Utility of adding electrodes in patients undergoing invasive seizure localization: A case series. (August 2022)

• Record Type: Journal Article
• Authors: Chan, Alvin Y.; Lien, Brian V.; Brown, Nolan J.; Gendreau, Julian; Beyer, Ryan S.; Yang, Chen Yi; Choi, Elliot H.; Hsu, Frank P.K.; Vadera, Sumeet
• Is Part Of: Annals of medicine and surgery. Volume 80(2022)
• Publication Date: 2022-08
• Subjects: Electrode -- Epilepsy -- SEEG -- Seizure -- Stereoelectroencephalography -- Subdural grid; Surgery -- Periodicals; Medicine -- Periodicals; General Surgery -- Periodicals; Education, Medical -- Periodicals; Periodicals; 617
• DOI: 10.1016/j.amsu.2022.104139
• Languages: English
• ISSNs: 2049-0801

Abstract

Abstract: Introduction: Surgery can be an effective treatment for epilepsy if the seizure onset is adequately localized. Invasive monitoring is used if noninvasive methods are inconclusive. Initial invasive monitoring may fail if the pre-surgical hypothesis regarding location of epileptic foci is wrong. At this point, a decision must be made whether to remove all electrodes without a clearly defined location of onset or to implant additional electrodes with the aim of achieving localization by expanding coverage. Methods: Electrodes were placed according to a hypothesis derived from noninvasive monitoring techniques in adult patients with long term epilepsy. Seizure onset was not clearly localized at the end of the invasive monitoring period in ten patients, and additional electrodes were placed based on a new hypothesis that incorporated data from the invasive monitoring period. Results: Successful localization was achieved in nine patients. There were no complications with adding additional electrodes. At final follow up, four patients were seizure free while four others had at least a 50% reduction in seizures after undergoing surgical intervention. Conclusion: Seizure foci were localized safely in 90% of adult patients with long term epilepsy after implanting additional electrodes and expanding coverage. Patients undergoing invasive monitoring without clear localization should have additional electrodes placed to expand monitoring coverage as it is safe and effective. Highlights: Additional electrodes in invasive monitoring are safe and effective. Expanded coverage safely localized seizure foci in 90% of patients. Complete cessation or significant reduction in seizures was observed for all patients. No complications were associated with adding additional electrodes.