Pattern of abnormalities on gray matter in patients with medial temporal lobe epilepsy and hippocampal sclerosis: An updated meta-analysis

• Published in: Clinical neurology and neurosurgery 2024-10, Vol.245, p.108473, Article 108473
• Main Authors: Dos Santos Silva, Rhuann Pontes, Lima Angelo, Isabella Carla Barbosa, De Medeiros Dantas, Guilherme Cavalcanti, De Souza, Joana Martins, Pinheiro Pessoa, João Ricardo Caldas, Lopes, Laura Guerra, Telles, João Paulo Mota, Horta, Wagner Gonçalves
• Format: Article
• Language: English
• Subjects: Atrophy; Basal ganglia; Caudate nucleus; Cerebellum; Cluster analysis; Convulsions & seizures; Epilepsy; Epilepsy, Temporal Lobe - diagnostic imaging; Epilepsy, Temporal Lobe - pathology; Gray matter; Gray Matter - diagnostic imaging; Gray Matter - pathology; Hemispheric laterality; Hippocampal Sclerosis; Hippocampus; Hippocampus - diagnostic imaging; Hippocampus - pathology; Humans; Lentiform nucleus; Magnetic Resonance Imaging; Medial Temporal Lobe Epilepsy; Medical imaging; Meta-analysis; Metabolism; Morphometry; Neuroimaging; Parahippocampal gyrus; Patients; Putamen; Sclerosis; Sclerosis - pathology; Software; Spatial memory; Substantia grisea; Temporal lobe; Therapeutic targets
• ISSN: 0303-8467; 1872-6968; 1872-6968
• DOI: 10.1016/j.clineuro.2024.108473

Temporal lobe epilepsy (TLE) is a prevalent form of epilepsy originating in the temporal lobes. A common pathological feature is hippocampal sclerosis (HS), characterized by the loss of neuronal cells, which is associated with the typical temporal mesial lobe epilepsy (MTLE). In this study, we aimed to analyze gray matter alterations in patients with MTLE with right and left hemisphere HS using voxel-based morphometry and compare them with control groups. A meta-analysis was performed based on the guidelines contained in the Protocol Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), using the MEDLINE database, with the keywords: "gray matter" AND "temporal lobe epilepsy " AND ("hippocampal sclerosis" OR "hippocampal abnormalities") AND ("voxel-based morphometry" OR "VBM" OR "voxel-wise"). Of the 14 articles included in the review, 8 were added by the method, in which the meta-analysis was performed. Our results indicate that in the right hemisphere, the hippocampus, caudate nucleus, parahippocampal gyrus, thalamus, dorsalis medial nucleus, insula, and right claustrum were most commonly implicated. In the left hemisphere, a significant pattern of gray matter loss was observed in the putamen, lentiform nucleus, uncus, Brodmann areas 20 and 23, cingulate gyrus, caudate nucleus, cerebellum, and cuneus compared to healthy controls.Our study highlights distinct patterns of gray matter alteration in MLTE-HS and suggests that these regions may contribute to changes in verbal memory and visuospatial impairment based on their anatomical and hemispheric locations. Our findings can be potentially helpful for future diagnostic markers, therapeutic targets, and insights into disease progression, better understanding of these findings. ●In the right hemisphere, changes associated with visuospatial memory were were most commonly implicated.●In the left hemisphere, a significant pattern of gray matter loss was observed in verbal memory areas compared to healthy controls.●Our study highlights distinct patterns of gray matter alteration in MLTE-HS based on their anatomical locations.●These findings can be helpful for future diagnostic markers, therapeutic targets and insights into disease progression.