Abnormal functional connectivity of paracingulate gyrus in patients with temporal lobe epilepsy-comorbid sleep disorders.

Abnormalities in paracingulate gyrus (PCG) were found in both patients with temporal lobe epilepsy and patients with sleep disorders. These abnormalities include reduced functional connectivity between PCG and other brain regions, abnormal activity and reduced volume of PCG. PCG may be associated with comorbid sleep disorders in patients with temporal lobe epilepsy (TLE). This study aimed to explore the relationship between abnormal PCG function and comorbid sleep disorders in patients with TLE. We used Pittsburgh Sleep Quality Index -8/9 to divide fifty-eight patients into a group with sleep disorders and group without sleep disorders. Using the PCG as the seed, we examined the task-based seed-to-voxel functional connectivity identified by group-independent component analysis. Compared with the normal sleep group, we observed longer disease duration, higher frequency of seizures, higher Self-Rating Anxiety Scale scores in the comorbidity group (p < 0.05). During the verbal fluency character task, functional connectivity from the PCG to the right frontal and parietal regions was decreased in the comorbidity group (p < 0.05, FDR-corrected). Sensitivity analyses confirmed that our conclusions were not affected by factors such as laterality or hippocampal sclerosis. These abnormalities reveal brain lesions in patients with TLE comorbid sleep disorders, which may contribute to the pathogenesis of the comorbidity and be related to patients' preserved verbal functions.