Headache caused by a transient ischaemic attack (TIA) and accompanied by the sudden-onset transient focal signs of a TIA. It lasts less than 24 hours.
A. Any new headache fulfilling criterion C
B. A transient ischaemic attack has been diagnosed
C. Evidence of causation demonstrated by both of the following:
1. headache has developed simultaneously with other symptoms and/or clinical signs of TIA
2. headache resolves within 24 hr
D. Not better accounted for by another ICHD-3 diagnosis.
A transient ischaemic attack (TIA) is a transient episode of neurological dysfunction caused by focal brain or retinal ischaemia without clinical, imaging or other evidence of acute cerebral or retinal infarction. Symptoms of a TIA typically, but not invariably, last less than one hour. While more common with basilar- than carotid-territory TIA, headache is very rarely a prominent symptom of TIA.
The differential diagnosis between 6.1.2 Headache attributed to transient ischaemic attack and an attack of 1.2 Migraine with aura may be particularly difficult. The mode of onset is crucial: the focal deficit is typically sudden in a TIA and more frequently progressive in a migrainous aura. Furthermore, positive phenomena (eg, scintillating scotoma) are far more common in migrainous aura than in TIA, whereas negative phenomena are more usual in TIA.
The coincidence of an otherwise typical TIA and a severe headache should prompt the search for some arterial disorders that can directly induce severe headache (arterial dissection, among others).