Recovered vs. not-recovered from post-stroke aphasia: the contributions from the dominant and non-dominant hemispheres

Restor Neurol Neurosci. 2013;31(4):347-60. doi: 10.3233/RNN-120267.


Purpose: 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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Aphasia / etiology*
  • Aphasia / pathology
  • Brain / blood supply
  • Brain / pathology*
  • Comprehension / physiology*
  • Dominance, Cerebral / physiology*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Language Tests
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Oxygen
  • Recovery of Function
  • Semantics*
  • Stroke / complications


  • Oxygen