Headache caused by ischaemic stroke, usually with acute onset and associated with focal neurological signs. It has a self-limited course, and is very rarely the presenting or a prominent feature of ischaemic stroke.
A. Any new headache fulfilling criterion C
B. Acute ischaemic stroke has been diagnosed
C. Evidence of causation demonstrated by at least one of the following:
1. headache has developed in very close temporal relation to other symptoms and/or clinical signs of ischaemic stroke, or has led to the diagnosis of ischaemic stroke
2. headache has significantly improved in parallel with stabilization or improvement of other symptoms or clinical or radiological signs of ischaemic stroke
D. Not better accounted for by another ICHD-3 diagnosis.
6.1.1 Headache attributed to ischaemic stroke (cerebral infarction) is accompanied by focal neurological signs and/or alterations in consciousness, which in most cases allows easy differentiation from the primary headaches. It is usually of moderate intensity, and has no specific characteristics. It can be bilateral or unilateral ipsilateral to the stroke. Rarely, an acute ischaemic stroke, notably a cerebellar infarction, can present with an isolated sudden (even thunderclap) headache.
Headache accompanies ischaemic stroke in up to one third of cases; it is more frequent in basilar- than in carotid-territory strokes. It is of little practical value in establishing stroke aetiology except that headache is very rarely associated with lacunar infarcts but extremely common in acute arterial wall disorders such as dissection or reversible cerebral vasoconstriction syndrome. In these latter conditions, headache may be directly caused by the arterial wall lesions and may precede ischaemic stroke.