Neurology

Question 1

Forebrain, brainstem and cerebellum functions

Answer 1

forebrain - recognition of special senses, behaviour

brainstem - cranial extension of spinal cord, midbrain and hindbrain and cranial nerves - reaction to environment, damage will cause depressed mentation

cerebellum - fine movement control

Question 2

neuro exam - equine - behaviours

Answer 2

may indicate forebrain disease

seizures - specific to forebrain
head pressing
wondering
circling
changes in voice
changes in appetite
licking
aggression
yawning
blindness

Question 3

neuro exam - equine - mental state

Answer 3

RAS and forebrain

lowered awareness
lowered conciousness

Question 4

neuro exam - equine - head position

Answer 4

peripheral vestibular, central, cerebellar, MSK, or neuromuscular

head tilt
neck turn

Question 5

cranial nerve exam - equine

Answer 5

1 - olfactory - can’t really test

2 - optic - sight
menace response, PLR, swinging light test - PLR needs nerve intact before chiasm, swinging light test after

3 - occulomotor - PLR, eye position and movement

4 and 6 - trochlear and abducens - eye position and movement

5 - trigeminal - sensation to face, motor to mastication muscles

7 - facial - muscles of facial expression - asymmetry, often more pronounced at muzzle, eyelid palpation may be useful

8 - vestibulocochlear - head posture, induced eyeball movement/normal vestibular nystagmus, normal gait, blindfold (exacerbates head tilt), hearing - weakness towards side of lesion

9-12 - swallowing and tongue - pull out tongue and assess for tone and symmetry, observe swallow after tongue replaced

Question 6

upper motor neurone injury

Answer 6

spinal cord, brainstem to synapse with lower motor neurons at spinal cord

inhibit, modulate and control gait

increased muscle tone
increased reflexes
no atrophy
variable weakness

Question 7

lower motor neurone injury

Answer 7

spinal cord grey matter and peripheral nurves

cervical - forelimbs
lumbosacral - hindlimbs

decreased muscle tone
decreased reflexes
muscle atrophy
weakness
sensory loss

Question 8

motor neurone exam

Answer 8

ataxia - wide based stance
weakness - narrow based stance, paresis, mypometria, recumbency, postural deficits
hyperreflexia
increased muscle tone
hyporeflexia
decreased muscle tone
atrophy

Question 9

cervical vertebral malformation - equine

Answer 9

most common spinal cord disease
initial loss of proprioception
progresses to paresis and motor weakness
to loss of sensory perception and loss of pain

Question 10

ataxia - testing - equine

Answer 10

proprioceptive deficits
whole body or specific limb

poor coordination
swaying
excessive limb movement in swing phase
weaving
abduction
crossing limbs
stepping on themselves

signs exacerbated by tight circles, sudden stoppin, backing up, and going up and down hills

lift head so can’t watch their feet when testing

Question 11

weakness (paresis) - testing - equine

Answer 11

hoof wear - sign of dragging toes, hypometria
generalised weakness
prefer walking to standing still - have to fix muscles to stand still
hopping
circling
trembling
buckling of weak limb
knuckling over
localised weakness - lower motor neurone or peripheral
weakness and ataxia - upper motor neurone
generalisied weakness with no ataxia - neuromuscular

tail pull - reflex - at rest tests upper motor neurone, walking tests lower

Question 12

lesion localisation

Answer 12

C1-6 - UMN signs in both fore and hindlimbs

C7-T2 -
LMN signs in forelimb - weakness
UMN signs in hindlimb - ataxia

T3-L3 -
no forelimb signs
UMN signs in hindlimb

L4-S3 -
no forelimb signs
LMN signs in hindlimb

S3-end -
normal forelimbs and hindlimbs

Question 13

classification of spinal cord deficits

Answer 13

1 (+) - subtle
barely detectable at normal gait, may be seen during backing, stopping, turning, swaying etc

2 (++) - mild
can be seen at normal gait but exaggerated with maneuvers

3 (+++) - moderate
prominent deficits at normal gait, can buckle and fall during maneuvers

4 (++++) - severe
spontaneous tripping and falling at normal gait, can present as complete paralysis

forelimbs often a grade lower than hindlimbs with focal cervical or brainstem lesions

Question 14

hindlimb and brainstem signs

Answer 14

behaviour issues
seizures
blindness
coma
altered consciousness
head posture
some ataxia in conscious maneuvers

Question 15

perinatal asphyxia syndrome - equine

Answer 15

in utero hypoxia or interruption of oxygen supply during birth
hypoxic lesions in multiple organs
ischemia, oedema, and reperfusion injury to various organs

dummy foals
may not be obvious until 12-24 hours
severe cases - central respiratory depression

mild - unable to latch, poor suck reflex
moderate - aimless wandering and abnormal voalisations
severe - seizure

good prognosis with nursing care - up to 2 weeks - nutrition, antibiotics, eye care, gastric ulcer medication, protection from walking into things

Question 16

neonatal seizures and epilepsy - equine

Answer 16

trauma
sepsis
secondary to anemia, hypoglycemia, metabolic

benign epilepsy of foals - arabs up to 12 months, low seizure threshold

Question 17

cerebellar hypoplasia - equine

Answer 17

signs at birth or within first 6 months
developmental abnormality
usually arabs
sometimes dummy foals get this as well

signs -
intention tremor
loss of fine motor control
ataxia
wide based stance
still have full strength and otherwise alert

no treatment - euthanasia

Question 18

brainstem or cranial nerve disease

Answer 18

vestibular
facial nerve paralysis - common, associated with head collars or hitting head
ocular abnormalities - eg horners
pharyngeal/laryngeal nerve deficits - dysphagia
trigeminal neuritis - headshaking

Question 19

vestibular disease - equine

Answer 19

usually caused by trauma or otitis media/interna
can lead to temperohyoid/stylohyoid osteoarthropathy

signs - lead towards side of lesion, ataxia, nystagmus

radiography/CT to diagnose otitis
guttural pouch endoscopy - look for changes in stylohyoid bones

Question 20

dysphagia - equine

Answer 20

commonly associated with guttural pouch disease
less common to have neurological presentation
cranial nerves and internal carotid in guttural pouch

also lead poisoning

horners
accumulation of crud around nose from dysphagis

Question 21

facial nerve paralysis - equine

Answer 21

commonly iatrogenic from halter
or from trauma

prolonged deficits - eye injury, keratitis/dry eye, dysphagia, feed pouching, poor performance (nostril collapse)

Question 22

horners sundrome - equine

Answer 22

usually iatrogenic causes - extra vascular injection of irritant
loss of innervation to one side of the head
sweating to level around C2
drooping on one side
some myositis
protruding third eyelid
enophthalmus

Question 23

trigeminal neuritis - equine

Answer 23

headshaking - abnormal, rapid, vertical head flicking (like trying to get bee out of nose)
may rub nose on ground
nostril clamping during exercise
seek shady areas
stick nose under horses tails

in severe cases may hit themselves and cause damage

grades -
0 - no shaking
1 - shaking at exercise but not enough to interfere with riding
2 - shaking at exercise too much to be safe riding
3 - shaking even at rest

diagnosis by exclusion of other causes - nothing up the nose, no nostril inflammation, check ears, teet, temperomandibular junction

treatment - nose nets, gabapentin, antihistamines, percutaneous nerve stimulation treatment (PENS - most common treatment)

Question 24

spinal trauma - equine

Answer 24

sudden onset ataxia or recumbency
sometimes will have observed incident

often see improvement so should wait and see if they get better
can have initial improvement then worsening as scar tissue forms

most commonly atlanto-occipital-axial region, caudal cervical, or mid back (less common, needs significant force)

signs vary - ataxia and paresis to recumbency
focal or diffuse sweating
may be panicky

Question 25

cervical vertebral malformation - equine

Answer 25

multifactorial causes - congenital and familial aspects usually large rapidly growing horses with unrestricted diet related to developmental orthopedic disease - may see this in other joints ataxic with wide based stance neck pain not common sweating types of lesions - stenosis - narrowing of vertebral canal - may only be evident in one position abnormal articular processes subluxation on flexion or extension of neck enlarged vertebral physeal growth regions overriding of vertebral arch and next cudal vertebral body proliferation of articular and soft tissues may be able to see on radiography, CT better management - surgery possible but don't really do it early detection and dietary restrictions best prognosis poor for riding the horse once disease advanced

Question 26

cauda equina syndrome - equine

Answer 26

affects sacrococcygeal spinal cord segments - to bladder, rectum, anus, tail and perineum incontinence flaccid anal, perineal and tail tone penile prolapse weakness and paresis of pelvic limbs causes - trauma - breeding infectious - polyneuritis equi, EHV-1 toxic - sorghum rare congenital abnormalities neoplasia

Question 27

EHV-1 management

Answer 27

localise lesion rule out other causes history of respiratory signs or abortion isolate can recover with good nursing carer better prognosis if not recumbent - if down for more than 24 hours then prognosis poor may see residual deficits for a year can cause cauda equina syndrome

Question 28

peripheral nerve and neuromuscular disease - equine

Answer 28

localised weakness - peripheral nerve diffuse weakness - neuromuscular abnormal hind limb gait - shivering and stringhalt generalised tetany - tetanus prognosis depends on degree of damage to the nerve - neuropraxia - loss of function only - may resolve in 14 days axonotmesis - severence of axons - 6 months neurotmesis - severence of entire nerve fibre - prolonged or permanent loss of function scarring and fibrous tissue can lead to permanent worsening of nerve injury brachial plexus injury - shoulder and carpus involvement radial nerve - more albow sweeney - suprascapular nerve trapped support other limbs to prevent weight bearing laminitis

Question 29

equine motor neurone disease

Answer 29

neuromuscular generalised weakness trembling hungry weakness but not ataxia shifting weight reluctance to stand still elevation of tail head diagnosis - signs mild muscle enzyme increase low serum vitamin E muscle biopsy of tail head muscle - atrophy retinal lipopigment deposits treatment - vitamin E supplement, physio often not fixable

Question 30

botulism - equine

Answer 30

clostridium botulinum - contaminated feed, water, or in ingesta of suckling foals blocks acetylcholine at presynapses flaccid paralysis of skeletal muscle classic tongue paralysis --> respiratory depression

Question 31

stringhalt - equine

Answer 31

hyperreflexia in hindlimb - classic stringhalt - unilateral toxic stringhalt - bilateral can recover from classic form - take off pasture, takes about 18 months

Question 32

tetany - equine

Answer 32

distressed face flared nostils elevated tail head stiffness third eyelid pulled across clostridium tetani entrance through wound muscles continuously contracting, often elicited by sound, light and touch poor prognosis can try antitoxins toxin increases necrosis at wound site of entry

Question 33

sections of the vetebrae

Answer 33

C1-C5 - neck C6-T2 - cervical intumescence - thoracic limbs T3-L3 - thoracolumbar - trunk L4-S3 - lumbosacral intumesence - pelvic limbs Cd1-end - tail

Question 34

toxins that cause seizures

Answer 34

xylitol raisins chocolate alcohol cannabis

Question 35

stage of seizure

Answer 35

pre-ictal - altered behaviour ictal - actual seizure - lack of response to external stimuli, involuntary urination post-ictal - disorientation

Question 36

post seizure exam

Answer 36

temperature - hyperthermia --> more seizures neuro exam - check for deficits (over 5 mins or cluster seizures can cause lasting brain damage), check for signs of CNS neoplasia gait - any signs of weakness or ataxia

Question 37

categorising neuro lesions - 5 finger rule

Answer 37

localisation - location in CNS lateralisation pain/non painful progression - progressive/stable/improving onset - chronic/acute/peracute

Question 38

ddx for seizures

Answer 38

toxins idiopathic epilepsy thromboembolism neoplasia - meningioma, glioma, lymphoma haemorrhage - increased intracranial pressure immune mediated meningitis - bacterial, viral, protozoan (neospora) trauma hydrocephalus - big head chihuahua liver disease - and any metabolic disease affecting the liver pancreatic disease - insulinoma

Question 39

diagnostics for seizures

Answer 39

MRI - mass bloods - liver - liver enzymes - bile acid stim, albumin, bilirubin, clotting pancreas - blood glucose anemia serology - specific disease testing c reactive protein - raised if lots of inflammation CSF tap - neutrophilia and bacteria in spinal fluid - bacterial meningitis

Question 40

treatment - idiopathoc epilepsy

Answer 40

consider frequency and length of seizures cluster seizures particularly bad diazepam - reduces electrical seizure in brain when already having seizure phenobarbitol - takes 3 weeks to work properly, hepatotoxic potassium bromide - alongside other drugs, lots of side effects once on them have to stay on forever all options have side effects - sedation, liver toxicity, ataxia, PUPD, weakness, behaviour changes

Question 41

ddx vestibular syndrome

Answer 41

otitis neoplasia encephalitis antibiotic reaction thiamine deficiency head trauma hypothyroidism idiopathic vestibular disease head tilt towards side of lesion fast phase nystagmus away from side of lesion

Question 42

IVDD - hansen type 1

Answer 42

nucleus pulposus broken out of disc completely acute and explosive onset around age 2 mostly at thoracolumbar junction painful over time - haemorrhage, necrosis, infarcation most common sausage dog type

Question 43

IVDD - hansen type 2

Answer 43

bulge of disc but not complete break out usually at only one site more chronic painful - neck pain more apparent than lower back can lead to nerve root compression - very painful, radiating down nerve older dogs terriers, dalmation, GSDs

Question 44

IVDD - cervical myelopathy

Answer 44

wobbler syndrome large and giant breeds weakness and ataxia, first seen in pelvic limbs lameness and stiffness in thoracic limbs neck pain and stiffness - more obvious than lower back weird posture - wobbly back legs reduced proprioception 2 types - disc associated - middle aged dobermans - hypertrophy of annulus (abnormally shaped disc) bone associated - youn great danes - bone malformation and osteoarthritis, multiple levels often affected (overgrowth of bone around spinal cord) handling can cause ongoing damage

Question 45

IVDD - grading

Answer 45

1 - painful, no neuro deficits 2 - painful, wobbly but ambulatory 3 - non ambulatory but in tact motor function if needed 4 - no motor function, in tact deep pain 5 - no motor and deep pain gone

Question 46

IVDD - management

Answer 46

conservative - cage rest, anti-inflammatories, analgesia, bladder management grades 1-2 or if surgery not possible surgery - fenestration - more simple, prophylactic to prevent further, doesn't penetrate spinal canal decompressive surgery - enter spinal canal to remove extruded material

Question 47

fibrocartilaginous embolism

Answer 47

large breeds + mini schnauzers and shelties sudden onset vocalisation - acute pain knuckling, weakness, collapse - one or more limbs, progressing for first 24 hours cause - piece of fibrocartilage goes intramedullary and causes acute vascular injury and embolism medical management - NSAIDs, steroid can't operate absence of deep pain is a poor prognostic sign cen develop ascending damage - can't be treated

Question 48

chronic degenerative radiomyelopathy

Answer 48

chronic hind limb dysfunction pain wobbling loss of proprioception scuffing toes (similar to ALS in humans) usually progress to non-ambulatory in a year large breeds need CT and MRI to diagnose lots of differentials - hip dysplasia, disc disease, spinal tumours

Question 49

atlanto-axial instability

Answer 49

young, toy breeds cervical pain - ddx for hansen 1 IVDD lesion at C1-C5 - all 4 legs, can cause tetraplegia and respiratory distress usually acute trauma from fall or RTA keep neck supported management - mild - medical - rest, NSAIDs, 6-8 week neck brace severe - surgery - high risk of complications

Question 50

Neoplasia - spinal

Answer 50

primary - meningioma, glioma, nerve sheath tumours (forelimb problems, axillary pain), lymhoma secondary - rich cancellous bone site, common for mets - first sign of neoplasia can be spine fracture

Question 51

hypervitaminosis A

Answer 51

cats fed too much liver - chronic lethargy poor coat - stiff so don't want to groom constipation anorexia stiffnedd/reluctance to move new bone formation around spine, compresses spinal cord and nerve roots makes movement difficult and painful

Question 52

discospondylitis

Answer 52

infection of disc and vertebral endplates hematogenous spread - bite wounds, foreign bodies, surgical site infection middle aged large breeds gradual onset pain stiffness ataxia sometimes paresis pyrexia ataxia in chronic cases management - cage rest, antibiotics, NSAIDs, surgery - decompress, debride and collect samples prognosis fair to good but poor if fungal infection