Table 3 Alternative diagnostic criteria for acute headache attributed to ischemic stroke

A. Any headache fulfilling criteria B and C.

B. Acute ischaemic stroke has been diagnosed.

C. Evidence of causation demonstrated by the following:

 1. a new headache has developed within 24 hours of other symptoms and/or clinical signs of ischaemic stroke

 2. a previous headache with altered characteristics has developed within 24 hours of other symptoms and/or clinical signs of ischemic stroke

D. Either of the following:

 1. headache has resolved within three months

 2. headache has not yet resolved but three months have not yet passed

E. Not better accounted for by another ICHD-3 diagnosis.