Longitudinal analysis of metabolic changes in mesial temporal lobe epilepsy measured by proton magnetic resonance spectroscopy

Abstract

Mesial temporal lobe epilepsy (MTLE) presents with high rates of pharmacoresistance. It has been reported that even pharmacoresponsive patients may present progression of structural damage in the hippocampus. However, this association remains inconclusive. Furthermore, the progression of possible metabolic changes, such as N-acetylaspartate (NAA), a marker of neuronal damage or dysfunction, in patients with MTLE is not fully understood. This project hypothesizes that there is a decrease in the NAA concentration levels over time, similar to the possible progression of structural damage observed in magnetic resonance (MR) exams, more observed in pharmacoresistant MTLE patients. To address this issue, proton magnetic resonance spectroscopy (1H-MRS) will be used in pharmacoresponsive and pharmacoresistant MTLE patients. Objectives: to analyze MR and 1H-MRS images obtained with a time interval of, at least, six months in MTLE patients in order to longitudinally quantify the variation of NAA concentration levels in the hippocampus and its correlation to pharmacoresponse in these patients. Methods: there will be selected MR and 1H-MRS images from MTLE patients. Patients with only one 1H-MRS and RM image acquisition obtained, at least, six months ago, will be recruited to obtain the second image acquisition. Metabolic images will be acquired using the single-voxel technique. The archives will be processed using the LCModel software. Hippocampal volume quantification will be performed automatically using the Freesurfer software. (AU)