Cerebrovascular outcomes in reversible cerebral vasoconstriction syndrome with and without posterior reversible encephalopathy syndrome

Background The prognostic significance of posterior reversible encephalopathy syndrome (PRES) among patients with reversible cerebral vasoconstriction syndrome (RCVS) is uncertain. Methods We performed a retrospective cohort study using TriNetX database. Adults with an index diagnosis of RCVS were stratified by concomitant PRES. Patients with prior stroke, hemorrhage, or cerebral edema were excluded. Propensity-score matching (1:1) balanced covariates. Primary outcomes at 1 and 5 years were ischemic stroke, subarachnoid hemorrhage, and a composite of these events; secondary outcomes included inpatient readmissions. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated. Results Among 152 patients with RCVS+PRES and 3233 with RCVS alone, 150 matched pairs were generated (standardized differences <0.10). At 1 year, ischemic stroke occurred more frequently in the RCVS+PRES group compared with the RCVS-alone group (37.1% vs. 16.67%; HR, 2.50; 95% CI, 1.528–4.093), and inpatient readmissions were higher (54.11% vs. 25.74%; HR, 2.596; 95% CI, 1.731–3.892). Rates of subarachnoid hemorrhage were not significantly different between groups. At 5 years, RCVS+PRES remained associated with higher risks of ischemic stroke, inpatient readmissions, and the composite outcome of stroke or subarachnoid hemorrhage. Conclusions Among patients with RCVS, the presence of concomitant PRES identifies a higher-risk subgroup characterized by increased rates of ischemic stroke and hospital readmission at 1 year, with persistent cerebrovascular risk over 5 years. These findings suggest that PRES may represent a marker of more severe cerebrovascular dysregulation requiring closer monitoring.