Brainstem auditory evoked responses and quantitative saccade studies in multiple sclerosis: a comparative evaluation.

Brainstem auditory evoked responses (BAERs) and quantitative saccadic eye movement studies provide information on the integrity of pathways traversing the brainstem. To compare the relative yield of abnormalities with the two techniques, the findings in a group of 46 patients with clinically definite, probable or suspected multiple sclerosis, in whom both procedures were performed, were analysed. BAERs were abnormal in 18 cases (39%), the abnormalities being subclinical in 10 (22%). One or more saccade parameters (reaction time, velocity, accuracy) were abnormal in 31 cases (67%), the abnormalities being subclinical in 19 (41%). When the results of both procedures were taken into account, the overall incidence of abnormalities was 76% and the overall incidence of subclinical abnormalities was 52%. Abnormalities were found with both techniques in 15 cases and with neither technique in 12 cases. Sixteen cases with normal BAERs had an abnormal saccade study, but only three cases with a normal saccade study had abnormal BAERs. It is concluded that BAERs and quantitative saccade studies have a complementary role in the investigation of patients with multiple sclerosis.