INTRATHECAL STEROIDS TO REDUCE PAIN AFTER LUMBAR DISC SURGERY - A DOUBLE-BLIND, PLACEBO-CONTROLLED PROSPECTIVE-STUDY

This double-blind, placebo-controlled prospective study investigated whether corticosteroids (beta-methasone) influence residual radicular pain after lumbar disc surgery. The study population consisted of 26 patients undergoing surgery for a herniated lumbar disc at our University Neurosurgical Department. Thirteen patients received beta-methasone intrathecally prior to wound closure, and 13 patients received normal saline. Main outcome measures were pain intensity graded on a 100-mm visual analogue pain scale (VAS) and consumption of non-steroidal anti-inflammatory agents (NSAIDs). Both patient groups had comparable presurgical findings and pain intensity level (55 mm and 54 mm, respectively, on a 100-mm VAS). After surgery, residual pain declined gradually in the placebo group (mean 39, 29, 24, 20 mm on days 1-4; 10 mm on day 8) and abruptly in the corticosteroid group (mean 15, 15, 11, 8, mm on days 1-4; 5 mm on day 8). Analysis of variance (ANOVA) showed a highly significant influence of time (P < 0.001), a significant influence of steroid application (P = 0.014) and interaction between time and application of steroids (P = 0.042). Mean daily consumption of NSAIDs did not differ significantly in either group: 124 mg in the treatment vs. 150 mg in the placebo group (P > 0.25). At follow-up after 6 months, residual radicular pain was rated equally by both groups (4 mm in the treatment vs. 5 mm in the placebo group, P > 0.5). Intrathecal application of steroids provides short-lasting, statistically significant pain reduction after lumbar disc surgery. Benefits of intrathecal steroids are probably outweighed by the risks associated with violation of the dural barrier.