Recovery from vestibular ototoxicity.
OBJECTIVE
Determine whether subjects with documented vestibular ototoxicity recover vestibular function and, if so, investigate the recovery dynamics.


METHODS
Prospective and retrospective reviews and repeated measures.


METHODS
Clinical research and technology center.


METHODS
Twenty-eight subjects who received vestibulotoxic medications were followed for at least 12 months after initial treatment.


METHODS
Our subject sample was compared with a published database of normal individuals.


METHODS
All 28 subjects received systemically administered medications known to be ototoxic. The subjects' treating physicians controlled medication, dosage, and administration schedules.


METHODS
Tests of horizontal canal vestibulo-ocular function were performed. Subjects' auditory and vestibular symptoms were recorded.


RESULTS
Eleven subjects (39%) showed changes in horizontal canal vestibulo-ocular gain constant (GC) and/or time constant (TC) consistent with vestibular ototoxicity. When tested 1 year after ototoxic drug administration, eight of the nine subjects who experienced ototoxic decrease in GC showed a recovery of GC to normal limits. Only one of the eight subjects who experienced ototoxic decrease in TC showed recovery of TC to within normal limits. Ototoxicity onset and recovery were independent of baseline vestibular function, and ototoxicity onset did not correlate with cumulative dose of ototoxic medication. There was no relationship between subjective symptoms and ototoxicity onset.


CONCLUSIONS
Recovery of GC after vestibular ototoxicity is more commonly observed than recovery of TC. Because ototoxic changes developed and continued in an unpredictable time and manner in relation to ototoxic drug administration, we propose that once ototoxic changes in vestibulo-ocular reflex are detected, ototoxic medications should be discontinued as soon as possible.
Black
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Neurotology Research, Legacy Clinical Research and Technology Center, Portland, Oregon 97208-3950, USA.
Gianna-Poulin
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Pesznecker
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D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D000970:Antineoplastic Agents / Q000009:adverse effects*; D002945:Cisplatin / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D005839:Gentamicins / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020127:Recovery of Function; D012027:Reflex, Vestibulo-Ocular / Q000187:drug effects; D012189:Retrospective Studies; D013307:Streptomycin / Q000009:adverse effects*; D014031:Tobramycin / Q000009:adverse effects*; D014640:Vancomycin / Q000009:adverse effects*; D014724:Vestibular Function Tests; D014722:Vestibule, Labyrinth / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D005839:Gentamicins; D014640:Vancomycin; D002945:Cisplatin; D014031:Tobramycin; D013307:Streptomycin