Effect of cortical cooling on interictal epileptiform activities

AbstractObjectiveTo determine if applying chilled solution to exposed cerebral cortex can reduce interictal epileptiform activities in patients during surgery.MethodsElectrocorticography 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.ResultsCortical irrigation with 150-cm3, chilled (4°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.ConclusionThe 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

Stroke due to middle cerebral artery aneurysm clipping when the intraoperative angiogram was normal

Objective: An intraoperative angiogram (IOA) may be used to check the clipping of middle cerebral artery (MCA) aneurysms. This study analyzes the occurrence of a stroke when the IOA was normal as this has not been looked into before. Methods: The records of all patients with a normal IOA after MCA aneurysm clipping were reviewed. Patients who woke up with a stroke were selected for this study and analyzed in detail. Results: Thirty-one patients with 34 aneurysms had a normal IOA. Of those, 7 woke up with a new deficit from perforator or small artery ischemia resulting in a stroke rate of 22.6%. Five out of the 7  strokes were potentially avoidable. Conclusion: An IOA is still an important tool to check the adequacy of clip placement. However, our experience has taught us that the intent to use it should not lessen the amount of time spent dissecting and exposing the aneurysm as completely as possible. The urge to clip the neck and hope that the IOA will be favorable, when the aneurysm is not maximally exposed, should be resisted. Ideally, a full 360 degrees dissection of the aneurysm should be done to identify perforators and small arteries en passage before clipping. If this had been done, it is likely that the stroke rate would have dropped towards 6.5%