Auditory function in hereditary motor and sensory neuropathy (Charcot-Marie-Tooth disease).

Fourteen patients with hereditary motor and sensory neuropathy (HMSN), 12 of Type I and 2 of Type II, were assessed for auditory dysfunction. Five patients complained of hearing loss and all had pure-tone audiograms outside the normal range, while one patient who did not complain of hearing impairment also had an abnormal pure-tone audiogram. Assessment of loudness function, speech audiometry and brainstem auditory evoked potentials (BAEP) suggested that the hearing loss was the result of VIII nerve dysfunction, a conclusion supported by the abnormality of the electrocochleogram (ECochG) in one patient.