Intracranial arteriovenous malformation and migraine.

To define more closely the clinical relationship between migraine and intracranial arteriovenous malformation (iAVM), the clinical features of 57 reported instances and of 7 personal cases were analysed. Migraine attacks symptomatic of AVM include: late onset, frequent absence of (familial) migraine history, diminution or even inversion of the usual sex-ratio in migraine, brevity of attacks, disruption of the usual sequence of attack symptoms and, finally, unusual or permanent neurologic deficit. An attempt has also been made to clarify the epidemiological relationship. The reported frequency of migraine in cases of AVM, and AVM in cases of migraine is reflected against an inquiry into the number of annually diagnosed cases of AVM in 20 Dutch neurological/neurosurgical centres, covering 12.10(6) inhabitants in 8 of the 11 provinces. The annual incidence of migraine is estimated at 1:3,500 population, that of diagnosed iAVM is 120, i.e. 1:100,000. Coincidental occurrence of the two conditions works out at 1:4 X 10(8) per year. The presented case series of 7 seen in 2 of the 20 centres strongly militates against such a chance hypothesis.