Effect of cortical cooling on interictal epileptiform activities

OBJECTIVE To determine if applying chilled solution to exposed cerebral cortex can reduce interictal epileptiform activities in patients during surgery. METHODS Electrocorticography was used to record the epileptiform activity of 12 patients (ages 18-53) undergoing cortical mapping and resection surgery. Interictal spikes were counted at baseline and compared with spikes after applying room temperature and chilled Lactated Ringer's or normal saline solution. RESULTS Cortical irrigation with 150-cm(3), chilled (4 degrees C) normal saline solution reduced the mean number of interictal spikes from 11.46 to 4.87 spikes per minute (p=0.04). There was no significant reduction in the epileptic spike frequency when room temperature normal saline was used. CONCLUSION The application of chilled solution directly to the cortex can reduce interictal epileptiform activities, suggesting that seizure potential can be suppressed to avoid evoked seizures during intraoperative surgery.