Updated on 23/02/2024
Reversible cerebral vasoconstriction syndrome (RCVS) refers to constriction and dilation of many blood vessels in the brain, occurring in a patchy manner, typically starting with recurrent thunderclap headaches and resolving over days to weeks. Many patients develop cortical subarachnoid hemorrhage (cSAH), distal territory infarctions, or edema. As the name implies, the condition is reversible, and the clinical outcome is usually excellent.
Although the incidence is estimated to be three per million, it is believed to be more common. The female-to-male ratio varies between 2:1 and 10:1. The average age of onset is 42-51 years. It tends to occur at a younger age in men, can be associated with sexual activity, and has a better prognosis in males.
The classic presenting symptom is a sudden, thunderclap headache reaching its maximum intensity within one minute. Patients describe this pain as the most severe headache of their life. Approximately 10-30% of cases occur without this type of headache. A key feature of the headache is its recurrent nature. Between recurrent severe headaches, patients typically experience mild-to-moderate dull, diffuse headache. Headache exacerbations can be triggered by the Valsalva maneuver, sexual activity, or physical exertion. Blurred vision is common among patients, and scotomas and cortical blindness can develop. Complications such as stroke or cerebral edema manifesting as aphasia, hemiparesis, ataxia, cortical blindness, or encephalopathy can occur in 9-63% of hospitalized patients. Initially, epileptic seizures are reported in up to 20% of cases.
RCVS has been associated with various conditions including pregnancy, migraines, use of vasoconstrictive medications, brain surgical procedures, high blood calcium levels, unruptured aneurysms, cervical artery dissections, posterior reversible encephalopathy syndrome, Takotsubo cardiomyopathy (broken heart syndrome), and transient global amnesia. However, there is insufficient epidemiological evidence to support a causal relationship with individual risk factors, triggers, and conditions associated with RCVS. Some authors speculate an association with transient vasculitis, but there is no evidence supporting the role of inflammation. Cerebrospinal fluid examination and comprehensive serological tests are typically normal, and pathological studies of brain and temporal arteries show no abnormalities.
The diagnosis of RCVS is based on characteristic clinical, brain imaging, and angiographic features. Although initial brain imaging may be normal, approximately half of patients develop complications such as cortical subarachnoid hemorrhages, lobar hemorrhages, ischemic strokes in arterial watershed territories, and reversible edema either alone or in combination. Vasoconstriction develops within hours to days, initially affecting distal arteries.
Thunderclap headache is a medical emergency. The patient should initially be evaluated for serious secondary causes such as ruptured brain aneurysms, intracranial hemorrhage, and cervical artery dissection. Urgent brain and cerebral vascular structures should be visualized with cranial computed tomography or magnetic resonance imaging and head and neck CT or MR angiography. If initial imaging is normal, cerebrospinal fluid examination should be performed to exclude subarachnoid hemorrhage and infectious causes of thunderclap headache.
There is no established treatment for RCVS. While most patients completely recover over time, one-third may develop transient symptoms within the first few days, and progressive clinical courses are rare but possible. Therefore, hospitalization for observation, pain control, and supportive care is advisable during the first few days after symptom onset. If necessary, vasoconstrictive calcium channel blockers or medications such as magnesium sulfate may be used. In some rare cases, intra-arterial treatments may be required. Corticosteroid therapy is not recommended. Thunderclap headaches typically resolve over days to weeks. Similarly, visual and other focal neurological signs and symptoms disappear within days to weeks in most patients. Deficits due to stroke may remain in 15-20% of patients. Massive strokes resulting in severe morbidity or death occur in less than 5% of cases of progressive cerebral arterial vasoconstriction syndrome.
REFERENCES:
1. Aneesh B Singhal. Reversible cerebral vasoconstriction syndrome: A review of pathogenesis, clinical presentation, and treatment. International Journal of Stroke 2023; 18(10):1151-1160.
2. Aneesh B Singhal. Reversible cerebral vasoconstriction syndrome. Up to Date Mar 01, 2022.
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