AssessmentParticipants were asked to complete standardized forms so as to provide us with details of their general medical history (including body mass index: weight in kilograms divided by the square of height in meters), and of their neurological, ophthalmological, and family histories. All patients were interviewed and examined by the same two neurologists, and headaches were diagnosed according to the criteria established by the IHS (1). Postural headache were diagnosed whether headache worse in recumbence and improved in the upright posture. To avoid risk of diagnostic errors resulting from differing diagnoses by the two neurologists, the principal investigator (F. B.) evaluated the patient in debated cases.