Loss of Venous Integrity in Cerebral Small Vessel Disease

BACKGROUND AND PURPOSE: Previous pathological studies in humans or in animal models have shown alterations of small arteries and veins within white matter lesions in cerebral small vessel disease. We aimed to evaluate in vivo, the integrity of the cerebral venous network using high-resolution MRI both within and outside white matter hyperintensities in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). METHODS: High-resolution T2*-weighted images were obtained at 7-T in 13 CADASIL patients with no or only mild symptoms and 13 age- and sex-matched controls. Macroscopic veins were automatically counted in the centrum semiovale and compared between patients and controls. In addition, T2* was compared between groups in the normal-appearing white matter. RESULTS: Vein density was found lower in CADASIL patients compared with that in controls (-14.6% in patients, P<0.001). This was detected both within and outside white matter hyperintensities. Mean T2*, that is presumably inversely related to the venous density, was also found increased in normal-appearing white matter of patients (+7.2%, P=0.006). All results were independent from the extent of white matter hyperintensities. CONCLUSIONS: A significant reduction in the number of visible veins was observed in the centrum semiovale of CADASIL patients both within and outside white matter hyperintensities, together with an increase of T2* in the normal-appearing white matter. Additional studies are needed to decipher the exact implication of such vasculature changes in the appearance of white matter lesions.