Association of imaging-defined brain age with disease severity and adverse outcomes in CADASIL.

INTRODUCTION

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is caused by cysteine-altering NOTCH3 variants. We examined whether neuroimaging-defined brain age is altered in CADASIL and its association with disease severity and outcomes.

METHODS

A brain-age prediction model was constructed using magnetic resonance imaging from 1482 healthy individuals and applied to 153 individuals with NOTCH3 variants and 30 controls. Brain age gap (BAG) was calculated as predicted minus chronological age. Associations between BAG, imaging markers, and clinical outcomes were analyzed.

RESULTS

Individuals with NOTCH3 variants exhibited significantly higher BAG than controls. Higher BAG was associated with greater disease severity, neuroimaging markers - most prominently peak width of skeletonized mean diffusivity - and poorer clinical performance. In addition, BAG showed a partial mediation effect in the association between disease stage and cognitive performance.

DISCUSSION: Accelerated brain aging is evident in CADASIL, and the BAG reflects the cumulative microvascular injury burden and may be involved in the pathophysiological pathway linking disease progression to cognitive impairment.