Hearing Loss in Patients With Vestibulotoxic Reactions to Gentamicin Therapy

Abstract

Aminoglycosides can cause permanent damage to inner ear hair cells, resulting in hearing loss (cochleotoxicity) and/or vestibular disturbances such as disequilibrium (vestibulotoxicity). Gentamicin, an aminoglycoside that is widely used parenterally to treat serious infections, is considered to be more vestibulotoxic than cochleotoxic.1 Black et al2 reported a clinical series of 33 adult patients, seen at a tertiary neurotology clinic a year or more after gentamicin therapy, all of whom had disabling vestibular symptoms beginning after gentamicin therapy as well as vestibulotoxic reactions documented by objective tests of vestibulo-ocular reflex function. Twenty-seven of the 33 patients underwent audiometry, including pure-tone and speech thresholds and speech intelligibility tests; 17 of these 27 had sensorineural hearing loss thought to be attributable to cochleotoxic effects of gentamicin. However, this group was predominantly middle aged (mean age, 55 years) and male (63%); age and male sex are strong predictors of sensorineural hearing loss. In the absence of pretreatment audiometry in any of these cases, it is difficult, as Black et al2 acknowledged, to estimate the magnitude of the cochleotoxic insult.