Relative distribution of lactate, pyruvate, and glucose in cerebrospinal fluid, arterial blood, and jugular blood has been determined in patients in status of coma following cerebrovascular accidents and compared with values obtained in patients without CNS disorders. Ratios of lactate/pyruvate and arteriovenous differences were calculated. In the cerebrospinal fluid of these patients a significant increase of lactate concentration and of the lactate/pyruvate ratio was observed.