Electrophysiologic and behavioral auditory findings in multiple sclerosis.

An auditory test battery composed of seven behavioral and electrophysiologic measures, in addition to pure tone testing, was administered to 33 subjects with definite multiple sclerosis. More than 40% of the subjects with normal peripheral hearing presented with subjective complaints of hearing difficulties. Auditory brainstem response (ABR) was found to be the most sensitive individual test in detecting central auditory dysfunction. Further analyses suggested that the combination of ABR and masking level difference (MLD) tests was essentially as effective as the entire test battery in detecting dysfunction in these subjects. Dichotic speech measures, unlike other tests, showed a definite laterality effect with the left ear consistently poorer, possibly reflecting interhemispheric involvement.