Abstract WP228: Reversible Cerebral Vasoconstriction Syndrome: Presenting Symptoms, Incidence, and Outcomes in a Multi-State Cohort in the United States

Abstract

Introduction: Reversible cerebral vasoconstriction syndrome (RCVS) is a syndrome of recurrent thunderclap headaches with transient cerebral vasoconstriction which can cause stroke. There are few population-based data on the incidence of RCVS as well as associated risk factors and complications. Methods: We performed a retrospective cohort study using administrative claims data from all nonfederal emergency department (ED) visits and hospitalizations in 11 U.S. states during 2016. Using ICD-10 diagnosis code I67.841, we identified adult patients hospitalized with RCVS and evaluated associated diagnoses during prior, concurrent, and subsequent ED visits and hospitalizations. We used U.S. census data to estimate the age- and sex-standardized incidence of RCVS in the U.S. adult population. In a validation study, we reviewed the records of patients with a discharge diagnosis of RCVS and a random sample of patients with other cerebrovascular diagnoses at our medical center to estimate the sensitivity and specificity of the RCVS diagnosis code, and calculated the RCVS 2 score of patients with RCVS. Results: In our validation study, the sensitivity of the RCVS ICD-10 code was 100% (95% CI, 66-100%) and the specificity 90% (95% CI, 74-98%); the median RCVS 2 score among patients diagnosed with RCVS was 6, supporting that the diagnosis code generally identified true cases of RCVS. In our statewide analysis, we identified 222 patients diagnosed with RCVS in 2016, equating to a U.S. incidence of 2.7 (95% CI, 2.4-3.1) per million adults per year. The mean age was 46.8 (±14.3) years, 63.5% of patients were white, and 77.5% were female. There were 17 ED visits (22% of all ED visits) for headache in the 3 months before RCVS diagnosis. During the RCVS hospitalization, the most common complications were subarachnoid hemorrhage (33.5%), followed by ischemic stroke (14.9%), intracerebral hemorrhage (9.3%), and seizures (9.3%). Most patients were discharged home after admission for RCVS (76.6%). Conclusions: Hospitalization with a recognized case of RCVS occurs in about 3 per million adults in the U.S. per year. Although majority of patients hospitalized with RCVS were discharged home, a substantial proportion had serious cerebrovascular complications.