Amygdala enlargement in patients with mesial temporal lobe epilepsy without hippocampal sclerosis

Autor(es)

Coan, Ana Carolina ^[1] ; Morita, Marcia Elisabete ^[1] ; de Campos, Brunno Machado ^[1] ; Yasuda, Clarissa Lin ^[1] ; Cendes, Fernando ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Dept Neurol, Neuroimaging Lab, Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN NEUROLOGY; v. 4, 2013.
• Citações Web of Science: 21

Resumo

Purpose: Patients with mesial temporal lobe epilepsy (MTLE) without MRI abnormalities (MTLE-NL) represent a challenge for definition of underlying pathology and for presurgical evaluation. In a recent study we observed significant amygdala enlargement (AE) in 14% of MILE patients with MRI signs of hippocampal sclerosis. Areas of gray matter volume (GMV) increase could represent structural abnormalities related to the epileptogenic zone or part of a developmental abnormality. Our objective was to look for undetected areas of increased GMV in MILE-NL using post processing MRI techniques to better understand the pathophysiology of this condition. Methods: We evaluated 66 patients with MILE-NL on visual analysis and 82 controls. Voxel-based morphometry (VBM) group analysis was performed with VBM8/SPM8 looking for areas of increased GMV. We then performed automatic amygdala volumetry using FreeSurfer software and T2 relaxometry to confirm VBM findings. Results: Voxel-based morphometry group-analysis demonstrated increased amygdala volume in the MILE-NL group compared to controls. Individual volumetric analysis confirmed AE in eight (12%) patients. Overall, from all patients with AE and defined epileptic focus, four (57%) had the predominant increased volume ipsilateral to the epileptic focus. These results were cross-validated by a secondary VBM analysis including subgroups of patients according to the volumetric data. T2 relaxometry demonstrated no amygdala hyperintense signal in any individual with significant AE. There were no clinical differences between patients with and without AE. Discussion: This exploratory study demonstrates the occurrence of AE in 12% of patients with MILE-NL. This finding supports the hypothesis that there might be a subgroup of patients with MILE-NL in which the enlarged amygdala could be related to the epileptogenic process. Further studies are necessary but this finding could be of great importance in the understanding of MILE-NL. (AU)

• Processo FAPESP: 05/56578-4 - Centro multimodal de neuroimagens para estudos em epilepsia
• Beneficiário: Fernando Cendes
• Modalidade de apoio: Auxílio à Pesquisa - Programa CINAPCE - Temático
• Processo FAPESP: 09/54552-9 - Estudo da progressão de dano na epilepsia de lobo temporal mesial com ou sem sinais de esclerose hipocampal
• Beneficiário: Ana Carolina Coan
• Modalidade de apoio: Bolsas no Brasil - Doutorado