title: Monopolar high-frequency language mapping: can it help in the surgical management of gliomas? A comparative clinical study.
abstract: OBJECT Intraoperative language mapping is traditionally performed with low-frequency bipolar stimulation (LFBS). High-frequency train-of-five stimulation delivered by a monopolar probe (HFMS) is an alternative technique for motor mapping, with a lower reported seizure incidence. The application of HFMS in language mapping is still limited. Authors of this study assessed the efficacy and safety of HFMS for language mapping during awake surgery, exploring its clinical impact compared with that of LFBS. METHODS Fifty-nine patients underwent awake surgery with neuropsychological testing, and LFBS and HFMS were compared. Frequency, type, and site of evoked interference were recorded. Language was scored preoperatively and 1 week and 3 months after surgery. Extent of resection was calculated as well. RESULTS High-frequency monopolar stimulation induced a language disturbance when the repetition rate was set at 3 Hz. Interference with counting (p = 0.17) and naming (p = 0.228) did not vary between HFMS and LFBS. These results held true when preoperative tumor volume, lesion site, histology, and recurrent surgery were considered. Intraoperative responses (1603) in all patients were compared. The error rate for both modalities differed from baseline values (p < 0.001) but not with one another (p = 0.06). Low-frequency bipolar stimulation sensitivity (0.458) and precision (0.665) were slightly higher than the HFMS counterparts (0.367 and 0.582, respectively). The error rate across the 3 types of language errors (articulatory, anomia, paraphasia) did not differ between the 2 stimulation methods (p = 0.279). CONCLUSIONS With proper setting adjustments, HFMS is a safe and effective technique for language mapping.
authors.affiliation: Neurosurgery, Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Rozzano (MI).
authors.forename: Marco
authors.initials: M
authors.lastname: Riva
authors.affiliation: Neurosurgery, Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Rozzano (MI).|Unit of Neurosurgical Oncology, Humanitas Research Hospital, Rozzano (MI), and.
authors.forename: Enrica
authors.initials: E
authors.lastname: Fava
authors.affiliation: Faculty of Psychology, Università di Milano Bicocca, Milan, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Gallucci
authors.affiliation: Unit of Neurosurgical Oncology, Humanitas Research Hospital, Rozzano (MI), and.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Comi
authors.affiliation: Unit of Neurosurgical Oncology, Humanitas Research Hospital, Rozzano (MI), and.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Casarotti
authors.affiliation: Neurosurgery, Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Rozzano (MI).
authors.forename: Tommaso
authors.initials: T
authors.lastname: Alfiero
authors.affiliation: Neurosurgery, Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Rozzano (MI).
authors.forename: Fabio A
authors.initials: FA
authors.lastname: Raneri
authors.affiliation: Unit of Neurosurgical Oncology, Humanitas Research Hospital, Rozzano (MI), and.
authors.forename: Federico
authors.initials: F
authors.lastname: Pessina
authors.affiliation: Neurosurgery, Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Rozzano (MI).|Unit of Neurosurgical Oncology, Humanitas Research Hospital, Rozzano (MI), and.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bello
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000503:physiopathology* / Q000601:surgery*; D004558:Electric Stimulation / Q000295:instrumentation / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D007432:Intraoperative Period; D007802:Language; D007806:Language Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D061214:Patient Safety; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control
keywords: AD = afterdischarge; DES = direct electrical stimulation; ECoG = electrocorticography; EEG = electroencephalography; EMG = electromyography; EOR = extent of resection; HFMS = high-frequency monopolar stimulation; HGG = high-grade glioma; LFBS = low-frequency bipolar stimulation; LGG = low-grade glioma; MEP = motor evoked potential; awake brain surgery; diagnostic and operative techniques; direct electrical stimulation; glioma; language mapping