Blood-brain barrier permeability changes over the lifespan

Blood-brain-barrier (BBB) dysfunction is a hallmark of aging-related disorders, including cerebral small vessel disease and Alzheimer’s disease. An emerging biomarker of BBB dysfunction is time of exchange (Tex) of water across the BBB as measured by multi-echo arterial spin labeling MRI. We evaluated Tex across the age spectrum in 40 adults from two cohorts of healthy controls, and demonstrated that Tex is higher in gray than in white matter, higher in females than in males, and that Tex decreases with age. These findings suggest that BBB permeability changes over the lifespan can be investigated using arterial spin labeling approaches.