Cerebrovascular CirculationPosterior Cerebral ArteryInfarction, Posterior Cerebral ArteryCerebral ArteriesCircle of WillisCerebral AngiographyCerebral InfarctionHemianopsiaIntracranial AneurysmCerebral Arterial DiseasesBasilar ArteryVertebral ArteryAnterior Cerebral ArteryMiddle Cerebral ArteryMagnetic Resonance ImagingUltrasonography, Doppler, TranscranialAneurysm, RupturedMagnetic Resonance AngiographyOccipital LobeBrainTomography, X-Ray ComputedBlood Flow VelocityBrain IschemiaDyslexia, AcquiredVertebrobasilar InsufficiencyCerebral PalsyInfarction, Middle Cerebral ArteryOculomotor Nerve DiseasesCollateral CirculationEmbolization, TherapeuticMoyamoya DiseaseOphthalmoplegic MigraineBlood CirculationSubarachnoid HemorrhageIntracranial Arteriovenous MalformationsTonic PupilAmobarbitalAnisocoriaDominance, CerebralCerebrovascular DisordersIntracranial Embolism and ThrombosisEchoencephalographyEclampsiaHemiplegiaCarotid Artery, InternalAngiography, Digital SubtractionCranial Fossa, PosteriorIntracranial ArteriosclerosisCerebral RevascularizationCerebral VeinsMalaria, CerebralIschemic Attack, TransientRegional Blood FlowExtracorporeal CirculationArterial Occlusive DiseasesCerebral HemorrhageThalamusTreatment OutcomePulmonary CirculationTemporal LobeBlood PressureImage Processing, Computer-AssistedNeurologic ExaminationRetrospective StudiesFunctional LateralityVasoconstriction