Language impairment in Temporal Lobe Epilepsy associated with hippocampal sclerosis: association and correlation with advanced neuroimaging findings (tractography and volumetry)

• Grant number: 16/13107-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2017
• End date: June 30, 2018
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Luiz Henrique Martins Castro
• Grantee: Matheus Mendonça Péres
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Temporal Lobe Epilepsy with unilateral hippocampus sclerosis (TLE-uMTS), the most prevalent type of focal and treatment-refractory epilepsy, is associated with cognitive impairment. Different patterns of cognitive impairment, such as in language, have been associated with lesions in each cerebral hemisphere. Verbal fluency, visual confrontation and responsive naming, responsive and word comprehension impairment have been reported in TLE. Changes in hemispheric language lateralization patterns and white matter tracts changes have been described in this patient population, but underlying mechanisms are still poorly understood. Few studies have evaluated the association between volumetric and white matter tract changes and language impairment in TLE-uMTS patients. This study will evaluate the association between language impairment, measured with different language tests, and volumetric and white matter tracts changes, using Diffusion-Tensor Imaging and Structural Magnetic Resonance Volumetry in TLE-uMTS patients. Methods: A series of 55 adult patients with right or left TLE-uMTS, previously included in the CINAPCE Study Protocol (Funding: FAPESP - Process 2005/56464-9), that included neuropsychological and languagetests, continuous Video-EEG monitoring (with recording of at least three seizures with adequate EEG recordings) and advanced neuroimaging techniques. Using a 3T MRI (Phillips), brain imaging was acquired and post-processed with the Freesurfer software (Athinoula A. Martinos Center for Biomedical Imaging, MGH, MA, USA) for volumetric studies, and with Diffusion-Tensor Imaging of white matter tracts with the software TBSS. (http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/TBSS)Volumetric data from different cerebral structures and fractional anisotropy values for 18 white matter tracts will be compared among both study and control groups. Patients will be classified according to performance in the language tests, as good or bad performance, using cut-off scores established with ROC analysis. We will also evaluate possible correlations between patients´ performances in the language tests and the volumetric and white matter tract changes. (AU)