Auditory brain-stem response audiometry in patients with Bell's palsy.

To evaluate the hypothesis of central nervous system involvement in Bell's palsy, the auditory brain-stem responses (ABR) of 32 patients were studied. In 14 (43.7%) of these patients ABR abnormalities were found. In each case the ABR deviation suggested prolonged brain-stem conduction time, independent of the side or severity of the paralysis. Site of lesion tests in this sample failed to demonstrate eighth nerve dysfunction and, thus, does not support a theory of a polyneuropathy that involves the auditory nerve.