Effect of propofol on the electrocorticogram in epileptic patients undergoing cortical resection

We have compared the effect of clinical doses of propofol with thiopental on epileptiform activity in the electrocorticograms (ECoG) of 20 epileptic patients undergoing temporal lobe resection. After baseline ECoG had been obtained, with inspired concentrations of 0.5-1% isoflurane and 70% nitrous oxide to provide background anaesthesia, subjects were allocated randomly to receive boluses of either thiopental 25 mg or propofol 20 mg i.v. every 30 s to a maximum of 5 mg kg-1 or until burst suppression was seen. The ECoG was recorded throughout administration and for 10 min thereafter. After return of baseline ECoG tracings, the alternate agent was administered. The amount of epileptiform activity was recorded on an ordinal rating scale, an increase being indicated by either a rise of at least one category on the scale or discharges occurring at a minimum of one new site. Activation occurred more frequently with thiopental but the difference was not significant. This study suggests that propofol has no greater proconvulsive effect than thiopental, a drug commonly used in managing status epilepticus.