“…The origin of the sixth and seventh component is unknown. The investiga tion of ABEPs has shown to be of great advan tage in various diseases affecting the brain stem, as was demonstrated in patients with brain stem tumors (Starr and Achor, 1975;Starr and Hamilton, 1976), in acoustic neuromas (Sellers and Brackmann, 1977;Thomsen et al, 1978;Maurer et al, 1979), in comatose states (Starr and Achor, 1975 ;Uziel and Benezech, 1978), anoxic brain damage (Starr and Hamilton, 1976) as well as in multiple sclerosis (MS) (Starr and Achor, 1975;Robinson and Rudge, 1975. The MS patients, who were presented by these authors, were all clinically definite cases (see below), except 3 patients in the study of Robinson and Rudge (1975), who were classified as probable.…”