Reversible Cerebral Vasoconstriction Syndromes

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by sudden explosive and severe headaches that occur over days to weeks due to underlying widespread cerebral vasoconstriction. Although typically benign and self-limited, RCVS can lead to severe complications such as ischemic stroke, convexity subarachnoid or other intracerebral hemorrhage, and posterior reversible encephalopathy syndrome (PRES).

RCVS is now understood as a syndrome of cerebrovascular dysregulation. This condition is characterized by severe, sudden-onset headaches, often described as "thunderclap" headaches (TCHs), with peak intensity typically reached within the first minute. Recurrent TCHs are diagnostic of RCVS. Triggers, especially eclampsia or vasoconstrictive and many chemotherapeutic agents, have been recognized. RCVS is almost always reversible and self-limited in its clinical course.

RCVS is a descriptive term subsumed with the PRES under the designation of cerebrovascular dysregulation. Both syndromes feature similar clinical and imaging manifestations, including headaches, visual symptoms, seizures, and confusion. Management of the condition includes removal of any triggers, symptomatic treatment of headaches and seizures, and control of moderate blood pressure.

RCVS, which likely results from endothelial dysfunction and abnormal cerebrovascular tone, can be visualized on cerebral angiography, where the constriction of cerebral arteries presents a classic "sausage on a string" appearance. However, structural neuroimaging is frequently unrevealing, especially in the early stages.

Before the recognition and description of RCVS, many patients were misidentified as having primary angiitis of the central nervous system (PACNS) and, consequently, were exposed to the risks of brain biopsy and chronic immunosuppression. Better characterization of RCVS through diagnostic scores, such as the RCVS₂ score (described below), has significantly eliminated this confusion.