Cerebral Cortical Reorganization After Intracerebral Hemorrhage in Children

BACKGROUND AND PURPOSEStructural changes following pediatric intracerebral hemorrhage (ICH) caused by ruptured brain vascular malformations remain poorly understood. We conducted a longitudinal study to examine morphometric changes in brain volume and cortical thickness across ipsilesional and contralesional hemispheres following unilateral ICH. METHODSBrain magnetic resonance imaging (MRI) was acquired in 20 patients aged 6-18 years (Median: 13, IQR: 9.3-16) at presentation of ICH prior to treatment of the hemorrhage etiology (baseline/Session 1) and repeated at 6 months (Session 2) and 12 months (Session 3) post-ICH. T1- and T2-weighted Fluid-Attenuated Inversion Recovery (T2-FLAIR) MR images were segmented into cortical and subcortical regions, with gray matter parcellated based on the Desikan-Killiany-Tourville (DKT) atlas. We used deep learning-based lesion extraction to enable more precise measurements of brain volume and cortical thickness. Morphometric changes were quantified as percentage change from baseline with signed values denoting increase or decrease. We analyzed longitudinal change in volume and cortical thickness of contralesional and ipsilesional hemispheres and lobes. Structural covariance analyses focused on correlations of thickness between homologous and non-homologous cortical regions. Significant correlations were classified based on the sensorimotor-association axis, Mesulam laminar differentiation, DKT regions, von Economo-Koskinas cytoarchitecture, and Yeo 7-network functional MRI (fMRI) atlases. RESULTSPediatric post-ICH recovery was characterized by dynamic and spatially divergent morphometric changes. At 6 months, contralesional cortical regions exhibited increases in volume and thickness; however, by 12 months, ipsilesional cortical, subcortical, and white matter structures showed progressive reductions. Morphological reorganization was prominent in the contralesional hemisphere; association, heteromodal, and frontal cortices; and within default mode and frontoparietal functional networks. CONCLUSIONSOur findings highlight the vulnerability and plasticity of higher-order cortical regions and implicate contralesional cortical networks as substrates of resilience in recovery.