Electrocochleographic Study of Meniere's Disease

Abstract

Electrocochleography (ECOG) reflects the functional state of the cochlea, and can be used as a tool of clinical otology. It is thus valuable when making a diagnosis of the different pathological conditions which affect the cochlea.In the present series, 16 ears in patients with Meniere's disease were examined by ECOG. As a control, 6 normal hearing ears and 10 high tone loss ears also served as subjects. Short tone bursts were used as stimuli, and the trans-tympanic recording method was used.Main findings in the case of Meniere's disease are summarized as follows.(1) The N1 thresholds were similar to the subjective ones.(2) The waveforms of the AP-SP potentials recorded in Meniere's cases were broad.(3) Both in Meniere's ears and high tone loss ears, a positive summating potential (SP+) was recorded when using high frequency tone bursts.(4) In the ears of those with Meniere's disease, the large negative summating potential (SP-) was obvious for low frequency tone bursts.(5) In the fluctuant stage of hearing loss, the negative summating potential (SP-) amplitude related to the attack of Meniere's disease, but not to the degree of hearing loss.(6) In those with Meniere's disease, the input-output curves of N1 amplitude were rather steep compared to normal ears, and a steep slope thus was indicative of a positive recruitment.(7) In the late stage of Meniere's disease, the difference between those with the disease and those with a high tone loss was not evident using ECOG.