Balance: Vertigo, ataxia Flashcards
Benign positional vertigo
Pathophysiology:
- most common cause of vertigo of peripheral origin
- usually 2/2 head trauma
- canalithiasis results in stimulation of semicircular canals by debris floating in endolymph
Clinical:
- brief episodes of severe vertigo +/- N/v
- usually most severe in lateral decubitus position
- (-) hearing loss!
- nystagmus
Dx/Rx:
dx: dix-halpike testing
rx: epley maneuver
Meniere’s disease
Pathophysiology:
- related to mutation in the cochlin gene Chr 14
- onset at 20-50 with M>F
- 2/2 increase in volume of labyrinthian endolymph
Clinical:
- repeated episodes of vertigo, n/v, tinnitus
- progressive sensorineural hearing loss
- sensation of ear fullness
- nystagmus
Dx/Rx: diuretics
Vestibular neuronitis
Pathophysiology:
- +/- recent febrile illness
- ill appearing patient often lies on their side with affected ear up
Clinical:
- acute onset vertigo, n/v that lasts up to 2 weeks
- (+) nystagmus away from the affected nerve
Dx/Rx: prednisone
Otosclerosis
Pathophysiology:
- 2/2 immobility of stapes
- auditory symptoms begin < 30 yo
Clinical:
- conductive hearing loss bilaterally
- recurrent episodes of vertigo
Dx/Rx:
- sodium fluoride
- calcium gluconate
- vitamin D
Cerebellopontine tumor
Pathophysiology:
- most common = acoustic/vestibular schwannoma
- often affects CN V, VII, VIII
- can be 2/2 neurofibromin mutation on chr 17
Clinical:
- insidious unilateral hearing loss
- vertigo (20-30%)
- increased CSF protein
Dx/Rx:
dx: MRI
rx: surgical excision
EtOH
Toxic Vestibulopathies
Pathophysiology:
- decreased cupula density in relationship to endolymph
- makes vestibular apparatus sensitive to gravity, position
Clinical:
- acute positional vertigo
- occurs at blood levels >40 mg/dL
- vertigo, nystagmus accentuated with closed eyes
Dx/rx: d/c EtOH
Aminoglycosides
Toxic Vestibulopathies
Pathophysiology:
- -> streptomycin, gentamycin, tobramycin
- dose-dependent concentration in the perilymph and endolymph –> destruction of hair cells
Clinical:
- vertigo
- N/V
- gait ataxia
- spontaneous nystagmus
- (+) Romberg
Dx/rx: d/c offending agent
Salicylates
Toxic Vestibulopathies
Pathophysiology: cochlear and vestibular end organ damage
Clinical: reversible vertigo, tinnitus, sensorineural hearing loss
Dx/rx:
Quinine/Quinidine
Toxic Vestibulopathies
Pathophysiology: cinchonism
Clinical:
- tinnitus
- impaired hearing
- vertigo
- n/v
- visual defects
Dx/rx:
Cis-platinum
Pathophysiology:
- tinnitus
- hearing loss
- vestibular dysfunction
Clinical:
Dx/rx:
EtOh cerebellar degeneration
Pathophysiology:
- 2/2 nutritional deficiency
- occurs with 10+ yr hx of EtOH
- degenerative changes in cerebellar vermis
Clinical:
- progresses over weeks to months
- gait ataxia (universal feature)
- limb ataxia on heel-shin
Dx/rx: thiamine
Paraneo-cerebellar degeneration
Pathophysiology:
- lung cancer, ovarian cancer, Hodkin disease, breast cancer
- affects the vermis and hemispheres diffusely
- involves antibodies (anti-Hu, anti Yo, anti-Ri) in many cases
Clinical:
- prominent gait and limb ataxia
- no nystagmus
Dx/rx:
- remove tumor
- immunosuppression
Friedrich ataxia
Pathophysiology:
- autosomal recessive
- 2/2 expanded GAA repeat in non coding region of frataxin gene on Chr9
- loss of function mutation
- increased risk of DM
Clinical:
- spinocerebellar tract/DRG degeneration
- progressive gait ataxia with all limbs involved in 2 yrs
- loss of knee/ankle reflexes
- impaired joint position/vibration
- (+) babinski
- cardiomyopathy
Dx/Rx: none
Ataxia telangiectasia
Pathophysiology:
- inherited AR disorder
- onset in infancy
- 2/2 mutations in the ATM gene
- thought to result in defective DNA repair
Clinical:
- progressive cerebellar ataxia
- oculocutaneous telangiectasia
- immunologic deficiency (IgG, IgA)
- nystagmus, dysarthria, ataxia
- increased AFP, CEA
Dx/Rx:
- antibiotics
- avoid X-rays
Spinocerebellar ataxia
Pathophysiology:
- inherited disorders (AD)
- avg age onset 20-30
- considerable clinical variability
- most begin in childhood w anticipation
- 2/2 CAG expanded repeates in ataxins and P/Q calcium channel
- altered proteins conjugated with ubiquitin and transported to proteasome for destruction
Clinical:
- slowly progressive
- affects gait primarily
Dx/Rx: genetic testing
