[Diagnostic value of the cerebrospinal fluid-blood lactate quotient in mental disorders in elderly persons].

The lactate levels of cerebrospinal fluid and blood were measured enzymatically and simultaneously in 40 gero-psychiatric patients. After calculating the fluid-blood-lactate-quotients, two distinct groups emerged, whose mean quotients showed significant difference. In the first group (15 patients) with a mean quotient of 1.06, the diagnosis of cerebral arteriosclerosis was clinically confirmed in only one case. In the second group (21 patients) with a mean quotient of 1.42, however, this occurred sixteen times, which represents a proportion of 2/3. Thus, it appears that a higher quotient suggests the diagnosis of cerebral arteriosclerosis. Further examinations are though necessary.