Cerebral metabolism following brain injury. II. Lactic acid changes.

Lactic acid levels were estimated in cerebrospinal fluid and blood of 25 normal individuals and 50 patients with varying grades of head injury. CSF lactic acid levels showed significant elevation proportionate to the degree of brain injury. Elevation of blood lactic acid was less pronounced. CSF lactic acid levels closely correlated with the prognosis of the case, and an increase above 50 mgm% was not compatible with life.