title: Sentinel Headache: A Warning Sign Preceding Every Fourth Aneurysmal Subarachnoid Hemorrhage.
authors.affiliation: Department of Neurosurgery Cantonal Hospital St. Gallen St. Gallen, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Joswig
authors.affiliation: Department of Neurosurgery Cantonal Hospital St. Gallen St. Gallen, Switzerland.
authors.forename: J Y
authors.initials: JY
authors.lastname: Fournier
authors.affiliation: Department of Neurosurgery Cantonal Hospital St. Gallen St. Gallen, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Hildebrandt
authors.affiliation: Department of Neurosurgery Cantonal Hospital St. Gallen St. Gallen, Switzerland Department of Neurosurgery Hôpitaux Universitaires de Genève Geneva, Switzerland.
authors.forename: M N
authors.initials: MN
authors.lastname: Stienen