Reversible cerebral vasoconstriction syndrome

The key symptom of RCVS is recurrent thunderclap headaches, which over 95% of patients experience. In two-thirds of cases, it is the only symptom. This condition features the unique property that the patient's cerebral arteries can spontaneously constrict and relax back and forth over a period of time without intervention and without clinical findings. Vasospasm is common post subarachnoid hemorrhage and cerebral aneurysm, but in RCVS only 25% of patients have symptoms post subarachnoid hemorrhage. ==Causes==

The direct cause of the symptoms is believed to be either constriction or dilation of blood vessels in the brain. ==Diagnosis==

The clinician should first rule out conditions with similar symptoms, such as subarachnoid hemorrhage, ischemic stroke, pituitary apoplexy, cerebral artery dissection, meningitis, and spontaneous cerebrospinal fluid leak. This may involve a CT scan, lumbar puncture, MRI, and other tests. Posterior reversible encephalopathy syndrome has a similar presentation, and is found in 10–38% of RCVS patients. RCVS is diagnosed by detecting diffuse reversible cerebral vasoconstriction. Catheter angiography is ideal, but computed tomography angiography and magnetic resonance angiography can identify about 70% of cases. Multiple angiographies may be necessary. Because other diseases (such as atherosclerosis) have similar angiographic presentations, it can only be conclusively diagnosed if vasoconstriction resolves within 12 weeks. ==Treatment==

As of 2014, no treatment strategy has yet been investigated in a randomized clinical trial. Verapamil, nimodipine, and other calcium channel blockers may help reduce the intensity and frequency of the headaches. A clinician may recommend rest and the avoidance of activities or vasoactive drugs which trigger symptoms (see § Causes). Analgesics and anticonvulsants can help manage pain and seizures, respectively. ==Prognosis==

All symptoms normally resolve within three weeks, and may only last days. Permanent deficits are seen in a minority of patients, ranging from under 10% to 20% in various studies. Less than 5% of patients experience progressive vasoconstriction, which can lead to stroke, progressive cerebral edema, or even death. Severe complications appear to be more common in postpartum mothers. ==Epidemiology==

The incidence of RCVS is unknown, but it is believed to be "not uncommon", and likely under-diagnosed. ==History==

Case studies of the condition first appeared in the 1960s, but it was not then recognized as a distinct entity. The name Call-Fleming syndrome refers to these researchers. This name merges various conditions that were previously treated as distinct entities, including Call-Fleming syndrome, postpartum angiopathy, and drug-induced angiopathy. Other names may still be used for particular forms of the condition. ==See also==