Headaches during intracranial endovascular procedures: a possible model of vascular headache

We report a series of 11 patients who developed headaches during intracranial endovascular procedures performed for the treatment of arteriovenous malformations (10 cases) or aneurysms (1 case). Headache was precipitated either by balloon inflation (3 cases) or by embolization (8 cases), and had a very constant pattern. In all cases the pain started suddenly, reaching maximum intensity at once. Headache was focal, unilateral, ipsilateral to the occluded artery, nonthrobbing and short-lasting (usually less than 10 minutes). It was not associated with gastrointestinal, autonomic, or aura-like symptoms. Headache localization depended upon the catheterized artery, being constant for each of the major vascular territories. Yet, in all patients pain was felt in the cutaneous territory of the ophthalmic division of the trigeminal nerve. The occurrence of headache was not associated with cortical deficit nor cortical irritation (assessed both clinically and by the EEG) and therefore seems to be directly related to the stimulation of the arterial wall. This type of pain can be used as a model of pure vascular headache. Its study can contribute not only to understand the pattern of intracranial vascular innervation but also to understand or to refute the vascular components of migraine.