Cerebral ischemia and brain related complications after cardiac surgery

The prognostic estimation of cerebral complications after cardiac surgery is a major problem in the early postoperative period. Neuropsychologic testing and neurologic examination have been common methods of assessing cerebral injury (2, 6). Recent investigations have found clinically significant neurologic or neuropsychologic residuals in 5 % to 15 % of the patients (5, 10, 14, 17, 19 – 23). But we have been interested in finding biochemical markers capable of detecting and quantifying the extent of cerebral injury. Neuron specific enolase (NSE) is an enzyme involved in glycolysis which is localized in neurons and axonal processes, S-100 is an astroglial specific protein with calcium-binding capacity and a molecular weight of 21000. Both peptides escape into the blood and cerebrospinal fluid at the time of neural injury (3, 8, 9, 11, 17, 21). Very recently, increased NSE serum levels in human cerebral infarction, subarachnoid hemorrhage and head injury have been reported and also preliminary findings of NSE and Protein S-100 in blood after open-heart surgery (1, 3, 4, 7, 12 – 14). Primary goal of the study was to assess the value of NSE and S-100 as markers for brain ischemia after cardiac surgery.