Decreased functional connectivity within a language subnetwork in benign epilepsy with centrotemporal spikes

Abstract

<jats:title>Summary</jats:title><jats:sec><jats:title>Objective</jats:title><jats:p>Benign epilepsy with centrotemporal spikes (<jats:styled-content style="fixed-case">BECTS</jats:styled-content>, also known as Rolandic epilepsy) is a common epilepsy syndrome that is associated with literacy and language impairments. The neural mechanisms of the syndrome are not known. The primary objective of this study was to test the hypothesis that functional connectivity within the language network is decreased in children with <jats:styled-content style="fixed-case">BECTS</jats:styled-content>. We also tested the hypothesis that siblings of children with <jats:styled-content style="fixed-case">BECTS</jats:styled-content> have similar abnormalities.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Echo planar magnetic resonance (<jats:styled-content style="fixed-case">MR</jats:styled-content>) imaging data were acquired from 25 children with <jats:styled-content style="fixed-case">BECTS</jats:styled-content>, 12 siblings, and 20 healthy controls, at rest. After preprocessing with particular attention to intrascan motion, the mean signal was extracted from each of 90 regions of interest. Sparse, undirected graphs were constructed from adjacency matrices consisting of Spearman's rank correlation coefficients. Global and nodal graph metrics and subnetwork and pairwise connectivity were compared between groups.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>There were no significant differences in graph metrics between groups. Children with <jats:styled-content style="fixed-case">BECTS</jats:styled-content> had decreased functional connectivity relative to controls within a four‐node subnetwork, which consisted of the left inferior frontal gyrus, the left superior frontal gyrus, the left supramarginal gyrus, and the right inferior parietal lobe (p = 0.04). A similar but nonsignificant decrease was also observed for the siblings. The <jats:styled-content style="fixed-case">BECTS</jats:styled-content> groups had significant increases in connectivity within a five‐node, five‐edge frontal subnetwork.</jats:p></jats:sec><jats:sec><jats:title>Significance</jats:title><jats:p>The results provide further evidence of decreased functional connectivity between key mediators of speech processing, language, and reading in children with <jats:styled-content style="fixed-case">BECTS</jats:styled-content>. We hypothesize that these decreases reflect delayed lateralization of the language network and contribute to specific cognitive impairments.</jats:p></jats:sec>