Neuroimaging Biomarkers of Disease Progression and Cognitive Change in Patients With Retinal Vasculopathy With Cerebral Leukoencephalopathy

BACKGROUND AND OBJECTIVES: A monogenic, age-related cerebral small vessel disease (cSVD), retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S), causes accelerated vascular dementia, vision loss, and premature death. Given knowledge is limited regarding its pathophysiology, we examined the natural history of progression in imaging and cognitive endpoints to define the rate and variability of progression in a prospective RVCL-S cohort. We hypothesized that cerebral blood flow (CBF) and oxygen extraction fraction (OEF), as metrics of cerebral hypoxia-ischemia, would be associated with neurologic disease progression. METHODS: We performed sequential brain MRI and a cognitive battery in a prospective RVCL-S cohort. Arterial spin labeling and asymmetric spin echo quantified CBF and OEF in normal-appearing white matter (WM), respectively. Three neuroimaging endpoints of cSVD included the following: log-transformed, normalized fluid-attenuated inversion recovery WM hyperintensity (WMH) volume; WM microstructure using mean diffusivity; and normalized WM volume. Five cognitive and motor endpoints included Digit Symbol Substitution Test (DSST), category fluency, free recall, Montreal Cognitive Assessment (MoCA), and gait speed. Linear mixed-effects models examined age, CBF, and OEF in association with neuroimaging and cognitive progression. RESULTS: = 0.029). Neither OEF nor CBF was independently associated with cognitive decline. DISCUSSION: Elevated OEF in at-risk WM was associated with progression in WMH and impairment in WM microstructure, suggesting a role for tissue hypoxia-ischemia in underlying RVCL-S pathophysiology. Cerebral OEF holds promise as a predictive biomarker to risk-stratify patients with RVCL-S and other forms of cSVD.