THE EFFICACY OF TYMPANIC ELECTROCOCHLEOGRAPHY IN THE DIAGNOSIS OF ENDOLYMPHATIC HYDROPS

Electrocochleography (ECoG), an objective electrophysiologic test, is useful in the clinical diagnosis of endolymphatic hydrops. The purpose of this study was further to define the role of ECoG in the diagnosis of this disease. A retrospective chart review of 100 patients undergo ing tympanic ECoG was undertaken comparing symptoms, degree of hearing loss, duration of disease, and diagnosis with ECoG results. The appar ent sensitivity and specificity of ECoG in the diagnosis of endolympha tic hydrops were determined to be 57% and 94%, respectively. Three of 30 positive ECoG results were falsely positive. Fluctuating hearing lo ss and the degree of hearing loss (<40 dB) and duration of disease (<4 8 months) were statistically significant in predicting positive ECoG r esults. We conclude that a positive ECoG result is helpful in objectiv ely confirming the disease. However, a negative result does not rule o ut hydrops.