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Extraoperative neurostimulation mapping: Results from an international survey of epilepsy surgery programs
Author(s) -
Hamberger Marla J.,
Williams Alicia C.,
Schevon Catherine A.
Publication year - 2014
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/epi.12644
Subject(s) - neurostimulation , epilepsy surgery , epilepsy , medicine , brain mapping , clinical practice , physical medicine and rehabilitation , psychology , stimulation , physical therapy , neuroscience , psychiatry , radiology
Summary Objective Extraoperative electrical stimulation mapping ( ESM ) to identify functional cortex is performed prior to neurosurgical resection at epilepsy surgery programs worldwide. However, the procedure remains unstandardized, with no established clinical guidelines. We sought to determine the current range in ESM practice parameters across established epilepsy surgery centers. Methods We developed and distributed a 31‐question survey to 220 epilepsy centers worldwide regarding current practice parameters of ESM . Questions addressed preoperative assessment, technical stimulation parameters, language testing protocols, criteria for identification of positive or negative functional sites, management of mapping complications, and postoperative functional outcome. Results Survey responses were obtained from 56 centers. These revealed marked practice variability in virtually all aspects of the ESM procedure. These aspects included critical procedure components such as electrical stimulation settings, the types of language functions tested, the operational definition of a language error, size of surgical resection margin, cortical locations mapped for language, testing in the presence of afterdischarges, and medical management of mapping complications. Forty‐one percent of centers reported at least one persistent adverse language outcome despite preserving all eloquent sites defined by their stimulation mapping procedure. Significance The striking variations in practice across centers are likely to influence mapping results, which directly affect the boundaries of cortical resection and, consequently, might worsen either seizure or functional outcomes. Clearly, adverse functional outcomes occur despite mapping procedures that were perceived to be adequate. Investigation of critical technical and procedural aspects of stimulation mapping is warranted, with the ultimate goal of establishing empirically based practice guidelines to improve the safety and efficacy of ESM and resective epilepsy surgery. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here .