gms | German Medical Science

Objective: Cerebrovascular hemodynamic insufficiency can be quantified using XeCT, but only limited data is available regarding cerebral blood flow (CBF) and cerebrovascular reserve capacity (CVRC) in Moyamoya disease (MMD); Therefore, further detailed analysis regarding to age, anatomical location and disease severity is warranted and the purpose of this study.

Method: We analyzed 67 consecutive patients, who underwent XeCT for angiographically demonstrated MMD and included 5 healthy patients as controls. We used a classification system of region of interests (ROIs) that observes angiographic findings and the severity of the disease as previously described in cerebrovascular atherosclerotic disease. We calculated CBF, CVRC as well as baseline and stimulation hemodynamic stress distribution for each ROI. Particular emphasis was put on ROIs that are typically involved in MMD, such as the supracallosal territory (along the Fisher anastomosis) and the basal ganglia (along the rete mirabilis).

Results: In MMD, cortical and central CBF decreases significantly with age, while reserve capacity and hdSD remain stable over time. Disease progression, however, is characterized by a significant decrease in both CBF and CVRC (cortex and supracallosal ROIs). Within the basal ganglia, CBF remains stable with disease progression, while the reserve capacity is exhausted, illustrating the characteristic proximal collateralization pattern of MMD. Regression analysis of hdSD delineates a CVRC threshold of 35% to discriminate disease severity.

Conclusions: MMD is characterized by territory-specific CBF and CVRC changes over time and with disease progression that correlate well with established angiographical features, such as proximal collateralization.