6.7.3.1 Headache probably attributed to reversible cerebral vasoconstriction syndrome (RCVS)

Description:
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:
A. Any new headache fulfilling criterion C
B. Reversible cerebral vasoconstriction syndrome (RCVS) is suspected, but cerebral angiography is normal
C. 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 min
      b) severe intensity
      c) lasting ≥5 min

    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

D. Not fulfilling ICHD-3 criteria for any other headache disorder
E. Not better accounted for by another ICHD-3 diagnosis, and aneurysmal subarachnoid haemorrhage has been excluded by appropriate investigations.

Comment:
Large series of patients with confirmed RCVS have shown that up to 75% of patients presented with isolated headaches. The arterial abnormalities of RCVS may be difficult to demonstrate. Some RCVS cases need repeated CT- or MR-angiography two to three 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 and normal initial cerebral angiography, and in whom another cause of the headaches has been excluded by appropriate investigations, a diagnosis of 6.7.3.1 Headache probably attributed to reversible cerebral vasoconstriction syndrome (RCVS) can be made.