Evaluation of postmortem S100B levels in the cerebrospinal fluid with regard to the cause of death in medicolegal autopsy.

Previous studies have suggested the usefulness of the postmortem serum S100B level as a marker of the severity of brain damage. In this study, we investigated the S100B level in the cerebrospinal fluid (CSF) in serial autopsy cases (n=216, within 3 days postmortem), including those of blunt injury (n=34: fatal head injury, n=20; others, n=14), sharp instrument injury (n=9), mechanical asphyxiation (n=19), drowning (n=11), fire fatality (n=26), intoxication (n=20), hypothermia (cold exposure, n=16), hyperthermia (heat stroke, n=9), acute cardiac death (n=52) and pneumonia (n=20). The CSF S100B level showed a moderate postmortem time-dependent increase for acute cardiac death (r=0.58, p<0.0001) and asphyxia (r=0.741, p<0.001). In cases of survival time within 48 h, drowning and hypothermia usually showed a lower CSF S100B level (around 500 ng/ml), and the level was higher for delayed head injury death, asphyxia, intoxication, and hyperthermia (around 1500 ng/ml) (p<0.05). In fatal head injury cases, however, CSF S100B did not correlate with the survival time or postmortem interval. A CSF S100B level of >2000 ng/ml in the early postmortem period might be considered a biochemical sign of fatally severe brain damage.