Abstracts

Rationale: Focal epilepsy is a progressive disorder, with structural imaging showing ongoing cortical thinning, even contralateral to the epileptic focus. With drug-resistant epilepsy (DRE), there is evidence that surgery interrupts, and in some cases, even reverses global cortical thinning (Galovic et al., 2020). However, such work has focused on adults. As there is growing evidence to support DRE epilepsy surgery at earlier ages (because of child brain plasticity), understanding whether surgery interrupts cortical thinning in children is of growing importance. Moreover, other morphometric measures, such as cortical volume and surface area, are important indices of typical and atypical neurodevelopment, but are relatively understudied post-DRE surgery. Thus, there is a need to determine whether cortical thickness, volume, and surface area in pediatric DRE surgery patients together deviate from normative neurodevelopment.

Methods: T1 images were acquired from 24 patients (median age = 15 years; median absolute deviation (MAD) of age = 2 yr; 12 females, 12 males) who underwent resection or ablation (9 left (LH) and 15 right hemisphere (RH)) for DRE and 43 age- and gender-matched controls (median age = 14 yr, MAD of age = 3 yr; 20 f, 23 m). The intact hemisphere of patients and both hemispheres of controls were parcellated on the Desikan-Killiany atlas. Cortical thickness, gray matter volume, and surface area were derived for each region. Lateral ventricle size was also derived. Analysis of Variance was run on each measure with region as a within-subjects variable, and hemisphere, group, and gender as between-subjects variables. Age was modeled as a covariate. Tukey Least Significant Difference post-hoc testing was used (p < 0.01).