Language lateralization and neuroplasticity in pediatric drug-resistant focal epilepsy: A case study

Abstract

Objective: To analyze the functional and structural reorganization of language over a six-month period in a pediatric patient with drug-resistant focal epilepsy (DRE), using functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) tractography. Methods: We report a right handed, 7 year old boy with nonlesional drug resistant epilepsy; seizures began at age 7, and the epileptogenic zone localized to the left temporoparietal junction. Pre-surgical fMRI studies were performed to assess language lateralization, and DTI was employed to evaluate structural connectivity changes in language-related pathways. In addition, stereo­electroencephalography (SEEG) was carried out to delineate the epileptogenic zone and to validate functional findings through cortical mapping. Results: Baseline fMRI demonstrated typical left-hemispheric language dominance. Six months later, the laterality index had reversed, indicating functional reorganization toward the right hemisphere. DTI revealed increased fractional anisotropy (FA) in the right arcuate fasciculus and reduced connectivity on the left. SEEG confirmed the feasibility of surgical resection without significant language decline. Neuropsychological testing in the acute postoperative phase showed no major changes in test scores, including the Intelligence Quotient, and no significant alterations in language performance. Conclusions: This case illustrates early brain plasticity and its contribution to functional reorganization of language in response to epileptogenic activity, as well as its potential protective role for cognitive function. The integration of fMRI, DTI, and SEEG is essential for surgical planning in pediatric drug-resistant epilepsy.