Reading difficulty is associated with failure to lateralize temporooccipital function. Issue 5 (11th April 2014)

• Record Type: Journal Article
• Authors: Tailby, Chris; Weintrob, David L.; Saling, Michael M.; Fitzgerald, Carly; Jackson, Graeme D.
• Is Part Of: Epilepsia. Volume 55:Issue 5(2014:May)
• Page Start: 746
• Page End: 753
• Publication Date: 2014-04-11
• Subjects: Epilepsy -- Reading disorder -- Dyslexia -- Functional magnetic resonance imaging; Epilepsy -- Periodicals; 616.853
• DOI: 10.1111/epi.12607
• Languages: English
• ISSNs: 0013-9580

Abstract

Summary: Objective: Studies of focal epilepsy have revealed abnormalities of language organization; however, little attention has been paid to disorders of reading in this group. We hypothesized that language functional magnetic resonance imaging (fMRI) would reveal differences in language organization between focal epilepsy patients with and without reading difficulties. Methods: We conducted language fMRI studies of 10 focal epilepsy patients with reading difficulties, 34 focal epilepsy patients without reading difficulties, and 42 healthy controls. Results: We defined regions of interests on the basis of activation patterns on an orthographic lexical retrieval task. Comparison of activations within these ROIs on a second Noun‐Verb task revealed epilepsy‐related effects (relative to healthy controls: reduced activation in left inferior frontal cortex), as well as greater activation in the right temporooccipital cortex specific to the reading difficulty group. Significance: These findings identify a focal epilepsy effect in the left frontal region (present in patients with and without reading difficulties), and a functional abnormality specific to the reading difficulty group localized to right temporooccipital cortex—a region implicated in lexicosemantic processing. Our observations suggest a failure of left hemisphere specialization among focal epilepsy patients with reading difficulties. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here .