Morphometric correlates in patients with functional seizures with and without comorbid epilepsy

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Functional seizures (FS), also known as psychogenic non-epileptic seizures (PNES), are behavioral events mimicking epileptic seizures but without epileptic brain activity.
• Individuals with epilepsy have an elevated risk of developing FS, highlighting a potential link between these conditions.

Purpose of the Study:

• To investigate morphometric brain differences in patients with FS compared to healthy controls (HC).
• To examine morphometric brain differences in patients with both FS and epilepsy (EFS) compared to HC.
• To compare FS and EFS groups to understand the impact of co-occurring epilepsy on brain structure.

Main Methods:

• Retrospective analysis of 3D T1-weighted MRI scans from 21 FS patients, 15 EFS patients, and 21 age- and gender-matched HC.
• Utilized FreeSurfer version 6.0 for two general linear model analyses to assess cortical thickness (Cth) and curvature.

Main Results:

• Both FS and EFS groups exhibited increased Cth in the right prefrontal lobe (superior frontal, rostral middle frontal, and orbitofrontal cortex).
• Decreased Cth was observed in the right lateral occipital lobe in the FS group.
• The EFS group showed bilateral decreases in Cth, including the left paracentral, superior frontal, caudal middle frontal, lateral occipital, and right superior frontal gyri. No significant changes in curvature were found in either patient group.

Conclusions:

• Patients with FS, regardless of epilepsy comorbidity, demonstrate structural brain alterations.
• These alterations are primarily located in brain regions associated with emotional processing and executive control.
• The findings suggest a neurobiological basis for functional seizures involving specific cortical regions.