The cochlear nerve in various forms of deafness.

Operative specimens of cochlear nerve of 56 patients with profound deafness of varying origin were examined under the light microscope and the number of myelinated nerve fibers in each specimen was counted. The transverse fascicular area of each nerve was also determined. When the resulting neuron populations were evaluated with regard to the cochlear implant program the only truly unsuitable ears for artificial stimulation were found to be those with cholesteatoma involving the cochlear nerve and ears with local pathology in the internal auditory canal severe enough to cause atrophy of the cochlear nerve.