USE OF DISTORTION-PRODUCT OTOACOUSTIC EMISSIONS FOR AUDITORY EVALUATION IN MENIERES-DISEASE

Otoacoustic emissions are a relatively new tool for assessment of inne r ear function. We studied 65 patients diagnosed as having Meniere's d isease. In order to obtain and characterize responses at different fre quencies we used distortion-product otoacoustic emissions (DPOAE). In unilateral cases, the difference in response between ears on the disea sed and healthy sides was evident at all frequencies. In the former th e result was lower than expected for a group of normally hearing subje cts, while in the latter it was better than expected according to pure tone averages. Reduction in amplitude and increment in threshold of t he DPOAE in the diseased ear was a significant finding and could be co rrelated to the stage of the disease. In those subjects treated with B etahistine after 1 year's follow-up, DPOAE testing showed the recovery of response at low frequencies and a reduction of its threshold at al l frequencies studied.