Reversible Cerebral Vasoconstriction Syndrome

Objective To estimate the incidence of hospitalization for reversible cerebral vasoconstriction syndrome (RCVS), we identified RCVS-related hospital admissions across 11 US states in 2016.

Methods We tested the validity of ICD-10 code I67.841 in 79 patients with hospital admissions for RCVS or other cerebrovascular diseases at 1 academic and 1 community hospital. After determining that this code had a sensitivity of 100% (95% confidence interval [CI], 82%–100%) and a specificity of 90% (95% CI, 79%–96%), we applied it to administrative data from the Healthcare Cost and Utilization Project on all hospital admissions across 11 states. Age- and sex-standardized RCVS incidence was calculated using census data. Descriptive statistics were used to analyze associated diagnoses.

Results Across 5,067,250 hospital admissions in our administrative data, we identified 222 patients with a discharge diagnosis of RCVS in 2016. The estimated annual age- and sex-standardized incidence of RCVS hospitalization was 2.7 (95% CI, 2.4–3.1) cases per million adults. Many patients had concomitant neurologic diagnoses, including subarachnoid hemorrhage (37%), ischemic stroke (16%), and intracerebral hemorrhage (10%). In the 90 days before the index admission, 97 patients had an emergency department (ED) visit and 34 patients a hospital admission, most commonly for neurologic, psychiatric, and pregnancy-related diagnoses. Following discharge from the RCVS hospital admission, 58 patients had an ED visit and 31 had a hospital admission, most commonly for neurologic diagnoses.

Conclusions Using population-wide data, we estimated the age- and sex-standardized incidence of hospitalization for RCVS in US adults as approximately 3 per million per year.