Neurology Flashcards
UMN functions
initiate voluntary movement
maintain tone (posture)
inhibit extensor mm (moderate activity)
LMN functions
link between CNS & effector muscles
direct innervation of effector mm
efferent motor tracks
brain to muscles
movement
afferent motor tracks
muscles to brain
coordination
what happens when something goes wrong with the motor tracts?
weakness, paresis or plegia
what happens when something goes wrong with the sensory tracts?
ataxia (reduced coordination)
when can you see both weakness and ataxia together? lesion in the ____
UMN spinal cord region
UMN signs
Paresis or paralysis of innervated muscles
↑ stride length
Normal to ↑ reflexes “hyperreflexia”
none/mild muscle atrophy, occurs slowly due to “disuse atrophy”
Normal to hypertonic/spastic muscle tone
+ standing/walking on dorsum of foot or dragging/scruffing foot “nail wear”
LMN signs
Paresis or paralysis of innervated muscles
↓ stride length
↓ to absent reflexes “hyporeflexia”
Severe, rapid muscle atrophy (5-7 days) “denervation atrophy”
hypotonic/atonia/flaccid muscle tone
paresis localizes to LMN and paralysis localizes to UMN
true or false
false
intention tremor
no proprioceptive deficits & paresis
wide based stance
irregular foot placement
dysmetria (hypermetria or hypometria)
ipsilateral absent menace
Cerebellar Ataxia
asymmetric gait
head tilt, circling
spontaneous nystagmus
proprioceptive deficits & paresis
Vestibular Ataxia
proprioceptive deficits & paresis
knuckling
long overreaching “solider marching”
UMN hypermetria
General Proprioceptive Ataxia
(caudal brainstem and spinal cord lesion)
Indications of multifocal lesions
LMN signs in both limbs
what part of the brain does proprioception
cerebellum & brainstem
what part of the brain does gait
brainstem & cerebrum
schiff sherington posture
lesion?
signs?
T3-L3 lesion - no prognostic significance
PL flexed, TL extended
forebrain lesion clinical signs
behavior change
contralateral blindness
ipsilateral head turn, body turn, circling, head press, pacing
deficits in contralateral limbs
contralateral facial hypoalgesia
seizures
what is the imaging modality of choice for the brain
MRI
CSF analysis contraindications
in absence of MRI
increased ICP
coagulopathy
cerebellomedullary cistern contraindicated with chiari-like malformation, AA instability or cervical trauma
cat ddx for forebrain disease of infectious origin
toxoplasma gondii
FIV
FeLV
FCov
CSF max volume
1ml/5kg
SRMA does NOT result in forebrain disease but may cause CSF abnormalities
true/false
true – results in neutrophillic, mononuclear or mixed pleocytosis
function of an EEG
assess forebrain activity
identifies seizures activity
DDX for forebrain diseases in older animals
intracranial neoplasia (most common is meningioma)
canine cognitive dysfunction (degenerative)
Slowly progressive, confusion, anxiety, loss of sleep-wake cycle, decreased pet-owner interaction
> 8 yr old dog
females & smaller breeds more common
disease?
canine cognitive dysfunction
treatment for intracranial neoplasia
prenisolone
treatment for canine cognitive dysfunction
MCT Diet, omega3, carnitoids, vitamin E & A
Selegiline
cognitive enrichment
levetiracetam
what are the DDX for any aged animal with forebrain disease due to metabolic dysfunction?
hypernatremia (>170-175)
hyponatremia (<125)
chronic hypernatremia treatment
corrected slowly 48-72 hrs
not faster than 0.5 mEq/L/hr
half or normal saline then 5% dextrose
acute hypernatremia treatment
5% dextrose
acute hyponatremia treatment
correct quick with normal saline
chronic hyponatremia treatment
what is the risk of rapid correction?
corrected slowly 48-72 hrs
normal saline
not faster than 0..5 mEq/L/hr
risk of central myelinolysis with rapid correction
younger animal DDX for forebrain diseases
hepatic encephalopathy
hypoglycemia
hydrocephalus
treatment for hepatic encephalopathy
IV fluids, enemas, lactulose, diet
antibiotics (metronidazole or potentiated amoxicillin)
Levetiracetam
small breed, toy breed or brachycephaic dog with domed shape head and fontanelles, obtundation, behavior abnormalities, difficulty training, decreased vision, circling and pacing
disease?
hydrocephalus
hydrocephalus diagnostic modality of choice & treatment
MRI
glucocorticoids
furosemide
omeprazole
acetazolamide
surgery
type of seizure:
sustained increase in muscle contraction followed by repetitive involuntary muscle contractions at a frequency of 2-3 seconds
tonic-clonic (most common)
type of seizure:
sudden brief involuntary contraction of a muscle or group of muscles
myoclonic
type of seizure:
sustained increase in muscle contraction lasting a few seconds-minutes
tonic
type of seizure:
regular repetitive myoclonus, involving the same muscle groups, freq 2-3 sec
clonic
type of seizure:
sudden loss of muscle tone
atonic
what are 3 forms of focal seizure
motor
autonomic
behavioral
idiopathic head tremor syndrome is found in what breeds
dobermans
english bull dogs
boxers
episodic falling due to paroxysmal hypertonicity is found in what breed
calvalier king charles spaniels
paroxysmal gluten sensitive dyskinesia (canine epileptoid cramping) is found in what breed
border terrier
causes of reactive seizures
metabolic or toxic
causes of structural epilepsy
inflammatory, neoplastic, traumatic
causes of idiopathic epilepsy
genetics
- diagnosis of exclusion
- dogs 6 mo - 6 yr
most common cause of reactive seizures in cats
hypoglycemia, hepatic encephalopathy and intoxication
most common cause of structural epilepsy in cats
hippocampal necrosis
criteria for starting treatment for seizures
structural epilepsy or reactive seizures
status epilepticus or cluster seizures
2+ seizures in 6 month period
post-ictal signs are severe or last longer than 24 hours
type of seizure:
seizure lasting > 5 min or >2 seizures without full recovery of consciousness
status epilepticus
type of seizure:
2 or more seizures within 24 hours
cluster seizures
only antiepileptic that is FDA approved in dogs? cats?
primidone
none in cats
phenobarbital
MOA:
steady state reached:
metabolism:
increased inhibitory effect of GABA
2-3 weeks
induces cytochrome P450 (contraindicated in dogs with hepatic dysfunction)
Potassium Bromide (KBr)
MOA:
steady state reached:
contraindications:
competes with Cl transporter, inhibits Na, membrane hyperpolarization
12 weeks
not used in cats due to eosinophillic bronchitis
must be given along consistent diet
don’t use in patients with kidney disease
Levetiracetam (keppra)
MOA:
indications:
unknown
AED of choice in PSS/liver disease
Zonisamide
MOA:
metabolism:
dose:
blocks propagation of epileptic discharges
metabolized by liver, use in dogs and cats
dose increased when used with phenobarbital
treatment for stopping seizures immediately
diazepam per rectum
midazolam intranasal
treatment if the patient is still seizing
phenobarbital then levetiracetam
treatment for breakthrough seizures
infusion of diazepam, midazolam, propofol
after 30 min of sustained seizure activity (prolonged status epilepticus) what drug do you use
NMDA receptor antagonists
= Ketamine + dexmedetomidine
Hansen type I IVDD
chondroid degeneration
nucleus pulposus extrusion
young/middle aged chondrodystrophic breeds (dachunds)
acute, painful
Hansen type II IVDD
fibroid degeneration
annulus fibrosus protrusion
older large breed (GSD)
chronic, painful
gold standard diagnostic for IVDD
MRI
treatment for IVDD
crate rest 4-8 weeks
medical management (pain)
surgery recurrent/persistent pain or unresp to conservative therapy
young, middle aged, active dog that is acutely (hours) painful, non-progressive clinical signs
fibrocartilaginous embolism (FCE)
DDX for a FCE
acute non compressive nucleus pulposus etrusion (ANNPE)
type I IVDD
young-middle aged, medium-giant breed dogs that have severe pain (spinal hyperesthesia), fever, inappetance, decreased mentation and reluctance to move
diskospondylitis
diskospondylitis diagnosis and treatment
radiographs (at 3 weeks) or MRI (right away)
cephalosporins
> 7 yr old german shepherd, boxer or corgi with insidious onset, slowly progressive, non-painful T3-L3 signs
degenerative myelopathy
middle aged-older german shepherd with DJD at L7-S2
lumbosacral syndrome
- bony proliferation = stenosis + type II disc protrusion
lumbosacral syndrome treatment
dorsal laminectomy
conservation therapy
2 types of caudal cervical spondylomyelopathy “wobbelers”?
- young great danes and mastiffs - degeneration/thickening of articular processes, dorsolateral compression
- older dobermans - hypertrophy of articular processes, dorsal and ventral compression
what breeds are predisposed to atlantoaxial instability and what are the 2 causes
toy breeds, < 1 yr
1. congenital malformation of C2
2. trauma of dens
