AUTHOR=Visoná de Figueiredo Nathália Stela , Jardim Anaclara Prada , Mazetto Lenon , Corso Duarte Jeana Torres , Comper Sandra Mara , Alonso Neide Barreira , da Silva Noffs Maria Helena , Scorza Carla Alessandra , Cavalheiro Esper Abrão , Centeno Ricardo Silva , de Araújo Filho Gerardo Maria , Yacubian Elza Márcia Targas TITLE=Do Hippocampal Neurons Really Count for Comorbid Depression in Patients With Mesial Temporal Lobe Epilepsy and Hippocampal Sclerosis? A Histopathological Study JOURNAL=Frontiers in Integrative Neuroscience VOLUME=15 YEAR=2021 URL=https://www.frontiersin.org/journals/integrative-neuroscience/articles/10.3389/fnint.2021.747237 DOI=10.3389/fnint.2021.747237 ISSN=1662-5145 ABSTRACT=

Depression is the most frequent psychiatric comorbidity seen in mesial temporal lobe epilepsy (MTLE) patients with hippocampal sclerosis (HS). Moreover, the HS is the most frequent pathological hallmark in MTLE-HS. Although there is a well-documented hippocampal volumetric reduction in imaging studies of patients with major depressive disorder, in epilepsy with comorbid depression, the true role of the hippocampus is not entirely understood. This study aimed to verify if patients with unilateral MTLE-HS and the co-occurrence of depression have differences in neuronal density of the hippocampal sectors CA1–CA4. For this purpose, we used a histopathological approach. This was a pioneering study with patients having both clinical disorders. However, we found no difference in hippocampal neuronal density when depression co-occurs in patients with epilepsy. In this series, CA1 had the lowest counting in both groups, and HS ILAE Type 1 was the most prevalent. More studies using histological assessments are needed to clarify the physiopathology of depression in MTLE-HS.