Impaired mesial synchronization in temporal lobe epilepsy.

OBJECTIVE Temporal lobe epilepsy is commonly associated with synchronous, hyper-synchronous and des-synchronous activity. The aim of the present work is to explore synchronization activity in both mesial areas in temporal lobe epileptic patients during the interictal state. METHODS Using a cluster technique, we analyzed 17 temporal lobe epilepsy patients' records of foramen ovale electrodes activity during the inter-ictal state. RESULTS There exists a clear tendency in the mesial area of the epileptic side to be organized as isolated clusters of electrical activity as compared with the contra-lateral side, which is organized in the form of large clusters of synchronous activity. The number of desynchronized areas is larger in the epileptic side than in the contra-lateral side in 16 out of 17 temporal lobe epileptic patients. CONCLUSIONS The mesial area responsible for the seizures is less synchronous than the contra-lateral; the different kind of synchronous organization accounts for a lower synchronization activity at the epileptic side, suggesting that this lack of synchronous cluster organization would favour the appearance of seizures. SIGNIFICANCE Our results shed new light regarding synchronization issues in temporal lobe epilepsy and also it would help in reducing drastically the time of study.