title: Changes in white matter connectivity following therapy for anomia post stroke.
abstract: BACKGROUND
  The majority of studies investigating the neural mechanisms underlying treatment-induced recovery in aphasia have focused on the cortical regions associated with language processing. However, the integrity of the white matter connecting these regions may also be crucial to understanding treatment mechanisms.
  
  
  OBJECTIVE
  This study investigated the integrity of the arcuate fasciculus (AF) and uncinate fasciculus (UF) before and after treatment for anomia in people with aphasia.
  
  
  METHODS
  Eight people with aphasia received 12 treatment sessions to improve naming; alternating between phonologically-based and semantic-based tasks, with high angular resolution diffusion imaging conducted pre and post treatment. The mean generalized fractional anisotropy (GFA), a measure of fiber integrity, and number of fibers in the AF and UF were compared pre and post treatment, as well as with a group of 14 healthy older controls.
  
  
  RESULTS
  Pre treatment, participants with aphasia had significantly fewer fibers and lower mean GFA in the left AF compared with controls. Post treatment, mean GFA increased in the left AF to be statistically equivalent to controls. Additionally, mean GFA in the left AF pre and post treatment positively correlated with maintenance of the phonologically based treatment. No differences were found in the right AF, or the UF in either hemisphere, between participants with aphasia and controls, and no changes were observed in these tracts following treatment.
  
  
  CONCLUSIONS
  Anomia treatments may improve the integrity of the white matter connecting cortical language regions. These preliminary results add to the understanding of the mechanisms underlying treatment outcomes in people with aphasia post stroke.
authors.affiliation: 1University of Queensland Centre for Clinical Research, Brisbane, Australia.
authors.forename: Sophia
authors.initials: S
authors.lastname: van Hees
authors.forename: Katie
authors.initials: K
authors.lastname: McMahon
authors.forename: Anthony
authors.initials: A
authors.lastname: Angwin
authors.forename: Greig
authors.initials: G
authors.lastname: de Zubicaray
authors.forename: Stephen
authors.initials: S
authors.lastname: Read
authors.forename: David A
authors.initials: DA
authors.lastname: Copland
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D000849:Anomia / Q000209:etiology / Q000473:pathology* / Q000628:therapy*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007807:Language Tests; D007808:Language Therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009434:Neural Pathways / Q000473:pathology; D020521:Stroke / Q000150:complications* / Q000473:pathology; D000071939:Stroke Rehabilitation; D013997:Time Factors; D016896:Treatment Outcome; D066127:White Matter / Q000473:pathology*
keywords: aphasia; arcuate fasciculus; diffusion imaging; rehabilitation; uncinate fasciculus