Intracranial Monitoring And Resective Epilepsy Surgery: Preoperative Predictors Of Nonprogression To Therapeutic Surgery And Long-Term Outcomes

Background: Resective surgery is efficacious in treating intractable epilepsy when an epileptogenic focus is accurately identified. Invasive monitoring is crucial when noninvasive studies are indeterminate or nonconcordant. Objective: Some patients do not progress to definitive surgery, following invasive monitoring; we aim to elucidate predictive characteristics and determine long-term outcome. Methods: Characteristics of patients in the Institutional Review Board-approved Rush University Surgical Epilepsy database who underwent invasive electroencephalography monitoring for were retrospectively analyzed to determine premonitoring factors correlating with nonprogression to definitive surgery. Results: Among 127 patients analyzed, 112 underwent resective surgery and 15 did not. Seizure freedom (Engel Class I) was realized in 63% of the surgery group and 7% of the nonsurgical group. The most common reason for not undergoing resective surgery was indeterminate epileptogenic focus localization. Factors correlating with nonprogression to surgery included bilateral pathology (P = 0.023), and factors exhibiting a trend include location, with frontal and parietal having lowest operative rates, and female gender. Conclusions: In all patient categories studied, subgroups that progressed to therapeutic surgery had better outcomes than those that did not. Lengthening invasive monitoring duration, employing newer diagnostic technologies for better seizure localization, and optimization of patient selection should be explored to improve overall outcomes. The following core competencies are addressed in this article: Medical knowledge, Patient care, Practice-based learning and improvement, Systems-based practice.