The cause of Migraine is unknown, but evidence indicates a functional disturbance of cranial circulation. Prodromal symptoms (e.g. flashes of light) are probably due to intracerebral vasoconstriction, and the head pain to dilation of extracerebral cranial arteries. Migraine may occur at any age, usually beginning between ages 10 and 30. Women are affected more frequently than men. Remission not uncommonly occurs after age 50. Headache is usually the presenting symptom. It may be preceded by a short period of depression, irritability, restlessness, or anorexia, and in a few cases by visual field defects. These symptoms may disappear shortly before the headache appears or they may persist and merge with it. Pain is usually generalized but not infrequently is confined to one side of the head. Symptom in an individual case are apt to follow a pattern, except that a patient with unilateral headache often has the pain on the right side in some attacks, on the left in others. Patients may have attacks daily or only once in several months. An untreated attack of migraine may last for hours or days. Nausea, vomiting are common. The extremities are cold and the patient is irritable and desires seclusion. Various procedures have been recommended for decreasing the frequency of attacks ( foreign protein infections, diet, hormones, histamine, sedatives and operative procedures on cranial arteries). None is specific, and relief depends largely o the enthusiasm of the physician and the patient's confidence in him/her. The most effective prophylaxis is systematic psychotherapy. Aspirin or codeine may alleviate mild attacks. In severe attacks, only ergot derivatives offer relief and usually only if taken before the headache has lasted 2 hr.