Acute headache probably attributed to reversible cerebral vasoconstriction syndrome (RCVS)


Headache typical for reversible cerebral vasoconstriction syndrome (RCVS), namely thunderclap headache recurring over 1-2 weeks and triggered by sexual activity, exertion, Valsalva manœuvres and/or emotion, but the intracranial arterial beading typical of RCVS has not been demonstrated by cerebral angiography.

Diagnostic criteria:
  1. Any new headache fulfilling criterion C
  2. Reversible cerebral vasoconstriction syndrome (RCVS) is suspected, but cerebral angiography is normal
  3. Probability of causation demonstrated by all of the following:
    1. at least two headaches within 1 month, with all three of the following characteristics:
      • a) thunderclap onset, and peaking in <1 minute
      • b) severe intensity
      • c) lasting ≥5 minutes
    2. at least one thunderclap headache has been triggered by one of the following:
      • a) sexual activity (just before or at orgasm)
      • b) exertion
      • c) Valsalva-like manœuvre
      • d) emotion
      • e) bathing and/or showering
      • f) bending
    3. no new thunderclap or other significant headache occurs >1 month after onset
  4. Either of the following:
    1. headache has resolved within 3 months of its onset
    2. headache has not yet resolved but 3 months from its onset have not yet passed
  5. Not better accounted for by another ICHD-3 diagnosis1.

In particular, aneurysmal subarachnoid haemorrhage has been excluded by appropriate investigations.


ICHD-3 does not generally propose criteria for probable secondary headaches. However, the arterial abnormalities of reversible cerebral vasoconstriction syndrome (RCVS) may be difficult to demonstrate. Some RCVS cases need repeated CT- or MR-angiography during 2-3 weeks after headache onset and others need invasive conventional angiography to be detected. In patients who have recurrent, triggered thunderclap headaches typical for RCVS over a period of less than one month but normal initial cerebral angiography, and in whom another cause of the headaches has been excluded by appropriate investigations, a temporary diagnosis of Headache probably attributed to reversible cerebral vasoconstriction syndrome can be made.