Reversible Cerebral Vasoconstriction Syndrome (RCVS) is a rare cause of severe headache that can mimic other causes of sudden, severe headache and result in frequent emergency department (ED) visits.

This narrative review provides an evidence-based update concerning the presentation, evaluation, and management of RCVS for the emergency clinician.

RCVS can present as recurrent, severe headaches that may be maximal in onset, known as a thunderclap headache. Distinguishing from other causes of thunderclap headache such as aneurysmal subarachnoid hemorrhage, cerebral venous thrombosis, and posterior reversible encephalopathy syndrome is challenging. Risk factors for RCVS include use of vasoactive substances, exertion, coughing, showering, sexual activity, and cervical artery dissection. Diagnosis relies on clinical features and imaging. Cerebral catheter digital subtraction angiography (DSA) is considered the gold standard imaging modality; however, computed tomography angiography or magnetic resonance angiography are reliable non-invasive diagnostic modalities. Treatment focuses on avoiding or removing the offending agent, administration of calcium channel blockers such as nimodipine, and reversing anticoagulation if bleeding is present. Although most cases have a benign course and resolve within 3 months, focal subarachnoid hemorrhage, intracerebral hemorrhage, permanent neurologic disability, or death can occur in a minority of cases.

Diagnosis and appropriate management of RCVS can be aided by understanding key aspects of the history and examination. The emergency clinician can then obtain indicated imaging, confirming the diagnosis and allowing for appropriate management.