Background and purpose: Leptomeningeal artery abnormalities in Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) have not been extensively characterized. We quantified substructure and diameter of leptomeningeal arteries in CADASIL compared with age-matched controls and the very old; in addition, we characterized intimal thickening in CADASIL using immunohistochemistry.
Methods: Frontal and temporal cortex of 6 genetically proven CADASIL brains (average age, 66 years), 6 controls without symptoms of cerebrovascular disease, and 6 very old brains (average age, 89 years) were examined for leptomeningeal artery intimal, medial, and adventitial thickness; inner diameter; and sclerotic index and for smooth muscle markers.
Results: The intima of CADASIL arteries was thickened 5-fold compared with controls and the very aged (P<0.0001). Medial thickness was lower in CADASIL compared with controls and the very old (P<0.01). The adventitia was not significantly increased in CADASIL compared with age-matched controls. Arterial diameters were not smaller in CADASIL compared with controls. Sclerotic index was significantly increased in CADASIL compared with other groups (P<0.00001). Intimal cells in CADASIL expressed smooth muscle actin, S100A4, and vimentin but not desmin.
Conclusions: Principle changes of leptomeningeal arteries in CADASIL include intimal thickening and medial thinning, but not luminal narrowing. Smooth muscle-like cells participate in neointimal thickening of CADASIL arteries.