Cerebrospinal fluid cystatin C levels following treatment for aneurysmal subarachnoid hemorrhage.

Aim: To investigate the changes of cerebrospinal fluid (CSF) cystatin C (CC) levels associated with the postoperative ischemic conditions and prognostic outcome in patients with aneurysmal subarachnoid hemorrhage (SAH).
Material and Methods: The study group consisted of 40 patients with microsurgically clipped intracranial aneurysms (IA's) and 22 control CSF samples. In patients, CSF samples were taken from the lumbar intrathecal catheter for CC measurement, at the beginning of operation, immediately after the operation (early postoperative), and the first postoperative day (late postoperative).
Results: CC levels in three periods were significantly higher in patients with Hunt-Hess scores of 4, 5 than 1, 2, 3. There was a significant difference between the CC concentrations on the first postoperative day and controls. In patients who developed focal cerebral ischemia, CC levels at early and late postoperative periods were significantly higher than the group without ischemia. In addition, patients with poor prognostic outcome (GOS score of 1, 2, 3) had significantly higher levels of CC in all three periods than that of patients with good outcome (GOS score of 4, 5).
Conclusion: The raised CSF CC concentrations appear to be associated with the severity of bleeding, intraoperative ischemic events and poor prognostic outcome in patients with aneurysmal SAH.