title: [Always investigate first onset thunderclap headache].
authors.affiliation: Neurologiska kliniken, Universitetssjukhuset, Linköping. anne-marie.landtblom@lio.se
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Landtblom
authors.forename: Jörgen
authors.initials: J
authors.lastname: Boivie
mesh_terms: D000208:Acute Disease; D001927:Brain Diseases / Q000175:diagnosis; D003937:Diagnosis, Differential; D006261:Headache / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000175:diagnosis