Vestibular and Cerebellar Disease Flashcards
describe what would be seen in a patient with left peripheral vestibular localization
- left head tilt
- left vestibular ataxia
- spontaneous nystagmus fast phase to the right
- left miosis and ptosis
- normal mentation
- normal postural reactions
- other CN normal
using VITAMIND what are possible differentials for a cat with left peripheral localization?
V: no vascular disease of inner ear exists
describe otitis media/interna
- infection of middle (tympanic cavity/bulla) and inner ear
-only otitis internal will cause vestibular signs!! - commonly associated with otitis externa, but not always!
- can be occult (extend up eustachian/auditory tube)
- COMMON IN:
-cats
-brachycephalic dogs
-dogs with crazy ears (hairy or heavy) - often secondary to something:
-breed conformation (see above!!)
-allergies
-ear mites: cats
-inflammatory polyp: cats
-neoplasia
-swimming
describe the etiology of otitis media/interna
typically bacterial, rarely fungal!
staph, strep, pseudomonas, pasteurella, proteus, E.coli, etc.
describe diagnosis of otitis media/interna
- presumptive in SA practice
-signalment, presentation, otic exam
-otic exam can support but NOT definitive - definitive: cross sectional imaging
-CT, MRI
-infectious material in bullae (should be black and full of fluid normally) - myringotomy: anesthetize, take an otoscope, use to stick a needle down through tympanic membrane, flush sterile saline and then culture it
describe treatment of otitis media/interna
- systemic antibiotics:
-ideally based on culture
–if can’t culture, treat empirically for what you know is commonly present
-MUST penetrate bone
-minimum 8 weeks - treat underlying cause (allergies)
- NO!!! SYSTEMIC STEROIDS!!!
-topical only if need steroids - +/- surgery (bulla osteotomy)
describe nasopharyngeal polyps
- cats > dogs; 1-5 years old
- inflammation of eustachian (auditory) tube leads to mass lesion
- associated with secondary OMI
- oral/otic exam +/- imaging with CT/MRI
- treatment:
-manual removal + anti-inflammatory steroids; recurrence uncommon
-bulla osteotomy if involves middle ear
describe ototoxic meds
- over 200 compounds are ototoxic; prescribed when otitis externa
- often concurrent hearing loss; reversible or permanent
- caution with ear meds if tympanic membrane ruptured!
- most common
-ear meds with aminoglycoside antibiotics
–otomax: GENTAMICIN, betamethasone, and clotrimazole
–tri-otic: GENTAMICIN, betamethasone, clotrimazole
–mometamax: GENTIMICIN, momentasone, clotrizamole
-ear flush (chlorhexidine)
describe canine vestibular hypothyroidism
- test ALL peripheral vestibular cases for T4, free T4, and TSH!!!
- rule out ear disease as best you can (otoscope)
- treat if blood work suggests hypothyroidism
- neuro cases don’t always have traditional signs; lethargy, weight gain
- hypothyroidism can also be a cause of DIFFUSE neuromuscular disease!!!! (one of those metabolic causes that if you see diffuse LMN you should metabolic test ALWAYS first to rule out!!)
describe peripheral vestibular neoplasia
- diagnosis:
-palpation: not always feel it but worth trying
-otoscopic exam!!
-radiographs may reveal destruction of tympanic bulla
-CT/MRI - treatment:
-total ear canal ablation
-radiation if complete surgical resection not possible
-TREATMENT not for exam!!!!
what is a common history for idiopathic peripheral vestibular disease?
difficulty walking after waking up from a nap
describe idiopathic vestibular disease
- ALWAYS PERIPHERAL
- peracute to acute onset (minutes to hours)
- not always older patients!
-but typically >6 years - diagnosis of exclusion
describe treatment of idiopathic vestibular disease
- supportive care
- meclizine 6.25-25mg once daily
-anti-histamine for vertigo/motion sickness - ondansetron or cerenia if vomiting
-CN 8 goes to vomit center in brain so if acutely vestibular will also commonly be vomiting
describe improvement from idiopathic vestibular disease
- nystagmus resolves in 3 days
- ataxia resolves in 3 weeks
- head tilt resolves over 3 months
-but could be residual!
describe idiopathic vestibular disease in cats
- cats can get it too!!
- ANY AGE: median 4 years
- ANY breed
- indoor/outdoor
- any time of year (july, august)
- slower recovery than dog
-complete recovery 4-6 weeks
-residual deficits (25%)
compare and contrast idiopathic and OMI peripheral vestibular disease in dogs
idiopathic:
1. peracute onset (hours); vomiting
2. no concurent signs
3. resolution
-nystagmus: 1-3 days
-complete: 1-3 weeks
-head tilt: 1-3 months
OMI:
1. onset: days to 3 weeks
2. +/- clinical ear disease (otitis externa)
3. many have facial nerve deficits and Horner’s
4. resolution: recurrent/persistent
if unsure, give time for peracute (wait 3 days and then reassess)
-empirical antibiotic treatment for 8 weeks!
DO NOT GIVE ANTI-INFLAMMATORY STEROIDS
-if ear disease, could spread to the brain
-IS okay to give NSAIDs
describe strokes
- peracute to acute onset (minutes to hours)
- non-progressive
- require MRI to confirm and rule out inflammation and neoplasia
- supportive care
-most do well and return to good QOL - NOT ALL OLD DOGS WITH ACUTE ONSET VESTIBULAR SIGNS HAVE CANCER
describe neoplasia
- vestibular disease in old dog does not ALWAYS mean neoplasia (just most likely)
- typically chronic, progressive but may be peracute or acute
- treatment options:
-sometimes surgery
-radiation
-palliative
what is MUE? (will have a whole lecture on this)
- meningoencephalitis of unknown etiology
- autoimmune inflammation of brain and/or spinal cord
-acute to chronic (<3 months) progressine
-young to middle aged toy and small breed dogs
-any CNS localization; often multifocal and aysmmetrical; typically brain, can just be myelopathy, can just be neck or back pain - disease of dogs, not cats!!
- treatment:
-steroids and second immunosuppressive
-1/3 do not respond
-1/3 respond and relapse
-1/3 do well long term
what to do with central vestibular disease in private practice?
- ideally refer
- always check ears! could be extension of OMI
- peracute, non-progressive history consistent with stroke
-time - breed consistent with MUE
-rule out infection with titers
-antinflammatory steroids
-consult - neoplasia typically chronic and progressive (may be acute but should be progressive)
-rule out infection
-steroids palliative for weeks to months
describe metronidazole toxicity
- ALWAYS CENTRAL
-get better once remove metronidazole - reported >66mg/kg/day
-recommend: <30mg/kg/day
-Barber doesn’t give more than 20mg/kg/day - do NOT give metronidazole to that patient again; causes changes in brain that makes them more susceptible again
- can also happen with ronidazole
describe neospora caninum
predilection for cerebellum, in dogs
(other places too but will have a whole lecture on)
describe neuronal ceroid lipofuscinosis (likely not on exam)
- middle aged staffordshire and pit bull terriers
- symmetrical
- SLOWLY progressive (yearish history)
- genetic test; no treatment but can live like this for years
-DONT LET THEM SWIM (any vestibulocerebellar animal) - vestibulocerebellar
-mild to mod cerebellar ataxia
-may delay postural reactions
-positional nystagmus, mostly vertical
