Cranial Nerve Disorders

Question 1

who is most affected by trigeminal neuropathy?

Answer 1

golden retriever
middle aged dogs

Question 2

is there a known definitive cause of trigeminal neuropathy?

Answer 2

no

Question 3

what diagnostics can be done with trigeminal neuropathy?

Answer 3

MRI to rule out tumors
CSF with normal cell count and mildly elevated protein concentration

Question 4

does prednisone shorten the recovery time of trigeminal neuropathy?

Answer 4

no

Question 5

what is the prognosis of trigeminal neuropathy?

Answer 5

self-limiting in idiopathic cases
recovery within 3 weeks

Question 6

what is variation of nerve sheath tumor of CN V like?

Answer 6

large variation in histological subtypes

Question 7

what are the signs of nerve sheath tumor of CN V?

Answer 7

chronic progressive
unilateral temporal muscle and masseter atrophy
face rubbing
rarely Horner’s
jaw weakness rare

Question 8

who is primarily impacted by nerve sheath tumor of CN V?

Answer 8

older dogs

Question 9

can surgery be performed on a nerve sheath tumor of CN V?

Answer 9

difficult: often invasion of brain stem

Question 10

what is the etiology of idiopathic facial nerve paralysis?

Answer 10

idiopathic, specific cause unclear
immune mediated disorder suspected

Question 11

what is the histopathology of idiopathic facial nerve paralysis?

Answer 11

axonal degeneration, large diameter fibers more affected

Question 12

what clinical signs are associated with idiopathic facial nerve paralysis?

Answer 12

ear drop
lip paralysis
salivation
difficulty in food uptake
deviation nasal septum, widened nostril
absent palpebral reflex
absent menace reflex

Question 13

what are some differentials for idiopathic facial nerve paralysis?

Answer 13

otitis media/interna
trauma
fractures
hypothyroidism
neoplasia

Question 14

what are some helpful diagnostics for idiopathic facial nerve paralysis?

Answer 14

CBC, chemistry profile, free T4, C-TSH
CT or MRI
CSF
eye exam, schirmer’s tear test

Question 15

what is part of the peripheral vestibular system?

Answer 15

semicircular ducts
sacculus, utriculus
vestibulocochlear nerve

Question 16

what drives vestibular function?

Answer 16

comparison input left versus right side

Question 17

what are the clinical signs of vestibular disease?

Answer 17

head tilt
vestibular ataxia
ventral strabismus
facial nerve palsy
horner’s syndrome

Question 18

is proprioception normal or abnormal with central vestibular disease?

Answer 18

abnormal

Question 19

what type of pathologic nystagmus is associated with central vestibular disease?

Answer 19

vertical

Question 20

what cranial nerve deficits can occur with peripheral vestibular disease?

Answer 20

VII, VIII possible

Question 21

what is the etiology of otitis media and interna?

Answer 21

infection of bulla tympanica via ear canal, tuba eustachii, or hematogenous

Question 22

what bacteria can cause otitis media/interna?

Answer 22

Staphylococcus aureus
Proteus
Pseudomonas
E. coli
Streptococcus
Enterbacter
Malassezia sp

Question 23

what are the clinical signs of otitis media/interna?

Answer 23

often fast progressive
head tilt
vestibular ataxia
spontaneous nystagmus
facial nerve paralysis in 2/3 of cases
horner’s syndrome in 10%

Question 24

how can otitis media/interna be diagnosed?

Answer 24

otoscopy
bulla series
CT
MRI
myringotomy

Question 25

what is treatment of otitis media/interna?

Answer 25

long-term antibiotics
lavage of bulla tympanica
surgery

Question 26

does idiopathic vestibular syndrome have facial nerve paralysis or horner’s syndrome?

Answer 26

no

Question 27

what clinical signs are associated with idiopathic vestibular syndrome?

Answer 27

peracute to acute onset
head tilt
vestibular ataxia
often unable to stand
salivation
fast spontaneous, rotary nystagmus most common

Question 28

what are some differentials for idiopathic vestibular syndrome?

Answer 28

otitis media/interna
stroke
trauma
neoplasia

Question 29

what is the treatment of idiopathic vestibular syndrome?

Answer 29

supportive
IV fluids
sedation: midazolam, acepromazine, chlorpromazine

Question 30

what are the possible causes of trigeminal neuropathy?

Answer 30

idiopathic
immune mediated
paraneoplastic
lymphoma
Neospora canis infection

Question 31

what are the histiologic subtypes of nerve sheath tumors of cranial nerve V?

Answer 31

neurioma, neurilemmoma
schwannoma, malignant schwannoma
neurofibroma, neurofibrosarcoma

Question 32

who is most affected by idiopathic facial nerve paralysis?

Answer 32

cocker spaniel, beagle
middle aged: 3-6 years

Question 33

what is the prognosis of idiopathic facial nerve paralysis?

Answer 33

idiopathic: recovery 2-3 months
other side affected 2-4 months later in 50%

Question 34

what makes up the central vestibular system?

Answer 34

4 vestibular nuclei
flocculonodular lobe of cerebellum
caudal cerebellar peduncle
cortex
MFL with connection to CN III, IV, VI
vestibulo-spinal tracts

Question 35

what cranial nerve deficits may be seen with peripheral vestibular disease?

Answer 35

CN VII, VIII possible

Question 36

what is the prognosis of idiopathic vestibular syndrome?

Answer 36

improvement within 24-72 hours
recovery up to 2 weeks
relapses possible

Question 37

what is the presentation of trigeminal neuropathy?

Answer 37

acute to peracute
dropped jaw
inability of water/food uptake
hypersalivation
sensory deficits 25%
horners 10%

Question 38

what is the main treatment for a nerve sheath tumor of CN V?

Answer 38

radiation therapy