title: Recovered vs. not-recovered from post-stroke aphasia: the contributions from the dominant and non-dominant hemispheres.
abstract: OBJECTIVE
  Several adult studies have documented the importance of the peri-stroke areas to aphasia recovery. But, studies examining the differences in patterns of cortical participation in language comprehension in patients who have (LMCA-R) or have not recovered (LMCA-NR) from left middle cerebral artery infarction have not been performed up to date.
  
  
  METHODS
  In this study, we compare cortical correlates of language comprehension using fMRI and semantic decision/tone decision task in 9 LMCA-R and 18 LMCA-NR patients matched at the time of stroke for age and handedness. We examine the cortical correlates of language performance by correlating intra- and extra-scanner measures of linguistic performance with fMRI activation and stroke volumes.
  
  
  RESULTS
  Our analyses show that LMCA-R at least 1 year after stroke show a return to typical fMRI language activation patterns and that there is a compensatory reorganization of language function in LMCA-NR patients with shifts to the right hemispheric brain regions. Further, with increasing strength of the left-hemispheric fMRI signal shift there are associated improvements in performance as tested with standardized linguistic measures. A negative correlation between the size of the stroke and performance on some of the linguistic tests is also observed.
  
  
  CONCLUSIONS
  This right-hemispheric shift as a mechanism of post-stroke recovery in adults appears to be an ineffective mode of language function recovery with increasing right-hemispheric shift associated with lower language performance. Thus, normalization of the post-stroke language activation patterns is needed for better language performance while shifts of the activation patterns to the non-dominant (right) hemisphere and/or large stroke size are associated with decreased linguistic abilities after stroke.
authors.affiliation: Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA. szaflaj@uab.edu
authors.forename: Jerzy P
authors.initials: JP
authors.lastname: Szaflarski
authors.forename: Jane B
authors.initials: JB
authors.lastname: Allendorfer
authors.forename: Christi
authors.initials: C
authors.lastname: Banks
authors.forename: Jennifer
authors.initials: J
authors.lastname: Vannest
authors.forename: Scott K
authors.initials: SK
authors.lastname: Holland
mesh_terms: D000328:Adult; D000368:Aged; D001037:Aphasia / Q000209:etiology* / Q000473:pathology; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D032882:Comprehension / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen; D020127:Recovery of Function; D012660:Semantics; D020521:Stroke / Q000150:complications
chemical_list: D010100:Oxygen