Neuro Flashcards
brain oedema
flattened gyri
cerebellar coning - herniation
vascular occulsion
wallerian degeneration
response of axons and myelin to injury
swollen axon
degeneration of myelin sheath
macrophage infiltration
proximal and distal axon degeneration
neuronal cell body degeneration
anything causing spinal cord compression - IVDD, cerebral compression
thiamine deficiency
cerebrocortical necrosis
usually caused by sudden shift to concentrates or sulphur contamination of food or water
signs -
wandering, circling, cortical blindness, incoordination, head pressing, recumbancy, nystagmus, seizure
post mortem - swelling in brain, flourescence
copper deficiency
lambs
congenital - sway back
acquired (as neonate) - enzootic ataxia
signs - ascending paresis, ataxia
caused by myelin degeneration
post mortem - collapsed brain, symmetrical cavitation of white matter
tetanus
blocked transmission of nerves to muscles
muscle stiffness and spasm
protruding third eyelid
sweating
over reaction to bright lights or loud sounds
botulism
clostridium botulinum
muscle paralysis - difficulty chewing and swallowing
death due to paralysis of lungs or heart
TSEs
BSE - cattle - notifiable
Scrapie - sheep and goats - notifiable
chronic wasting disease - deer - notifiable
camelid prion disease - camelids
transmissible mink encephalopathy - mink
classical and atypical forms
classical -
transmissible - vertical and lateral
affects multiple animals
wide age range
detectable in lymph tissue - distal ileum and various nodes
atypical -
spontaenous
single animals affected
older animals
not detectible in lymphoid tissue
pathogenesis -
prion uptake into GIT
spread to CNS - vagal nerve, lymphoid or hematogenous spread
prions to obex in brain
spread to periphery
atypical - spontenous accumulation in brain
needs susceptibility gene
signs -
progressive neurological disease
changes in behaviour, sensation, and movement
(atypical - difficulty rising and positive scratch test)
diagnosis -
ELISA - no anatomical context
IHC - has anatomical context
routes of nervous system infection
hematogenous - thrombotic meningoencephalitis, cryptococcus, strongylus vulgaris
direct extension - otitis media, aspergillosis, trueperella pyogenes, brucells (via spine)
retrograde axonal transport - listeria monocytogenes, rabies - transport up neuronal axons
leukocyte trafficking - in macrophages
hydrocephalus
increased fluid in ventricles
usually congenital
deformed skull
signs - head pressing, inappetence, seizures, lethargy, altered mental state
BVD
hydraencephaly
formation of cavity, filled with CSF
destruction of developing neural tissues
signs - lethargy, circling, head pressing, blindness
bluetongue, schmallenberg, akbane virus
porencephaly
cystic structures in neutropil
akbane virus, BVD, malignant cathharal fever
bluetongue and schmallenberg CNS findings
cerebellar hypoplasia
arthrogryposis
hydraencephaly
aujeszky’s
pigs
herpes suid - viral inclusions
“mad itch”
signs - respiratory, dermal, neuro, repro
myasthenia gravis
pathogenesis - reduced function of acetylcholine receptors
lack of communication from nervous system to muscle
brief relief when given chloride (tensilon test)
acquired - autoantibody production
congenital - gene mutations
rule out myopathy - CK levels
radiography for megaoesophagus
horner’s
loss of sympathetic innervation to adnexa and globe of eye
3 potential sites -
1 - brain stem - T1-3
2 - T1-3 and joining vago-sympathetic trunk
3 - cranial cervical ganglion joining trigeminal nerve
signs - 3rd eyelid protrusion, ptosis (dropping eyelid), miosis (small pupil)
cause by species -
dog - idiopathic
cat - otitis media, nasopharyngeal, iatrogenic
horse - guttural pouch mycosis
diagnosis -
penyleprine in eyes - response in affected eye (mydriasia)
head radiography or CT
guttural pouch scope
equine grass sickness
clostridium botulinum
degeneration of neurons in brain, ganglia and enteric nervous system
adult horses at grass
signs - tachycardia, ileus, colic, bilateral horners
biopsy - biopsy (rectal or ileal), histology of cervical ganglion post mortem
listeria monocytogenes
sepsis, meningitis/meningoencephalitis, corneal ulcer, abortion, still birth
unilateral clinical signs - drooling, facial paralysis, micro abscesses
transmission to CNS in macrophages from GIT or retrograde axonal transport up vagus nerve
from contaminated silage via damage to oral mucosa
nervous system neoplasms
nervous system disorders caused by vascular disease
infarction cause by IVDD or orthopedic surgery
CKD or cushings - through causing hypercoagulability
feline hypertension encephalopathy or feline ischemic encephalopathy
west nile virus
necrosis in grey matter
signs - incoordination, hind limb weakness, inability to stand, muscle weakness, muscle twitching, blindness, sudden death
blood test
vax available
indications for cerebrospinal tap
suspicion of inflammatory or neoplastic lesions in CNS
don’t do collection high up if signs of brain herniation
advantages - often useful diagnostic findings
disadvantages - may be non-specific, need GA, risk of herniation or convulsions
test with PCR for infectious disease - neospora
histophilus somni
calves
thrombotic meningioencephalitis
cryptococcus
cats
neoformans and gati (infectious)
strongylus vulgaris
horse
