Ischemic Attack, TransientStrokeCerebrovascular DisordersCarotid StenosisPrognosisEndarterectomy, CarotidAspirinRecurrenceCarotid Artery DiseasesCarotid Artery, InternalBrain IschemiaRisk FactorsIntracranial Embolism and ThrombosisProspective StudiesCerebral InfarctionFollow-Up StudiesIntracranial EmbolismCerebral AngiographyTime FactorsDipyridamoleTreatment OutcomeUltrasonography, Doppler, TranscranialPlatelet Aggregation InhibitorsMagnetic Resonance AngiographyAtrial FibrillationEchocardiography, TransesophagealRisk AssessmentCarotid ArteriesAnticoagulantsGreat BritainReferral and ConsultationRetrospective StudiesTomography, X-Ray ComputedFibrinolytic AgentsSeverity of Illness IndexCerebrovascular CirculationPredictive Value of TestsEnglandPatient SelectionCohort StudiesAge FactorsIncidenceVertebrobasilar InsufficiencyEmbolismMyocardial IschemiaAcute DiseaseMyocardial InfarctionCardiovascular DiseasesMagnetic Resonance ImagingEndarterectomyIntracranial ArteriosclerosisIschemiaMigraine DisordersComplement Membrane Attack ComplexAmaurosis FugaxNeurologyIntracranial Arterial DiseasesSecondary PreventionMoyamoya DiseaseCerebral HemorrhageRiskCalciumCerebral ArteriesSurvival AnalysisSulfinpyrazoneSeptember 11 Terrorist AttacksBrainArterial Occlusive DiseasesDiffusion Magnetic Resonance Imaging