title: Real-time functional mapping: potential tool for improving language outcome in pediatric epilepsy surgery.
abstract: Accurate language localization expands surgical treatment options for epilepsy patients and reduces the risk of postsurgery language deficits. Electrical cortical stimulation mapping (ESM) is considered to be the clinical gold standard for language localization. While ESM affords clinically valuable results, it can be poorly tolerated by children, requires active participation and compliance, carries a risk of inducing seizures, is highly time consuming, and is labor intensive. Given these limitations, alternative and/or complementary functional localization methods such as analysis of electrocorticographic (ECoG) activity in high gamma frequency band in real time are needed to precisely identify eloquent cortex in children. In this case report, the authors examined 1) the use of real-time functional mapping (RTFM) for language localization in a high gamma frequency band derived from ECoG to guide surgery in an epileptic pediatric patient and 2) the relationship of RTFM mapping results to postsurgical language outcomes. The authors found that RTFM demonstrated relatively high sensitivity (75%) and high specificity (90%) when compared with ESM in a "next-neighbor" analysis. While overlapping with ESM in the superior temporal region, RTFM showed a few other areas of activation related to expressive language function, areas that were eventually resected during the surgery. The authors speculate that this resection may be associated with observed postsurgical expressive language deficits. With additional validation in more subjects, this finding would suggest that surgical planning and associated assessment of the risk/benefit ratio would benefit from information provided by RTFM mapping.
authors.affiliation: Functional Brain Mapping and Brain-Computer Interface Lab, Center for Pediatric Research and Outcomes and Comprehensive Pediatric Epilepsy Center;
authors.forename: Milena
authors.initials: M
authors.lastname: Korostenskaja
authors.forename: Po-Ching
authors.initials: PC
authors.lastname: Chen
authors.forename: Christine M
authors.initials: CM
authors.lastname: Salinas
authors.forename: Michael
authors.initials: M
authors.lastname: Westerveld
authors.forename: Peter
authors.initials: P
authors.lastname: Brunner
authors.forename: Gerwin
authors.initials: G
authors.lastname: Schalk
authors.forename: Jane C
authors.initials: JC
authors.lastname: Cook
authors.forename: James
authors.initials: J
authors.lastname: Baumgartner
authors.forename: Ki H
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000927:Anticonvulsants / Q000627:therapeutic use; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000503:physiopathology*; D004558:Electric Stimulation; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000188:drug therapy / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007802:Language; D009483:Neuropsychological Tests; D012680:Sensitivity and Specificity; D013060:Speech
chemical_list: D000927:Anticonvulsants
keywords: ECoG = electrocorticography; EEG = electroencephalography; ESM = electrical cortical stimulation mapping; RTFM = real-time functional mapping; SIGFRIED; SIGFRIED = SIGnal modeling For Real-time Identification and Event Detection; brain-computer interface; cortical stimulation mapping; electrocorticography; epilepsy surgery; real-time functional mapping