title: Brain edema predicts outcome after nonlacunar ischemic stroke.
abstract: OBJECTIVE
  In malignant infarction, brain edema leads to secondary neurological deterioration and poor outcome. We sought to determine whether swelling is associated with outcome in smaller volume strokes.
  
  
  METHODS
  Two research cohorts of acute stroke subjects with serial brain MRI were analyzed. The categorical presence of swelling and infarct growth was assessed on diffusion-weighted imaging (DWI) by comparing baseline and follow-up scans. The increase in stroke volume (ΔDWI) was then subdivided into swelling and infarct growth volumes using region-of-interest analysis. The relationship of these imaging markers with outcome was evaluated in univariable and multivariable regression.
  
  
  RESULTS
  The presence of swelling independently predicted worse outcome after adjustment for age, National Institutes of Health Stroke Scale, admission glucose, and baseline DWI volume (odds ratio, 4.55; 95% confidence interval, 1.21-18.9; P<0.02). Volumetric analysis confirmed that ΔDWI was associated with outcome (odds ratio, 4.29; 95% confidence interval, 2.00-11.5; P<0.001). After partitioning ΔDWI into swelling and infarct growth volumetrically, swelling remained an independent predictor of poor outcome (odds ratio, 1.09; 95% confidence interval, 1.03-1.17; P<0.005). Larger infarct growth was also associated with poor outcome (odds ratio, 7.05; 95% confidence interval, 1.04-143; P<0.045), although small infarct growth was not. The severity of cytotoxic injury measured on apparent diffusion coefficient maps was associated with swelling, whereas the perfusion deficit volume was associated with infarct growth.
  
  
  CONCLUSIONS
  Swelling and infarct growth each contribute to total stroke lesion growth in the days after stroke. Swelling is an independent predictor of poor outcome, with a brain swelling volume of ≥11 mL identified as the threshold with greatest sensitivity and specificity for predicting poor outcome.
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.).
authors.forename: Thomas W K
authors.initials: TW
authors.lastname: Battey
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.).
authors.forename: Mahima
authors.initials: M
authors.lastname: Karki
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.).
authors.forename: Aneesh B
authors.initials: AB
authors.lastname: Singhal
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.).
authors.forename: Ona
authors.initials: O
authors.lastname: Wu
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.).
authors.forename: Saloomeh
authors.initials: S
authors.lastname: Sadaghiani
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.).
authors.forename: Bruce C V
authors.initials: BC
authors.lastname: Campbell
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.).
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Davis
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.).
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Donnan
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.).
authors.forename: Kevin N
authors.initials: KN
authors.lastname: Sheth
authors.affiliation: From the Center for Human Genetic Research (T.W.K.B., M.K., W.T.K.), Division of Neurocritical Care and Emergency Neurology (T.W.K.B., M.K., W.T.K.), J. Philip Kistler Stroke Research Center (T.W.K.B., M.K., A.B.S., O.W., S.S., W.T.K.), and Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology (O.W.), Massachusetts General Hospital, Boston; Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia (B.C.V.C., S.M.D.); Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia (B.C.V.C., G.A.D.); and Division of Neurocritical Care and Emergency Neurology, Yale New Haven Hospital, CT (K.N.S.). wtkimberly@mgh.harvard.edu.
authors.forename: W Taylor
authors.initials: WT
authors.lastname: Kimberly
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001929:Brain Edema / Q000209:etiology* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D020521:Stroke / Q000150:complications* / Q000473:pathology*
keywords: brain edema; magnetic resonance imaging; stroke; swelling