Impact of contralateral electroencephalografic activity in epilepsy associated to unilateral hippocampal sclerosis: a diffusion tensor imaging study

• Grant number: 14/00457-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): September 01, 2014
• Effective date (End): November 30, 2014
• Field of knowledge: Health Sciences - Medicine - Medical Radiology
• Principal Investigator: Luiz Henrique Martins Castro
• Grantee: Augusto Quaresma Coelho
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Introduction: the temporal lobe epilepsy (TLE) represents approximately 40% of the epilepsy cases, as well the most common cause of epilepsy in adults. Hippocampal sclerosis and other structural alterations in the mesial temporal structures associated to TLE are present in 60% of patients with temporal epilepsy. Hippocampal sclerosis can be currently designed as an epileptic syndrome with clinical, electroencephalographic, anatomopathological and neuroimaging well defined presentations. Recent studies of magnetic resonance imaging (MRI) with tractography technique in the TLE associated to hippocampal sclerosis evidenced anatomical abnormalities in white substance tracts that extent beyond the temporal lobe. The impact of the contralateral electroencephalographic involvement on white tract substance in patient s with TLE have not yet been studied. The current study pretends to evaluate the impact of the contralateral commitment related to the white tract integrity in patients with unilateral hippocampal sclerosis, testing the hypothesis that the contralateral electroencephalographic involvement in patients with unilateral lesion would lead to greater aggression on contralateral white matter tracts, compared to patients with unilateral lesion and predominant ipsilateral involvement at electroencephalographic observations. Methods: patients with ELT associated with unilateral mesial temporal sclerosis (MTS) diagnosis previously selected by CINAPCE project and submitted to a protocol that includes functional and imaging exams will be studied by electroencephalographic behavior on seizures (ictal) and off-seizures (interictal) periods. These patients will be classified according to the electroencephalographic predominance ipsi or contralateral to MST. The MRI data of the patients will be analyzed using the tractography studies based on diffusion tensor imaging (DTI). The fractionated anisotropy (FA) and the mean diffusivity (MD) of the white tracts will be used in order to quantify the tract lesions, comparing the results with a control group. (AU)