Diagnostic criteria:
  1. Head pain occurring spontaneously as a single stab or series of stabs
  2. Two only of the following:
    1. each stab lasts for up to a few seconds
    2. stabs recur with irregular frequency, from one to many per day
    3. no cranial autonomic symptoms
  3. Not fulfilling ICHD-3 criteria for any other headache disorder
  4. Not better accounted for by another ICHD-3 diagnosis.