title: Patterns of poststroke brain damage that predict speech production errors in apraxia of speech and aphasia dissociate.
abstract: OBJECTIVE
  Acquired apraxia of speech (AOS) is a motor speech disorder caused by brain damage. AOS often co-occurs with aphasia, a language disorder in which patients may also demonstrate speech production errors. The overlap of speech production deficits in both disorders has raised questions on whether AOS emerges from a unique pattern of brain damage or as a subelement of the aphasic syndrome. The purpose of this study was to determine whether speech production errors in AOS and aphasia are associated with distinctive patterns of brain injury.
  
  
  METHODS
  Forty-three patients with history of a single left-hemisphere stroke underwent comprehensive speech and language testing. The AOS Rating Scale was used to rate speech errors specific to AOS versus speech errors that can also be associated with both AOS and aphasia. Localized brain damage was identified using structural magnetic resonance imaging, and voxel-based lesion-impairment mapping was used to evaluate the relationship between speech errors specific to AOS, those that can occur in AOS or aphasia, and brain damage.
  
  
  RESULTS
  The pattern of brain damage associated with AOS was most strongly associated with damage to cortical motor regions, with additional involvement of somatosensory areas. Speech production deficits that could be attributed to AOS or aphasia were associated with damage to the temporal lobe and the inferior precentral frontal regions.
  
  
  CONCLUSIONS
  AOS likely occurs in conjunction with aphasia because of the proximity of the brain areas supporting speech and language, but the neurobiological substrate for each disorder differs.
authors.affiliation: From the Aphasia Lab, Department of Communication Sciences and Disorders (A.B., J.F.), Department of Psychology (C.R.), University of South Carolina, Columbia; Department of Neurosciences, Medical University of South Carolina, Charleston (L.B.); and Department of Communication Sciences & Disorders, University of New Hampshire, Durham (D.M.).
authors.forename: Alexandra
authors.initials: A
authors.lastname: Basilakos
authors.affiliation: From the Aphasia Lab, Department of Communication Sciences and Disorders (A.B., J.F.), Department of Psychology (C.R.), University of South Carolina, Columbia; Department of Neurosciences, Medical University of South Carolina, Charleston (L.B.); and Department of Communication Sciences & Disorders, University of New Hampshire, Durham (D.M.).
authors.forename: Chris
authors.initials: C
authors.lastname: Rorden
authors.affiliation: From the Aphasia Lab, Department of Communication Sciences and Disorders (A.B., J.F.), Department of Psychology (C.R.), University of South Carolina, Columbia; Department of Neurosciences, Medical University of South Carolina, Charleston (L.B.); and Department of Communication Sciences & Disorders, University of New Hampshire, Durham (D.M.).
authors.forename: Leonardo
authors.initials: L
authors.lastname: Bonilha
authors.affiliation: From the Aphasia Lab, Department of Communication Sciences and Disorders (A.B., J.F.), Department of Psychology (C.R.), University of South Carolina, Columbia; Department of Neurosciences, Medical University of South Carolina, Charleston (L.B.); and Department of Communication Sciences & Disorders, University of New Hampshire, Durham (D.M.).
authors.forename: Dana
authors.initials: D
authors.lastname: Moser
authors.affiliation: From the Aphasia Lab, Department of Communication Sciences and Disorders (A.B., J.F.), Department of Psychology (C.R.), University of South Carolina, Columbia; Department of Neurosciences, Medical University of South Carolina, Charleston (L.B.); and Department of Communication Sciences & Disorders, University of New Hampshire, Durham (D.M.). jfridrik@sc.edu.
authors.forename: Julius
authors.initials: J
authors.lastname: Fridriksson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001037:Aphasia / Q000209:etiology / Q000503:physiopathology; D001072:Apraxias / Q000209:etiology / Q000503:physiopathology; D001930:Brain Injuries / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D020521:Stroke / Q000150:complications / Q000503:physiopathology
keywords: aphasia; apraxia, articulatory; neuroimaging; stroke