Audiological assessment in patients with mitochondrial myopathy.

Mitochondrial myopathies comprise a heterogeneous group of disorders characterized by the presence of ragged red fibres in muscle biopsy. The present study investigates the audiological features in a group of 14 patients in whom diagnosis was histologically confirmed. A complete ENT, neurological and audiological work-up was performed for every patient, including measurement of brainstem auditory evoked potentials (BAEPs). Most patients presented with a varying degree of hearing loss and occasional abnormalities of the latencies and interpeak latencies of the BAEPs, but only the increased latencies of waves I and V have been statistically confirmed. Audiological data suggest non-specific involvement at one or more sites along the auditory pathway.