A. Any headache fulfilling criterion C
B. An arteriovenous malformation (AVM) has been diagnosed
C. Evidence of causation demonstrated by at least two of the following:
1. headache has developed in close temporal relation to other symptoms and/or clinical signs of AVM, or has led to the discovery of an AVM
2. either or both of the following:
a) headache has significantly worsened in parallel with worsening of the AVM
b) headache has significantly improved in parallel with improvement of the AVM
3. headache is localized to the site of the AVM
D. Not better accounted for by another ICHD-3 diagnosis, and intracranial haemorrhage has been excluded by appropriate investigations
Cases have been reported highlighting the association of AVM with a variety of headaches such as 3.1 Cluster headache, 3.2.2 Chronic paroxysmal hemicrania and 3.3.1 Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), but these cases had atypical features. There is no good evidence of a relationship between AVM and these primary headache disorders.
1.2 Migraine with aura has been reported in up to 58% of women with AVM. A strong argument in favour of a causal relationship is the overwhelming correlation between the side of the headache, or of the aura, and the side of the AVM. There is thus a strong suggestion that AVM can cause attacks of migraine with aura (symptomatic migraine). Yet in a large AVM series, presenting features frequently included epilepsy or focal deficits with or without haemorrhage and, much more rarely, migraine-like symptoms.