Fig. 5. Graph showing the time course of cerebrospinal fluid (CSF) interleukin 6 (IL-6) concentration in three groups of patients: placebo (control), 1-day preoperative cyclooxygenase-2 (COX-2) inhibitor, 5-day preoperative COX-2 inhibitor. Baseline values did not differ between groups. Asterisks indicate significant difference (  P < 0.05) from placebo group. Note: IL-6 values at 1 and 3 h for the 1-day drug group and at 1, 3, and 24 h for the 5-day group are below the detection limit.