A-37 Effects of Atypical Language Representation in Populations Suffering From Intractable Epilepsy

Abstract

Abstract Objective Atypical language laterality, secondary to refractory epilepsy, presents complications to surgical planning/cognitive outcomes. Extant research shows the non-dominant hemisphere reallocates neural resources for language compensation in response to left-sided lesions (resulting in decreased visuoperceptual/visual memory). The present study examined relationships between 1) lesion location and atypical language organization and 2) lesion location/language laterality on performance on memory (California Verbal Memory Test 2nd-edition (CVLT; Delayed Recall), and visuoperceptual (Rey-Osterrieth Complex Figure Test, ROCFT; Copy) tests in relation to lesion location in a sample of patients with intractable epilepsy. Method Retrospective data was compiled on patients with refractory epilepsy undergoing interdisciplinary pre-surgical workup (N = 101), mean age of 37.2 (SD = 11.9) and mean education of 12.3 (SD = 3.7). The sample was then stratified by non-lesional (n = 48), left (n = 26), right (n = 21) or bilateral (n = 6) mesial temporal sclerosis (MTL); and, language laterality was confirmed by neuroradiologists via functional Magnetic Resonance Imaging (fMRI) scans. Results Analyses showed patients with left MTS were more likely to have atypical language organization, X2 (1, N = 47) = 6.6, p = .01. Moreover, significant differences on T-scores for CVLT, F (3,15) = 3.81, p = .04, 95% Cl [-1.73, -.08] and ROCFT, F(4,28) = 2.85, p = .046 95% Cl [31.62, 46.17] were found between groups stratified by lesion location/language laterality, respectively. Conclusions Organization of language in epileptic populations presents atypically in conjunction with left-sided lesions. Additionally, cognitive processes such as verbal memory and visuoperceptual abilities suffer based on lesion presence/location and language laterality in this fMRI confirmed sample.