Abstract Details

Title Differential Reduction in Activation of Language and Executive Function Networks in Right and Left Mesial Temporal Sclerosis Patients in a Language-Based Decision fMRI Paradigm

Topic Epilepsy

Presentation(s) P06 - (-)

Poster/Presentation
Number 166

Objective

Background BACKGROUND: Patients with hippocampal sclerosis (HS) show impairment of executive functions and language. Executive functions have been less studied with fMRI in patients with epilepsy.

Design/Methods DESIGN/METHODS: We studied 23 patients with left (LHS), 16 right (RHS) HS and 22 healthy controls (C). Subjects performed a phonologic (rhyme) and a semantic (classes) decision-making paradigm. Data were acquired using 3T MRI scanner, GRE EPI BOLD images. Data was processed with FSL package (Oxford University, UK). Statistical inference was based in a nonparametric approach. Between groups analysis was performed with ANOVA (LHSxRHSxC) with a p<0.05 significance level.

Results RESULTS: In the rhyme task LHS showed reduced BOLD response in the left middle and inferior frontal girus compared to C while RHS showed decreased activation, compared to C, in a large number of clusters, comprising bilateral superior temporal gyri, right inferior frontal gyrus, right supramarginal and angular gyri, left pre-central gyrus, precuneus and left hippocampus. In the semantic task, RHS showed reduced BOLD response compared to C in similar areas, with minor diferences. There were no statistical diferences in the activation patterns between LHS and C.

Conclusions CONCLUSIONS: Network disruption of language-based decision paradigms showed distinct patterns for LHS and RHS. While LHS only displayed reduced BOLD effect in traditional language areas, RHS failed to produce BOLD response in an extended network, which may be more related to executive disfunction. Further analyses should be performed to investigate correlation of reduced activation patterns and performance in language and executive function tests in RHS and LHS.

Authors/Disclosures
PRESENTER	No disclosure on file
	No disclosure on file
	No disclosure on file
Rosa M. Valerio, PhD	No disclosure on file
	No disclosure on file
Luiz H. Castro, MD (University of Sao Paulo)	Dr. Castro has nothing to disclose.
	No disclosure on file

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