[Electrocochleography and topographic diagnosis]

We present a group of 50 patients with retrocochlear pathology, divided on 41 (82 per 100) non tumoral and 9 (18 per 100) tumoral: 8 cerebello-pontine angle meningiomas and 1 intracranial cholesteatoma. The retrocochlear diagnosis of the pathology is assessed by the results of the audiovestibular explorations, specially the electrophysiology (early auditory evoked response, electrocochleography). The neuroradiologic explorations (TAC, MNR) define the tumoral or non tumoral nature of the pathology. We review some technical aspects of the common electrocochleographic practice, as actually is realised by the Bordeaux group; also, the different parameters of a retrocochlear pathologic response. In this group, the electrocochleography was necessary on 64 per 100 of the cases to obtain an electrophysiologic retrocochlear diagnostic.