Atypical language in lesional and nonlesional complex partial epilepsy

Abstract

Early seizure onset and atypical handedness, as well as the location and nature of pathologic substrate, are important factors in language reorganization.

Insights into Adult Postlesional Language Cortical Plasticity Provided by Cerebral Blood Oxygen Level–Dependent Functional MR Imaging

“…Brain injury or epilepsy onset before 6 years of age is associated with interhemispheric transfer of language representation as demonstrated by Wada testing or fMRI and is also supported by behavioral studies of children with early brain injury. 10,[14][15][16][17] There is ample evidence that early-onset left hemispheric brain lesions do not result in long-term language disabilities that are common in adult patients who experience left-hemispheric stroke. 18 Transcallosal reorganization is often seen in such cases with involvement of right hemispheric cortical regions that are homotopic to the left hemispheric regions involved in language processing under normal conditions, with resultant normal language function, though subtle deficits in certain nonlanguage functions (eg, visuospatial processing) generally represented in the right hemisphere have been noted in some individuals on neuropsychological testing.…”

Principal Component Analysis and Assessment of Language Network Activation Patterns in Pediatric Epilepsy

“…The primary barrier to identifying factors that modulate developmental plasticity of brain networks in relation to surgical outcome lies in the difficulty of studying a sufficient number of patients with atypical brain activations to guide prognostic indicators of outcome (Gaillard et al, 2002(Gaillard et al, , 2007Yuan et al, 2006). The only realistic solution is to thus build a multisite in support of a research platform for the cohesive study of the human brain, bringing in synergy several hospitals and academic institutions that share the same objectives.…”

“…Therefore, 122 data sets were considered valid for this study, and were distributed as follows: sixty four control and fifty eight children with LRE (see Table 2.1). For all the participating institutions, each subject was asked to perform an auditory description decision task (a word definition task) which was designed to activate both temporal (Wernicke's area) and inferior frontal (Broca's area) cortex (Gaillard et al, 2007). The task required comprehension of a phrase, semantic recall, and a semantic decision.…”

“…The participant was instructed to press a button each time he/she heard a tone that followed the auditory string (70% true responses, 30% foils). The baseline was designed to control for first and second order auditory processing, attention, and motor response, while engaging the broad language processing network on an individual basis necessary for effective pre-surgical evaluation (Gaillard et al, 2007;Mbwana et al, 2009). Four age appropriate levels of difficulty were available (4-6, 7-9, 10-12, >12).…”

“…Recall there are 64 control and 58 children with LRE (patient population) included in this study; each subject was asked to perform an auditory description decision task (a word definition task) which was designed to activate both temporal (Wernicke's area) and inferior frontal (Broca's area) cortex (Gaillard et al, 2007). All the 4D fMRI data sets go through the same standard preprocessing using FSL for obtaining the resulting 3D (axial x coronal x sagittal) activation maps, which are with the resolution of 61x73x61.…”