Experimental Studies on Headache

Distention of cranial arteries induces pain of an aching quality.1On the other hand, when the distended cranial arteries associated with the attack of migraine headache are constricted, the pain is abolished.2The speed with which vasoconstrictor agents, such as ergotamine tartrate, reduce the intensity of the headache approximates the rate of constriction of the cranial arteries. In many patients the headache arises in the distended branches of the external carotid arteries,3although any or all of the cranial arteries may be involved at one time or another in migraine headache. Secondary to such pain from prolonged distention of cranial arteries, the skeletal muscles of the neck and scalp contract. Such prolonged contraction in itself becomes painful and adds a component to the migraine headache.4 Certain additional phenomena of the migraine headache which have not been studied before are the subject of this discussion. They may