Relationship of neuron specific enolase and protein S-100 concentrations in systemic and jugular venous serum to injury severity and outcome after traumatic brain injury

Neuron specific enolase (NSE) and protein S-100 have previously been described as markers of brain injury. We aimed to discover whether concentrations of either were raised in arterial and jugular venous serum after traumatic brain injury, and whether serum profiles were related to injury severity and neurological outcome. We recruited 22 patients with a traumatic brain injury who were admitted to the intensive care unit. Paired arterial and jugular venous blood samples were taken on admission, and at 24, 48 and 96 hrs after injury. Samples were analysed for NSE and S-100 by RIA. Concentrations of both NSE and S-100 were increased above controls--mean NSE concentration was highest on admission, whilst mean S-100 peaked at 24 hours after injury. There was a small, but significant difference between jugular venous and arterial concentrations of S-100 (p = 0.022). High NSE and S-100 concentrations were significantly related to poor neurological outcome (p = 0.004 and p < 0.001 respectively). Both serum NSE and S-100 may be of some value in helping to predict outcome after a traumatic brain injury