RCVS₂ score

In a retrospective study of consecutive patients with RCVS (n = 30) or non-RCVS arteriopathy (n = 80), recurrent or single thunderclap headache, vasoconstrictive trigger, female sex, and convexity subarachnoid hemorrhage were predictors of RCVS; intracranial carotid artery involvement (ie, segmental narrowing) was a negative predictor. In the derivation cohort, RCVS₂ scores ≥5 had a high specificity and sensitivity (99 and 90%, respectively) for diagnosing RCVS, while scores ≤2 had a high specificity and sensitivity (100 and 85%) for excluding RCVS; intermediate scores of 3 to 4 had a lower specificity and sensitivity (86 and 10%) for diagnosing RCVS. Performance was similar in the validation cohort.