Alpha coma.

Six personal cases of alpha coma are reported: 3 following a cerebrovascular accident and 3 resulting from cerebral concussion. Two patients survived. On the basis of differences in pathogenesis, EEG characteristics and prognosis, the following classification is proposed: alpha coma resulting from brain stem vascular accident; cerebral concussion; diffuse cerebral hypoxia; drug intoxication. The clinical course of each of the classes of alpha coma is outlined. The alpha coma state is not restricted to cases with structural brain stem lesions c.q. lesions of the pontomesencephalic region.