Table of Contents
Epilepsy Research and Treatment
Volume 2012 (2012), Article ID 823683, 9 pages
Clinical Study

Extrahippocampal Desynchronization in Nonlesional Temporal Lobe Epilepsy

1Clinical Neurophysiology, Hospital Universitario and Instituto de Investigación La Princesa, 28006 Madrid, Spain
2School of Medicine, San Pablo-CEU University, 28008 Madrid, Spain
3Departamento de Neurocirugía (planta 7), Hospital Universitario and Instituto de Investigación La Princesa, Diego de León 62, 28006 Madrid, Spain

Received 12 May 2011; Revised 14 September 2011; Accepted 25 September 2011

Academic Editor: Warren T. Blume

Copyright © 2012 Jesús Pastor 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.


Although temporal lobe epilepsy (TLE) is traditionally associated with both hypersynchronous activity in the form of interictal epileptic discharges and hippocampal sclerosis, recent findings suggest that desynchronization also plays a central role in the dynamics of this pathology. The objective of this work is to show the imbalance existing between mesial activities in patients suffering from mesial TLE, with normal mesial structures. Foramen ovale recordings from six patients with mesial TLE and one with lateral TLE were analyzed through a cluster analysis and synchronization matrices. None of the patients present findings in the MRI presurgical evaluation. Numerical analysis was carried out in three different situations: awake and sleep interictal and also during the preictal stage. High levels of desynchronization ipsilateral to the epileptic side were present in mesial TLE patients. Low levels of desynchronization were present in the lateral TLE patient during the interictal stage and almost zero in the preictal stage. Implications of these findings in relation with seizure spreading are discussed.