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    Reversible Cerebral Vasoconstriction Syndrome


    Last Updated Apr 16, 2021
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    Headache is a common presentation in the emergency department (ED) that can sometimes herald a life-threatening etiology.

    • Classic teaching is that a thunderclap headache (TCH) is pathognomonic for subarachnoid hemorrhage from a ruptured intracranial aneurysm. However, there are multiple other dangerous medical conditions that can present with TCH.

    One of these etiologies is reversible cerebral vasoconstriction syndrome (RCVS).

    • Described in 2007 by Calabrese et al. RCVS is a fairly new clinical entity comprising a group of disorders characterized by prolonged, but reversible, vasoconstriction of the cerebral arteries.
      • Previous names for RCVS include isolated benign cerebral vasculitis, Call-Fleming syndrome, postpartum angiopathy, cerebral vasculopathy, among others.
    • RCVS has been reported in patients from age 10 to 76, however occurrence peaks at 42 years of age.
    • It’s more commonly reported in women.
    • Most patients report at least one trigger, including:
      • Postpartum state
      • Sexual activity
      • Exposure to heat or cold
      • Drugs
        • Immunosuppressive drugs, ergotamines, caffeine, triptans, SSRIs, pseudoephedrine, cocaine, amphetamines, ecstasy, cannabis, bromocriptine.

    Even though “reversible”, RCVS is not benign and complications include cortical subarachnoid hemorrhages, focal intracerebral hemorrhages, strokes, PRES, and seizures.

    • Case fatality ~1-2%
    • Persistent focal neurologic deficits from stroke at follow-up 3-20%

    RCVS may be hard to diagnose in the ED.

    • One study reported that patients with RCVS who presented with TCH had an average of 5 physician evaluations in the ED before the diagnosis was made.
    • RCVS is thought to account for most cases of TCH that are classified as unexplained or benign.

    Diagnostic Process

    TCH is the defining clinical feature of RCVS, which is defined as a severe, throbbing headache that reaches maximal intensity within 60 seconds of onset.

    • TCH is reported in 94-100% of patients with RCVS
    • Sole symptom in 70-76% of patients

    Recurrent TCH over multiple days has sensitivity (99%) and specificity (90%) for the diagnosis of RCVS.

    • Single attacks are most common, but patients often have repeated attacks with a mean of 4 attacks in 1-4 weeks.
    • Moderate headache can persist between attacks.


    Work-up and Imaging

    In a patient presenting with TCH, it is critical to rule out a SAH.

    • The Ottawa SAH rule and 6-hour CT rule are well validated and very sensitive in ruling out SAH in a patient presenting with TCH who meets the inclusion criteria.
    • However, RCVS may present with TCH as the sole symptom, and would not be detected with only non-contrast CT head (NCCT) and LP alone.

    Cerebral angiography (CTA) is needed to show segmental narrowing and dilation of one or more arteries (described as a “string of beads”).

    • Narrowing of the arteries is not fixed and the 1st angiogram may even be normal.

    Recommended Treatment

    Consultation to Neurology

    • These patients will often get admitted for supportive management and observation.
    • Calcium channel blockers (CCBs) and oral magnesium are often initiated, but there is limited evidence to support their use.

    Take Home Points

    • The presentation of TCH can herald many dangerous diagnoses in the ED including SAH, and less commonly considered, RCVS.
    • RCVS is not benign, and patients can proceed to have complications such as subarachnoid hemorrhages, seizures, and strokes.
    • In patients presenting with TCH it is prudent to consider a diagnosis of RCVS, particularly if the patient has recurrent TCHs.
    • NCCT and LP are often are normal and diagnosis is by CTA, although even this can be normal early in the disease process.
    • Consult Neurology as the patient will likely get admitted for further supportive care, observation, and trial of CCBs and oral magnesium.

    Quality Of Evidence?


    This is a fairly new clinical entity and as such, overall evidence in this area is mixed from low to moderate quality. Most studies consist of retrospective reviews, however there are some larger reviews of combined prospective and prospective case-series data. There is limited evidence to support current treatments for RCVS.


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