Evaluation and graduation of brain stem auditory evoked potentials in patients with neurological diseases.

Based on normative data from 40 subjects, criteria for evaluating brain stem auditory evoked potentials have been elaborated. This system contained six grades from normal to diffusely abnormal, and was used in evaluating recordings from 142 patients, including 38 patients with definite and 48 with probable and possible multiple sclerosis, 18 patients with brain stem infarctions, six patients with other organic brain stem lesions, six patients with a postcommotional syndrome and 26 patients without any brain stem involvement. A statistically significant difference was found between normal persons and patients without evidence of brain stem lesions versus patients with such evidence, as well as between subgroups of slightly and severely affected patients. The system was found useful as a way of describing recordings, in company groups of patients and in a follow up of a few patients.