title: Commentary from the Refractory Headache Special Interest Section on defining the pharmacologically intractable headache for clinical trials and clinical practice.
authors.affiliation: Neurology, Jefferson School of Medicine and Lankenau Institute for Medical Research, Lancaster Avenue, Wynnewood, PA 19096, USA.
authors.forename: Elliott A
authors.initials: EA
authors.lastname: Schulman
authors.forename: Richard
authors.initials: R
authors.lastname: Lipton
authors.forename: B Lee
authors.initials: BL
authors.lastname: Peterlin
authors.forename: Morris
authors.initials: M
authors.lastname: Levin
authors.forename: Brian M
authors.initials: BM
authors.lastname: Grosberg
mesh_terms: D002986:Clinical Trials as Topic; D004351:Drug Resistance; D006261:Headache / Q000188:drug therapy*; D006801:Humans; D008881:Migraine Disorders / Q000188:drug therapy; D011364:Professional Practice; D009626:Terminology as Topic; D017211:Treatment Failure