Brainstem auditory evoked potentials in patients with cerebellopontine angle tumors.

Changes in the brainstem auditory evoked potentials of 27 patients with cerebellopontine angle tumors were analyzed. It was found that the most characteristic change was an increase in the latency of wave III on the affected side. In patients with tumors large enough to cause displacement of the brainstem, there was in addition an increase in the latency of wave III on the unaffected side. These results are consistent with recent observations regarding the neural generators of the brain stem auditory evoked potentials in humans.