Neurology Flashcards
which cranial nerve damage are these clinical signs associated with
Blindness- no menace response
optic nerve damage
which cranial nerve damage are these clinical signs associated with
jaw drop
absent palate reflex- press palate and mouth should open
trigeminal
which cranial nerve damage are these clinical signs associated with
cannot close eyelid
lower lip hanging off , one sided mouth closure failure
facial
which cranial nerve damage are these clinical signs associated with
animal unable to swallow (test with tube) or cough (tracheal pinch)
disturbed rumen contraction
vagal
which cranial nerve damage are these clinical signs associated with
tongue hanging out of mouth, unable to retract
hypoglossal
what do neurological tests test for?
o Pinch the withers
o Tail reflex (touch perineum or perineal side of tail)
o Anus reflex (thermometer – contraction sphincter)
o Scrotal reflex (wrinkling of the scrotal skin when it is touched)
o Patella reflex (calves)
o Radio-carpal extensor reflex (calves)
o Pinch skin between claws – animal will bend leg
spinal reflexes
calves 1 week old
lack of colostrum
Diarrhoea, fever, anorexia, stiff neck, hyperaesthesia; spasmodic extension of limbs (when stimulated), muscle fasciculations; depression or ‘mania’, signs of pain when neck extended, tetraparesis, hyperflexia, circling, falling over; cranial nerves may be involved (nystagmus, facial palsy, blindness etc.); coma/fitting.
May present like hypomagnesaemia (‘staggers’)
ddx?
tx?
meningitis
antibiotics that penetrate BBB
trimethoprim, sulfonamide doxycycline
need to contact APHA neurological conditions?
lead poisoning aujeskys rabies BSE brain tumour
slower onset and more asymmetric signs
Initially vision loss/mydriasis in contralateral eye, may progress to compulsive walking, head pressing, circling, head tilt (towards lesion), depression or mania, coma.
When extending to base of the brain may give ‘cranial nerve signs’.
Later stages: hypertonicity, hyperflexia, opisthotonus, coma, convulsions.
brain abscess
tx for brain abscess
ABs as for meningitis
Domed cranium
Diffuse cerebral signs mania head pressing muscle tremor, convulsions blindness weakness
Hydrocephalus
breeds predisposed to hydrocephalus
holstein
jersey
friesian
guernsey
cause of cerebrocortical necrosis (CCN)
Absolute: thiamine deficiency in re ruminant claves
Relative: large amount of bacterial thiaminases produced (bacteria use up thiamine) when cows have overindulging on concentrates; bracken? Oral wormers?
which ages of cattle prone to CCN
6-18 months
Early signs: head up in the air and appear blind; diarrhoea (concentrates?); hyperesthesia and muscle tremors also possible.
Late signs: opisthotonos= star gazing, headpressing, strabismus, miosis, excitement,
repetitive chewing, facial twitching, nystagmus, head tilt, convulsions.
ddx?
CCN
how to diagnose CCN?
History: diet change, oral wormers recently, clinical signs+ response to tx
blood thiaminase
PME shows
brain pale,
swollen,
patchy yellow discolouration (accumulation of lipofuscin pigments in lipophages)
fluoresce under U.V light
ddx?
CCN
Tx of CCN
0.15mg/kg thiamine vitamin B1repeated every 4 hours for 24hrs
o Respond in 3-6 hours
Corticosteroids
Identify and rectify underlying cause
Thiamine-supplemented ration; introduce concentrates slowly