MEG Assessment of Expressive Language in Children Evaluated for Epilepsy Surgery


Establishing language dominance is an important step in the presurgical evaluation of patients with refractory epilepsy. In the absence of a universally accepted gold-standard non-invasive method to determine language dominance in the preoperative assessment, a range of tools and methodologies have recently received attention. When applied to pediatric age, many of the proposed methods, such as functional magnetic resonance imaging (fMRI), may present some challenges due to the time-varying effects of epileptogenic lesions and of on-going seizures on maturational phenomena. Magnetoencephalography (MEG) has the advantage of being insensitive to the distortive effects of anatomical lesions on brain microvasculature and to differences in the metabolism or vascularization of the developing brain and also provides a less intimidating recording environment for younger children. In this study we investigated the reliability of lateralized synchronous cortical activation during a verb generation task in a group of 28 children (10 males and 18 females, mean age 12 years) with refractory epilepsy who were evaluated for epilepsy surgery. The verb generation task was associated with significant decreases in beta oscillatory power (13–30 Hz) in frontal and temporal lobes. The MEG data were compared with other available presurgical non-invasive data including cortical stimulation, neuropsychological and fMRI data on language lateralization where available. We found that the lateralization of MEG beta power reduction was concordant with language dominance determined by one or more different assessment methods (i.e. cortical stimulation mapping, neuropsychological, fMRI or post-operative data) in 89% of patients. Our data suggest that qualitative hemispheric differences in task-related changes of spectral power could offer a promising insight into the contribution of dominant and non-dominant hemispheres in language processing and may help to characterize the specialization and lateralization of language processes in children.

Publication DOI:
Divisions: College of Health & Life Sciences > School of Psychology
College of Health & Life Sciences > Aston Institute of Health & Neurodevelopment (AIHN)
College of Health & Life Sciences
College of Health & Life Sciences > Clinical and Systems Neuroscience
Additional Information: © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Uncontrolled Keywords: Beamformers,Children,Epilepsy surgery,Functional mapping,Hemispheric dominance,Language lateralization,Magnetoencephalography,Anatomy,Radiological and Ultrasound Technology,Radiology Nuclear Medicine and imaging,Neurology,Clinical Neurology
Publication ISSN: 1573-6792
Last Modified: 08 Jul 2024 07:48
Date Deposited: 27 Mar 2019 10:05
Full Text Link:
Related URLs: http://link.spr ... 548-019-00703-1 (Publisher URL)
http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2019-05-01
Published Online Date: 2019-03-20
Accepted Date: 2019-03-07
Authors: Foley, Elaine (ORCID Profile 0000-0003-4459-9855)
Cross, J. Helen
Thai, Ngoc J.
Walsh, A. Richard
Bill, Peter
Furlong, Paul (ORCID Profile 0000-0002-9840-8586)
Wood, Amanda G. (ORCID Profile 0000-0002-1537-6858)
Cerquiglini, Antonella
Seri, Stefano (ORCID Profile 0000-0002-9247-8102)



Version: Published Version

License: Creative Commons Attribution

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