Lactate and pyruvate content of the human cisternal cerebrospinal fluid. Normal values, age and sex dependency, correlations with glucose concentrations.

Cisternal CSF specimens were obtained from 144 fasted individuals free from organic brain disease (42 males and 102 females; mean age 41 +/- 10.3 years, range 16-69 years). In 30 cases a simultaneous lumbar puncture was also performed. The concentration of CSF glucose (G1) was measured by the o-toluidine method, and that of lactate (La) and pyruvate (Py) by enzymatic tests. No significant difference was found between the mean G1 and Py values of the lumbar and cisternal CSF but the lumbar La was somewhat higher than the cisternal one (P less than 0.10). In the cisternal CSF the frequency distribution of G1, La and Py samples was a Gaussian one (P less than 0.05). The normal ranges, as mean +/- 2SD, were for La 0.680-2.100 mM/1, and for Py lower limits of the range (between mean +/- 2 SD and mean +/- 1 SD) are considered to be potentially pathological. No significant difference was found between the mean G1, La and Py values in males and females. Consistent age-related changes could not be detected either in the G1 or Py levels, however, a tendency for La increase was observed in the oldest-age-group (over 54 years). A negative correlation was found between the G1 and La concentrations of the cisternal CSF (r = 0.375; P less than 0.001).