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Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

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RCVS should be suspected in patients who presents with

  • recurrent thunderclap headache for a few days
  • cryptogenic stroke, especially when the patient also has headache (1)

Typically patients will report at least one trigger - eg, sexual activity (usually just before or at orgasm), straining during defecation, stressful or emotional situations, physical exertion, coughing etc (1).


RCVS with isolated headaches will have normal plain brain CT and normal or 'near normal', (with a mild increase in blood cell counts and protein concentrations) CSF (2)

Presence of segmental narrowing and dilatation (string of beads) of one or more arteries cerebral angiography, usually magnetic resonance angiography (MRA) or CT angiography (CTA) is diagnostic of RCVS (2).

Proposed diagnostic criteria for reversible cerebral vasoconstriction syndrome:

  • acute and severe headache (often thunderclap) with or without focal deficits or seizures
  • uniphasic course without new symptoms more than 1 month after clinical onset
  • segmental vasoconstriction of cerebral arteries shown by indirect (eg, magnetic resonance or CT) or direct catheter angiography
  • no evidence of aneurysmal subarachnoid haemorrhage
  • normal or near-normal CSF (protein concentrations <100 mg/dL, <15 white blood cells per μL)
  • complete or substantial normalisation of arteries shown by follow-up indirect or direct angiography within 12 weeks of clinical onset (2)

Other causes of thunderclap headaches should be considered in the differential diagnosis.


  • clinicians should note that early investigations (MRA, CTA, and even catheter angiography) may be normal up to six or seven days after headache onset in patients who are ultimately shown to have RCVS on repeat angiography (2)
  • haemorrhagic and ischaemic stroke can occur, sometimes after a few days of isolated headaches in patients with initial normal brain imaging (2)


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