To characterize morphometric differences in pediatric cortical resection patients' preserved cortex relative to typical brain morphometry.

Cortical morphometry can be an informative biomarker of function, and multiple studies have evaluated morphometry following adult neurosurgery. However, fewer studies have comprehensively evaluated morphometrics after pediatric resection.

Pediatric epilepsy resection patients (n=13 left resection, median age 16 years; n=19 right resection, median age 15yr) and age-matched, healthy controls (n=51, median age 15yr) underwent T1-weighted magnetic resonance imaging. We fit general linear models to compare patients' preserved hemisphere to controls' corresponding hemisphere on (1) total gray and white matter volume, (2) thickness, volume, and surface area of 34 cortical parcellations, and (3) volume of nine subcortical segmentations.

While both left and right resection patients had significantly less total white matter volume relative to controls, only left resection patients had significantly less gray matter volume. Relative to controls' right hemisphere, left resection patients' preserved right hemisphere had significantly less: thickness in 15 parcels (primarily frontal and temporal cortices), surface area in three parcels (lateral orbitofrontal, parahippocampal, and paracentral cortices), and volume in one parcel (rostral middle frontal cortex). Relative to controls' left hemisphere, right resection patients' preserved left hemisphere showed no significant differences in any cortical parcel on any metric. Regarding subcortex, relative to controls, left resection patients had less hippocampal volume; right resection patients had less caudate, pallidum, and putamen volume; and both patient groups had less accumbens volume.

Left but not right pediatric cortical resection is associated with less total gray matter volume, and less thickness, volume, and surface area in select cortical regions, primarily frontal and temporal. As the left hemisphere typically specializes for language function, our results lay a foundation for future work probing whether structural differences in the right hemisphere after left pediatric resection relate to language maintenance or recovery.