Exam 2 - Vestibular Disease Flashcards
what are the 4 cardinal signs of vestibular disease?
- head tilt
- nystagmus
- vestibular ataxia - leaning, falling, rolling to one side
- vestibular strabismus - ventrolateral & induced with head elevation
what cranial nerve deficits can be seen in peripheral vestibular disease?
VII & horner’s syndrome
are there proprioceptive deficits & mentation changes in peripheral vestibular disease?
no
are there proprioceptive deficits & mentation changes in central vestibular disease?
yes or no
is the vestibular disease paradoxical in nature in peripheral lesions?
no
is the vestibular disease paradoxical in nature in central lesions?
yes or no
what cranial nerve deficits can be seen in central vestibular disease?
VII, V, IX, X, & XII
if the vestibular disease is paradoxical, what 2 things are true?
- lesion is ipsilateral to proprioceptive/other CN deficits
- it is a central lesion
what are the main differential groups for peripheral vestibular disease?
- inflammatory
- masses
- metabolic - including toxic
- idiopathic
what are the 2 main inflammatory causes of peripheral vestibular disease?
infectious - otitis interna
non-infectious - primary secretory otitis media (PSOM)
what organisms are involved in causing otitis interna?
staph, strep, enterics, & anaerobes
what organism typically causes otitis media in cats?
pastuerella multocida
what organism typically causes otitis media in dogs with chronic disease?
pseudomonas aeruginosa
how is otitis interna definitively diagnosed?
identification of the organism on myringotomy
what is the treatment for bacterial otitis interna?
antibacterials
what is the treatment for systemic disease caused by otitis interna?
targeted is better than empirical!
efficacy of treatment is improved by removal of the gross disease - osteomyelitis minimum of 6-8 weeks
recurrence is likely if underlying cause remains
what is the pathogenesis of primary secretory otitis media?
excess mucus builds up in the tympanic bulla cavity
what breed is commonly affected by primary secretory otitis media?
cavalier king charles - 3-7 years old
what is the most common clinical sign of primary secretory otitis media?
pain - but up to 25% have vestibular signs
what is the treatment for primary secretory otitis media?
myringotomy & check for secondary infections to see if antibiotics should be used
T/F: most animals with PSOM only need one treatment to clear the disease and never have other problems
false - 50% require more than 1 treatment & 25% have a symptomatic relapse
what are examples of non-neoplastic & neoplastic causes of peripheral vestibular disease?
non-neoplastic - polyps
neoplastic - ceruminous gland adenocarcinoma/squamous cell carcinoma & peripheral nerve sheath tumor/lymphoma
what animals are most commonly affected by nasopharyngeal polyps?
young cats - 1-3 years old
what clinical signs are seen in cats with nasopharyngeal polyps?
horner’s syndrome - CN VII is in the middle ear
vestibular signs - inner ear
what is the treatment for nasopharyngeal polyps?
traction-avulsion +/- ventral bulla osteotomy & curettage (check for concurrent infection)
post surgical horner’s syndrome may be seen in 50% of cases - should resolve in 2-4 weeks
what is the recurrence of nasopharyngeal polyps like?
<10% is the osteotomy is done, but 30-60% without
steroids may help reduce recurrence
what disease is a metabolic cause of peripheral vestibular disease?
hypothyroidism
T/F: any topical application that penetrates the tympanic membrane may cause transient vestibular disease
true
what are examples of 2 topical drugs that can cause peripheral vestibular disease?
chlorhexidine
aminoglycosides - especially gentamicin
what systemic drugs are known to cause peripheral vestibular disease?
aminoglycosides & furosemide
why does hypothyroidism cause metabolic peripheral vestibular disease?
we don’t know - give them meds for hypothyroidism & they typically get better
what is the former name of idiopathic peripheral vestibular disease?
old dog vestibular disease
how is idiopathic peripheral vestibular disease diagnosed?
diagnosis of exclusion
what is the treatment for idiopathic peripheral vestibular disease?
no treatment - improves on its own in 1-4 weeks
what is the onset & progression for idiopathic peripheral vestibular disease?
peracute onset & short-term progression
idiopathic peripheral vestibular disease affects dogs or cats more?
dogs >7 years but still can happen to cats
what are the 5 main differentials for central vestibular disease?
- inflammatory
- neoplastic
- vascular
- metabolic - including nutritional & toxic
- secondary to foramen magnum herniation
what is the general cause of non-infectious central vestibular disease?
immune mediated encephalitis
what are the general causes of infectious central vestibular disease?
viral - distemper & FIP
protozoal - toxoplasma, neospora
bacterial - extension from otitis interna
fungal
rickettsial
how are steroids used as a lifelong therapy in treating meningoencephalitis in central vestibular disease?
affect the lymphocytes & macrophages but unacceptable adverse effects are often the limiting factor for use
how is cyclosporine used as a lifelong therapy in treating meningoencephalitis in central vestibular disease?
blocks the genes for cytokine production & potentially affects many cell types
metabolized by P450
how is azathioprine used as a lifelong therapy in treating meningoencephalitis in central vestibular disease?
blocks DNA synthesis & primarily acts on lymphocytes with 10-14 days to see a clinical effect
how is cytarabine (cytosar) used as a lifelong therapy in treating meningoencephalitis in central vestibular disease?
blocks DNA synthesis & affects lymphocytes
crosses the blood brain barrier
what is the general treatment for central vestibular disease caused by meningoencephalitis?
long-term or lifelong immunosuppressive therapy
central vestibular disease caused by bacterial infections often occurs why?
as an extension of otitis interna
what clinical signs are seen in bacterial infections causing central vestibular disease?
may be few to no signs systemically - in chronic infections will see rapid development of neurological signs
what 2 forms of vascular events can causes central vestibular disease?
ischemic & hemorrhagic
how is central vestibular disease caused by a vascular event diagnosed?
presumptive diagnosis via MRI - restricted diffusion
what is the major differential for central vestibular disease caused by a vascular event?
intra-axial neoplasia (glioma)
what are the 3 general causes of metabolic central vestibular disease?
toxic - metronidazole
nutritional - thiamine deficiency
metabolic - hypothyroidism
