Avaliação volumétrica dos núcleos da amigdala como fator preditor de desfecho cirúrgico em pacientes com esclerose do lobo temporal mesial

Abstract

Introduction: Mesial temporal lobe epilepsy (MTLE) is the most common form of focal- onset epilepsy in young adults. Hippocampal sclerosis (HS) is the main cause of MTLE, being found in 60-70% of patients undergoing surgical treatment for refractory seizures. The occurrence of different responses to surgical treatment leads us to assume that MTLE-HS is not a single homogeneous disease. The amygdala encompasses different nuclei defined according to its cytoarchitecture, cell composition and connections. The verification of segmental alterations in the amygdala suggests the existence of different patterns of involvement in any pathology, especially in MTLE-HS. In the present study, we analyzed the volumetric findings of the amygdala nuclei and its relationship with the surgical result. Objective: We prospectively analyzed 72 patients with MTLE who are candidates for surgical treatment. The volumetric analysis of the amygdala nuclei was performed through the Freesurfer software, using 3 Tesla T1 weighted MRI. Results: We correlated the amygdala nuclei volumes with seizure control after surgery. Lower volumes of the basal nucleus, paralaminar nucleus and total amygdala, contralateral to the hippocampal sclerosis (HS), were related to a better surgical result after surgery. A significant difference was found between the HS side and the non-HS side for the total volumes of amygdala and 8 of their nuclei. Conclusion: The automated evaluation of amygdala performed through FreeSurfer proved to be an effective method for defining amygdala atrophy patterns. Understanding the determining factors for good postoperative outcomes can avoid unnecessary surgeries and improve the selection of surgical patients, as well as reduce costs and risk factors.