RCVS₂ Score for Reversible Cerebral Vasoconstriction Syndrome

Use in patients 18-55 years old with a new presentation of intracranial arteriopathy on intracranial vascular imaging to differentiate RCVS from non-RCVS causes of intracranial arteriopathy.

• Detailed history-taking is imperative, with clear characterization of the hyperacute onset of severe headache and identification of vasoconstrictive triggers. 
• Failure to identify a trigger that is present may change the diagnosis from RCVS to non-RCVS arteriopathy. Clinical judgment should be used when identifying triggers since vasoconstrictive potency can vary and a temporal relationship may be important.
• A new angiographic abnormality (CTA, MRA, or catheter cerebral angiogram) is required to apply the RCVS2 score.
• Intermediate scores of 3-4 were equivocal with a sensitivity of 10% and specificity of 86% for diagnosing RCVS.
• RCVS may have normal intracranial vascular imaging early or late in the course, in which case the RCVS2 score is inapplicable. 
• Not applicable to children <18 or adults >55.
• Note that intracranial internal carotid artery narrowing scores negative points (-2) to avoid misdiagnosis in patients with Moyamoya disease.

• Provides a discriminatory clinical tool using variables that are readily available at first presentation.
• Early distinction between RCVS and non-RCVS arteriopathies is diagnostically challenging and has important management implications particularly because steroids, often used in non-RCVS arteriopathies, worsen outcomes in RCVS. 
• A score ≥5 diagnosed RCVS with 90% sensitivity and 99% specificity. A score ≤2 excluded RCVS with 85% sensitivity and 100% specificity.
• Accurately distinguishes RCVS from its closest mimic, primary angiitis of the CNS (PACNS).