Electrophysiological analysis of various brain stem reflexes in multiple sclerosis

: An electrophysiological study of "blink reflex" and "jaw reflex" was carried out on 20 sicilian patients with "definited" Multiple Sclerosis. The R1 component of the "blink reflex" was abnormal in 13 patients on 20 (65%), the R2 component in 8 patients on 20 (40%). Considering together the R1 and R2 responses, the abnormal percentage was 75%. The "jaw reflex" showed abnormal responses in 5 patients on 20 (25%). Considering both the "blink reflex" and "jaw reflex", the pathological percentage was 75%, in order that no patients had isolated changes of the "jaw reflex". The simultaneous study of the two reflexes does not increase the probability to prove pathological responses. The frequency of the clinically silent brain-stem lesions in our patients was not substantially different from that showed by other authors on different populations.