Original Research ARTICLE
Language dominance in patients with malformations of cortical development and epilepsy
- 1Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Austria
- 2Department of Neurology, Medical University of Innsbruck, Austria
- 3Department of Neuroradiology, Medical University of Innsbruck, Austria
- 4Sanatorium Chain Bridge of the Sisters of Mercy, Austria
- 5Neuroscience Institute, Christian Doppler Klinik, Paracelsus Medical University of Salzburg, Austria
- 6Department of Psychology and Centre for Cognitive Neuroscience, University of Salzburg, Austria
- 7Department of Pediatrics, Medical University of Innsbruck, Austria
- 8Hospital in the City of Dornbirn, Austria
- 9Institute of Psychology, University of Graz, Austria
- 10Department of Diagnostic and Interventional Radiology and Neuroradiology, Community Center Mittelrhein gGmbH, Germany
- 11Centre for Cognitive Neuroscience, University of Salzburg, Austria
Objective: Language function may be reorganized in patients with malformations of cortical development (MCD). This prospective cohort study aimed assessing language dominance in a large group of patients with MCD and epilepsy by use of functional MRI (fMRI).
Methods: Sixty-eight patients (40 women) aged 10 - 73 years (median 28.0; interquartile range 22-41) with MCD and epilepsy underwent 1.5 Tesla MRI and fMRI (word generation task). Single-subject image analysis was performed with statistical parametric mapping (SPM12). Language lateralization indices (LIs) were defined for statistically significantly activated voxels in Broca's and Wernicke's areas using the formula: LI = (VL -VR)/(VL + VR) x100, where VL and VR were sets of activated voxels on the left and on the right respectively. Language laterality was considered typical if LI was between +20 and +100 or atypical if LI was between +19 and -100.
Results: FMRI signal was elicited in 55/68 (81%) patients. In 18/55 (33%) patients, language dominance was typical and in 37/55 (67%) - atypical (in 68% – right hemispheric; in 32% – bilateral). There was a tendency of occurrence of an atypical language dominance in left-handers and in patients with left-hemispheric and bilateral MCD vs. right-hemispheric MCD as well as in those with left-hemispheric and bilateral vs. right-hemispheric seizure foci. Language dominance was not influenced by other electro-clinical and imaging features.
Conclusions: In this prospective study on a large group of patients with MCD and epilepsy, about two-thirds had atypical language dominance. These results may contribute to assessing risks of post-surgical language deficits and could assist in planning of "cortical mapping" with intracranial electrodes in patients who undergo pre-surgical assessment.
Keywords: Epilepsy, functional MRI (fMRI), Language, epilepsy surgery, Malformations of cortical development (MCD)
Received: 21 May 2019;
Accepted: 30 Oct 2019.
Copyright: © 2019 Kuchukhidze, Siedentopf, Unterberger, Koppelstaetter, Kronbichler, Zamarian, Haberlandt, Ischebeck, Delazer, Felber and Trinka. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: MD, PhD. Giorgi Kuchukhidze, Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria, email@example.com