Regional Differences in Presentation, Cause, and Outcome of Reversible Cerebral Vasoconstriction Syndrome

BACKGROUND: National studies on reversible cerebral vasoconstriction syndrome (RCVS) point to differences between Asian and European patients. We investigated geographic variations in neurological complications, outcomes, and causes. METHODS: We conducted an exploratory analysis of pooled individual patient data from the Reversible Cerebral Vasoconstriction Syndrome International Collaborative network, a multicenter observational cohort study including patients with definite RCVS from 2 French, 32 Italian, 1 South Korean, and 1 Taiwanese centers. Data on demographics, precipitants, symptoms, imaging, treatment, and outcomes were collected. The primary end point was RCVS-associated brain lesions, including ischemic stroke, cortical subarachnoid hemorrhage, intracerebral hemorrhage, posterior reversible encephalopathy syndrome, and subdural hematoma. Secondary end points included unfavorable 3-month outcomes (modified Rankin Scale score ≥1) and causes (idiopathic versus secondary). Odds ratios and 95% CIs were calculated using multivariable logistic regression, adjusting for potential confounders. RESULTS: From 2009 to 2021, we included 1127 patients (528 European and 599 Asian). Recruitment occurred either through emergency settings or outpatient clinics, with most Asian patients recruited from outpatient clinics (65.8%) and most European patients from emergency settings (99.8%). Brain lesions were more frequent in European patients (29.2% versus 6.3%; odds ratio, 4.09 [95% CI, 2.66–6.30]). In a sensitivity analysis restricted to hospitalized patients (n=651), the association persisted. Unfavorable 3-month outcomes (5.5% versus 1.7%; odds ratio, 3.01 [95% CI, 1.35–6.68]) and secondary RCVS (50.4% versus 10.9%; odds ratio, 7.09 [95% CI, 5.14–9.76]) were also associated with European residency. CONCLUSIONS: RCVS presentations vary across regions, with higher lesion rates, more secondary forms, and worse outcomes in European patients. While these exploratory results may reflect selection bias from differing health care structures, further research is needed to determine the contribution of genetic, environmental, and societal factors.