Implications for a Deeper Clinical Understanding of Moyamoya Disease: Temporal Evolution of Suzuki Staging

BACKGROUND AND OBJECTIVES: Moyamoya disease (MMD) is a rare cerebrovascular disorder discovered in Japan, characterized by progressive internal carotid artery stenosis and fragile collateral vessel formation. Diagnosis relies on imaging, with Suzuki staging commonly used to classify disease severity. There is limited literature on MMD in non-Asian, non-White populations. This study evaluated clinical factors associated with disease presentation, severity, treatment, and progression, with a novel focus on longitudinal changes in Suzuki stage. METHODS: A retrospective cohort study was conducted using electronic medical records. Clinical data, including demographics, Suzuki stages, surgical interventions, stroke frequency, and outcomes, were collected and analyzed. RESULTS: Of 114 patients diagnosed with MMD, 89 were from underrepresented populations in Moyamoya literature. Imaging from 91 patients showed Suzuki scores following a bell-curve distribution. Higher initial Suzuki scores were significantly associated with an increased likelihood of surgery ( P < .001). In a subcohort of 71 patients with at least 2 Suzuki scores 1 year apart, scores remained largely stable, although a weak, nonsignificant trend toward worsening was seen in nonsurgical patients ( P = .14). Notably, Mann-Whitney U analysis revealed a significant difference in Suzuki stage changes, with nonsurgical patients showing greater radiographic progression and surgically treated patients exhibiting stability or improvement ( P < .05). No significant correlation was found between changes in Suzuki stage and functional outcomes or stroke events. CONCLUSION: This study expands understanding of MMD in a diverse, non-Asian population and supports Suzuki staging as a reliable tool for disease assessment and surgical planning. Surgical intervention appears to slow radiographic progression, supporting its role in management. Further prospective studies are needed to refine Suzuki staging in monitoring disease trajectory and guiding treatment.