Characteristics of the Extratympanic Electrocochleography in the Patients with Meniere's Disease

ABSTRACT

BACKGROUND AND OBJECTIVES:Electrocochleography is the only proven investigation and diagnostic tool to demonstrate the endolymphatic hydrops at this time. We designed this study to assess the characteristics of transtympanic electrocochleographic findings and to estimate the clinical value of the test results in the patients with Meniere's disease. MATERIALS AND METHOD:Electrocochleographic duration and amplitude were measured in a clinically defined definite Meniere's disease group and the results were compared with those from a normal hearing control group. RESULTS:The summating potential (SP)/action potential (AP) amplitude ratio was significantly different among study groups with 0.40+/-.10 in the bilateral Meniere's group, 0.34+/-.08 in the unilateral Meneire's group and 0.22+/-.08 in the normal group (p<0.01). The elevated SP/AP ratio in the patients with such a relatively long duration of Meniere's disease in this study was mainly due to the decreased AP amplitude rather than the enhanced SP amplitude. CONCLUSION:Measuring electrocochleography and demonstrating the elevated SP/AP ratio could be quite valuable to diagnose the patients with Meniere's disease. The recognition of decreased AP amplitude might be helpful to understand the cochlear pathologic status in the patients with Meniere's disease.