Altered Gray Matter Structure and White Matter Microstructure in Patients with Congenital Adrenal Hyperplasia: Relevance for Working Memory Performance

Congenital adrenal hyperplasia (CAH) has been associated with brain structure alterations, but systematic studies are lacking. We explore brain morphology in 37 (21 female) CAH patients and 43 (26 female) healthy controls, aged 16-33 years, using structural magnetic resonance imaging to estimate cortical thickness, surface area, volume, subcortical volumes, and white matter (WM) microstructure. We also report data on a small cohort of patients (n = 8) with CAH, who received prenatal dexamethasone (DEX). Patients with CAH had reduced whole brain volume (4.23%) and altered structure of the prefrontal, parietal, and superior occipital cortex. Patients had reduced mean FA, and reduced RD and MD, but not after correcting for brain volume. The observed regions are hubs of the visuospatial working memory and default mode (DMN) networks. Thickness of the left superior parietal and middle frontal gyri was associated with visuospatial working memory performance, and patients with CAH performed worse on this task. Prenatal treatment with DEX affected brain structures in the parietal and occipital cortex, but studies in larger cohorts are needed. In conclusion, our study suggests that CAH is associated with brain structure alterations, especially in the working memory network, which might underlie the cognitive outcome observed in patients.