AT A MEETING of the Section on Nervous and Mental Diseases in San Francisco in 1946, Charles Brenner, H. Houston Merritt, and I presented a report on "The Management of Patients with Chronic Headache."1 In the intervening 18 years, some progress has been made in our knowledge about headache—its causes, mechanisms, diagnoses, and treatment. But the intensive study by many investigators has raised more questions than it has answered.
The advances may be briefly summarized as follows: (1) We now recognize the role of the patient's personality and life experiences in the causation of headache. (2) More is known about the pathophysiology and the pain-inducing biochemical changes in the tissues in and around the head and the agents affecting the physiologic and biochemical factors in the headache patient. (3) We have devised a useful classification of headache. (4) Finally, progress has been made in the treatment of chronic