Cutaneous Blood Flow In Vascular Headaches Of The Migraine Type

AN INTIMATE CONNECTION between migrainous headaches and local vascular changes has long been suspected and several investigators have studied this relationship. Tunis and Wolffl recorded an increased amplitude of temporal arterial pulse waves during an attack and suggested that the pain is accompanied by dilation of the extracranial arteries. In other studies2 involving visualization of the conjunctival vessels, vasoconstriction frequently preceded and vasodilation invariably accompanied the headache. The action of certain vasoactive drugs in migrainous headaches further points to a close relationship between the state of the vessels and occurrence of pain. Thus, the administration of arterial vasoconstrictor agents such as ergotamine tartrate or norepinephrine has been shown to reduce both the amplitude of arterial pulsations and the headache.3 However, vasodilator agents do not produce vascular headaches as consistently as vasoconstrictor agents terminate the attack. Nitroglycerin, a vasodilator, may intensify a migraine episode and, in susceptible individuals, may induce In one study, reserpine in large doses regularly produced typical unilateral headache in migrainous subjects,5 but its site of action is presumably a central one. Because the interruption of migraine is closely related to changes in the local vessels, it was postulated that investigation of the local circulation might provide useful information concerning the mechanism of the attack. However, direct studies of the circulation through the tissues involved in cephalgic states have not been reported. This prompted Onel and associates6 in this laboratory to undertake the study of blood flow by a tissue clearance