Correlation between a unilateral midbrain-pontine lesion and abnormalities of brain-stem auditory evoked potential.

Brain-stem auditory evoked potentials (BAEPs) were evaluated over a 39 day period in a patient with a unilateral pontine-midbrain lesion verified by CAT scan and at autopsy. Waves I, II and III were present on the side of lesion, whereas all 5 waves were present on the side opposite the lesion. The findings suggest that the BAEPs may be obtained with only an intact ipsilateral auditory pathway. Crossing fibers in the trapezoid body also appear to make contributions to the normal generation of wave V.