title: The International Headache Society classification and diagnostic criteria are valid and extremely useful.
authors.affiliation: Department of Neurology, University of Copenhagen, Glostrup Hospital, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Olesen
mesh_terms: D003937:Diagnosis, Differential; D005069:Evaluation Studies as Topic; D006261:Headache / Q000145:classification* / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D012955:Societies, Medical