correct for brain shift
Packer and McGrath 2020
T/F: The neuronavigation-guided resection of brain masses w/ NICO myriad was feasible?
True
McGrath, Packer 2020
What percent of gliomas are diagnosed as infarctions?
12%
Gutmann 2020
The MRI-based personalized 3D printed stereotactic brain biopsy device achieved ___________ precision in targeting predefined intracranial points in the caudate nucleus and piriform lobes of cadavers
The MRI-based personalized 3D printed stereotactic brain biopsy device achieved excellent precision in targeting predefined intracranial points in the caudate nucleus and piriform lobes of cadavers
Gutmann et al 2020
What is the histopathologic finding associated with meningeal fibrosis in pugs?
circumferential meningeal fibrosis with concomitant focal, malacic destruction of the neuroparenchyma in the thoracolumbar spinal cord in 24/30 pugs
vertebra lesions accompanied the focal spinal cord lesion, and lympho-histiocytic inflammation associated or not to the parenchymal lesion in 43% of the pugs
Rohdin et al 2020
RE pugs with meningeal fibrosis - the finding of meningeal fibrosis unrelated to the thoracolumbar spinal cord lesion more likely suggests a predisposition to ______ ______
meningeal proliferation
the profound meningeal fibrosis could interfere with vascular supply to the spinal cord, as well as cause obstruction of CSF flow with subsequent parenchymal spinal cord destruction
Rohdin et al 2020
What concomitant conditions are suspected to be related to meningeal fibrosis in pugs?
CNS inflammation and neighboring vertebral column pathology
High prevalence suggests they are part of the underlying etiology
Rohdin et al 2020
Leakage of ________has been shown in clinically normal pugs, and is suggested to be the result of a breed-specific astrocyte fragility
GFAP
Rohdin et al 2020
When comparing dogs with brain-tumor associated seizures treated medically or with RT, how did seizure freedom and survival time compare?
RT: mean duration of seizure freedom 24 mos, mean survival time 34.6 mos (significantly greater than…)
medical: mean duration of seizure freedom 1.7 mos, mean survival time 6.2 mos
Monforte Monteiro et al
What % of patients improved after C-LOX distraction/stabilization for CCSM?
10/11 (90%)
King et al 2020
What complications are associated with C-LOX distraction/stabilization for CCSM?
screw loosening (40%) cage subsidence (50%)
King et al 2020
Does single site vs. multiple site IVDH ventral slot decompression alter postoperative outcome?
no
There was no difference in the TIME TO REACH AMBULATION and the PRESENCE OF NEUROLOGIC DEFICITS after surgery between dogs that underwent single and multiple VSD.
Guo et al 2020
What two breeds are reported to suffer from cervical IVDH at multiple sites?
Shih tzus and Yorkshire Terriers
Guo et al 2020
Which micro RNAs can *potentially* be used to differentiate glioma and other brain diseases?
miR-15b and miR-342-3p
micro RNA = small noncoding molecules that regulate gene expression following transcription
Narita et al 2020
Is cell-free DNA useful as a diagnostic marker in CSF of dogs?
No
Start et al 2020 - There were no substantial differences in cell-free DNA concentrations identified between dogs with or without neurologic disease. Cell free DNA did not correlate with CSF RBC, NCC, or protein
What is the definition of a movement disorder?
episode of abnormal involuntary hyperkinetic movement without altered consciousness - no autonomic dysfunction - no postictal behavior
What mutation is associated with paroxysmal dyskinesia in Wheaten Terriers?
PIGN gene
The natural course of paroxysmal dyskinesia is self-limiting in which two breeds of dogs?
labrador retrievers
JRT
32% of dogs undergoing spontaneous remission
75% of dogs showing marked improvement
What 5 drugs are reported to be successful in the treatment of dogs with PD?
acetazolamide
fluoxetine
clonazepam diazepam phenobarbital
Stress and exercise have been identified as a trigger for paroxysmal dyskinesia in which two breeds of dogs? Which breed tends to have episodes at rest?
Norwich Terriers and Maltese - stress/exercise
Border terriers - episodes occur mainly at rest
what is “an epileptic seizure that is objectively and consistently evoked by a specific afferent stimulus or by activity of the patient?”
Reflex epilepsy
How does F-wave amplitude differ between normal dogs and dogs w/ experimentally induced TL myelopathy?
F-wave amplitude and persistence increased in dogs with experimentally induced myelopathy
Does mean F-wave duration correlate with clinical grade of IVDH in dachshunds?
Yes - mean F-wave duration is well correlated with clinical grade of IVDH
Okuno 2020
How does duration of surgery affect outcome in dogs with absent pain perception treated surgically for TL IVDH?
- Median anesthesia duration in dogs that regained ambulation within 1 year of surgery was significantly shorter than those that did not
- significant negative association between both duration of surgery and total anesthesia time and ambulation at one year, when controlling for body weight and number of disc spaces operated on
Fenn, 2020
What is the incidence of post-operate paraspinal SCI-associated neuropathic pain?
~ 15%
Zidan 2020
How is neuropathic pain evaluated objectively?
measure mechanical sensory threshold
What are the disadvantages of fiberoptic ICP monitoring systems?
high profile cranial bolt
fragile fiberoptic monitoring cable
Giannasi 2020
What is the definition of intracranial hypertension when measuring via direct ICP?
Does not exist in dogs yet!
Giannasi 2020
How are cord dorsum potential onset latency, F-wave onset latency, and F-ratio affected in dogs with lumbosacral foraminal stenosis?
All were increased in dogs with LS foraminal stenosis
- Consistent with decreased conduction velocity in the proximal segment of the nerve and affecting both motor and sensory axons
Harcourt-Brown et al 2020
What is the prognosis for cats with acquired MG that do NOT have a cranial mediastinal mass?
Excellent!
retrospective case series n=8 - all cats achieved immune remission within 6 mos. 4 cats received no treatment
Megnan et al 2020
How does imepitoin compare with phenobarbital as a monotherapy for dogs with IE?
“AME-naive dogs receiving imepitoin-monotherapy developed cluster seizures significantly more frequently and earlier in the course of disease, developed aggression, and required earlier discontinuation of monotherapy than AEM-naive dogs receiving phenobarbital monotherapy”
Stabile et al 2019
English springer and cocker spaniel paradoxical pseudomyotonia:
- Age at onset? - Appearance of episodes?
- Trigger? - Diagnostics?
- Disease course?
- Age at onset? < 24 mos - Appearance of episodes? myotonic-like generalized muscle stiffness, spontaneously resolve with rest in < 45 seconds (in all but 1 dog) - Trigger? exercise, extreme outside temperatures seemed to worsen episode frequency and severity - why this is PARADOXICAL PSEUDOMYOTONIA - Diagnostics? bloodwork, MRI, CSF, electrodiagnostics, echocardiogram normal in all dogs - Disease course? episodes remained stable or decreased in severity and frequency in 6/7 dogs
Stee 2020
Main changes seen in the brain of dogs with cognitive dysfunction syndrome? (6)
- Cerebral vascular changes (blood vessel wall fibrosis, microhemorrhages and infarcts)
- meningeal thickening
- gliosis, axonal degeneration
- ventricular dilation
- accumulation of beta-amyloid in and around neurons
- intraneuronal accumulation of tau protein, lipofuscin, polyglucosan bodies, ubiquitin
- cerebral atrophy
Dewey
Name 8 metabolic encephalopathies
- hepatic encephalopathy
- Renal associated encephalopathy
- hypoglycemic encephalopathy
- electrolyte-associated encephalopathy
- Miscellaneous endocrine-related encephalopathies
- acid-base disturbance encephalopathy
- mitochondrial encephalopathy
- organic acidurias
Dewey
how does chronic bony compression at the cervicomedullary junction, turbulent CSF flow and pressure changes in this region alter the composition of the meninges?
Meninges become hypertrophied with time
Pathological evidence of dural fibrosis in the region of the malformation
Dewey
T/F: The brain has glycogen stores
FALSE
(Dewey)
in globoid cell leukodystrophy, the deficient enzyme leads to the accumulation of ______ which is toxic to which cells?
in globoid cell leukodystrophy, the deficient enzyme leads to the accumulation of psychosine (splingolipid) which is toxic to oligodendrocytes and Schwann cells
White matter in the CNS and PNS are affected
(Dewey)
Name 5 degenerative encephalopathies
- Lysosomal storage disease 2. Leukodystrophy/spongy degeneration 3. Neuronal vacuolation of Rottweilers and Boxer dogs 4. Multisystem neuronal degeneration/abiotrophy of Cocker Spaniels 5. Canine cognitive dysfunction syndrome (CCDS)
Dewey
Name the 5 lysosomal storage disorders that have cerebellar dysfunction as an early sign of disease
- Mannosidosis 2. Gangliosidoses (GM1, GM2) 3. Globoid cell leukodystrophy (Krabbe’s disease) 4. Glucocerebridosis (Gaucher’s disease) 5. Sphingomyelinosis (Niemann-Pick disease)
Dewey
Name the 3 lysosomal storage diseases where prosencephalic dysfunction predominates
- Neuronal glycoproteinosis (Lafora’s disease) 2. ceroid lipofuscinosis (Batten’s disease) 3. Fucosidosis
Dewey
which two lysosomal storage diseases tend to have a relatively late onset of clinical signs?
ceroid lipofuscinosis fucosidosis
Dewey
2 mechanisms that result in leukodystrophy?
Abnormal synthesis of myelin in the CNS Abnormal maintenance of myelin in the CNS
Rare, poorly understood, heritable, progressive diseases
Dewey
What are the most common extraneural abnormalities associated with mannosidosis/MPS and mucolipidosis?
skeletal abnormalities - craniofacial malformation, joint immobility
PL paresis often develops in cases of mucopolysaccharidoses and mucolipidosis (bony vertebral crowths that cause spinal cord compression)
Histologic findings associated with leukodystrophy/spongy degeneration?
CNS white matter loss with vacuolation of the brain tissue (spongiform change) ROSENTHAL fibers = astrocytic inclusion bodie
Dewey
Neuronal vacuolation and spinocerebellar degeneration of Rottweilers/Boxers - histopathologic findings
- intraneuronal vacuoles primarily in the brainstem, cerbellum, and spinal cord grey matter. *reminiscent of scrapie-associated spongiform change - axonal necrosis dorsolateral and ventromedial funiculi of the cervical and thoracic spinal cord
- Selective distal neuropathy of the recurrent laryngeal nerves
Dewey
A group of related _____ (breed) was described with suspected neuronal abiotrophy
red-haired cocker spaniels
Cocker spaniels with neuronal abiotrophy were reported to develop clinical signs at approximately _____ years old
1 year old - signs of forebrain and cerebellar dysfunction
Dewey
What are the signs and progression seen in Cocker Spaniels with neuronal abiotrophy?
Onset of signs at 1 year old, disease progresses slowly over several months
Dewey
In what parts of the brain are neuritic plaques most prominent?
frontal cortex and hippocampus
neuritic plaques = accumulations of beta-amyloid
Dewey
what physiologic processes are thought to contribute to CDS?
increased oxygen free radical mediated cellular damage decreased endogeneous antioxidant edfenses inflammation decreased mitochondrial function DNA damage altered gene expression vascular compromise decreased capacity for neurogenesis synaptic dysfunction neurotransmitter imbalance
Dewey
What neurochemical changes occur in the aging brain and are thought to contribute to cognitive impairment?
decline in: acetylcholine, dopamine, norepinephrine, serotonin, and GABA increase in: acetylcholinesterase, MOA B CSF: elevated lactate, pyruvate, and potassium
Dewey
An interthalamic adhesion diameter of less than ____ mm was found to be consistent with a diagnosis of CDS in dogs
5mm
Dewey
MOA of selegiline?
irreversible inhibitor of monoamine oxidase B * MAO B catalyzes the breakdown of dopamine with a subsequent formation of free radicals
Dewey
The acetylcholinesterase inhibitor ______ has exhibited efficacy in improving function in dogs with CDS in clinical trials
phenserine * not commercially available for dogs
Dewey
Potential causes for Congenital hydrocephalus? (5)
1) intraventricular hemorrhage (dystocia related) 2) viral infections (parainfluenza in digs, coronavirus in cats) 3) Teratogen exposure 4) Nutritional deficiencies (vitamin A) 5) heritable malformations
Dewey
What is the “bulk flow” concept of CSF accumulation in congenital hydrocephalus?
Excessive fluid accumulation results from: 1) obstruction of CSF flow within the ventricular system - and/or - 2) insufficient absorption of CSF into the venous system at the arachnoid villi level
Dewey
How do ventricular to brain brain ratio and basilar artery resistive index (via doppler ultrasonography) vary between dogs with clinical hydrocephalus and dogs with ventriculomegaly and no neurologic dysfunction?
basilar artery resistive index (RI) and ventricular to brain ratio (VB) were both significantly higher in clinically hydrocephalic dogs - combining these measurements provided a sensitivity of 77% and specificity of 84% for identifying clinical hydrocephalic dogs - RI changed with changes in neurologic status (but not VB ratio)
Dewey
Dewey
T/F: The occipital bone, C1 and C2 develop together
True
Dewey
What 3 conditions compose Dandy Walker Syndrome?
Lack of a cerebellar vermis
Cystic dilation of the 4th ventricle
Hydrocephalus
What is thought to be the underlying cause for the development of intracranial arachnoid fluid accumulation?
split of the arachnoid membrane during embryogenesis - aberration of CSF flow from the choroid plexuses during development forces a separation within the forming arachnoid layer - fills w. fluid (identical to CSF)
Dewey
Experimental studies have shown that ______ of the ventricles dilate first in dogs with internal hydrocephalus
temporal horns
(Laubner et al 2018)
What do epidermoid cysts look like on CT? MRI? How does this vary from DERMOID cyst??
Epidermoid:hypoattenuating on CT images hypointense on T1WI with RING enhancement hyperintense on T2WI
Dermoid: hyperintense on T1WI and T2WI (due to fat content)
(Dewey)
What is the role of “false neurotransmitters” in dogs with HE?
increased circulating levels of aromatic amino acids and benzodiazepine-like substances –> act on brain GABA receptors –> HE signs
(Dewey)
Proposed MOA of uremic encephalopathy (7)
1) Elevated PTH –> directly toxic and causes elevated Ca –> neuronal mineralization 2) Hyperosmolality –> cerebral neuronal dehydration 3) Hypertension –> changes in cerebral vasculature 4) Uremic vasculitis 5) Acid-base imbalance (acidosis depresses cerebral function) 6) uremia-induced neurotransmitter imbalance 7) anemia
(Dewey)
_____ is caused by an an overly-rapid hemodialysis causing osmotic gradient between the brain and ECF
Dialysis disequilibrium syndrome (DDS)
(Dewey)
What is the MOA of dialysis disequilibrium syndrome?
uremic state –> production of idiogenic osmoles –> brain becomes hyoerosmotic
rapid dialysis –> brain remains hyperosmotic to the blood –> gradient causes neurons to “imbibe” water –> cerebral edema
(Dewey)
Glucose enters the brain via a ____ _____ ____ mechanism
noninsulin-dependent facilitated transport mechanism *Requires a minimum BG to operate effectively
(Dewey)
How does the brain cope with chronic hyponatremia?
Hyponatremia –> swelling of brain parenchymal cells –> brain edema
Brain parenchymal cells compensate by extruding osmotically active intracellular components (K and amino acids)
(Dewey)
What occurs ic hyponatremia is too rapidly corrected?
brain parenchymal cells compensate for chronic hyponatremia by actively extruding osmotically active components
Correction of hypoNa –> axonal shrinkage –> demyelination in the brainstem (similar to central pontine myelinolysis)
What three dogs are most notable for having mitochondrial encephalopathy?
Alaskan Huskies
Australian Cattle Dogs
Shetland Sheepdogs
(Dewey)
How does respiratory acidosis cause encephalopathy?
Hypercapnia –> CO2 diffuses across BBB readily –> alters brain neurotransmitter balance and increases blood brain volume –> increased ICP Hypoxia –> exacerbates the effects of hypercapnia on the brain Metabolic acidosis may lead to mild encephalopathic signs
(Dewey)
Underlying cause for organic acidurias?
inherited (usually autosomal recessive) deficiencies of mitochrondrial respiratory chain enzymes (some involve cytosolic enzymes) - enzyme deficiency leads to accumulation of 1+ organic acids - organic acids accumulate in serum, CSF or urine - differ from mitochondrial encephalopathy in the presence of accumulation of organic acids in the urine and other body fludis
(Dewey)
Causes of acquired organic aciduria?
B12 deficiency Malabsorption (EPI) Toxin (Proplyene glycol toxicity)
How does organic aciduria lead to carnitine deficiency?
carnitine serves as a buffer for accumulated organic acids –> binds with excess organic acids (typically fatty acids) –> excreted in the urine –> secondary carnitine deficiency develops
(Dewey)
How is organic aciduria diagnosed? (what sample and testing method)
Demonstrate abnormally high levels of specific organic acids in urine, serum, and/or CSF using gas chromatography-mass spectroscopy
Dewey
What are MRI findings associated with organic aciduria?
bilaterally symmetric lesions of white or gray matter structures that are hyperintense on T2W images Slightly hypointense on T1W images Noncontrast enhancing
How are organic acidurias treated?
Manipulating diet (high carb, low fat, low protein) vitamin supplementation (L-carnitine supplementation, B-vicamins) anticonvulsant therapy PRN Dewey
What are the two forms of gliomatosis cerebri?
Type I (more common) - diffusely infiltrative form. No mass effect Type II - mass lesion in addition to diffuse neoplastic infiltration Dewey
What is the frequency of finding multiple meningiomas in the cat?
17%
Dewey
What is brachytherapy for brain tumor?
local application of radiation via a catheter inserted into the lesion
(Dewey)
What is N-TIRE treatment for brain tumor?
place electrodes within the target and induce a regional electric field with low energy impulses that disrupts cell membranes
(Dewey)
What is the current standard protocol for definitive megavoltage radiation therapy of brain tumors in dogs and cats?
fractionated daily doses of 2.5 - 4 Gy on a Monday through Friday schedule for 4 weeks
Total cumulative dose of 40 - 50 Gy
(Dewey)
What is convection-enhanced delivery of chemo for brain tumors?
infusion catheter inserted into the region to be treated the chemotherapeutic agent is infused via the catheter through the interstitial spaces under a pressure gradient
(Dewey)
T/F: notrosourea chemotherapy drugs easily cross the BBB?
True high lipid soluble alkylating agents that cross BBB readily
(Dewey)
How can lomustine administration affect the metabolism of phenobarbital?
p450 enzymes are responsible for generating anti-neoplastic metabolites from lomustine AND metabolism of phenobarbital
Being on phenobarbital can REDUCE the drug efficacy of lomustine
(Dewey)
Delayed dose-related hepatotoxicity has been reported to occur in approximately ___% of patients receiving lomustine
6% (Dewey)
Average survival time for dogs with intracranial meningiomas treated with prednisone alone?
4 mos
(Dewey)
in a recent report of 121 cases of feline meningioma treated surgically, median postoperative survival time was ____ mos
58 mos
(Dewey)
Cats with what two subtypes of meningioma had significantly shorter survival times?
anaplastic and meningothelial subtypes – significantly shorter survival times
(Dewey)
Tumor recurrence for feline meningioma has been estimated to be around ___%?
20 - 25%
(Dewey)
In one large study, it was found that ___% of canine intracranial meningiomas had aggressive histologic grade tumors
43% (Dewey)
There is a documented association with the degree of malignancy and an _____ expression of VEGF and nuclear protein (MIB-1) in canine brain tumors
increased
(Dewey)
What are the top 5 most common secondary brain tumors?
1) hemangiosarcoma (29%)
2) pituitary tumor (25%)
3) lymphosarcoma (12%)
4) metastatic carcinoma (11%)
5) invasive nasal tumors (6%)
(Dewey)
An ____ CSF level of uric acid and glutamate have been demonstrated in dogs with primary brain tumors
increased
uric acid is an indicator of oxidative injury and potential glutamate excitotoxicity
(Dewey)
What are the second and third most common feline brain tumors?
1) meningioma 2) multicentric lymphoma 3) Pituitary tumor
(Dewey)
T/F: dogs and cats can produce endogenous thiamine
False - must be provided in the diet
(Dewey)
Causes of thiamine deficiency in cats? Dogs?
Cats - feeding all fish diet (high in thiaminase)
Dogs - overcooking canned food or meat (heat destruction of thiamine), meat preserved with sulfur dioxide, possibly amprolium induced?
(Dewey)
Elevated blood pyruvate and lactate levels, and decreased erythrocyte transketolase activity are supportive of a diagnosis of what nutritional encephalopathy?
thiamine deficiency
(Dewey)
In animals that die due to thiamine deficiency, characteristic bilaterally symmetric lesions (petechial hemorrhages) are appreciable throughout the brain at necropsy, especially in the _____
In animals that die due to thiamine deficiency, characteristic bilaterally symmetric lesions (petechial hemorrhages) are appreciable throughout the brain at necropsy, especially in the caudal colliculi of the midbrain
(Dewey)
CBC abnormalities such as leukocytosis, leukopenia, and thrombocytopenia have been reported to occur in approximately ___% of cases of canine bacterial meningoencephalitis
57% (Dewey)
T/F: TMS crosses the BBB even when not inflammed
True
(Dewey)
What breed of dog and breed of cat appear predisposed to developing CNS cryptococcosis?
American Cocker Spaniels Siamese cat
(Dewey)
What two antifungal drugs readily cross the BBB?
Flucytosine and fluconazole
(Dewey)
Cat with PSS and HE - was there a significant association between preoperative seizures, postoperative seizures, and survival to discharge?
no
Valiente 2020
Cat with PSS and HE undergoing surgery - does preoperative plasma ammonia concentration, pre/post feeding bile acid concentration alter survival to discharge?
no
Valiente 2020
Recent study of 34 cats undergoing surgery for PSS - what percentage experienced post-operative seizures?
23%
Valiente 2020
T/F: Cats that undergo surgery for PSS - of the cats that had postoperative seizures, most also had preoperative seizures
FALSE - of the cats that developed seizures postoperatively, 5 of 8 (62%) did NOT have seizures before surgery
* all the cats that developed seizures after surgery had received antiepileptic drugs before surgery *most seizures occurred within 5 days of surgery
Valiente et al 2020
T/F: Male cats are overrepresented to have a portosystemic shunt
true * also domestic shorthair
Valiente 2020
Ptyalism is a common sign of what condition in cats?
PSS
Median survival time for cats with benign spinal tumors treated surgically
518 days
16/18 of these cats had meningioma
Rossmeisl 2006
What cohort of dogs are predisposed to systemic aspergillosis?
Middle age female german shepherd dogs
Schultz 2008
Dogs with vertebral OSA and FSA - what is the median survival time? does radiation or chemotherapy improve survival?
Median survival time is 135 days
Overall poor survival not impacted by various treatments employed (curative intent radiation, palliative radiation, cisplatin)
Dernell 2000
Dernell et al - how does post-treatment neurologic status influence the outcome of patients with vertebral tumors?
Post-treatment neurological status had a significant influence on outcome
Dernell 2000
______ bone destruction appears to be a late event in the sequence of spinal cord invasion by metastatic cells (in humans)
cortical bone destruction
Dernell 2000
T/F: Age at time of diagnosis is a significant predictor of survival in cats with spinal cord neoplasm (non-lymphoid) Pre-operative neurologic status was not a significant predictor of survival time in cats with spinal cord neoplasm (non-lymphoid)
Both false
Rossmeisl 2006
The input terminal of the differential EEG amplifier at which negativity, relative to the other input terminal, produces an UPWARD trace deflection
Input terminal one
BrainCamp lecture
The input terminal of the differential EEG amplifier at which negativity, relative to the other input terminal, produces a DOWNWARD trace deflection
Input terminal 2
Brain Camp lecture
1) the process of recording from a pair of electrodes in an EEG channel, 2) The EEG record obtained by this process
Derivation
Brain Camp lecture
The particular arrangement by which a number of derivations are displayed simultaneously in an EEG record
Montage
Brain Camp lecture
What can be used as a reference electrode for EEG?
Average (av) = a summaion of all EEG electrodes Linked ear electrodes (A1 + A2) Contralateral ear electrode * The ideal reference is inactive, but no cephalic electrodes qualify
Brain Camp Lecture
EEG artifacts (7)
- Muscle
- Motor unit action potentials
- Eye movement
- Electrode out
- 60 Hz interference
- ECG
- Operator
Brain Camp Lecture
Sedation protocol for EEG? dog/cat/equine
canine: meperidine/hydromorphone + acepromazine OR dexmedetomidine alone
Feline: Dexmedetomidine +/- butorphanol
Equine: Detomidine
Brain Camp Lecture
The EEG signal is generated primarily by _____ neurons
Cerebral pyramidal neurons
BSAVA Ch. 4
EEG electrodes - odd numbers refer to the ____ side of the head and even numbers refer to the ____ side of the head. Electrodes along the midline are denoted with the letter ____.
EEG electrodes - odd numbers refer to the left side of the head and even numbers refer to the right side of the head. Electrodes along the midline are denoted with the letter Z
BSAVA Ch. 4
What is a bipolar montage? How does the site of maximum voltage appear? What is the benefit of bipolar montage?
bipolar montage - input 1 and 2 are connected to active recording electrodes. They are linked sequentially in longitudinal or transverse lines
the site of maximum voltage within a field appears as a phase reversal (because the waveforms amplified by input 1 and 2 are facing each other)
benefit - eliminate the effect of contaminated references, localize relatively discrete focal abnormalities
BSAVA Ch. 4
What is a reference montage? How does the site of maximum voltage appear? What is the benefit of reference montage?
Reference montage - common reference electrode is connected to input 2 of each amplified, and usually placed 2cm distal to the last midline electrode
Site of maximum voltage appears as maximal amplitude
allows clear characterization of widespread or complex potential field by recognizing the location of maximum potential on the head
BSAVA Ch. 4
