Slow tremor and delayed brainstem auditory evoked responses in alcoholics.

Interpeak intervals of the auditory brainstem evoked electric response (ABR) were measured in 13 patients showing a characteristic slow rhythmic tremor and a more or less marked chronic cerebellar ataxia. Eleven of these patients were advanced alcoholics; two were less severe alcoholics. The tremor appeared primarily in the legs, and displayed distinctive features when examined in appropriate postures. Ten of the patients displayed a significant increase of the I-V interval of the ABR. The occurrence of the slow tremor with abnormal electric brainstem responses may provide objective evidence of lesions affecting extracerebellar regions of the CNS.