BSER abnormalities in a multiple sclerosis patient with normal peripheral hearing acuity.

The measurement of brain stem evoked potentials has proven clinically useful in determining the presence of multiple sclerosis plaques along the auditory areas of the brain stem. Abnormalities in brain stem evoked responses (BSER) have been identified in patients who manifest normal hearing acuity when evaluated via conventional audiometric techniques. The following case presentation illustrates this confounding clinical finding. The patient was a 20-year-old female who had been previously diagnosed as having multiple sclerosis. Within one month after being evaluated by BSER testing, she was struck and killed by lightning. Although she had a detailed history of normal hearing acuity (documented over the last six years), BSER test results yielded significantly abnormal neural conduction times when the left ear was ipsilaterally stimulated. A histopathologic examination of the patient's brain stem verified involvement of the auditory tracts. Thus physical corroboration of the abnormal BSER results was obtained in the presence of normal hearing acuity.