Overlooked cerebral venous features associated with disease progression in moyamoya disease: insights from a single-center case-control study.

Moyamoya disease (MMD) is a rare cerebrovascular disorder characterized by progressive steno-occlusion of the internal carotid artery system and aberrant collateral vessel formation. While MMD is primarily recognized for its arterial pathology, venous changes have been less explored. In this study, we investigated cerebral venous features in MMD and their association with disease progression. A total of 129 MMD patients (219 hemispheres) and 219 control patients with intracranial aneurysms (219 healthy hemispheres) were evaluated using digital subtraction angiography. MMD patients demonstrated significantly lower venous scores (cortical, deep, and total) compared to controls, with scores further declining as the disease advanced. Additionally, MMD patients exhibited delayed cortical venous filling times, which correlated with higher Suzuki stages. Venous drainage patterns also differed, with MMD patients predominantly showing posterior drainage, whereas controls exhibited anterior drainage. These findings underscore significant venous abnormalities in MMD, suggesting that the disease affects both the arterial and venous systems, challenging the conventional view of MMD as solely an arterial disorder.