title: Severity of hypoperfusion in distinct brain regions predicts severity of hemispatial neglect in different reference frames.
abstract: OBJECTIVE
  Hemispatial neglect is among the most common and disabling consequences of right hemisphere stroke. A variety of variables have been associated with the presence or severity of neglect but have not evaluated the independent effects of location, severity, and volume of ischemia. Few have determined areas involved in different types of neglect. We identified the contributions of these variables to severity of viewer-centered versus stimulus-centered neglect in acute ischemic right hemisphere stroke.
  
  
  METHODS
  We studied 137 patients within 24 hours of stroke onset with MR diffusion- and perfusion-weighted imaging and a test of hemispatial neglect that distinguishes between viewer-centered and stimulus-centered neglect. Using multivariable linear regression, we identified the independent contributions of severity of ischemia in specific locations, volume of ischemia, and age in accounting for severity of each neglect type.
  
  
  RESULTS
  Severity of hypoperfusion in angular gyrus was the only variable that significantly and independently contributed to severity of viewer-centered neglect. Volume of dysfunctional tissue and hypoperfusion in posterior frontal cortex also accounted for some variability in severity of viewer-centered neglect. Severity of hypoperfusion of superior temporal cortex was the only variable that independently and significantly contributed to severity of stimulus-centered neglect.
  
  
  CONCLUSIONS
  Location, severity, and volume of ischemia together determine the type and severity of neglect after right hemisphere stroke. Results also show that perfusion-weighted MRI can be used as a semiquantitative measure of tissue dysfunction in acute stroke and can account for a substantial proportion of the variability in functional deficits in the acute stage.
authors.affiliation: Department of Medicine, Harbor Hospital, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Peyman
authors.initials: P
authors.lastname: Shirani
authors.forename: Julia
authors.initials: J
authors.lastname: Thorn
authors.forename: Cameron
authors.initials: C
authors.lastname: Davis
authors.forename: Jennifer
authors.initials: J
authors.lastname: Heidler-Gary
authors.forename: Melissa
authors.initials: M
authors.lastname: Newhart
authors.forename: Rebecca F
authors.initials: RF
authors.lastname: Gottesman
authors.forename: Argye E
authors.initials: AE
authors.lastname: Hillis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D055420:Perfusion Imaging / Q000379:methods; D011237:Predictive Value of Tests; D012720:Severity of Illness Index