Table of Contents
Epilepsy Research and Treatment
Volume 2015 (2015), Article ID 746745, 8 pages
http://dx.doi.org/10.1155/2015/746745
Review Article

Semantic Processing Impairment in Patients with Temporal Lobe Epilepsy

1Proyecto de Neurociencias, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, 54090 Ciudad de México, MEX, Mexico
2Departamento de Neuropsicología, Instituto Nacional de Neurología y Neurocirugía, 14269 Ciudad de México, DF, Mexico
3Clínica de Epilepsia, Instituto Nacional de Neurología y Neurocirugía, 14269 Ciudad de México, DF, Mexico

Received 21 May 2015; Accepted 2 July 2015

Academic Editor: József Janszky

Copyright © 2015 Amanda G. Jaimes-Bautista et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The impairment in episodic memory system is the best-known cognitive deficit in patients with temporal lobe epilepsy (TLE). Recent studies have shown evidence of semantic disorders, but they have been less studied than episodic memory. The semantic dysfunction in TLE has various cognitive manifestations, such as the presence of language disorders characterized by defects in naming, verbal fluency, or remote semantic information retrieval, which affects the ability of patients to interact with their surroundings. This paper is a review of recent research about the consequences of TLE on semantic processing, considering neuropsychological, electrophysiological, and neuroimaging findings, as well as the functional role of the hippocampus in semantic processing. The evidence from these studies shows disturbance of semantic memory in patients with TLE and supports the theory of declarative memory of the hippocampus. Functional neuroimaging studies show an inefficient compensatory functional reorganization of semantic networks and electrophysiological studies show a lack of N400 effect that could indicate that the deficit in semantic processing in patients with TLE could be due to a failure in the mechanisms of automatic access to lexicon.