2017
Recrudescence of Deficits After Stroke: Clinical and Imaging Phenotype, Triggers, and Risk Factors
Topcuoglu M, Saka E, Silverman S, Schwamm L, Singhal A. Recrudescence of Deficits After Stroke: Clinical and Imaging Phenotype, Triggers, and Risk Factors. JAMA Neurology 2017, 74: 1048-1055. PMID: 28783808, PMCID: PMC5710180, DOI: 10.1001/jamaneurol.2017.1668.Peer-Reviewed Original ResearchConceptsTransient ischemic attackRisk factorsIschemic attackChronic strokeMean ageDiagnostic criteriaPSR groupHealth Stroke Scale scoreIntravenous tissue plasminogen activatorMiddle cerebral artery territoryResearch Patient Data RepositoryCrossover cohort studyHypertensive brain hemorrhagePatients' mean ageStroke Scale scoreFocal neurologic deficitsSmall vessel diseaseCase-control studyPreliminary diagnostic criteriaTissue plasminogen activatorStroke-related deficitsMagnetic resonance imagingWhite matter tractsDiffusion-weighted imagingPatient data repository
2015
In Acute Stroke, Can CT Perfusion-Derived Cerebral Blood Volume Maps Substitute for Diffusion-Weighted Imaging in Identifying the Ischemic Core?
Copen W, Morais L, Wu O, Schwamm L, Schaefer P, González R, Yoo A. In Acute Stroke, Can CT Perfusion-Derived Cerebral Blood Volume Maps Substitute for Diffusion-Weighted Imaging in Identifying the Ischemic Core? PLOS ONE 2015, 10: e0133566. PMID: 26193486, PMCID: PMC4508041, DOI: 10.1371/journal.pone.0133566.Peer-Reviewed Original ResearchConceptsComputed tomography perfusion imagingDiffusion-weighted magnetic resonance imagingCerebral blood volumeInfarct volumeSensitivity/specificityCBV mapsDWI lesionsIschemic coreCore lesionsDWI-positive patientsRegional cerebral blood volumeAcute ischemic strokeFinal infarct volumeTreatment of patientsTomography perfusion imagingPresence of infarctionMagnetic resonance imagingDiffusion-weighted imagingAcute strokeIschemic strokeSymptom onsetLesion volumeIndividual patientsInter-rater agreementPatients
2014
Time and Diffusion Lesion Size in Major Anterior Circulation Ischemic Strokes
Hakimelahi R, Vachha B, Copen W, Papini G, He J, Higazi M, Lev M, Schaefer P, Yoo A, Schwamm L, González R. Time and Diffusion Lesion Size in Major Anterior Circulation Ischemic Strokes. Stroke 2014, 45: 2936-2941. PMID: 25190444, DOI: 10.1161/strokeaha.114.005644.Peer-Reviewed Original ResearchConceptsAnterior circulation ischemic strokeMiddle cerebral artery occlusionDiffusion-weighted imagingCerebral artery occlusionStroke onsetIschemic strokeInfarct sizeDWI lesionsInfarct volumeArtery occlusionIntravenous tissue-type plasminogen activatorProximal middle cerebral arteryDistal internal carotid arteryAcute infarct volumeDWI lesion volumeMajority of patientsMiddle cerebral arteryInternal carotid arteryAcute infarct sizeSame inclusion criteriaTraditional time windowTissue-type plasminogen activatorCerebral perfusionConsecutive patientsInfarct growth
2012
Reliability of cerebral blood volume maps as a substitute for diffusion‐weighted imaging in acute ischemic stroke
deIpolyi A, Wu O, Macklin E, Schaefer P, Schwamm L, Gonzalez R, Copen W. Reliability of cerebral blood volume maps as a substitute for diffusion‐weighted imaging in acute ischemic stroke. Journal Of Magnetic Resonance Imaging 2012, 36: 1083-1087. PMID: 22761110, PMCID: PMC4110961, DOI: 10.1002/jmri.23740.Peer-Reviewed Original ResearchConceptsDiffusion-weighted MRIAcute ischemic strokeCerebral blood volume mapsBlood volume mapsCBV mapsDWI lesionsIschemic strokeProportion of lesionsScan durationDiffusion-weighted imagingAcute strokeStroke onsetInfarct coreContralateral hemisphereRegional CBVMR perfusionVolume mapsLesion centerLesionsCBVStrokeShort durationPerfusionDurationLinear regression
2010
Combining Acute Diffusion-Weighted Imaging and Mean Transmit Time Lesion Volumes With National Institutes of Health Stroke Scale Score Improves the Prediction of Acute Stroke Outcome
Yoo A, Barak E, Copen W, Kamalian S, Gharai L, Pervez M, Schwamm L, González R, Schaefer P. Combining Acute Diffusion-Weighted Imaging and Mean Transmit Time Lesion Volumes With National Institutes of Health Stroke Scale Score Improves the Prediction of Acute Stroke Outcome. Stroke 2010, 41: 1728-1735. PMID: 20595665, DOI: 10.1161/strokeaha.110.582874.Peer-Reviewed Original ResearchMeSH KeywordsAdultAgedAged, 80 and overBrainBrain IschemiaDiffusion Magnetic Resonance ImagingFemaleHumansImage Processing, Computer-AssistedMaleMiddle AgedNational Institutes of Health (U.S.)Predictive Value of TestsPrognosisROC CurveSeverity of Illness IndexStatistics, NonparametricStrokeTime FactorsTreatment OutcomeUnited StatesConceptsAcute diffusion-weighted imagingDiffusion-weighted imagingAcute ischemic strokeNIHSS scorePoor outcomeLesion volumeIschemic strokeRankin ScaleBetter outcomesHealth Stroke Scale scoreAcute stroke outcomeDWI lesion volumeBaseline NIHSS scoreHealth Stroke ScaleStroke Scale scoreLower NIHSS scoreModified Rankin ScaleNational InstituteQuantitative diffusion-weighted imagingMTT volumesStroke ScaleStroke outcomeSymptom onsetClinical outcomesPrognostic yield
2008
Intravenous desmoteplase in patients with acute ischaemic stroke selected by MRI perfusion–diffusion weighted imaging or perfusion CT (DIAS-2): a prospective, randomised, double-blind, placebo-controlled study
Hacke W, Furlan A, Al-Rawi Y, Davalos A, Fiebach J, Gruber F, Kaste M, Lipka L, Pedraza S, Ringleb P, Rowley H, Schneider D, Schwamm L, Leal J, Söhngen M, Teal P, Wilhelm-Ogunbiyi K, Wintermark M, Warach S. Intravenous desmoteplase in patients with acute ischaemic stroke selected by MRI perfusion–diffusion weighted imaging or perfusion CT (DIAS-2): a prospective, randomised, double-blind, placebo-controlled study. The Lancet Neurology 2008, 8: 141-150. PMID: 19097942, PMCID: PMC2730486, DOI: 10.1016/s1474-4422(08)70267-9.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAgedAged, 80 and overBrain IschemiaCerebral HemorrhageDouble-Blind MethodFemaleFibrinolytic AgentsHumansInjections, IntravenousMagnetic Resonance ImagingMaleMiddle AgedPerfusionPlasminogen ActivatorsProspective StudiesSample SizeStrokeTomography, X-Ray ComputedTreatment FailureYoung AdultConceptsSymptomatic intracranial hemorrhageClinical response rateAcute ischemic strokeDiffusion-weighted imagingResponse rateNIHSS scoreIschemic strokeIntracranial hemorrhageLesion volumeDay 90Mortality ratePerfusion imagingScale scoreHealth Stroke Scale scoreMedian baseline NIHSS scoreModified Rankin Scale scoreMagnetic resonance perfusion imagingComposite of improvementBaseline NIHSS scorePlacebo-controlled studyStroke Scale scoreDose-ranging studyRankin Scale scoreSymptoms of strokeOnset of strokeClinical- and Imaging-Based Prediction of Stroke Risk After Transient Ischemic Attack
Ay H, Arsava E, Johnston S, Vangel M, Schwamm L, Furie K, Koroshetz W, Sorensen A. Clinical- and Imaging-Based Prediction of Stroke Risk After Transient Ischemic Attack. Stroke 2008, 40: 181-186. PMID: 18948609, DOI: 10.1161/strokeaha.108.521476.Peer-Reviewed Original ResearchMeSH KeywordsAgedAged, 80 and overBrainComorbidityComputer SimulationDiffusion Magnetic Resonance ImagingDisease ProgressionEarly DiagnosisEmergency Medical ServicesFemaleHumansIncidenceIschemic Attack, TransientLogistic ModelsMaleMiddle AgedNeurologic ExaminationPredictive Value of TestsPrognosisReproducibility of ResultsRisk FactorsStrokeConceptsTransient ischemic attackIschemic attackStroke riskClinical featuresDiffusion-weighted imagingAcute infarctsClinical transient ischemic attackDiffusion-weighted imaging findingsEarly stroke riskRelevant clinical settingsCharacteristic curveLogistic regression modelsConsecutive patientsSymptom onsetIndependent predictorsRisk stratificationImaging findingsTherapeutic measuresHospital resourcesEarly riskClinical settingResponse criteriaPredictive instrumentStrokeSubsequent stroke
2006
Transient ischemic attack with infarction: A unique syndrome?
Ay H, Koroshetz W, Benner T, Vangel M, Wu O, Schwamm L, Sorensen A. Transient ischemic attack with infarction: A unique syndrome? International Congress Series 2006, 1290: 45-55. DOI: 10.1016/j.ics.2006.04.007.Peer-Reviewed Original ResearchTransient ischemic attackIschemic strokeIschemic attackSymptom durationDistinct prognostic featuresSeparate clinical syndromesRecurrent ischemic strokeMinor ischemic strokeUnderwent diffusion-weighted imagingDiffusion-weighted imagingInfarct volumeConsecutive patientsTIA ratePrognostic featuresTransient symptomsBrain syndromeClinical syndromeUnique syndromeInfarctionPatientsStrokeSyndromeSymptomsDurationInfarcts
2005
Transient ischemic attack with infarction: A unique syndrome?
Ay H, Koroshetz W, Benner T, Vangel M, Wu O, Schwamm L, Sorensen A. Transient ischemic attack with infarction: A unique syndrome? Annals Of Neurology 2005, 57: 679-686. PMID: 15852402, DOI: 10.1002/ana.20465.Peer-Reviewed Original ResearchConceptsTransient ischemic attackIschemic strokeIschemic attackSymptom durationDistinct prognostic featuresSeparate clinical syndromesRecurrent ischemic strokeMinor ischemic strokeUnderwent diffusion-weighted imagingDiffusion-weighted imagingInfarct volumeConsecutive patientsTIA ratePrognostic featuresTransient symptomsBrain syndromeClinical syndromeUnique syndromeInfarctionPatientsStrokeSyndromeSymptomsDurationInfarcts
2004
Characterization and evolution of diffusion MR imaging abnormalities in stroke patients undergoing intra-arterial thrombolysis.
Schaefer P, Hassankhani A, Putman C, Sorensen A, Schwamm L, Koroshetz W, Gonzalez R. Characterization and evolution of diffusion MR imaging abnormalities in stroke patients undergoing intra-arterial thrombolysis. American Journal Of Neuroradiology 2004, 25: 951-7. PMID: 15205129, PMCID: PMC7975652.Peer-Reviewed Original ResearchConceptsIntra-arterial thrombolysisDiffusion-weighted imagingDWI findingsDWI ratioADC ratioReperfusion therapyAcute strokeApparent diffusion coefficientInitial diffusion-weighted imagingPretreatment diffusion-weighted imagingADC valuesRespective mean changesEventual infarctionAcute occlusionAnterior circulationStroke patientsLesion volumeMean changePatientsThrombolysisLesion growthMR imagingTissue viabilityLesionsInfarction
2002
‘Footprints’ of Transient Ischemic Attacks: A Diffusion-Weighted MRI Study
Ay H, Oliveira-Filho J, Buonanno F, Schaefer P, Furie K, Chang Y, Rordorf G, Schwamm L, Gonzalez R, Koroshetz W. ‘Footprints’ of Transient Ischemic Attacks: A Diffusion-Weighted MRI Study. Cerebrovascular Diseases 2002, 14: 177-186. PMID: 12403950, DOI: 10.1159/000065682.Peer-Reviewed Original ResearchConceptsTransient ischemic attackFast fluid attenuated inversion recoveryDiffusion-weighted imagingIschemic attackDWI lesionsFocal neurologic symptomsHalf of patientsDiffusion-weighted MRI studiesFluid attenuated inversion recoveryAttenuated inversion recoveryBrain infarctionClinical characteristicsNeurologic symptomsConsecutive patientsIndependent predictorsIschemic injuryMotor symptomsRecent infarctionCerebrovascular abnormalitiesClinical syndromeVascular territoriesStroke mechanismMRI studiesPatientsInfarction
2001
Diagnostic Value of Apparent Diffusion Coefficient Hyperintensity in Selected Patients With Acute Neurologic Deficits
Schaefer P, Gonzalez R, Hunter G, Wang B, Koroshetz W, Schwamm L. Diagnostic Value of Apparent Diffusion Coefficient Hyperintensity in Selected Patients With Acute Neurologic Deficits. Journal Of Neuroimaging 2001, 11: 369-380. PMID: 11677876, DOI: 10.1111/j.1552-6569.2001.tb00065.x.Peer-Reviewed Original ResearchConceptsAcute neurologic deficitsMagnetic resonance imagingDiffusion-weighted imagingNeurologic deficitsMRI abnormalitiesClinical syndromeMRI T2 hyperintensityVenous sinus thrombosisIschemic brain injuryEvaluation of patientsSubset of patientsConventional magnetic resonance imagingApparent diffusion coefficient (ADC) mapsDiffusion coefficient mapsHIV encephalopathyHypertensive encephalopathyNonischemic etiologyPosterior leukoencephalopathySinus thrombosisCarotid endarterectomyT2 hyperintensityNeurologic conditionsVasogenic edemaBrain injuryDiffusion magnetic resonance imagingUnilateral Temporal Lobe Stroke Causing Ischemic Transient Global Amnesia: Role for Diffusion‐Weighted Imaging in the Initial Evaluation
Greer D, Schaefer P, Schwamm L. Unilateral Temporal Lobe Stroke Causing Ischemic Transient Global Amnesia: Role for Diffusion‐Weighted Imaging in the Initial Evaluation. Journal Of Neuroimaging 2001, 11: 317-319. PMID: 11462302, DOI: 10.1111/j.1552-6569.2001.tb00054.x.Peer-Reviewed Original ResearchConceptsTransient global amnesiaDiffusion-weighted imagingInitial diffusion-weighted imagingLeft mesial temporal lobeSmall ischemic lesionsApparent diffusion coefficient imagingMesial temporal lobeOnset of symptomsT2-weighted imagingIschemic infarctIschemic lesionsAcute infarctsGlobal amnesiaTemporal lobeInitial evaluationEarly detectionInfarctsLesionsSymptomsImagingMagnetic resonanceDaysIschemiaEmboliPatientsManagement of Brain Edema Complicating Stroke
Rosand J, Schwamm L. Management of Brain Edema Complicating Stroke. Journal Of Intensive Care Medicine 2001, 16: 128-141. DOI: 10.1046/j.1525-1489.2001.00128.x.Peer-Reviewed Original ResearchCerebral blood flowSecondary brain injuryBrain edemaMagnetic resonance imagingBrain parenchymaVasogenic edemaBrain injuryBlood-brain barrier integrityGlobal cerebral blood flowIschemic brain swellingLocal tissue dysfunctionSerial Neurologic AssessmentIschemic brain edemaOnset of symptomsIntracranial blood volumeIschemic cell injuryResult of injurySpecific MRI sequencesAccumulation of fluidDiffusion-weighted imagingRheologic agentsNeurologic deteriorationBrain swellingDecompressive surgeryIschemic strokeManagement of Brain Edema Complicating Stroke
Rosand J, Schwamm L. Management of Brain Edema Complicating Stroke. Journal Of Intensive Care Medicine 2001, 16: 128-141. DOI: 10.1177/088506660101600303.Peer-Reviewed Original ResearchCerebral blood flowSecondary brain injuryBrain edemaMagnetic resonance imagingBrain parenchymaVasogenic edemaBrain injuryBlood-brain barrier integrityGlobal cerebral blood flowIschemic brain swellingLocal tissue dysfunctionSerial Neurologic AssessmentIschemic brain edemaOnset of symptomsIntracranial blood volumeIschemic cell injuryResult of injurySpecific MRI sequencesAccumulation of fluidDiffusion-weighted imagingRheologic agentsNeurologic deteriorationBrain swellingDecompressive surgeryIschemic stroke
1999
Diffusion-Weighted Imaging Identifies a Subset of Lacunar Infarction Associated With Embolic Source
Ay H, Oliveira-Filho J, Buonanno F, Ezzeddine M, Schaefer P, Rordorf G, Schwamm L, Gonzalez R, Koroshetz W. Diffusion-Weighted Imaging Identifies a Subset of Lacunar Infarction Associated With Embolic Source. Stroke 1999, 30: 2644-2650. PMID: 10582991, DOI: 10.1161/01.str.30.12.2644.Peer-Reviewed Original ResearchConceptsLacunar syndromeSmall infarctsIdentifiable causeClinical syndromeCareful pathological studyClassic lacunar syndromeDWI hyperintense lesionsSingle lacunar infarctionBrain stem lesionsDay of admissionDistinct clinical syndromeDiffusion-weighted imagingMultiple infarctionsEmbolic mechanismEmbolic sourceArtery territoryClinical characteristicsLacunar infarctionSecondary preventionConsecutive patientsAcute lesionsIndex lesionSuch infarctsEmergency roomPathological studiesDiffusion-weighted MR Imaging: Diagnostic Accuracy in Patients Imaged within 6 Hours of Stroke Symptom Onset
González R, Schaefer P, Buonanno F, Schwamm L, Budzik R, Rordorf G, Wang B, Sorensen A, Koroshetz W. Diffusion-weighted MR Imaging: Diagnostic Accuracy in Patients Imaged within 6 Hours of Stroke Symptom Onset. Radiology 1999, 210: 155-62. PMID: 9885601, DOI: 10.1148/radiology.210.1.r99ja02155.Peer-Reviewed Original ResearchConceptsFinal clinical diagnosisDiffusion-weighted imagesDiffusion-weighted MR imagingDiffusion-weighted imagingConventional MR imagingMR imagingSymptom onsetBlinded reviewClinical diagnosisDiagnostic accuracyStroke symptom onsetDiffusion-weighted magnetic resonance imagingMagnetic resonance imagingT2-weighted MR imagingAcute strokeStroke symptomsFinal diagnosisTomographic scanStrokelike symptomsPatientsPatient recordsResonance imagingStrokeDiagnosisCT
1998
Regional Ischemia and Ischemic Injury in Patients With Acute Middle Cerebral Artery Stroke as Defined by Early Diffusion-Weighted and Perfusion-Weighted MRI
Rordorf G, Koroshetz W, Copen W, Cramer S, Schaefer P, Budzik R, Schwamm L, Buonanno F, Sorensen A, Gonzalez G. Regional Ischemia and Ischemic Injury in Patients With Acute Middle Cerebral Artery Stroke as Defined by Early Diffusion-Weighted and Perfusion-Weighted MRI. Stroke 1998, 29: 939-943. PMID: 9596239, DOI: 10.1161/01.str.29.5.939.Peer-Reviewed Original ResearchMeSH KeywordsAcute DiseaseAdultAgedAged, 80 and overArterial Occlusive DiseasesBrain IschemiaCerebral ArteriesCerebral InfarctionCerebrovascular CirculationCerebrovascular DisordersDiffusionFemaleHumansMagnetic Resonance AngiographyMagnetic Resonance ImagingMaleMiddle AgedPerfusionReperfusion InjuryConceptsPerfusion-weighted imagingMiddle cerebral artery strokeDiffusion-weighted imagingCerebral blood volumeMCA strokeArtery strokeMR angiographyCBV abnormalityRegional ischemiaAcute middle cerebral artery strokeInitial diffusion-weighted imagingAcute stroke syndromeDistal branch occlusionDWI lesion volumeInitial DWI lesionMCA stem occlusionGroup 2 patientsMRI techniquesFinal infarct sizeFinal infarct volumeHours of onsetIntravenous contrast bolusAbnormal tissue perfusionProgression of infarctionPerfusion-Weighted MRI
1997
Diffusion-weighted imaging discriminates between cytotoxic and vasogenic edema in a patient with eclampsia.
Schaefer P, Buonanno F, Gonzalez R, Schwamm L. Diffusion-weighted imaging discriminates between cytotoxic and vasogenic edema in a patient with eclampsia. Stroke 1997, 28: 1082-5. PMID: 9158653, DOI: 10.1161/01.str.28.5.1082.Peer-Reviewed Original ResearchConceptsT2 hyperintense signal abnormalityDiffusion-weighted imagingHyperintense signal abnormalitiesVasogenic edemaSignal abnormalitiesRoutine MRIMajority of patientsPermanent neurological impairmentReversible neurological deficitsSubcortical white matterAdjacent gray matterDifferent treatment protocolsPathophysiology of eclampsiaEcho-planar diffusion-weighted imagingEclamptic patientsIschemic encephalopathyNeurological deficitsPosterior predominancePatient groupDiffusion-weighted imagesCytotoxic edemaNeurological impairmentPremature twinsTreatment protocolEdema