Electrocochleography in the diagnosis of Meniere's disease

This study prospectively analyses electrocochleography (ECoG) recordings obtained from ears demonstrating symptoms highly suggestive of Meniere's disease. Comparison is made with ECoG recording from ears in which the diagnosis of Meniere's is considered unlikely (control ears). Electrocochleograph recordings were made through a transtympanic recording needle, situated in the round window niche. Analysis was made of the 1 kHz tone burst summation potential (SP) and the summation potential:action potential (SP/AP) ratio response to a 90 dB click. All patients were prospectively awarded a Meniere's score based on a 10-point scale, and comparison was made between ears awarded a score of 7 or greater (Meniere's ears; n > 500), and ears awarded a score 3 or less (control ears; n > 900). Results demonstrate a significant difference in the 1 kHz SP response, and the SP/AP ratio, between "control" and "Meniere's" ears. Furthermore, we show that SP negativity is proportional to the amplitude of the AP click response, and in patients producing an AP click amplitude exceeding 10 V, sensitivity of the tone burst test approaches 85%. This study provides further evidence suggesting the useful role of electrocochleography in determining a diagnosis of endolymphatic hydrops, and demonstrates improved sensitivity of the 1 kHz SP response, compared with SP/AP click ratio, in the diagnosis of Meniere's disease.