Cortical thickness, surface area and folding in patients with psychogenic nonepileptic seizures

To determine cortical thickness (CTh), cortical surface area (CSA), curvature and sulcal depth (SD) in patients with psychogenic nonepileptic seizures (PNES).

Freesurfer software was used to identify differences between active and control group in Cth, CSA, curvature, and SD. Neuropsychological tests intending to document possible frontal lobe deficit were applied.

We included 37 patients with PNES (age 37.3±13.8; female/male 31/6; age of disease onset 26.1±10.6; age of disease duration 11.1±11.1), and 37 healthy controls (age 38.4; ±12.7; female/male 26/11). No difference in CSA and curvature was detected between groups. Patients with PNES had increased CTh in the left insula, left and right medial-orbitofrontal, and left lateral-orbitofrontal, and decreased CTh in the left and right precentral, right enthorinal, and right lateral-occipital region than healthy controls. SD was increased at the level of the left and right insula, right rostral anterior cingulate, right posterior cingulate, and left cuneus, and reduced at the level of the right and left medial-orbitofrontal sulci in patients with PNES compared to healthy controls.

Individuals with PNES display a distinct profile of changes in CTh, in association with increase in SD in both insula as compared to controls. Our results may contribute to the understanding of the neurobiological background of PNES. Further research, to include replication of the findings and directed to understand the role of insula is needed.