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
Cerebral and GI signs
First stages: stand alone and depressed; hyperaesthesia, muscular fasciculations
Progresses to ataxia, blindness (pupillary reflexes present), head pressing, episodic manic behaviour, convulsions, coma
Also abdominal pain, rumen atony (bloat), diarrhoea, frothing at the mouth
Severe will die 12-24 hrs; sudden death may also occur
lead poisoning
tx lead poisoning
Control fits with i.v. pentobarbitone (dose to effect)(care food chain)
Chelate lead CaEDTA slow drip every 2 nd day for 3 treatments
Thiamine subcut daily (mobilises intracellular lead into blood)
Oral magnesium sulphate to precipitate lead from GI tract
Acute onset of obsessive licking, circling, staggering, head pressing, pica, aggression (CARE)
Signs last 1-2 hours; recur at 10-hourly intervals
Dx: ketones blood or Rotheroes test
Nervous ketosis
tx for nervous ketosis
40% dextrose i.v, propylene glycol BID, corticosteroids
Hyperexcitable, may charge
Erect ears, ear twitching, hyperaesthesia
Muscle fasiculations / tremors
Frenzied running turning into staggering
Lateral recumbency with violent episodes of ophistotonus and convulsions (can be triggered by any stimulus CARE CAN INDUCE THE FITS IF NOISY/ ROUGH HANDLING)
Dead within an hour of the seizure episodes
Hypomagnesia
season when most likely to get hypomagnesia
spring> winter
sp/br hypomagnesia
pastured lactating beef cows in first months after calving
Dehydrated, depression, diarrhoea and colic, star-gazing, blindness, aggressiveness, hyperexcitability, vocalisation, head pressing, teeth grinding .
hisotry of water deprivation/ high salt
Salt poisoning
Depression, ataxia, conscious prioprioceptive deficit, circling, nystagmus, strabismus, aggression, pruritus (of the head), dead within 2 days.
Contact with pigs.
Pseudorabies
Hyperexcitability, fear, rage, depression, flaccid paralysis.
Try to moo but no sound comes out
rabies
Initial signs often subtle but always progressive, rate of progression variable 2-3 weeks to several months
Weight loss
Hyperaesthesia, fine fasciculations of head and neck shoulder flank, teeth grinding,
Apprehensive when approached, reluctant to be milked or moved through gate ways
Ataxia
Aggression
no diagnostic test, only histopathology, western blotting or immunocytochemsitry for PrPSC
BSE
Calves born to deficient dams – blindness, weakness, domed forehead, thickened carpal joints
Deficient calves – blindness, anorexia, diarrhoea, pneumonia (‘ill thrift’)
Older cattle – blindness, star gazing, nystagmus, ataxia (hind limbs first), convulsions; also diarrhoea and occasionally thickening and whitening of cornea.
Dx: pupillary light reflex
- Pale optic disc
hypovitaminosis
Febrile
Dull; loss of lip and cheek muscle tone: difficulty in eating chewing, accumulation cud in cheek, salivation, tongue protrude
Ptosis, drooping of ear on the deviant side, circling
Headpressing, propulsive walking
Infection travels up to brainstem from conjunctiva, face/mouth via trigeminal nerve
Listeriosis
tx of listeriosis
high dose penicillin
clinical signs of hypoplasia?
Balance (ataxia, falling backward) or unable to stand, tremor, hypermetria, nystagmus
Severe opisthotonus
breeds ore likely to get hypoplasia of cerebellum
Hereford, guernsey, holstein, shorthorn, ayrshire
Pain, heat, swelling; animals stiff, reluctant to eat from the ground;
if close to brain hyperaesthesia, spasmic muscle contractions, recurrent profuse sweating.
Treatment: antibiotics (see meningitis).
spinal abscess
Asymmetric spasticity and hypertonia of the extensor muscles of the rear limbs
Continuous when the animal stands but not when it lays down
due to excessive Tone of Gastrocnemius Muscle
spastic paresis
tx of spastic paresis
Neurectomy of the tibial nerve rootlets innervating the gastrocnemius muscle
cause of tetanus?
Clostridium tetani toxin
Stiffness, reluctance to move, muscle tremors
Prolapse 3 rd eyelid, RUMEN TYMPANY, elevation tail
Progression to generalized muscular tetany and “rocking horse” position
Recumbancy, convulsions, death
tetanus
dx of tetanus?
tx?
no test
more management, Animal well bedded kept in dark and quiet
- Antitoxin not much help unless very early.
- Penicillin high doses.
- Irrigation of infection site penicillin, antitoxin.
- Muscle relaxants?
Vaccination
Muscle weakness, progressing to ataxia and then paralysis
Anorexia, dilated pupils
Excessive drooling
Droopy expression, tongue may hang out of mouth
Decreased rumen motility, bloat, constipation
Respiratory failure leading to death
no sure diagnostic signs, smaples of feed and bedding may help
botulism
Clostridium botulinum
tx of botulism
supportive,
purgatives to remove toxins. Fluids.
cow just calved
unable to adduct limb (appears like doing splits)
ddx?
tx?
obturator nerve damage
chain legs , soft bedding , corticosteroids
Hyperextension of hock fetlock and digits flexed (knuckled over)
diagnosed by loss of skin sensation below fetlock dorsal surface
peroneal nerve damage
cow recumbent and struggling to rise
non weight bearing, no sensation distal to stifle
sciatic nerve damage
