title: The variability of stimulus thresholds in electrophysiologic cortical language mapping.
abstract: The aim of this study was to investigate the variability of electrical stimulation threshold in cortical language mapping in relationship to the lobar location of the mapped eloquent cortex and the distance between the latter and the location of the cortical lesion. A multivariate linear regression analysis was performed in a sample of 39 patients who underwent standardized successful language cortical mapping. Estimated stimulus threshold for temporal language cortex was 1.45 times higher than the estimated threshold for frontal language cortex, after adjusting for the other variables (P = 0.017). Stimulation of the mapped cortex in close proximity to the lesion or to the lesional edema increased the estimated threshold 2.6 or 1.8 times, respectively, compared with stimulation in other areas, after adjusting for the other variables (P < 0.0001, P = 0.0017). In concordance with prior findings, our results show that stimulus threshold in cortical language mapping is dependent on the lobar location of the mapped cortex. In addition, stimulus threshold is increased when the mapped cortex is in close proximity to the location of the lesion or perilesional edema.
authors.affiliation: Clinical Neurophysiology Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, U.S.A.
authors.forename: Sonya G
authors.initials: SG
authors.lastname: Wang
authors.forename: Emad N
authors.initials: EN
authors.lastname: Eskandar
authors.forename: Ronan
authors.initials: R
authors.lastname: Kilbride
authors.forename: Keith H
authors.initials: KH
authors.lastname: Chiappa
authors.forename: William T
authors.initials: WT
authors.lastname: Curry
authors.forename: Ziv
authors.initials: Z
authors.lastname: Williams
authors.forename: Mirela V
authors.initials: MV
authors.lastname: Simon
mesh_terms: D000328:Adult; D000368:Aged; D001900:Boston; D001929:Brain Edema / Q000503:physiopathology / Q000601:surgery; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology*; D016292:Procedural Sedation; D003399:Craniotomy / Q000009:adverse effects; D004558:Electric Stimulation; D004827:Epilepsy / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D007802:Language; D016014:Linear Models; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012684:Sensory Thresholds; D015173:Supratentorial Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D013702:Temporal Lobe / Q000503:physiopathology; D055815:Young Adult