title: Pharyngeal Swallowing Mechanics Secondary to Hemispheric Stroke.
abstract: BACKGROUND
  Computational analysis of swallowing mechanics (CASM) is a method that utilizes multivariate shape change analysis to uncover covariant elements of pharyngeal swallowing mechanics associated with impairment using videofluoroscopic swallowing studies. The goals of this preliminary study were to (1) characterize swallowing mechanics underlying stroke-related dysphagia, (2) decipher the impact of left and right hemispheric strokes on pharyngeal swallowing mechanics, and (3) determine pharyngeal swallowing mechanics associated with penetration-aspiration status.
  
  
  METHODS
  Videofluoroscopic swallowing studies of 18 dysphagic patients with hemispheric infarcts and age- and gender-matched controls were selected from well-controlled data sets. Patient data including laterality and penetration-aspiration status were collected. Coordinates mapping muscle group action during swallowing were collected from videos. Multivariate morphometric analyses of coordinates associated with stroke, affected hemisphere, and penetration-aspiration status were performed.
  
  
  RESULTS
  Pharyngeal swallowing mechanics differed significantly in the following comparisons: stroke versus controls (D = 2.19, P < .0001), right hemispheric stroke versus controls (D = 3.64, P < .0001), left hemispheric stroke versus controls (D = 2.06, P < .0001), right hemispheric stroke versus left hemispheric stroke (D = 2.89, P < .0001), and penetration-aspiration versus within normal limits (D = 2.25, P < .0001). Differences in pharyngeal swallowing mechanics associated with each comparison were visualized using eigenvectors.
  
  
  CONCLUSIONS
  Whereas current literature focuses on timing changes in stroke-related dysphagia, these data suggest that mechanical changes are also functionally important. Pharyngeal swallowing mechanics differed by the affected hemisphere and the penetration-aspiration status. CASM can be used to identify patient-specific swallowing impairment associated with stroke injury that could help guide rehabilitation strategies to improve swallowing outcomes.
authors.affiliation: Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia.
authors.forename: Nelson H
authors.initials: NH
authors.lastname: May
authors.affiliation: Department of Speech, Language and Hearing Sciences, Boston University, Boston, Massachusetts.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Pisegna
authors.affiliation: Department of Neurology, Stroke Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
authors.forename: Sarah
authors.initials: S
authors.lastname: Marchina
authors.affiliation: Department of Speech, Language and Hearing Sciences, Boston University, Boston, Massachusetts.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Langmore
authors.affiliation: Department of Neurology, Stroke Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia. Electronic address: wpearson@augusta.edu.
authors.forename: William G
authors.initials: WG
authors.lastname: Pearson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D054022:Cerebrum / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003679:Deglutition; D003680:Deglutition Disorders / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010614:Pharynx / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020521:Stroke / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D014741:Video Recording
keywords: Ischemic hemispheric stroke; aspiration; dysphagia; swallowing mechanics