Infections in Moyamoya Phenomenon: Current Evidence and Future Horizons-Narrative Review.

Moyamoya Disease (MMD) is a progressive cerebrovascular disorder characterized by the stenosis or occlusion of the terminal portions of the internal carotid arteries and fragile collateral vessel formation. While its etiology remains elusive, emerging evidence strongly implicates infections as key environmental triggers, particularly through immune-mediated vascular injury and interactions with genetic susceptibility (eg, RNF213 variants). This review explores the current understanding of the relationship between infections and MMD, examines epidemiological data, molecular and immunological mechanisms, genetic predispositions, and specific infections implicated in the disease. Critical limitations include causality ambiguity from reliance on anecdotal reports, methodological heterogeneity across studies, and mechanistic gaps in validating infection-endothelial dysfunction relationships. Future research must prioritize prospective cohorts and therapeutic strategies targeting infection-responsive pathways.