Cerebrospinal Fluid PressureSubarachnoid HemorrhageIntracranial PressureCerebrospinal FluidCerebrospinal Fluid ShuntsVasospasm, IntracranialSubarachnoid SpaceIntracranial HypotensionExtracellular FluidPressureHeadacheIntracranial AneurysmIntraocular PressureDogsCerebral HemorrhageIsofluraneAneurysm, RupturedHemorrhageHydrostatic PressureCerebral AngiographyBasilar ArteryBlood PressureCerebrospinal Fluid ProteinsSpinal PunctureHydrocephalusIntracranial HemorrhagesTomography, X-Ray ComputedTransducers, PressureCerebral ArteriesRupture, SpontaneousSubarachnoid Hemorrhage, TraumaticCisterna MagnaExtracellular SpaceGlasgow Outcome ScaleCerebral VentriclesCerebrovascular CirculationIntracranial HypertensionVentriculostomyIschemic Attack, TransientTime FactorsEdema