Feasibility Study of Language Lateralization using Thai Version of Language Paradigm for Functional MRI in Clinical...

Area of Science:

• Neuroimaging
• Neurology
• Language Neuroscience

Background:

• Determining language lateralization is crucial for neurosurgical planning.
• Functional magnetic resonance imaging (fMRI) offers a non-invasive method for language mapping.
• The Wada test and direct cortical stimulation (DCS) are considered gold standards but are invasive.

Purpose of the Study:

• To evaluate the concordance of language lateralization between fMRI and invasive methods (Wada test or DCS).
• To assess the utility of a Thai language paradigm for fMRI-based language lateralization.
• To identify optimal fMRI calculation methods for reliable language mapping.

Main Methods:

• Retrospective study of 13 patients (epilepsy or brain tumor) who underwent both fMRI and Wada test/DCS.
• fMRI utilized Thai language paradigms (word generation, verb generation, picture naming, sentence completion).
• Language lateralization index (LI) was calculated using LI-toolbox on SPM8 and visually assessed; Wada/DCS served as the gold standard.

Main Results:

• Visual assessment of fMRI showed 92.3% concordance with the gold standard.
• Concordance varied with fMRI calculation methods; frontal lobe and whole-brain (excluding cerebellum/occipital lobe) analyses yielded the best results (76.92-92.31%).
• The naming picture task showed lower concordance compared to other tasks.

Conclusions:

• fMRI with a Thai language paradigm demonstrates good concordance with invasive methods for language lateralization.
• Regional fMRI calculations, particularly from frontal lobes, provide reliable language mapping.
• fMRI is a feasible, non-invasive alternative for language dominant hemisphere determination in Thai patients, though invasive tests remain crucial for unclear cases.