Neurology

Question 1

which cranial nerve damage are these clinical signs associated with

Blindness- no menace response

Answer 1

optic nerve damage

Question 2

which cranial nerve damage are these clinical signs associated with

jaw drop
absent palate reflex- press palate and mouth should open

Answer 2

trigeminal

Question 3

which cranial nerve damage are these clinical signs associated with

cannot close eyelid
lower lip hanging off , one sided mouth closure failure

Answer 3

facial

Question 4

which cranial nerve damage are these clinical signs associated with

animal unable to swallow (test with tube) or cough (tracheal pinch)
disturbed rumen contraction

Answer 4

vagal

Question 5

which cranial nerve damage are these clinical signs associated with

tongue hanging out of mouth, unable to retract

Answer 5

hypoglossal

Question 6

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

Answer 6

spinal reflexes

Question 7

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?

Answer 7

meningitis
antibiotics that penetrate BBB
trimethoprim, sulfonamide doxycycline

Question 8

need to contact APHA neurological conditions?

Answer 8

lead poisoning 
aujeskys 
rabies
BSE
brain tumour

Question 9

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.

Answer 9

brain abscess

Question 10

tx for brain abscess

Answer 10

ABs as for meningitis

Question 11

Domed cranium

Diffuse cerebral signs mania head pressing muscle tremor, convulsions blindness weakness

Answer 11

Hydrocephalus

Question 12

breeds predisposed to hydrocephalus

Answer 12

holstein
jersey
friesian
guernsey

Question 13

cause of cerebrocortical necrosis (CCN)

Answer 13

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?

Question 14

which ages of cattle prone to CCN

Answer 14

6-18 months

Question 15

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?

Answer 15

CCN

Question 16

how to diagnose CCN?

Answer 16

History: diet change, oral wormers recently, clinical signs+ response to tx

blood thiaminase

Question 17

PME shows

brain pale,
swollen,
patchy yellow discolouration (accumulation of lipofuscin pigments in lipophages)
fluoresce under U.V light

ddx?

Answer 17

CCN

Question 18

Tx of CCN

Answer 18

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

Question 19

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

Answer 19

lead poisoning

Question 20

tx lead poisoning

Answer 20

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

Question 21

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

Answer 21

Nervous ketosis

Question 22

tx for nervous ketosis

Answer 22

40% dextrose i.v, propylene glycol BID, corticosteroids

Question 23

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

Answer 23

Hypomagnesia

Question 24

season when most likely to get hypomagnesia

Answer 24

spring> winter

Question 25

sp/br hypomagnesia

Answer 25

pastured lactating beef cows in first months after calving

Question 26

Dehydrated, depression, diarrhoea and colic, star-gazing, blindness, aggressiveness, hyperexcitability, vocalisation, head pressing, teeth grinding . hisotry of water deprivation/ high salt

Answer 26

Salt poisoning

Question 27

Depression, ataxia, conscious prioprioceptive deficit, circling, nystagmus, strabismus, aggression, pruritus (of the head), dead within 2 days. Contact with pigs.

Answer 27

Pseudorabies

Question 28

Hyperexcitability, fear, rage, depression, flaccid paralysis. Try to moo but no sound comes out

Answer 28

rabies

Question 29

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

Answer 29

BSE

Question 30

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

Answer 30

hypovitaminosis

Question 31

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

Answer 31

Listeriosis

Question 32

tx of listeriosis

Answer 32

high dose penicillin

Question 33

clinical signs of hypoplasia?

Answer 33

Balance (ataxia, falling backward) or unable to stand, tremor, hypermetria, nystagmus Severe opisthotonus

Question 34

breeds ore likely to get hypoplasia of cerebellum

Answer 34

Hereford, guernsey, holstein, shorthorn, ayrshire

Question 35

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).

Answer 35

spinal abscess

Question 36

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

Answer 36

spastic paresis

Question 37

tx of spastic paresis

Answer 37

Neurectomy of the tibial nerve rootlets innervating the gastrocnemius muscle

Question 38

cause of tetanus?

Answer 38

Clostridium tetani toxin

Question 39

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

Answer 39

tetanus

Question 40

dx of tetanus? tx?

Answer 40

no test more management, Animal well bedded kept in dark and quiet 1. Antitoxin not much help unless very early. 2. Penicillin high doses. 3. Irrigation of infection site penicillin, antitoxin. 4. Muscle relaxants? Vaccination

Question 41

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

Answer 41

botulism Clostridium botulinum

Question 42

tx of botulism

Answer 42

supportive, | purgatives to remove toxins. Fluids.

Question 43

cow just calved unable to adduct limb (appears like doing splits) ddx? tx?

Answer 43

obturator nerve damage chain legs , soft bedding , corticosteroids

Question 44

Hyperextension of hock fetlock and digits flexed (knuckled over) diagnosed by loss of skin sensation below fetlock dorsal surface

Answer 44

peroneal nerve damage

Question 45

cow recumbent and struggling to rise | non weight bearing, no sensation distal to stifle

Answer 45

sciatic nerve damage