Ictal and Interictal Electroencephalography of Mesial and Lateral Temporal Lobe Epilepsy; A Comparative Study

Background: Epilepsy is considered as one of the most important disorders in neurology. Temporal lobe epilepsy is a form of epilepsy including two main types of mesial and lateral (neocortex). Objectives: Determination and comparison of electroencephalogram (EEG) pattern in the ictal and interictal phases of mesial and lateral temporal lobe epilepsy. Materials and Methods: This cross-sectional descriptive study included 80 patients with mesial and lateral temporal lobe epilepsy who satisfied the inclusion criteria. The patients were monitored using EEG, and then the EEG results were compared between two groups of temporal epilepsies. Results: There was no significant difference between two groups of patients (mesial and lateral temporal lobe epilepsy) in terms of the type of seizure, history of tumor or trauma or hypoxia, and duration of seizure history (p>0.05). The ictal wave onset in 52.5% of the patients was in the left temporal region, and the ictal wave onset in 58.75% of patients was the slow wave. There was no significant difference between the two groups of patients in terms of ictal wave onset and its location. Conclusions: According to the results, EEG is a good method for detecting temporal lobe epilepsy, but it does not help to differentiate the type of mesial and lateral temporal epilepsy. In order to distinguish between these two types, EEG alone is not helpful, and other diagnostic methods are required.