HeadacheAspirinHeadache DisordersMigraine DisordersPituitary ApoplexyHeadache Disorders, PrimaryTension-Type HeadacheCluster HeadacheSubarachnoid HemorrhageAbducens Nerve DiseasesIntracranial AneurysmVascular HeadachesAngiostrongylus cantonensisAneurysm, RupturedCerebral AngiographyHematoma, SubduralCranial SinusesNeurosurgical ProceduresTomography, X-Ray ComputedSinus Thrombosis, IntracranialDura MaterAnterior Cerebral ArteryHeadache Disorders, SecondaryNeck PainMagnetic Resonance ImagingNational Institutes of Health (U.S.)Cerebral HemorrhagePlatelet Aggregation InhibitorsAnti-Inflammatory Agents, Non-SteroidalFatal OutcomeTreatment OutcomeEmbolization, TherapeuticQuestionnairesMigraine without AuraTiclopidineThromboxane B2Cyclooxygenase InhibitorsPlatelet AggregationSpinal PunctureMigraine with AuraSalicylatesPlatelet Function TestsAnalgesicsDrug Therapy, CombinationBlood Patch, EpiduralNeurologyDouble-Blind MethodTrigeminal Autonomic CephalalgiasTryptaminesSumatriptanBlood PlateletsSodium SalicylateFibrinolytic AgentsProspective StudiesIntracranial HypotensionAnticoagulantsRisk FactorsDose-Response Relationship, DrugWarfarinHemorrhageAsthma, Aspirin-InducedIbuprofen