Structural Changes in the Brain in Patients with Temporal Lobe Epilepsy and Comorbid Depression

Objectives. To assess the morphological features of brain structures in patients with temporal lobe epilepsy and comorbid depression. Materials and methods. A total of 80 patients with temporal lobe epilepsy (18–60 years old, including 38 with comorbid depression) and 48 healthy subjects of comparable age were examined over the period January 1, 2017 to December 31, 2020. Brain MRI scans were obtained following an epileptic protocol using a 1.5-T scanner. Diagnoses of focal temporal lobe epilepsy were established by neurologists specializing in epilepsy in accordance with the 2017 International League Against Epilepsy classification. The presence and severity of depressive disorder was determined by psychiatrists by clinical interview and Beck Depression Inventory (BDI-II) self-reports. Volumes of subcortical structures and cortical thickness were evaluated by processing MRI data in FreeSurfer 6.0 software. At the group level, analysis of covariance with the Holm–Bonferroni correction was used for statistical analysis. Results. Morphometric analysis revealed significant decreases in the volumes of the brainstem and thalamus bilaterally, along with an increase in the volume of the choroid plexus in the left hemisphere in patients with epilepsy as compared with healthy controls. In addition, patients with epilepsy, as compared with healthy controls, had significantly greater thickness of the entorhinal cortex and the temporal pole and isthmus of the cingulate gyrus in the left hemisphere, while in the right hemisphere patients had significantly lesser thickness of the middle temporal gyrus and inferior temporal gyrus. There was no association between the presence of depression and significant MRI structural changes. Conclusions. These data identify a relationship between temporal lobe epilepsy and the morphology of brain structures, while comorbid depression showed no such link.