Volumetrical analysis of patients with temporal lobe epilepsy associated to hippocampal sclerosis: Role of the ictals and interictals electroencephalografic findings

• Grant number: 14/00458-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2014
• End date: August 31, 2015
• Field of knowledge: Health Sciences - Medicine - Medical Radiology
• Principal Investigator: Luiz Henrique Martins Castro
• Grantee: Matheus Louzada Yamaki
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Introduction: Temporal Lobe epilepsy (TLE) is the most common and frequent form of focal epilepsy refractory to clinical therapy in adults. The TLE associated with hippocampal sclerosis and other (changes) in mesial temporal structures (MTS) corresponds to about 60% of cases of Temporal epilepsy, and is a well recognized syndrome with distinct clinical features, electroencephalografical, radiological, anatomo-pathological and neurophysiological. The EEG Record often presents with (pattern/standard) concordant and/or discordant discharges in relation to the lesion, either at the ictal onset or contralateral propagation, as well as contralateral interictal epileptiform discharges. There are studies that show an association between TLE-unilateral MTS and volumetric changes in several brain structures. However lack studies showing if the effect of EEG findings contralateral to the lesion in TLE-MTS is associated with more severe degrees of volumetric changes in the structures, ipsilateral and contralateral. The aim of this study is to evaluate (by/through) MRI volumetric methods an association between contralateral electroencephalographic findings and volumetric changes in encephalic ipsi- and contralateral structures in patients with unilateral hippocampal sclerosis testing the hypothesis that patients with contralateral electrographic involvement have higher volumetric impairment of temporal and extratemporal structures in the contralateral hemisphere. Methods: A series of 50 adult patients with TLE associated with unilateral mesial temporal sclerosis (MTS) previously selected and underwent the project CInAPCe (Funding: FAPESP - process 2005/56464-9) protocol, which includes functional exams, continuous video-EEG monitoring (with registration of at least three seizures with an EEG correlate) and image exams will be analyzed (from/by) the EEG behavior in periods between seizures (interictal) and during seizures (ictal) and classified in groups according to the predominance of EEG activity ipsi- or contralateral to the lesion. From the 3T MRI data will be obtained the cortical, white matter and several brain structures volumetric analysis by FreeSurfer software (Athinoula A. Martinos Center for Biomedical Imaging, MGH, MA, USA). Volumetric data of various encephalic structures will be compared between the groups of the study and controls.