[Electrophysiological identification of the cochlear and vestibular nerves in the cerebellopontine angle: experimental study and clinical implication].

Electrical stimulation was applied on the surface of the eighth cranial nerve in the cerebellopontine angle of dogs and the evoked potentials were recorded with surface electrodes on the scalp. The shape of the evoked potentials recorded was different according to the portion of the nerve stimulated electrically. It was, therefore, possible to precisely identify the nerve stimulated from the surface recorded evoked potentials. This electrophysiological method may be helpful for the surgeon to precisely locate the cochlear and vestibular nerves in various operations in the cerebellopontine angle in human. Our preliminary experience of this monitoring method in acoustic neuroma excision was presented.