Do blood concentrations of neurone specific enolase and S-100β protein reflect cognitive dysfunction after abdominal surgery?

Neurone specific enolase (NSE) and S-100 beta protein have been used as markers of brain damage. We hypothesized that blood concentrations of NSE and S-100 beta protein reflect cognitive dysfunction after abdominal surgery. We studied 65 elderly patients in whom neuropsychological testing was performed before abdominal surgery, at discharge from hospital and after 3 months. Serum concentrations of NSE and S-100 beta protein were measured before surgery and after 24, 48 and 72 h. Serum concentrations of S-100 beta protein increased significantly while NSE concentrations decreased significantly. The increase in S-100 beta protein concentration after 48 h was significantly greater in patients with delirium. No correlation was found between cognitive dysfunction and S-100 beta protein or NSE concentration. We conclude that blood concentrations of S-100 beta protein increase after abdominal surgery and may be related to postoperative delirium.