Open surgery, however, has a small, but real, risk of perisurgical complications such as bleeding, infection, and postoperative pain. Second, open surgery is expensive. Although a formal cost comparison for epilepsy treatment has not been done, the average cost per patient for open microsurgery was nearly 50% more than that for GKS for treatment of similar disorders.27Third, some of the reported adverse events of temporal lobectomy involve changes in results of neuropsychological testing. Fourth, some patients are reluctant to undergo elective open surgery with required inpatient stay and general anesthesia despite proven efficacy. Thus, GKS may offer a noninvasive alternative to open surgery in the pursuit of less postsurgical morbidity and less cost.