Original Research ARTICLE
Language mapping in multilingual patients: electrocorticography and cortical stimulation during naming
- 1 Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- 2 Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
Multilingual patients pose a unique challenge when planning epilepsy surgery near language cortex because the cortical representations of each language may be distinct. These distinctions may not be evident with routine electrocortical stimulation mapping (ESM). Electrocorticography (ECoG) has recently been used to detect task-related spectral perturbations associated with functional brain activation. We hypothesized that using broadband high gamma augmentation (HGA, 60–150 Hz) as an index of cortical activation, ECoG would complement ESM in discriminating the cortical representations of first (L1) and second (L2) languages. We studied four adult patients for whom English was a second language, in whom subdural electrodes (a total of 358) were implanted to guide epilepsy surgery. Patients underwent ECoG recordings and ESM while performing the same visual object naming task in L1 and L2. In three of four patients, ECoG found sites activated during naming in one language but not the other. These language-specific sites were not identified using ESM. In addition, ECoG HGA was observed at more sites during L2 versus L1 naming in two patients, suggesting that L2 processing required additional cortical resources compared to L1 processing in these individuals. Post-operative language deficits were identified in three patients (one in L2 only). These deficits were predicted by ECoG spectral mapping but not by ESM. These results suggest that pre-surgical mapping should include evaluation of all utilized languages to avoid post-operative functional deficits. Finally, this study suggests that ECoG spectral mapping may potentially complement the results of ESM of language.
Keywords: multilingual, naming, electrocorticography, ECoG, high gamma, functional mapping, electrocortical stimulation mapping, epilepsy surgery
Citation: Cervenka MC, Boatman-Reich DF, Ward J, Franaszczuk PJ and Crone NE (2011) Language mapping in multilingual patients: electrocorticography and cortical stimulation during naming. Front. Hum. Neurosci. 5:13. doi: 10.3389/fnhum.2011.00013
Received: 30 July 2010;
Accepted: 23 January 2011;
Published online: 22 February 2011.
Edited by:Olivier Bertrand, INSERM, France
Reviewed by:Catherine Liegeois-Chauvel, INSERM, France
Monica Baciu, Université Pierre Mendès-France, France
Copyright: © 2011 Cervenka, Boatman-Reich, Ward, Franaszczuk and Crone. This is an open-access article subject to an exclusive license agreement between the authors and Frontiers Media SA, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence: Mackenzie C. Cervenka, Department of Neurology, Johns Hopkins University School of Medicine, Meyer 2-147, 600 North Wolfe Street, Baltimore, MD 21287-7247, USA. e-mail: email@example.com