FMRI activation during paragraph reading in pediatric epilepsy

Abstract

Objective

This study examined brain activation differences during paragraph reading between children with and without epilepsy and if findings were related to neuropsychological performance. Exploratory analyses assessed activation in a subset of struggling readers.

Methods

The study included 41 children with focal epilepsy (M = 10.5 years, 2.2) and 41 healthy controls with a similar mean age (M = 10 years, 1.7) who completed a neuropsychological battery and a functional magnetic resonance imaging (fMRI) paragraph reading task. Analyses included group comparisons of activation, including exploratory analyses with a subset of struggling readers with epilepsy. Correlational analyses examined relationships between activation and neuropsychological performance.

Results

Despite significant differences in neuropsychological performance, there were no group differences in activation on reading fMRI between children with and without epilepsy. Across the combined sample, better sight word reading, reading fluency, and reading comprehension were positively correlated with activation of the left superior temporal gyrus. A subset analysis comparing healthy controls and non-struggling epilepsy readers to struggling epilepsy readers (SS < 85) showed more activation in the control groups compared to the struggling readers in focused areas including bilateral temporal gyrus, left cerebellum, and right inferior frontal gyrus. The subset of struggling readers was more likely than the non-struggling patient group to have frequent seizures and their seizure focus ipsilateral to their language dominance.

Significance

Despite worse neuropsychological performance, the reading network was similarly activated in children with and without epilepsy. Relative to the broader functional network for reading, small, focused areas—particularly in the superior temporal lobe—were associated with less activation for those who had worse reading performance. Use of an fMRI paragraph reading task matched to a child’s level show no to small differences related to epilepsy or reading performance which suggests its robustness as a task when the goal is to identify the language network such as for presurgical mapping.