Executive functions in chronic mesial temporal lobe epilepsy.

Laura Zamarian,Margarete Delazer,Elisabeth Bonatti,Thomas Bodner,Giorgi Kuchukhidze,Florian Koppelstaetter,Eugen Trinka,Thomas Benke

doi:10.1155/2011/596174

Abstract

There is no consensus as to whether mesial temporal lobe epilepsy (MTLE) leads to executive function deficits. In this study, we adopted an extensive neuropsychological test battery and assessed different executive functions in chronic, unilateral MTLE. Performance of MTLE patients was compared with that of healthy peers and with normative data. Several MTLE patients had scores below cut-off or below the 10th percentile of normative data. Scores of the whole patient group were overall in the average range of normative data. Relative to controls, MTLE patients performed poorly in tests of working memory, cognitive flexibility, categorical verbal fluency, set-shifting, categorization, and planning. These findings raise an important methodological issue as they suggest that executive function deficits in chronic MTLE may be individually variable and that their assessment should include different tests. Deficits in chronic MTLE are not limited to temporal lobe functions, such as memory, but may extend to extra temporal cognitive domains, such as executive functions.

Highlights

Mesial temporal lobe epilepsy (MTLE) is possibly the most frequent form of epilepsy [1] and is associated with overt or subtle structural abnormalities in the hippocampus, parahippocampal gyrus, and amygdala [2]
mesial temporal lobe epilepsy (MTLE) patients performed poorly in tests of working memory, cognitive flexibility, categorical verbal fluency, set-shifting, categorization, and planning. These findings raise an important methodological issue as they suggest that executive function deficits in chronic MTLE may be individually variable and that their assessment should include different tests
Basal ganglia, and frontal lobes are part of corticosubcortical circuits that are involved in the regulation of motor functions, behavior, and cognitive functions such as set-shifting, planning, and inhibitory control [9, 10]

Summary

Introduction

Mesial temporal lobe epilepsy (MTLE) is possibly the most frequent form of epilepsy [1] and is associated with overt or subtle structural abnormalities in the hippocampus, parahippocampal gyrus, and amygdala [2]. Volume reduction has been observed in extratemporal areas such as thalamus, caudate nuclei, lenticular nuclei, corpus callosum, and frontal lobes (for a review, see [3]). Basal ganglia, and frontal lobes are part of corticosubcortical circuits that are involved in the regulation of motor functions, behavior, and cognitive functions such as set-shifting, planning, and inhibitory control [9, 10]. As increasing evidence points to functional and structural alterations of these corticosubcortical circuits, it may be expected that MTLE patients experience executive function deficits

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