Neurology - FA Flashcards
how can you test un-conscious proprioceptive deficits
blindfold it - if it doesnt change motion when collides with obstacle - deficit.
what does the patatial reflex do and what does it test
press palate - mouth should open
tests trigem, v
what effects does a vagal lesions have
cant swallow, cough and rumenal contractions change (vagal indigestion)
*impt to know for sx as cows prod a lot of saliva!!
what are ‘cortical’ signs
Ataxia, proprioceptive deficit, blindness, circling, nystagmus, changes in behaviour/ conciousness, head pressing
what are cerebellar signs
imbalanced, wide based stance, head
tilt, dysmetria, nystagmus, tremors, hyperaesthesia
what dz may cause cortical signs - name a few
meningitis, CCN, Pb poisoning, nervous ketosis, hypo-Mg, salt poisoning
IBR, MCF, pseudorabies and rabies, BSE, hypovit-A, tumour/abscess
which of the dz causing cortical signs need reporting to AHVLA
Pb poisoning
Pseudorabies
Rabies
BSE
what are poss causes of meningitis in cattle, and signs
causes - extension/haematogenous inf. salmonella (calves) or pseudomonas mastitis (cows)
signs - pain, headpressing, d+, pyrexia, coma. ~staggers
how do you tx meningitis
IV, TPS, doxycycline, penicillin
dexamethasone
what causes CCN
vit b1 defic (thiamine)
- absolute (calves)
- relative (inc consumption of thiaminases, fish or brackens)
what is CCN and the signs
malacia or grey matter
signs - star-gazing/blindness, headpressing, nystagmus, head tilt, convulsions
how is CNN dx at PM
the lipofuscin fluoresces under UV, high thiaminase assay
how do you tx CCN
vit b1 (10mg/kg/4hrs)
csteroids and mannitol
rectify cause
Pb poisoning causes….
acute encephalopathy (cf horses)
what are the signs of Pb poisoning
depressed muscle fasciculations ataxia, blindness abdo pain + bloat, d+ convulsions coma + death
how do you tx Pb poisoning
phenobarb - to control fits
chelate Pb with EDTA
thiamine - mobilises itra-cellular Pb into the blood (less tox)
oral MgSO4 to precipitate Pb in GIT + stop abs
what are the signs of nervous ketosis
obsessive licking, head-pressing. signs are cyclical every 10hrs
what type of cow is classically at risk of hypo-Mg
beef suckler, 1mth after parturition
Mg stored, not ready for use and excreted in milk
spring (bad weather)
what are the signs of hypoMg
hyperexcitability muscle tremors staggers lat recumbancy + seizures death wi 1hr
what is the result of salt poisoning/water deprivation
Na deposits on brain - stop anaerobic glycolytic pathways
inc ICP
DH, depression, d+, star-gazing, head pressing,
what is aujeskys dz
pseudorabies
what are the signs of pseudorabies
VERY ITCHY HEAD
depression, circling, nystagmus. from pigs
what are the signs of rabies in cows
hyperexcitability, fear, depression, flaccid paralysis
what are the signs of ‘the occasional’ hydrocephalus in cows
failed drainage of CSF –> domed cranium, Inc ICP. mania, head pressing, tremors, convulsions
how do brain abscesses usually arise
extension from arcanobacterium pyogenes sinus inf
how do signs of meningitis and brain abscess vary
abscess = slwoer onset. 1 eye blindness –> walking, head pressing/tilt twd lesion, depression
late stages = CN involvmenent –> coma
what are the lesions formed by BSE
bstem vacuolisation
how does BSE ‘work’
PrP proteins are normal in CNS membranes. something triggers a change and this modification causes other PrP to change too –> degeneration of neurones
what are the signs of BSE
3-6yo
kg loss, head tossing, teeth grinding, fear, aggression and ataxia
what is necessary to be done for notifiable disease
if suspect - tell DEFRA
famer compensated
offspring traced and culled if dz confirmed
VO makes final call
why is BSE so hard to dx
cant do anything ‘live’
long incubation
PM - western blot, histopath, immunocytochem
what are the causes of hypovitA
animals on straw/cereal, indoor diets
of calves born to deficient dams
what are the signs of hypovit a (carotene)
thickened dura mater
bony growth in brain
inc CSF
retinal degen - no PLR
how do you treat hypovitA
give vit A - even in late stage, except in old cattle with severe ocular damage
400iu/kg
what can cause cerebellar hypoplasia
BVD inf (d90-170 gestation) in utero –> calf w hypoplasia
what area does a listeria monocytogenes infection affect
bstem
inf travelled from conjunctiva via trigeminal n and formed micro-abscesses there
what are the clinical signs of listeriosis
dull, not lip/cheek tone
ptosis of ear and eye
headpressing
how do you tx listeriosis
OTC/penicillin ++, aim to prevent progression, unlikely to mend deficits now
get rid of shitty soily silage
what are the causes of spinal fractures
calves
hypovit d
hypo ca
cu defic
what bacteria can cause spinal abscesses
s. aureus, pasterella haemoytica
fusobacterium necrophorum
desc spastic paresis and causes
assymetrically spasticity and hypertonia of extensor m (HL only)
only when standing
how can you tx spastic paresis of hL
neurectomy of tibial n (runs deep to gastrogneiums) dont cut the tibial n or lat sapheous
what is tetanus
caused by exotoxins from c. tetani found in soil/GIT
spores enter via wound or gi
anaerobic multiplication –> n-toxin
what are the clinical signs of tetanus
2-4wk incubation stiffness rumenal tympany prlapsed 3rd eyelid legs extended recumbancy - death
how can you tx tetanus
if fully dev - PTS
if starting - bed up warm and dark and quiet
anti-tox only helpful vvv early
penicillin +++
irrigate site of infection with both above
vaccinate
what are the signs of botulism
muscle weakness --> paralysis anoraxia, mydiasis drooling droopy face - tongue out dec rumen motility ,bloat resp failure = death
can botulinum be treated
if early yes - symptomatic and supportive - purge body of toxins
what are the casues of obturator neuropathies, ddx and also tx
dystocia (esp in heifers)
- foetus damages obturator, she cant adduct
ddx = pelvix fx
tx - csterios, chain together and soft bedding
what are the causes of peroneal neuropathies
branch of the sciatic over later stifle - damaged in falls or recumbant cows
- hyperext of hock, fetlock and digits
- loss of sensation here
- bandage
how can the sciatic nerve get damaged
recumbnt or struggling to get up
sigs = non-kg bearing, no sensation distal to stifle
