Effectiveness of antiepileptic prophylaxis used with supratentorial craniotomies: a meta-analysis.

Thirty publications on the effectiveness of prophylactic antiepileptic drugs (AEDs) with supratentorial craniotomies were reviewed (1980-1995). After a first selection, six controlled studies remained (11 publications). These six were evaluated according to previously defined methodological criteria. The criteria were divided into three main categories: (1) internal validity, (2) proper and relevant outcome-measures and (3) analysis. In this way a maximum of 145 points could be obtained for each study. Three studies were considered to be of satisfactory methodological quality (> or = 55% or 145 points) and the odds ratios were calculated as a measure of association between treatment and occurrence of convulsions. The odds ratios of these three studies were statistically pooled using the Mantel-Haenszel Estimator. From this test it appeared that prophylactically used AEDs showed a tendency to prevent postoperative convulsions, but this effect was certainly not statistically significant (P = 0.1 one-tailed). Points of attention concerning possible future investigations are stressed.