Neurology (1-10) Flashcards
name the 4 things to observe in the hands off neurological examination
- mentation/sensorium
- posture
- gait
- asymmetry
name the 4 parts of the hands on neurological exam
- proprioception
- spinal reflexes
- cranial nerves
- (nociception)
name 3 tools needed for a neurological exam
- artery forceps
- reflex hammer (pleximeter)
- pen torch
name 5 possible mentations - levels of consciousness
- normal
- dull/depressed
- obtundation
- stuporous
- comatose
name the term
heard turn + body turn
pleurothotonus
name the term
hunched spine;
rounded back
kyphosis
name the term
dip of the back;
characterized by the arching of the spine, the raising of the head
lordosis
name the special posture
stuporous or comatose;
extension of all limbs;
extension of head and neck (opisthotonus);
acute rostral brainstem injury
decerebrate rigidity
name the special posture
mentation normal;
extension of head and neck (opisthotonus);
thoracic limbs extended;
hips flexed;
acute rostral cerebellar injury
decerebellate rigidity
name the special posture
extension of thoracic limbs;
normal mentation;
reduced to normal tone in pelvic limbs;
normal postural responses in thoracic limbs;
acute thoracolumbar injury
Shiff-Sherrington
name 3 causes of ataxia (uncoordinated gait)
- cerebellar
- vestibular
- general proprioceptive/spinal
name the term
inability to generate movement;
(weakness)
paresis
based on the prefix, which limb(s) are affected?
mono-
one limb only
based on the prefix, which limb(s) are affected?
para-
pelvic limbs only
based on the prefix, which limb(s) are affected?
hemi-
one thoracic and one pelvc (same side)
based on the prefix, which limb(s) are affected?
tetra-
all four limbs
what is it called to test hopping proprioception on thoracic limbs only
wheelbarrow
what is it called to test hopping proprioception on pelvic limbs only
external postural thrust
do withdrawal reflexes travel to the brain?
no
(spinal reflex)
do patellar reflexes travel to the brain?
no
(spinal reflex)
what nerve does the patellar reflex test?
femoral nerve
what is the appropriate withdrawal reflex?
flexion of all flexors
what is the appropriate patellar reflex?
kicking out of limb
what is the appropriate cutaneous trunci reflex?
bilateral contraction of cutaneous trunci
does the cutaneous trunci reflex travel to the brain?
no
(spinal reflex)
what spinal cord segments are involved in the withdrawal reflexes
(afferent nerve)
C6-T2 or L4-S1
what spinal cord segments are involved in the patellar reflex?
(femoral nerve)
L4-L6
what spinal cord segments are involved in the cutaneous trunci reflex?
(afferent nerve, brachial plexus, lateral thoracic nerves, cutaneous trunci mm.)
C8-L4/5
what spinal cord segments are involved in the perineal reflex?
S1-S3
what two neuro responses should you test for the head
(hands on)
- menace response
- nasal septal mucosal response
name 5 neuro reflexes you should test for the head
(hands on)
- pupillary light reflex
- palpebral reflex
- corneal reflex
- vestibulo-ocular reflex
- gag reflex
what nerves are involved in the palpebral reflex?
CN V & VII
(trigeminal & facial)
what nerves are involved in the corneal reflex?
CN V, VI, & VII
(trigeminal, abducens, facial)
what nerves are involved in the gag reflex
CN IX & X
(glossopharyngeal & vagus)
what nerves are involved in the vestibulo-ocular reflex?
CN III, IV, VI, & VIII
(oculomotor, trigeminal, abducens, vestibulocochlear)
name the 5 spinal cord segments
- C1-C5
- C6-T2
- T3-L3
- L4-S1
- S2-S3
what part of the brain is the prosencephalon?
forebrain
what part of the brain is the telencephalon?
cerebral hemispheres
what part of the brain is the diencephalon?
thalamic region
name the part of the brain
more functional subdivision of the brain, including cerebrum and diencephalon (thalamus)
forebrain
disease of what part of the brain would show these clinical signs?
- head pressing
- staring at walls
- getting stuck in corners
- circling
- continuous pacing
- compulsive behaviour
- normal gait
forebrain disease
what is the most frequent clinical sign of forebrain disease?
generalised tonic clonic seizures
name the 11 categories of differential diagnoses
- Vascular
- Infectious/Inflammatory
- Traumatic
- Toxic
- Anomaly
- Metabolic
- Idiopathic
- Iatrogenic
- Neoplastic
- Nutritional
- Degenerative
(VITAMIN D) (VITTAMIINN D)
name 3 vascular diseases of the forebrain
- diffuse cerebral ischemia
- focal cerebral ischemia
- diffuse or focal hemorrhages
name the vascular disease of the forebrain
cardiopulmonary arrest;
anaesthetic complication;
severe cerebral oedema following a toxic or traumatic event
diffuse cerebral ischemia
name the vascular disease of the forebrain
causes:
chronic kidney disease, hyperadrenocorticism, idiopathic hypertension, septic or neoplastic emboli;
hypercoagulable state;
migrating parasites
focal cerebral ischemia
name 3 infectious diseases of the forebrain
- Rabies disease (Lyssavirus)
- canine distemper virus (CDV)
- Feline Infectious Peritonitis (FIP)
name the infectious disease of the forebrain
not endemic in the UK;
paralytic and furious manifestations
rabies
name the infectious disease of the forebrain
neurological abnormalities 1-3 weeks after systemic disease;
hyperesthesia, vestibular signs, ataxia, cerebellar signs, tetraparesis and myoclonus
canine distemper virus (CDV)
name the infectious disease of the forebrain
three presentations:
1. multifocal CNS disease
2. T3-L3 myelopathy
3. central vestibular syndrome
feline infectious peritonitis (FIP)
name the inflammatory disease of the forebrain
most common inflammatory disease in dogs;
unknown origin but autoimmune pathology;
2 forms:
1. necrotising
2. granulomatous
meningoencephalitis of unkown origin
this is the pressure exerted by tissues and fluids within the cranial vault
intracranial pressure (ICP)
name 4 causes of increased intracranial pressure (ICP) in head trauma
- intracranial hemorrhage
- cerebral oedema
- systemic hypotension
- hypoxaemia
name the 4 goals of head trauma management
- maintain ventilation
- avoid hypertension
- prevent/treat cerebral oedema
- treat increased ICP
name 1 anomalous disease of the forebrain
- hydrocephalus (congenital or acquired)
name the anomalous disease of the forebrain
increased CSF volume in dilated ventricular cavities
hydrocephalus
what are the 2 treatment options for congenital hydrocephalus?
- corticosteroids (medical)
- ventriculoperitoneal shunt (surgical)
name the metabolic disease of the forebrain
acquired or congenital portosystemic shunt;
“toxic” substances (ammonia) from intestinal degradation are not metabolised by liver or bypass it, reaching the brain
hepatic encephalopathy (HE)
name 3 ways to diagnose hepatic encephalopathy (HE)
- bile acid stimlation test
- abdominal ultrasound
- abdominal CT scan with angiogram
name 3 ways to medically treat hepatic encephalopathy (HE)
- low protein diet
- antibiotics
- lactulose
name the part of the brain
coordinates all the motor activities: voluntary movements, postural movements, reflex movements ;
assists in maintenance of the equilibrium;
controls RATE, RANGE, and FORCE of movement
cerebellum
name the term
swaying of the body (truncal ataxia) from side to side, forward and backward, and occasionally dorsoventrally
titubation
name the cerebellum disease
young dogs (<5y), small breeds;
mild non-suppurative encephalitis;
suspected autoimmune-mediated eitiology;
originally mistaken for seizures;
Tx with immunosuppressive doses of corticosteroids tapered over 3-6 months
idiopathic tremor syndrome
(‘white shakers’)
name the part of the brain
responsible for maintaing balance regulating the position of the eyes, trunk and limbs in relation to changes in position of the head
vestibular system
name 3 things that maintaining balance depends on
- vestibular receptors
- vision
- proprioceptive receptors in joints and tendons
name the 2 parts of the peripheral vestibular system
- vestibular receptors (in utricle and saccule and semicircular canals)
- vestibular nerve (CN VIII)
name the 2 parts of the central vestibular system
- vestibular nuclei (in brainstem)
- cerebellum
name the clinical sign of vestibular disease
involuntary rhythmic oscillation of the eyes (jerk eye movement with slow and fast phase) ;
physiological or pathological
nystagmus
The fast phase of nystagmus is (on the same side OR contralateral) to the lesion?
contralateral
name 4 clinical signs of Horner syndrome
(vestibular disease)
- ptosis (drooping of the upper eyelid)
- enophthalmus (eyes sinking deeper in socket)
- miosis (constriction of the pupil)
- 3rd eyelid protrusion
peripheral or central vestibular disease?
- proprioceptive deficits
- vertical resting or positional nystagmus
- nystagmus changing direction with changes in head position
- cranial nerve deficits other than CN VII
- cerebellar signs
- decreases level of consciousness
- paradoxical vestibuar syndrome
central vestibular disease
name the central vestibular disease
contradictory vestibular signs;
caused by loss of cerebellar inhibition of the vestibular output;
ex: Left head tilt & Right postural reactions deficits
paradoxical vestibular syndrome
name the vestibular disease
- absent physiological and/or pathologic nystagmus
- absent head tilt
- side-to-side swaying of the head
- broad-base stance
- falling to either side
bilateral vestibular disease
what nutritional deficiency can lead to central vestibular disease?
thiamine deficiency
what is the most common viral cause of central vestibular infectious disease?
FIP
name the central vestibular inflammatory disease
subacute ot chronic sterile inflammation, supected immune-mediated disorder;
middle age small breed dogs;
disseminated, focal and ocular form;
prognosis guarded to poor;
definitive diagnosis by histopathology;
traditional Tx: immunosuppressive doses of corticosteroids
granulomatous meningoencephalomyelitis (GME)
name the toxic central vestibular disease
characterized by anorexia, vestibular ataxia and vertical nystagmus;
recovery may be enhanced by administration of diazepam at 0.4 mg/kg TID for 3 days (competitively displaces cause from GABA receptors)
metronidazole intoxication
name the cranial nerve diseased
loss of appetite, anosmia (difficult to assess);
nasal discharge, nasal obstruction;
DD: viral, bacterial or fungal rhinitis; nasal adenocarcinoma, meningioma, neuroblastoma
CN I (olfactory)
name the cranial nerve diseased
blindness & pupillary light reflex (PLR) deficit
CN II (optic)
what 3 nerves/pathways are involved in the menace response?
- CN II
- complete visual pathway to occipital cortex
- CN VII
what 2 cranial nerves are involved in the blinking reflex
- CN V
- CN VII
what cranial nerve is involved in an obstacle course/cotton ball test
CN II
(optic)
what 4 cranial nerves/pathways are involved in the PLR (direct and consensual)
- CN II
- complete PLR pathway
- CN III
- sympathetic innervation
list the 7 parts of the visual pathway to occipital cortex
(Menace Response pathway)
- neuroepithelial cells, bipolar and ganglion cells
- optic nerve
- optic chiasm
- optic tract
- lateral geniculate nucleus
- optic radiation
- occipital lobe
name the 12 parts of the complete PLR pathway
- neuroepithelial cells, bipolar and ganglion cells
- optic nerve
- optic chiasm
- optic tract
- lateral geniculate nucleus
- optic radiation
- occipital lobe - pretectal nuclei
- Edinger-Westphal nucleus
- CN III (oculomotor nerve)
- ciliary ganglion
- ciliary nerves
- sphincter pupillae muscle
name the 5 step evaluation of blindness and PLRs
- menace response
- palpebral (blinking reflex)
- obstacle course/cotton ball test
- PLR (direct and consensual)
- ophthalmoscopic exam
what is the most common differential diagnosis for blindness WITHOUT PLRs
SARD (sudden acquired retinal degeneration)
where is the oculomotor (CN III) nuclei located?
midbrain
what nucleus is the parasympathetic component of CN III
Edinger-Westphal nucleus
name 3 functions of CN III (oculomotor nerve)
- innervation of dorsal, medial & ventral recti and ventral oblique extraocular muscles
- levator palpebral muscle of upper eyelid
- sphincter pupillae muscle for contricition of pupil
what extraocular muscle is innervated by CN IV (trochlear nerve)
dorsal oblique
what clinical ocular sign is seen with a CN IV deficit
lateral rotation of the eye
what 2 ocular muscles are innervated by CN VI (abducent nerve)
- lateral rectus extraocular muscle
- retractor bulbi muscle
what 2 clinical ocular signs will be seen with a CN VI (trochlear nerve) deficit?
- medial strabismus
- inability to retract the globe
name the 3 branches of CN V (trigeminal)
- mandibular branch
- ophthalmic branch
- maxillary branch
name the trigeminal nerve (CN V) branch
Motor - muscles of mastication;
sensory - lower jaw
mandibular branch
name the trigeminal nerve (CN V) branch
sensory - dorsal eyelid and cornea
ophthalmic branch
name the trigeminal nerve (CN V) branch
sensory - ventral eyelid and nasal area
maxillary branch
name the cranial nerve
Function:
motor - muscles of facial expresion
sensory - inner surface pinna
taste sensation rostral two-thirds tongue
CN VII (facial nerve)
what test can be performed to asses CN VIII (vestibulocochlear nerve)
BAER test
(brainstem auditory evoked response test)
name the cranial nerve
motor - muscles of pharynx
sensory - pharyngeal mucosa and caudal third of tongue
parasympathetic function - zygomatic and parotid salivary glands ;
gag and swallow reflex
CN IX (glossopharyngeal nerve)
name the cranial nerve
motor - muscles of pharynx, larynx (recurrent laryngeal nerve) and palate (deficit leads to dysphagia);
motor parasympathetic - viscera in chest and cranial abdomen (deficit leads to inspiratory dyspnea due to laryngeal paralysis);
sensory - pharynx, larynx and viscera (deficit leads to megaoesophagus)
CN X (vagus nerve)
name the cranial nerve
motor - neck muscles (trapezius, sternocephalicus and brachiocephalicus)
CN XI (accessory nerve)
name the cranial nerve
motor - intrinsic and extrinsic muscles of the tongue ;
deficits in tongue movements, atrophy, and deviation of the tongue
CN XII (hypoglossal nerve)
name the term
“a non-specific, proxysmal event of the body that represents an abnormality of forebrain neurotransmission”
originated by an imbalance of excitatory and inhibitory influences on the cerebral neurons
seizure
name the epileptic seizure phase
behavioural changes or autonomic signs that may precede an observable seizure
pre-ictal phenomenon
name the epileptic seizure phase
a sudden paroxysmal neurologic occurrence
ictus
name the epileptic seizure phase
a transient clinical abnormality of teh CNS function that appears or becomes more evident when the clinical signs of the seizure have ended;
disorientation, ataxia, central blindness, behavioural changes
post-ictal phenomenon
name the type of seizure
involvment of both the cerebral hemispheres;
tonic-clonic, tonic, atonic, absence seizures
generalized seizures
name the type of seizure
activation of only a part of a cerebral hemisphere;
simple or complex
focal seizures
name the type of focal seizure
consciousness is not impaired
simple focal seizure
name the type of focal seizure
with impairment of consciousness
complex focal seizure
name the term
two or more seizures in a 24-hour period or one seizure per day
cluster of seizures
name the term
a seizure that shows no clinical signs of arresting after 5 minutes of activity, or recurrent seizures with no recovery between them
status epilepticus
name 7 differential diagnoses for a seizure
- syncope
- narcolepsy/cataplexy
- neuromuscular
- paroxysmal diskinesia
- vestibular episode
- idiopathic head tremor
- pain
name the term
signs occur suddenly against a background of normality
paroxysmal
name the term
movement of the body that is involuntary
dyskinesia
name the 3 main categories of epilepsy aetiology
- idiopathic epilepsy
- symptomatic epilepsy
- cryptogenic epilepsy
name the epilepsy aetiology classification
no identifiable cause;
genetic/familial predisposition;
age dependent;
genetic
idiopathic epilepsy
name the epilepsy aetiology classification
result of identifiable intracranial disease (brain tumours, encephalitides, infarcts) or extracranial disease (toxic or metabolic disorders
symptomatic epilepsy
name the epilepsy aetiology classification
epilepsy of unknown cause;
usually older animals
cryptogenic epilepsy
name the 5 investigations that should be made for seizure activity
- signalment
- history
- physical and neurological examination
- CBC, biochem panel, Urinalysis
name 5 investigations that can be made for a more extensive work up for seizure activity
- bile acids, ammonia
- serological studies
- EEG
- CSF analysis
- MRI
name 5 guidelines for when to start anti-seizure medication
- more than 1 seizure w/in a 6 month period
- one period of cluster seizures
- one period of status epilepticus
- prolonged or severe post-ictal signs
- suspect structural brain disease
name 3 anti-seizure drugs (ASDs) licensed in dogs
- phenobarbitone/Phenobarbital
- Imepitoin
- Potassium bromide
any licensed anti-seizure drugs (ASDs) in cats?
NO
name 5 ‘off-label’ anti-seizure drugs (ASDs) used in dogs and cats
- Levetiracetam (Keppra)
- Zonisamide (Zonegram)
- Gabapentin (Neurontin)
- Pregabalin (Lyrica)
- Topiramate (Topamax)
name the anti-seizure drug (ASD)
GABA receptor agonist (potentiating inhibition);
barbiturate;
50% protein bound;
metabolized by liver (~75%, rest excreted unchanged in urine);
autoinducer of hepatic microsomal enzymes;
10-20 days for steady state
Phenobarbitone
what is one of the most important idiosyncratic side effects of Phenobarbitone
hepatotoxicity
what is the ideal range for phenobarbitone serum levels
25-30 mg/L
what is the Phenobarbitone dose in dogs and in cats?
dogs: 2-3 mg/kg PO BID
cats: 2 mg/kg PO BID
name the anti-seizure drug (ASD)
bromide hyperpolarises neurons entering via Cl- channels;
halide salt;
excreted in kidneys (no biotransformation);
half-life in dogs 15-30 days;
2-5 months for steady state (long time)
Potassium Bromide
which anti-seizure drug (ASD) should NOT be used in cats becuase it can cause eosinophilic bronchitis
Potassium bromide
what is the dose for Potassium bromide to treat seizures in dogs
20-40 mg/kg PO SID or split BID
name the anti-seizure drug (ASD)
partial GABA agonist;
linear pharmokinetic, so NOT currently monitoring serum levels ;
anxiolytic (licensed for noise phobia)
Imepitoin (Pexion)
name the anti-seizure drug (ASD)
inhibits neurotransmitter release (binds to synaptic vesicle protein 2A);
mostly excreted unchanged by the kidneys;
may cause hypersalivation in cats;
linear pharmokinetic, so NOT currently monitoring serum levels
Levetiracetam
name the anti-seizure drug (ASD)
inhibition of T-type Ca channels and CG-Na channels = inhibit excitation!;
allosterically bind to GABA R to increase function;
regulate transporters to decrease glutamate and increase GABA;
metabolised by CYP3A4;
free radical scavenger;
weak carbonic anhydrase inhibitor
Zonisamide
which emergency seizure medication should NOT be used in cats because it can cause idiosyncratic hepatic necrosis
benzodiazepines
name the 4 anti-seizure drugs (ASDs) that can be used in an emergency
- Phenobarbital
- Potassium bromide
- Levetiracetam
- Midazolam/Diazepam
what 4 tests should be done if a patient is newly seizuring naive of anti-seizure drugs (ASDs)
- Haematology (CBC)
- Biochem
- Ammonia
- Bile acids (if appropriate)
what 5 tests should be done for a returning patient on anti-seizure drugs (ASDs)
- CBC
- Biochem
- Ammonia
- Bile acids (if appropriate - phenobarbital)
- serum levels of anti-seizure drugs (ASDs) (when appropriate)
how to treat Status Epilepticus in the first 5-30 minutes?
Diazepam or Midazolam
how to treat Status Epilepticus after 30-60 minutes?
Phenobarbital, Levetiracetum, OR Potassium bromide
what is the dose of Diazepam for treating Status Epilepticus
0.5-1.0 mg/kg IV or rectally,
repeated admin. at least 5 min apart up to 3 times in 24h
what is the dose of Midazolam for treating Status Epilepticus
0.2-0.5 mg/kg IN/IV/IM,
repeated admin at least 5 min apart up to 3 times in 24h
what is the dose of Phenobarbital for treating Status Epilepticus in pre-treated patients
3-5 mg/kg IV as a bolus
what is the dose of Phenobarbital for treating Status Epilepticus in non-pretreated animals
loading: 2-4 mg/kg q6-8h (max of 24 mg/kg)
OR
3-5 mg/kg IV as a bolus
(or orally in event of cluster seizure)
what is the dose of Levetiracetam for treating Status Epilepticus
loading dose: 40-60 mg/kg IV or rectal
followed by: 20 mg/kg IV q8h
what is the loading dose of Potassium Bromide for treating Status Epilepticus in a non-pretreated patient
400-600 mg/kg/24h
(100 mg/kg PO q4-6h)
what is the treatment for Status Epilepticus after 60-120 minutes
Levetiracetum, Propofol
what is the treatment for Status Epilepticus after more than 120 minutes
(refractory or drug-resistant SE)
Ketamine OR Inhalant anaesthesia
name 4 degenerative diseases of the spinal cord of dogs
- intervertebral disc disease (IVDD)
- cervical spondylomyelopathy (CSM)
- Degenerative lumbosacral stenosis (DLSS)
- Degenerative myelopathy (DM)
name the 2 components of the intervertebral disc
- nucleus pulposus
- annulus fibrosus
name the component of the intervertebral disc
inner component, gelatinous in young normal animals
nucleus pulposus
name the component of the intervertebral disc
outer layer, fibrous, ventral portion thicker than dorsal
annulus fibrosus
name the structure
from T2 to T10;
cover annulus dorsally;
intervertebral disc disease unusual in these locations
intercapital ligament
name the type of IVDD
intervertebral disc extrusion (IVDE);
chrondrodystrophic breeds;
degeneration process starts < 1y old;
acute
Hansen type 1
name the type of IVDD
intervertebral disc protrusion (IVDP);
non-chondrodystrophic breeds;
older > 5y old;
chronic
Hansen type 2
name the 4 stages of IVD degeneration
- chondroid metaplasia
- dehydration of nucleus pulposus
- fissures in annulus fibrosus
- necrosis and calcification
what 3 things does the severity of neurological deficits with IVDD depend on?
- volume of disc material
- rate of extrusion
- duration of compression
name the 4 spinal refelxes that should be tested in a neurological examination
- withdrawal reflexes
- patellar reflex
- perineal reflex
- cutaneous trunci reflex
name the 5 grades of dysfunction
- pain or hyperaesthesia
- proprioceptive ataxia and ambulatory paresis
- non-ambulatory paresis
- plegia
- plegia with loss of pain perception
what 2 clinical signs will be seen with an upper motor neuron (UMN) lesion
- increased muscle tone
- normal or increased spinal reflexes
what 2 clinical signs will be seen with a lower motor neuron (LMN) lesion
- decreased motor tone
- decreased or absent spinal reflexes
localise the spinal lesion
tetraparesis/plegia;
UMN signs on all limbs (+ bladder);
ataxia on all limbs;
hypalgesia of all limbs + tail
C1-C5
localise the spinal lesion
tetraparesis/plegia;
LMN signs on thoracic limbs;
UMN signs on pelvic limbs (+ bladder);
ataxia on all limbs;
hypalgesia of all limbs + tail
C6-T2
localise the spinal lesion
paraparesis/plegia;
UMN signs on pelvic limbs + bladder;
ataxia of pelvic limbs;
hypalgesia/analgesia of pelvic limbs and tail
T3-L3
localise the spinal lesion
paraparesis/plegia;
LMN signs on pelvic limbs;
ataxia of pelvic limbs;
hypalgesia/analgesia of pelvic limbs and tail
L4-S1
localise the spinal lesion
tail paresis/plegia;
LMN signs on anus, tail, perineum + bladder;
hypalgesia/analgesia of tail
S1-Cd
localise the IVDD based on clinical signs
- pain/hyperaesthesia (reluctance to move)
- reduced range of movement in the neck
- low head carriage
- thoracic limb lameness = ‘nerve root signature’
- ambulatory tetraparesis and proprioceptive ataxia
- non-ambulatory tetraparesis
- tetraplegia
- respiratory arrest (phrenic nerve)
cervical IVDD
localise the IVDD based on clinical signs
- pain/hyperaesthesia (reluctance to move)
- Kyphosis
- pelvic limb lameness = ‘nerve root signature’
- ambulatory paraparesis and proprioceptive ataxia
- non-ambulatory paraparesis
- paraplegia
- loss of pain perception
- urinary and faecal incontinence
thoracolumbar IVDD
name 3 radiographic changes supportive of IVD extrusion
- narrowing of articular facets
- narrowing of intervertebral foramen
- presence of mineralised disc material w/in vertebral canal
what is the gold standard for imaging to diagnose IVDD?
can differentiate soft tissue structures of vertebral column with 98.5% sensitivity
MRI
what is the most frequent site of IVDD in the thoracolumbar region
T11-L4
what is the most frequent site of IVDD in the cervical region in small breeds
C2-3
what is the surgical treatment option for IVDD in the cervical vertebral column
ventral slot
what is the surgical treatment option for IVDD in the thoracolumbar vertebral column
Hemilaminectomy & Fenestration
name the term
softening or degeneration of spinal cord tissue
myelomalacia
name 3 other types of intervertebral disc disease (IVDD) besides disc protrusion/extrusion
- acute non-compressive nucleus pulposus extrusion (ANNPE)
- hydrated nucleus pulposus extrusion (HNPE)
- fibrocartilaginous embolism (FCE)
name the type of IVDD
sudden extrusion of small volume of disc material, impacts spinal cord with force;
any breed, often associated with trauma or high-impact activity;
acute onset, non-progressive lateralised neurological deficits;
may be painful in first 24h;
diagnose with MRI, treat conservatively
acute non-compressive nucleus pulposus extrusion (ANNPE)
name the type of IVDD
partially or non-degenerate disc extrudes, varying degree of compression;
any breed, spontaneous;
acute onset, non-progressive, symmetrical neurological deficits;
cervical location more common;
typicall non-painful;
diagnose with MRI and treat conservative - surgery if not improving;
excellent prognosis
hydrated nucleus pulposus extrusion (HNPE)
name the type of IVDD
ischaemic infarct secondary to occlusion of artery/vein supplying the spinal cord;
infarct caused by fragment of fibrocartilage thought to come from intervertebral disc;
most common in medium to large breed (mini schnauzer, rare in cats);
typically spontaneous;
peracute onset of non-painful, lateralising clinical signs;
diagnose with MRI and treat conservative, usually excellent prognosis depending on response in first 2 weeks
Fibrocartilaginous embolism (FCE)
name the degenerative disease of the spinal cord of dogs
causes vertebral canal stenosis;
2 forms (disc-associated and osseus-associated);
all canine breeds but most common in Doberman and Great Dane ;
aka “Wobblers”
Cervical Spondylomyelopathy (CSM)
name the type of Cervical Spondylomyelopathy (CSM)
middle-aged large breed dogs (Dobermans);
typically chronic;
same clinical signs as cervical IVDD;
intervertebral disc protrusion, ligament hypertrophy, C5-6 and C6-7 most commonly affected
disc-associated CSM
name the type of Cervical Spondylomyelopathy (CSM)
young, giant breed dogs;
typically chronic;
same clinical signs as cervical IVDD;
vertebral malformation + degenerative change leading to proliferation of vertebral arch, articular processes and pedicles;
C4-5, C5-6, and C6-7 most common
osseus-associated CSM
what is the surgical treatment option for disc-associated Cervical Spondylomyelopathy (CSM)
ventral slot for disc compression +/- stabilisation
what is the surgical treatment option for osseus-associated Cervical Spondylomyelopathy (CSM)
dorsal laminectomy to address osseous compression +/- stabilisation
name the degenerative disease of the spinal cord of dogs
cauda equina: L7, S1-3, Cd1-5 nerve roots;
medium to large dogs of middle-older age (GSDs);
congenital vertebral malformation;
L7-S1 intervertebral disc degeneration;
hypertrophy of ligaments of lumbosacral joint;
degenerative joint disease of articular processes;
spondylosis deformans
degenerative lumbosacral stenosis (DLSS)
name 6 clinical signs of degenerative lumbosacral stenosis (DLSS)
- pelvic limb hypometria
- lumbosacral pain
- lameness
- urinary or faecal incontinence
- tail weakness
- reduced perineal and pelvic limb withdrawal reflexes
name the 2 parts of conservative treatment for cervical spondylomyelopathy (CSM)
- exercise restriction, body harness
- anti-inflammatories and analgesia
name the 2 parts of conservative treatment for degenerative lumbosacral stenosis (DLSS)
- exercise restrictipn and analgesia
- epidural steroid injections
what is the surgical treatment for degenerative lumbosacral stenosis (DLSS)
dorsal laminectomy +/- foraminotomy
name the degenerative disease of the spinal cord of dogs
middle age to older dogs, usually large breeds;
slowly progressive, non-painful;
concurrent axonal and myelin degeneration of the spinal cord;
multifactorial;
genetic and clinical similarities with amyotrophic lateral sclerosis in humans;
diagnosed with supportive neurological signs, exclusion of other conditions and genetic test for SOD1 gene BUT only definitive with postmortem of spinal cord
Canine degenerative myelopathy (CDM)
name 2 immune mediated diseases of the spinal cord
- steroid responsive meningitis-arteritis (SRMA)
- meningomyelitis of unknown origin aka Granulomatous meningoencephalomyelitis (GME)
name the immune mediated disease of the spinal cord
young, med-large breed dogs (can also be small breeds);
acute onset, recurrent episodes, wax/waning;
immune-mediated inflammation of the meninges and associated blood vessels;
severe neck pain, loww carriage head and neck;
pyrexia; exercise intolerance and stiff gait
steroid responsive meningitis-arteritis (SRMA)
how to treat steroid responsive meningitis-arteritis (SRMA)
immunosuppressive dose of corticosteroids (prednisolone), slowly tapering over 4-6 months
name 3 infectious diseases of the spinal cord
- Discospondylitis
- Distemper myelitis
- Feline Infectious Peritonitis (FIP)
name the infectious disease of the spinal cord
infection of the intervertebral disc (IVD) and adjacent vertebral body endplates;
large breed (GSD and Dobermans), male intact dogs, reported in cats;
subacute or chronic, typically >72h duration;
vague spinal pain, lameness, pyrexia, lethargy, etc;
neurological deficits range from mild ataxia to plegia
Discospondylitis
name 4 bacterial or fungal causes of Discospondylitis
- Staph. intermedius (most common)
- E. coli, Bacteroides, Strep
- Brucella canis
- Aspergillus
name the 3 possible routes of infection for Discospondylitis
- haematogenous spread (most common)
- migrating foreign body (grass awn)
- iatrogenic (surgery or epidural complication)
what is the treatment for Discospondylitis?
- minimum 6-8 weeks antibiotics or antifungal agents
- analgesia
- surgery
name 4 anomalous (congenital) diseases of the spinal cord
- Syringomyelia (+ Chiari-like malformation)
- vertebral malformations
- Dermoid sinus
- spinal arachnoid diverticulum
name the anomalous (congenital) disease of the spinal cord
congenital malformation of small-breed dogs;
causes a mismatch between the volume available in the caudal fossa and the brain parenchyma located in this space, resulting in herniation of the cerebellum into the foramen magnum
Chiari-like malformation (CLM)
name the term
intracranial space between tentorium cerebelli and occipital bone;
contains cerebellum, pons and medulla
caudal fossa
name the term
fluid filled cavity within the spinal cord
syringomyelia
name 2 clinical signs of Chiari-like malformation and Syringomyelia (CLM/SM)
- ‘phantom-scratching’ neck/shoulder/flank
- spinal pain and/or allodynia
how to medically treat Chiari-like malformation and Syringomyelia (CLM/SM)? (3 meds)
- analgesia
- drugs that may reduce CSF production
- corticosteroids
what is the surgical method of treatment for Chiari-like malformation and Syringomyelia (CLM/SM)
foramen magnum decompression & cranioplasty
name the anomalous (congenital) disease of the spinal cord
failure of vertebrae to form properly, typically wedge-shaped;
vertebral column instability and spinal cord compression;
screw-tail brachycephalic breeds (pugs, frenchie, boston terriers);
conservative treatment, anti-inflammatories, pain relief;
surgical stabilisation
hemivertebrae
name the anomalous (congenital) disease of the spinal cord
congenital malformation of the dens (agenesis or hypoplasia) or abnormal ligaments, so joint is unstable;
mild: neck pain; moderate: ataxia and tetraparesis; severe: tetraplegia and respiratory difficulties;
toy or small breed dogs less than 2 years old
atlanto-axial subluxation
name the anomalous (congenital) disease of the spinal cord
fluid-filled dilation of subarachnoid space, leading to progressive compression of the spinal cord;
often associated with vertebral malformation, IVDD or myelitis;
congenital: Rottweilers; acquired: pugs and frenchies;
typically no associated pain;
tetra- or paraparesis and proprioceptive ataxia; urinary and faecal incontinence
spinal arachnoid diverticulum
what is the surgical treatment option for spinal arachnoid diverticulum
durectomy and treatment of concurrent disease
what is the conservative treatment for spinal arachnoid diverticulum
anti-inflammatories (steroids)
name 4 examples of primary spinal cord injury (SCI)
- vertebral fracture and luxation (VFL)
- traumatic intervertebral disc herniation
- extra-axial haemorrhage
- spinal cord contusion
name the term
complete dislocation of a joint
luxation
name the term
partial or incomplete dislocation of a joint
subluxation
name the primary spinal cord injury (SCI)
damage to blood vessels surrounding the spinal cord;
can result in haematoma formation and spinal cord compression;
rare secondary to trauma
extra-axial haemorrhage
name the primary spinal cord injury (SCI)
damage to blood vessels within spinal cord parenchyma;
rarely occurs alone, most often in combination with VFL or traumatic intervertebral disc herniation
spinal cord contusion
what is the gold standard for diagnostic imaging of the vertebral column?
allows 3D reconstruction, intravenous contrast allows identification of spinal cord oedema or haemorhage, full body to assess concurrent injuries
CT scan
what is the best modality for assessing spinal parenchyma and support soft tissue structures
MRI
name 3 indications for surgical treatment of primary spinal cord injury (SCI)
- severe neurological deficits
- unstable fracture
- deterioration despite medical treatment
name 3 indications for medical treatment of primary spinal cord injury (SCI)
- mild neurological deficits
- non-displaced/stable fracture
- financial constraints
what 2 things make up a motor unit
- single motor neuron
- all the muscle fibres it innervates
what 2 diagnostic procedures should all patients with suspected peripheral nerve or muscular diseases have done?
- physical and neurological exam
- CBC, biochem with electrolytes & urinalysis
name 3 electrodiagnostic tests for peripheral nerve or muscular diseases
- electromyography (EMG)
- nerve conduction velocity (NCV)
- repetitive nerve simulation (RNS)
name 5 clinical signs of lower motor neuron (LMN) dysfunction
- paresis or plegia
- hypometria
- hypotonia
- hyporeflexia or areflexia
- rapid onset muscle atrophy
name the term
short strided gait +/- reduced stride height
hypometria
name the term
decreased muscle tone
hypotonia
name the term
decreased or absent spinal reflexes
hyporeflexia or areflexia
name the vascular neuromuscular disease
most common in cats, also in dogs;
cat clinical signs: LMN dysfunction in 1 or both PLs; loss of pain perception; muscle firm and painful on palpation; loss of peripheral pulses, cyanotic nail beds and cool extremeties;
cat pathogenesis: assoc. with cardiomyopathy and aortic thromboembolism (ATE) interrupting blood supply to pelvic limbs;
supportive treatment and anti-coagulant therapy
ischaemic neuromyopathy
name 7 immune mediated and infectious neuromuscular diseases
- acute polyradiculoneuritis
- Myasthenia gravis (MG)
- Masticatory Muscle Myositis
- Protozoal Polyradiculoneuritis and myositis
- Botulism
- Tetanus
- Tick bite paralysis
name the immune mediated/infectious neuromuscular disease
some cases assoc. with bite/scratch from racoon “coonhound paralysis”;
raw chicken consumption is a risk factor (Campylobacter species);
clinical signs: paresis, reduced withdrawal reflexes, muscle tone and myotatic reflexes, neurogenic atrophy; hyperesthesia on spinal palpation;
suspected immune-mediated inflammation of axons and myelin of ventral nerve roots
acute polyradiculoneuritis
name the immune mediated/infectious neuromuscular disease
auto-immune disease affecting the neuromuscular junction - serum antibodies formed against nicotinic acetylcholine receptors (AChRs);
results in decr. numbers of functional receptorson post-synaptic surface;
more common in dogs v. cats (Abyssinian, Somali)
Myasthenia gravis (MG)
what test can be performed to diagnose acquired myasthenia gravis?
anticholinesterase challenge test
(incr. time ACh remains in synaptic cleft)
what is the anticholinesterase drug of choice for treatment of acquired myasthenia gravis?
pyridostigmine bromide (Mestinon)
name the immune mediated/infectious neuromuscular disease
GSD predisoposed;
painful swelling of masticatory muscles and trismus which progresses to muscle atrophy in chronic stages;
caused by Abs directed against the masticatory muscle;
treated with immunosuppressive dose of corticosteroids
masticatory muscle myositis
how to diagnose masticatory myositis?
serology - Abs against Type 2 myofibres
name the immune mediated/infectious neuromuscular disease
exposure to intermediate hosts (cattle or sheep);
acute paraparesis with rigid pelvic limb extension, patellar reflexes absent, severe muscle atrophy;
Toxoplasma gondii and Neospora caninum;
inflammation of lumbosacral nerve roots
protozoal polyradiculoneuritis and myositis
name the immune mediated/infectious neuromuscular disease
ingestion of spoiled or raw food;
toxin blocks release of ACh at the NMJ and cholinergic autonomic synapses
botulism
name the immune mediated/infectious neuromuscular disease
5-10 days following wound or procedure;
localised or generalised muscle stiffness, facial involvement;
spores of Clostridium introduced into tissues under anaerobic conditions, spores germinate to become exotoxin-producing, toxin enters NMJ of skeletal muscle and travels retrograde to CNS and interferes with inhibitor interneurons of the spinal cord
Tetanus
name the traumatic neuromuscular disease
associated with road traffic accident;
caused by severe abduction or traction on forelimb;
lameness, monoparesis, monoplegia, proprioceptive deficits
Brachial plexus avulsion
name 3 types of peripheral nerve injury
- neuropraxia
- Axonotmesis
- Neurotmesis
name the type of peripheral nerve injury
- little or no damage to axon and connective tissue supporting structures, can be due to ischaemia or mild myelin damage
- mild motor or proprioceptive dysfunction, nociception intact
- neurogenic muscle atrophy unlikely;
spontaneous recovery in days to a month
neuropraxia
name the type of peripheral nerve injury
- axons disrupted but connective tissue support intact (basal lamina of schwann cells, endo/peri/epi-neurium)
- axons can regrow along connective tissue scaffold
- substantial motor, proprioceptive and nociceptive dysfunction
- neurogenic muscle atrophy likely
axonotmesis
name the type of peripheral nerve injury
- axons and connective tissue support disrupted
- axons will not regrow without surgical intervention
- complete motor, proprioceptive and nociceptive dysfunction
- neurogenic muscle atrophy expected
neurotmesis
at what rate do axons regrow at?
1-4mm per day
name the traumatic neuromuscular disease
most common in cats, assoc. with road traffic accidents;
caused by traction on the tail, often in combo woth trauma to pelvis/nerve roots of terminal spinal cord
Sacrococcygeal or Intercoccygeal luxation
(“tail pull” injuries)
name the traumatic neuromuscular disease
- working dogs (labradors, pointers, setters, and foxhounds)
- strenuous exercise after period of under-conditioning, prolonged cage transport and cold weather
- transient tail flaccidity, painful on tail palpation
- treat with analgesia and anti-inflammatory
“limber tail”
coccygeal muscle injury
name the congenital (anomalous) neuromuscular disease
- springer spaniels, jack rusel terriers, smooth-haired fox terriers, Samoyeds, mini dachshunds
- recurrent and progressive muscle fatigue at 6-9 weeks old
- abnormal reduction in number of ACh receptors on muscle endplate
- diagnose with a muscle biopsy
congenital myasthenia gravis
name the congenital (anomalous) neuromuscular disease
- young adult labradors
- episodic limb weakness followed by ataxia and collapse 5-20 min after intense exercise, hyporeflexia during collapse
- mutation in Dynamin 1 (DNM1) gene which is involved in prolonged muscle stimulation
Exercise-Induced Collapse (EIC)
name the metabolic neuromuscular disease
- dogs and cats with diabetes mellitus
- symmetric pelvic limb LMN paresis (may extend to thoracic limbs), proprioceptive deficits, cats typically have plantigrade stance in PLs
- aetiology not fully understood, affects distal portions of peripheral nerves
Diabetic polyneuropathy
name the degenerative neuromuscular disease
- degenerative polyneuropathy of autonomic nervous system
- acute onset (dogs in rural area)
- mydriasis with absent PLR, third eyelid protrusion, dry MM, v+/regurgitation, megaoesophagus, dysphagia, dysuria , constipation (cats) or d+ (dogs)
- unknown pathogenesis
dysautonomia
are most brain tumours in dogs/cats primary or secondary?
primary
name 3 types of tumours originating from glial cells
- astrocytoma
- oligodendroglioma
- oligoastrocytoma
are the majority of meningiomas benign or malignant?
benign
based on the clinical signs, where is the brain tumour likely located?
- circling towards the side of the lesion
- pacing
- head pressing
- seizure activity
cerebral cortex
based on the clinical signs, where is the brain tumour likely located?
- altered mental state
- +/- Diabetes insipidus
- visual impairment )optic chiasma, optic II)
hypothalamus
based on the clinical signs, where is the brain tumour likely located?
- oculomotor (III) deficits
- strabismus
- pupil dilation
- contralateral spastic hemiparesis
midbrain
based on the clinical signs, where is the brain tumour likely located?
- irregular respiration
- paresis
- crania; nerve deficits (V, VI, VII, IX, X)
ventral brainstem
based on the clinical signs, where is the brain tumour likely located?
- head tilt
- circling
- nystagmus
- vestibular strabismus
vestibular region
based on the clinical signs, where is the brain tumour likely located?
- dysmetria
- ataxia
- wide-base stance
- intention tremor
cerebellum
what is a useful chemotherapy drug that is often used palliatively for a brain tumour since it can cross the BBB
Lomustine
name the spinal cord tumour
arise within the spinal cord;
tpyes:
* glial tumours
* metastatic tumours
* lymphoma
intramedullary
name the spinal cord tumour
arise from the connective tissue of the dura mater;
types:
* meningioma
* poorly differentiated tumour of young dogs
* peripheral nerve sheath tumours
* ependymoma (neuroepithelioma)
intradural extramedullary
name the spinal cord tumour
arise from connective tissue in the spinal cord/column;
types:
* primary bone tumours
* metastatic tumours
* lymphoma
* multiple myeloma
extradural
this type of therapy can induce ischaemic damage to the spinal cord and is therefore rarely performed to treat tumours
radiation therapy
what percent of cardiac output does the brain receive
15%
name the doctrine
the skull is a non-compliant closed ‘box’ filled with:
* brain parenchyma (84%)
* blood (4%)
* cerebrospinal fluid (16%)
increases in volume of one component must be compensated for by decreases in other components ;
failure to compensate results in increased intracranial pressure (ICP)
Monro-Kellie Doctrine
name the equation for cerebral blood flow
CBF = CPP/CVR
(cerebral blood flow = cerebral perfusion pressure / cerebral vascular resistance)
name the equation for cerebral perfusion pressure
CPP = MAP - ICP
(cerebral perfusion pressure = mean arterial pressure - intracranial pressure)
name the 4 determinants of cerebral blood flow
- CPP (cerebral perfusion pressure)
- PaCO2
- PaO2
- ICP
what range of MAP (mean arterial pressure) is CBF (cerebral blood flow) constant between
50-150 mmHg
what direction will the cerebral perfusion pressure (CPP) curve shift?
with chronic hypertension
shift to the right
what direction will the cerebral perfusion pressure (CPP) curve shift?
with anaesthesia OR reduced sympathetic tone
shifts to left
what will a CBF (cerebral blood flow) that is too high lead to
oedema and aneurysm
what will a CBF (cerebral blood flow) that is too low lead to?
tissue hypoxia
what is a normal ICP (intracranial pressure)
10-15 mmHg
name 5 ways to decrease ICP (intracranial pressure)
- elevate head <30 degrees
- analgesia
- hyperventilation
- cerebrospinal fluid drainage
- drugs (osmotic diuretics; barbiturates)
what is the major function of cerebrospinal fluid system
cushioning
name the anaesthetic
increases CSF production and inhibits reabsorption of CSF by the arachnoid villi
enflurane
name 5 clinical signs of raised ICP (intracranial pressure)
- neurologic changes
- nausea/vomiting
- papillary oedema
- anisocoria
- hypertension, bradycardia
name the 3 parts of Cushing’s triad
- increased MAP
- bradycardia
- altered breathing pattern
name the response/reflex
critical point is reached with increasing ICP (“cerebral hypoxic response”);
massive sympathetic discharge: neurogenic pulmonary oedema, neurogenic cardiomyopathy
Cushing’s Response
(Cushing’s Reflex)
name 4 possible pre-medications that can be used for anaesthesia for CNS disease
- alpha-2-agonists
- Acepromazine
- Opioids
- Benzodiazepines
name 2 induction agents that are preferrable for anaesthesia for CNS disease
- propofol
- alfaxalone
(over thiopental and ketamine)
what do isoflurane and sevoflurane disrupt at high concentrations?
therefore must be mindful when using with CNS disease
flow-metabolism coupling
name 5 analgesics that are suitable for CNS disease
- opiates
- lidocaine
- ketamine
- paracetamol
- NSAIDs
name the analgesic (suitable for CNS disease)
mainstay of analgesic approach;
premed, induction, intraoperative CRI, MAC reduction
opiates
name the analgesic (suitable for CNS disease)
useful at induction to reduce coughing;
MAC sparing effect of CRI;
local techniques
lidocaine
name the analgesic (suitable for CNS disease)
avoid in seizure disorders and intracranial disease;
useful as CRI for IVDD surgery;
good analgesic for surgical and chronic pain
ketamine
name the analgesic (suitable for CNS disease)
useful alternative to NSAIDs in the dog, must ensure NO liver disease;
very good adjunct to opiates and ketamine
paracetamol
