Patterns of Acute intracranial Hemorrhage in Adult Patients with Bilateral and Unilateral Moyamoya Disease

Background: Moyamoya disease (MMD) is a rare cerebrovascular disease. The difference of hemorrhagic patterns in adult patients with bilateral and unilateral MMD is still unclear. Objective: For a better understanding of their characteristics, we compared the patterns of acute intracranial hemorrhage in adult patients with bilateral and unilateral MMD. Methods: Adult MMD patients with acute intracranial hemorrhage were retrospectively included. Clinical and radiological characteristics of adult patients with bilateral and unilateral MMD were collected and analyzed. Chi-square test, t-test, or rank sum test were used for statistical analyses. Results: A total of 107 patients were included. Among 74 patients with bilateral MMD, 9 (12.2%) were at Suzuki Stage 2, 48 (64.9%) were at Stage 3, 16 (21.6%) were at Stage 4, and another (1.4%) was at Stage 5. However, in patients with unilateral MMD, 8 (24.2%) were at Stage 2, 23 (69.7%) were at Stage 3, and 2 (6.1%) were at Stage 4. Intraparenchymal hemorrhage was found in 40 (54.1%) patients with bilateral MMD and 16 (48.5%) patients with unilateral MMD (P=0.594). Intraventricular hemorrhage was shown in 65 (87.8%) patients with bilateral MMD and 19 (57.6%) patients with unilateral MMD (P<0.001). Subarachnoid hemorrhage was observed in 17 (23.0%) patients with bilateral MMD and 18 (54.5%) patients with unilateral MMD (P=0.001). Conclusion: Unilateral MMD patients with acute intracranial hemorrhage are at the earlier Suzuki stage than the bilateral MMD patients. Intraventricular hemorrhage occurs more frequently in bilateral MMD, while subarachnoid hemorrhage is more frequent in unilateral MMD.