Object: Moyamoya disease (MMD) is a rare cerebrovascular disease and its natural history is still unclear. The authors aimed to investigate the natural course of hemodynamically stable cases of adult MMD, with the analysis of stroke risk factors.
Methods: Two hundred forty-one patients were included in this retrospective study. One hundred sixty-six (68.9%) were female, and mean age (± SD) at first visit was 41.3 ± 12.0 years (range 18-69 years). Unilateral involvement was identified in 33 patients, and 19 patients (7.9%) had a family history of MMD. According to the clinical presentations, patients were classified into hemorrhagic (n = 62, 25.7%), ischemic (n = 144, 59.8%), and asymptomatic (n = 35, 14.5%) groups. The mean duration of follow-up was 82.5 ± 62.9 months (range 7.3-347.0 months).
Results: The annual stroke risk was 4.5%, and the annual risks of rebleeding in the hemorrhagic group and recurrent ischemic events in the ischemic group were 4.3% and 3.0%, respectively. There was no significant difference in cumulative stroke risk between the 3 groups (p = 0.461). Risk factors included thyroid disease for overall strokes (HR 2.56, 95% CI 1.16-5.67), initial hemorrhagic presentation for hemorrhagic strokes (HR 2.53, 95% CI 1.24-5.17), and initial ischemic presentation for ischemic strokes (HR 2.69, 95% CI 1.15-6.27). Familial MMD was a common risk factor for all types of stroke. Among the 3 clinical groups, the hemorrhagic group showed the worst clinical status at discharge and at most recent follow-up. Twenty-three patients (9.5%) eventually underwent revascularization surgery.
Conclusions: There was no statistically significant difference in the incidence of stroke in the different clinical groups; clinical status, however, was most severe in patients with hemorrhagic presentation. In patients who experienced stroke during the follow-up period, the stroke type tended to correspond to their initial presentation. Close follow-up is needed in patients with thyroid disease and a family history of MMD.
Keywords: KPS = Karnofsky Performance Scale; MMD = moyamoya disease; SAH = subarachnoid hemorrhage; SPECT = single photon emission computed tomography; TIA = transient ischemic attack; asymptomatic; clinical course; hemorrhage; ischemia; mRS = modified Rankin Scale; moyamoya disease; vascular disorders.