Neurology Problem-Based Studies Part I

Question 1

what are the top differential diagnoses for an equine with peripheral vestibular disease?

Answer 1

temporohyoid osteoarthropathy
otitis media-interna
extension of guttural pouch infection
trauma

Question 2

what is the mentation with central vestibular disease?

Answer 2

depressed

Question 3

what are some multifocal (central) diseases?

Answer 3

polyneuritis equi
equine herpesvirus
equine protozoal myeeloencephalitis

Question 4

what is temporohyoid osteoarthropathy?

Answer 4

disorder of temporohyoid joint formed by the stylohyoid and petrous temporal bones
progressive osseous proliferation
fusion of temporohyoid joint
stress fracture

Question 5

what is conservative management of temporohyoid osteoarthropathy?

Answer 5

steroidal/nonsteroidal anti-inflammatory drugs
maybe antimicrobials

Question 6

what are the surgical options for temporohyoid osteoarthropathy?

Answer 6

partial stylohyoidectomy
ceratohyoidectomy: standard

Question 7

what is otitis media/interna?

Answer 7

pyogenic infection of petrous temporal bone or membranous labyrinths

Question 8

how is otitis media/interna treated?

Answer 8

antimicrobial therapy (usually empirical)
NSAID
rest

Question 9

what can cause otitis media/interna in camelids?

Answer 9

Arcanobacter (Actinomyces) pyogenes
Staphylococcus spp
Bacillus spp
spinous ear ticks

Question 10

what are the most common causes of central vestibular disease in camelids?

Answer 10

Listeria
P. tenuis
eastern equine encephalitis/western equine encephalitis

Question 11

how is listeriosis in camelids treated?

Answer 11

high doses penicillin or ampicillin
tetracycline may carry higher resistance
long-term treatment
supportive care, anti-inflammatories

Question 12

what does the cerebellum do?

Answer 12

regulator of motor activity
receives input from upper motor neurons, general proprioceptive, and special proprioception

Question 13

what are the etiologies of equine cerebellar disorders?

Answer 13

cerebellar hypoplasia
transient cerebellar dysfunction
cerebellar abiotrophy

Question 14

what cranial nerve deficits can be present in central vestibular disease?

Answer 14

V-XII

Question 15

what cranial nerve deficits can be present in peripheral vestibular disease?

Answer 15

VIII +/- VII

Question 16

when are GP deficits and postural reaction deficits seen with vestibular disease?

Answer 16

only central: ipsilateral for both
GP if motor or GP systems involved

Question 17

what are the differentials for central vestibular disease?

Answer 17

multifocal disease
lightning strike
trauma

Question 18

what are the proposed etiologies of temporohyoid osteoarthropathy?

Answer 18

chronic inflammation, primary degenerative
repetitive microtrauma- cribbing
infection of middle/inner ear

Question 19

what is the goal of surgery for temporohyoid osteoarthropathy?

Answer 19

reduce load on temporohyoid articulation
decrease pain and prevent fracturee or refracture of petrous-temporal bone

Question 20

what is the proposed etiology of otitis media/interna?

Answer 20

hematogenous spread
extension from otitis externa and tympanic membrne unlikely
extension of guttural pouch infection unlikely

Question 21

is central or peripheral vestibular disease more common in camelids?

Answer 21

central

Question 22

what is listeriosis associated with?

Answer 22

diffuse suppurative meningoencephalitis

Question 23

what is Listeria moncytogenes?

Answer 23

gram positive
facultative intracellular

Question 24

what are the clinical signs of equine cerebellar disorders?

Answer 24

cerebellar ataxia
intention tremors
hypermetria and/or spasticity
no paresis if puree cerebellar

Question 25

what causes cerebellar abiotrophy?

Answer 25

autosomal recessive arabians most commonly inherited metabolic defect of cortical cerebellar neurons

Question 26

how does cerebellar disease cause an absent menace but not blindness?

Answer 26

pathway from visual cortex to facial nucleus passses through cerebellum