Neurology Flashcards
Trauma: ↑↑ most often Abscess Cholesterol granuloma Verminous Infectious meningoencephalomyelitis Neoplasia Toxins Intracarotid injection Sleep disorders: narcolepsy, (can get secondary to orthopaedic disease) sleep deprivation Metabolic: HE, intestinal hyperammoniaemia, electrolyte imbalances Hepatic encephalopathy
causes of which type of neuro conditions?
forebrain disease
Disorders of behaviour and personality: aggression, compulsive walking, loss of learnt behaviour, yawning
Seizures – mostly rapid lip movement as most of forebrain controls lips.
Blindness
Altered states of consciousness:
- Alert → Quiet → Depressed → Obtunded → Comatose – Head posture (head and neck turn, head pressing)
- Not responding to painful stimuli
which region affected?
Forebrain
young arab horse with seizures, hypoxoa in birth
cause?
juvenile idiopathic arab epilepsy
trauma, idiopathic, otitis media/ interna- not as common as in small animals temporohyoid osteoarthopathy (THO)
disease caused in which region?
vestibular
Head tilt
Nystagmus
Ventral strabismus
Ataxia
which region affected?
vestibular
which region is affected if when blindfolded, the ataxia gets worse?
brainstem / vestibular
what is temporohyoid osteoarthopathy (THO)
tylohyoid fractures causing inflammation which impacts on nerves
dropped ear, ptosis, nostril deviation
left untreated: exposure keratitis, dysphagia and poor performance due to nostril collapse
cause?
facial nerve paralysis
CN VII and VIII
(brainstem)
what are the cranial nerves O O O T T A F G V A H
I. Olfactory nerve II. Optic nerve III. Oculomotor nerve IV. Trochlear nerve V. Trigeminal nerve VI. Abducens nerve VII. Facial nerve VIII. Vestibulocochlear nerve IX. Glossopharyngeal nerve X. Vagus nerve XI. Accessory nerve XII. Hypoglossal nerve
All on affected side
Miosis, enophthalmos, ptosis, protruding nictitating membrane
Hyperaemic membranes, sweating
caused by extravascular injection of irritant eg buscopan
» interuption of sympathetic innervation to head and neck
horners syndrome
what is miosis
pupil shrinkage, even in dark light
NO ANAL TONE/ ANYTHING AROUND ANUS AND TAIL
Degrees of hypotonia, hyporeflexia ad hypalgesia of the tail, anus and perineal region, urinary bladder paralysis, rectal dilation, penile prolapse
+/- LMN weakness and paresis of pelvic limbs
condition?
Cauda Equina syndrome
EHV 1 can cause which neurological condition?
Cauda Equina syndrome ± ataxia, ± cranial nerve sign
Encephalopathy
Sudden onset and early stabilisation of signs including ataxia, paresis, urinary incontinence (and rarely cranial nerve signs)
clinical signs result from vasculitis and thrombosis of arterioles in spinal cord and brain
can occur sporadically or as an outbreak
EHV-1 encephalopathy
is this type I or type II cervical vertebra malformation
Young horses ,
Compression as a result of developmental abnormalities
Dynamic stenosis – Any site
type 1
is this type I or type II cervical vertebra malformation
Older horses
OA of articular processes
Static stenosis
C5-C6 and C6-C7 most common
type 2
what is calculated to diagnose cervical vertebra malformation (CVM)
cervical vertebral ratio
can see if canal has actually narrowed
most common cause of ataxia in horses UK
cervical vertebra malformation
all 4 limbs
hindlimbs» affected than forelimbs
OA
changes in spinal angulation
ski jumps
are seen in which condition
CVM
what is the
Intravertebral sagittal diameter
narrowest spinal canal measurement (a) : widest part of vertebra body
(b),
a should be at least 50% of b
lower % suggests narrowing of canal.
what is the Intervertebral sagittal diameter
= between 2 vertebra
tx for type I CVM
dietary restrictions and surgery
tx for type II CVM
intraarticular corticosteroids US guided
what is occipito-atlantoaxial malformation
See fusion of back of skull and C1 and C2
Arab horses
horse is ‘shivering’ with snappy gait
snatches up hindlimb when picked up, flexes and holds
accentuated when turning or backing horse or if excited
Reflex hypertonia of flexor muscles of pelvic limbs
always progressive
draft breeds
what is sudden involuntary exaggerated flexion of one or both hindlimbs during attempted movement
2 types
stringhalt
which type of stringhalt is caused by dandelion, flat weed
australian or plant associated
which type of stringhalt is treated with myotenectomy of lateral digital extensor
sporadic stringhalt
which nerve is damaged if a horse has the inability to flex shoulder, extend the limb or fix the elbow
radial nerve
which nerve is damaged if a horse has the inability to abduct limb or advance shoulder
it is nicknamed sweeny/ shoulder slip
less common now, more in hard working draft horses pulling things
suprascapular nerve
Atrophy of supra- and infraspinatus,
horse has weight loss (muscle wasting- looks like greyhound ), muscle fasciculations, prolonged recumbency
Ocular signs in 30-40% cases: brown pigment accumulation in retina
ddx?
dx?
tx?
Equine Motor Neurone Disease
vit E and selium levels (low levels cause motor neuron degeneration)
vit E supplementation
cause of botulism in horses?
Clostridial botulinum B,C and D
hisotry of water with dead waterfowl in/ contaminated feed
Symmetrical weakness (muscle tremors) – Stumble, ataxi
Tongue weakness, dysphagia
Hang head, nose on ground
Eventually recumbent
Dyspnoea: intercostal and diaphragm paralysis – GI stasis, urine dribbling
causes shaker foal syndrome rarely
ddx?
tx?
botulism
Antitoxin (USA, expensive) – Penicillin don’t know if it helps (not procaine!) – Supportive, fluids.
initial episodes of trembling
foal dies in 10 days due to respiratory muscle paralysis
history of contaminated feed
shaker foal syndrome
botulism
Elevated tail head Stiff gait Anxious: ears back, eyelids wide open, nostrils flared, head extended Lock jaw: drool, can’t swallow Prolapse 3rd eyelid Recumbency, rigidity Secondary ulcers, trauma
ddx?
tetanus
treatment for tetanus if unvaccinated
antioxin
toxoid
treatment for tetanus if vaccinated
tetanus toxoid vaccine
vaccine for tetanus
how often booster
toxoid
yearly
supportive treatment for tetanus in unvaccinated
muscle relaxation: acepromazine, diazepam
quiet dark environment
eliminate source
metronidazole to combat source
source of tetanus
gram positive anaerobic bacteria
sporulates in wounds and releases toxins
hence worry about tenanus if open wound, as provides right environment for this sporulation to occur
