Migraine: A vasomotor instability of the meningeal circulation.

The current view that the migraine aura arises from spasm of the major cerebral arteries and the ensuing headache from extracranial arterial vasodilatation is examined and refuted. It is proposed that the headache is due to stimulation of nociceptive nerve-endings in the walls of meningeal vessels (arterioles, venules, and particularly the dural venous sinuses); and that the aura arises from calibre changes in meningeal vessels that penetrate the outer cortex, resulting in localised inhibition or excitation. It is suggested that there are two types of migraine patients--vasodilators and vasoconstrictors.