Clinical MRI morphological analysis of functional seizures compared to seizure-naïve and psychiatric controls.

The linear mixed-effects model effect size (mean divided by standard error) of 90 patients with functional seizures (FS) compared to 576 seizure-naïve and psychiatric controls on cortical thickness in each region of interest on a cortical surface map. After Bonferroni–Holm correction, only bilateral superior temporal thinning and left lateral occipital thickening were significant. [Display omitted] • Structural correlates of functional seizures exist, but are inconsistent. • We examined MRI morphometry in 90 FS versus 576 psychiatric- and other- controls. • Differences were in superior temporal and occipital cortex, and cerebellum. • Magnetic resonance imaging quality was lower in FS, but this did not account for differences. • Further comparison to other relevant populations is needed. Functional seizures (FS), also known as psychogenic nonepileptic seizures (PNES), are physical manifestations of acute or chronic psychological distress. Functional and structural neuroimaging have identified objective signs of this disorder. We evaluated whether magnetic resonance imaging (MRI) morphometry differed between patients with FS and clinically relevant comparison populations. Quality-screened clinical-grade MRIs were acquired from 666 patients from 2006 to 2020. Morphometric features were quantified with FreeSurfer v6. Mixed-effects linear regression compared the volume, thickness, and surface area within 201 regions-of-interest for 90 patients with FS, compared to seizure-naïve patients with depression (n = 243), anxiety (n = 68), and obsessive–compulsive disorder (OCD, n = 41), respectively, and to other seizure-naïve controls with similar quality MRIs, accounting for the influence of multiple confounds including depression and anxiety based on chart review. These comparison populations were obtained through review of clinical records plus research studies obtained on similar scanners. After Bonferroni–Holm correction, patients with FS compared with seizure-naïve controls exhibited thinner bilateral superior temporal cortex (left 0.053 mm, p = 0.014; right 0.071 mm, p = 0.00006), thicker left lateral occipital cortex (0.052 mm, p = 0.0035), and greater left cerebellar white-matter volume (1085 mm3, p = 0.0065). These findings were not accounted for by lower MRI quality in patients with FS. These results reinforce prior indications of structural neuroimaging correlates of FS and, in particular, distinguish brain morphology in FS from that in depression, anxiety, and OCD. Future work may entail comparisons with other psychiatric disorders including bipolar and schizophrenia, as well as exploration of brain structural heterogeneity within FS. [ABSTRACT FROM AUTHOR]