HematomaHypotensionHematoma, Epidural, CranialHematoma, SubduralHematoma, Subdural, ChronicHypotension, ControlledHematoma, Subdural, AcuteHematoma, Epidural, SpinalHypotension, OrthostaticHematoma, Subdural, IntracranialIntracranial HypotensionHematoma, Subdural, SpinalCerebral HemorrhageTrephiningTomography, X-Ray ComputedCraniotomyBlood PressureSubdural SpaceSubdural EffusionPost-Exercise HypotensionSkull FracturesTrimethaphanDura MaterCerebral Hemorrhage, TraumaticBradycardiaAnesthesia, SpinalBasal Ganglia HemorrhageGlasgow Coma ScaleCraniocerebral TraumaHeart RateEphedrineNeurosurgical ProceduresTreatment OutcomeHemodynamicsRectus AbdominisMagnetic Resonance ImagingAnesthesia, ObstetricalAutonomic Nervous System DiseasesHead Injuries, ClosedIntracranial HemorrhagesRetrospective StudiesDrainageHemorrhagePostoperative ComplicationsCranial Fossa, PosteriorLaminectomyCerebrovascular CirculationTime FactorsIntracranial PressureRemission, SpontaneousRetroperitoneal SpaceBlood Patch, EpiduralSuctionShockArachnoid CystsLigamentum FlavumIntraoperative ComplicationsWounds, NonpenetratingProspective StudiesIntracranial Hemorrhage, HypertensiveCerebral AngiographyAnesthesiaAcute DiseaseHeadacheShock, SepticEsophageal DiseasesMidodrineAnticoagulantsFatal OutcomeBrain InjuriesBrain EdemaExtravasation of Diagnostic and Therapeutic MaterialsAnesthesia, EpiduralRupture, SpontaneousDecompression, SurgicalBrain Hemorrhage, TraumaticVascular ResistanceMyelographyNitroprussideOcular HypotensionSubarachnoid HemorrhageCardiac OutputHypovolemiaFerricyanidesSyncopeShy-Drager SyndromeGlasgow Outcome ScaleBrainPure Autonomic FailureOrbital DiseasesSpinal Cord CompressionTomography Scanners, X-Ray ComputedArachnoidCesarean SectionAortic DiseasesPostureCerebellar DiseasesNeurologic ExaminationAneurysm, RupturedCerebral Veins