Brain Tumor-Related Epilepsy: a Current Review of the Etiologic Basis and Diagnostic and Treatment Approaches.

PURPOSE OF REVIEW: The relationship of brain tumors and seizures remains poorly understood. This article is an overview of the epidemiology, etiology, and diagnostic and treatment approaches of tumor-related epilepsy primarily with regard to glial-based tumors, the most commonly considered brain tumor in this field. RECENT FINDINGS: Over the past many years, several novel etiologic mechanisms to explain how tumors induce seizures have been developed, which this article reviews, including the roles of glutamate-induced excitotoxicity, matrix metalloproteinases, isocitrate dehydrogenase, methylguanine methyltransferase, and functional network connectivity. As well, diagnostic and treatment approaches vary considerably. This article summarizes the evidence and provides the rationale for a reconsideration of how we deliver pre-operative, peri-operative, and post-operative care to these patients. Patients with brain tumors and epilepsy are a very challenging subgroup of patients, which necessitates not just a thorough understanding of the current principles regarding tumor-related epilepsy but also the development of collaborative research to advance our knowledge even further, and a concerted effort to develop a standardized, multi-disciplinary clinical approach to improve the care of these patients.

Development and Feasibility Testing of a Critical Care EEG Monitoring Database for Standardized Clinical Reporting and Multicenter Collaborative Research.

PURPOSE: The rapid expansion of the use of continuous critical care electroencephalogram (cEEG) monitoring and resulting multicenter research studies through the Critical Care EEG Monitoring Research Consortium has created the need for a collaborative data sharing mechanism and repository. The authors describe the development of a research database incorporating the American Clinical Neurophysiology Society standardized terminology for critical care EEG monitoring. The database includes flexible report generation tools that allow for daily clinical use. METHODS: Key clinical and research variables were incorporated into a Microsoft Access database. To assess its utility for multicenter research data collection, the authors performed a 21-center feasibility study in which each center entered data from 12 consecutive intensive care unit monitoring patients. To assess its utility as a clinical report generating tool, three large volume centers used it to generate daily clinical critical care EEG reports. RESULTS: A total of 280 subjects were enrolled in the multicenter feasibility study. The duration of recording (median, 25.5 hours) varied significantly between the centers. The incidence of seizure (17.6%), periodic/rhythmic discharges (35.7%), and interictal epileptiform discharges (11.8%) was similar to previous studies. The database was used as a clinical reporting tool by 3 centers that entered a total of 3,144 unique patients covering 6,665 recording days. CONCLUSIONS: The Critical Care EEG Monitoring Research Consortium database has been successfully developed and implemented with a dual role as a collaborative research platform and a clinical reporting tool. It is now available for public download to be used as a clinical data repository and report generating tool.

Effect of an external responsive neurostimulator on seizures and electrographic discharges during subdural electrode monitoring.

PURPOSE: Approved neural-stimulation therapies for epilepsy use prolonged intermittent stimulation paradigms with no ability to respond automatically to seizures. METHODS: A responsive neurostimulator that can automatically analyze electrocortical potentials, detect electrographic seizures, and rapidly deliver targeted electrical stimuli to suppress them was evaluated in an open multicenter trial in 50 patients, 40 of whom received responsive cortical stimulation via subdural electrodes implanted for epilepsy surgery evaluations. RESULTS: Four patients, ages 15 to 28 years, monitored at three institutions, with clinical and electrographic response to neurostimulation, are described. Electrographic seizures were altered and suppressed in these patients during trials of neurostimulation lasting < or =68 h, with no major side effects. In one patient, stimulation appeared also to improve the baseline EEG. CONCLUSIONS: Responsive cortical neurostimulation may be a safe and effective treatment for partial epilepsy. This information was derived from a small group of patients in an observation study. A double-blind, controlled Food and Drug Administration (FDA)-approved study of a permanently implanted responsive neurostimulation system to treat medically refractory partial seizures is under way.