Cranial Nerve Disorders Flashcards
who is most affected by trigeminal neuropathy?
golden retriever
middle aged dogs
is there a known definitive cause of trigeminal neuropathy?
no
what diagnostics can be done with trigeminal neuropathy?
MRI to rule out tumors
CSF with normal cell count and mildly elevated protein concentration
does prednisone shorten the recovery time of trigeminal neuropathy?
no
what is the prognosis of trigeminal neuropathy?
self-limiting in idiopathic cases
recovery within 3 weeks
what is variation of nerve sheath tumor of CN V like?
large variation in histological subtypes
what are the signs of nerve sheath tumor of CN V?
chronic progressive
unilateral temporal muscle and masseter atrophy
face rubbing
rarely Horner’s
jaw weakness rare
who is primarily impacted by nerve sheath tumor of CN V?
older dogs
can surgery be performed on a nerve sheath tumor of CN V?
difficult: often invasion of brain stem
what is the etiology of idiopathic facial nerve paralysis?
idiopathic, specific cause unclear
immune mediated disorder suspected
what is the histopathology of idiopathic facial nerve paralysis?
axonal degeneration, large diameter fibers more affected
what clinical signs are associated with idiopathic facial nerve paralysis?
ear drop
lip paralysis
salivation
difficulty in food uptake
deviation nasal septum, widened nostril
absent palpebral reflex
absent menace reflex
what are some differentials for idiopathic facial nerve paralysis?
otitis media/interna
trauma
fractures
hypothyroidism
neoplasia
what are some helpful diagnostics for idiopathic facial nerve paralysis?
CBC, chemistry profile, free T4, C-TSH
CT or MRI
CSF
eye exam, schirmer’s tear test
what is part of the peripheral vestibular system?
semicircular ducts
sacculus, utriculus
vestibulocochlear nerve
what drives vestibular function?
comparison input left versus right side
what are the clinical signs of vestibular disease?
head tilt
vestibular ataxia
ventral strabismus
facial nerve palsy
horner’s syndrome
is proprioception normal or abnormal with central vestibular disease?
abnormal
what type of pathologic nystagmus is associated with central vestibular disease?
vertical
what cranial nerve deficits can occur with peripheral vestibular disease?
VII, VIII possible
what is the etiology of otitis media and interna?
infection of bulla tympanica via ear canal, tuba eustachii, or hematogenous
what bacteria can cause otitis media/interna?
Staphylococcus aureus
Proteus
Pseudomonas
E. coli
Streptococcus
Enterbacter
Malassezia sp
what are the clinical signs of otitis media/interna?
often fast progressive
head tilt
vestibular ataxia
spontaneous nystagmus
facial nerve paralysis in 2/3 of cases
horner’s syndrome in 10%
how can otitis media/interna be diagnosed?
otoscopy
bulla series
CT
MRI
myringotomy
what is treatment of otitis media/interna?
long-term antibiotics
lavage of bulla tympanica
surgery
does idiopathic vestibular syndrome have facial nerve paralysis or horner’s syndrome?
no
what clinical signs are associated with idiopathic vestibular syndrome?
peracute to acute onset
head tilt
vestibular ataxia
often unable to stand
salivation
fast spontaneous, rotary nystagmus most common
what are some differentials for idiopathic vestibular syndrome?
otitis media/interna
stroke
trauma
neoplasia
what is the treatment of idiopathic vestibular syndrome?
supportive
IV fluids
sedation: midazolam, acepromazine, chlorpromazine
what are the possible causes of trigeminal neuropathy?
idiopathic
immune mediated
paraneoplastic
lymphoma
Neospora canis infection
what are the histiologic subtypes of nerve sheath tumors of cranial nerve V?
neurioma, neurilemmoma
schwannoma, malignant schwannoma
neurofibroma, neurofibrosarcoma
who is most affected by idiopathic facial nerve paralysis?
cocker spaniel, beagle
middle aged: 3-6 years
what is the prognosis of idiopathic facial nerve paralysis?
idiopathic: recovery 2-3 months
other side affected 2-4 months later in 50%
what makes up the central vestibular system?
4 vestibular nuclei
flocculonodular lobe of cerebellum
caudal cerebellar peduncle
cortex
MFL with connection to CN III, IV, VI
vestibulo-spinal tracts
what cranial nerve deficits may be seen with peripheral vestibular disease?
CN VII, VIII possible
what is the prognosis of idiopathic vestibular syndrome?
improvement within 24-72 hours
recovery up to 2 weeks
relapses possible
what is the presentation of trigeminal neuropathy?
acute to peracute
dropped jaw
inability of water/food uptake
hypersalivation
sensory deficits 25%
horners 10%
what is the main treatment for a nerve sheath tumor of CN V?
radiation therapy
