Electrocochleography in the diagnosis of Meniere's disease

This study prospectively analyses electrocochleography (ECoG) recordings ob tained from ears demonstrating symptoms highly suggestive of Meniere's dise ase. Comparison is made with ECoG recording from ears in which the diagnosi s of Meniere's is considered unlikely (control ears). Electrocochleograph r ecordings were made through a transtympanic recording needle, situated in t he round window niche. Analysis was made of the 1 kHz tone burst summation potential (SP) and the summation potential:action potential (SP/AP) ratio r esponse 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 aw arded 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 proporti onal to the amplitude of the AP click response, and in patients producing a n AP click amplitude exceeding 10 V, sensitivity of the tone burst test app roaches 85%. This study provides further evidence suggesting the useful rol e of electrocochleography in determining a diagnosis of endolymphatic hydro ps, and demonstrates improved sensitivity of the 1 kHz SP response, compare d with SP/AP click ratio, in the diagnosis of Meniere's disease.