fMRI Shows Atypical Language Lateralization in Pediatric Epilepsy Patients

• Published in: Epilepsia (Copenhagen) 2006-03, Vol.47 (3), p.593-600
• Main Authors: Yuan, Weihong, Szaflarski, Jerzy P., Schmithorst, Vincent J., Schapiro, Mark, Byars, Anna W., Strawsburg, Richard H., Holland, Scott K.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age Factors; Anticonvulsants. Antiepileptics. Antiparkinson agents; Biological and medical sciences; Brain Mapping; Cerebral Cortex - physiology; Cerebral Cortex - physiopathology; Child; Epilepsy; Epilepsy - diagnosis; Epilepsy - physiopathology; Female; fMRI; Frontal Lobe - physiology; Frontal Lobe - physiopathology; Functional Laterality - physiology; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Language Development; Lateralization index; Linear Models; Magnetic Resonance Imaging; Male; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Neuronal Plasticity - physiology; Neuropharmacology; Neurosurgery; Pediatric; Pharmacology. Drug treatments; Psychomotor Performance - physiology; Retrospective Studies; Sex Factors; Skull, brain, vascular surgery; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Temporal Lobe - physiology; Temporal Lobe - physiopathology
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1111/j.1528-1167.2006.00474.x

Purpose: The goal of this study was to compare language lateralization between pediatric epilepsy patients and healthy children. Methods: Two groups of subjects were evaluated with functional magnetic resonance imaging (fMRI) by using a silent verb‐generation task. The first group included 18 pediatric epilepsy patients, whereas the control group consisted of 18 age/gender/handedness‐matched healthy subjects. Results: A significant difference in hemispheric lateralization index (LI) was found between children with epilepsy (mean LI =−0.038) and the age/gender/handedness–matched healthy control subjects (mean LI = 0.257; t = 6.490, p < 0.0001). A dramatic difference also was observed in the percentage of children with epilepsy (77.78%) who had atypical LI (right‐hemispheric or bilateral, LI < 0.1) when compared with the age/gender/handedness‐matched group (11.11%; χ2= 16.02, p < 0.001). A linear regression analysis showed a trend toward increasing language lateralization with age in healthy controls (R2= 0.152; p = 0.108). This association was not observed in pediatric epilepsy subjects (R2= 0.004, p = 0.80). A significant association between language LI and epilepsy duration also was found (R2= 0.234, p < 0.05). Conclusions: This study shows that epilepsy during childhood is associated with neuroplasticity and reorganization of language function.