Dysphagia

, Volume 28, Issue 1, pp 33–42

The Effect of Bolus Viscosity on Laryngeal Closure in Swallowing: Kinematic Analysis Using 320-Row Area Detector CT

  • Yoko Inamoto
  • Eiichi Saitoh
  • Sumiko Okada
  • Hitoshi Kagaya
  • Seiko Shibata
  • Kikuo Ota
  • Mikoto Baba
  • Naoko Fujii
  • Kazuhiro Katada
  • Pattra Wattanapan
  • Jeffrey B. Palmer
Original Article

DOI: 10.1007/s00455-012-9410-4

Cite this article as:
Inamoto, Y., Saitoh, E., Okada, S. et al. Dysphagia (2013) 28: 33. doi:10.1007/s00455-012-9410-4

Abstract

The present study examined the effect of bolus viscosity on the onset of laryngeal closure (relative to hyoid elevation), the duration of laryngeal closure, and other key events of swallowing in ten healthy volunteers. All volunteers underwent 320-row area detector computed tomography swallow studies while swallowing 10 ml of honey-thick barium (5 % v/w) and thin barium (5 % v/w) in a 45° reclining position. Three-dimensional images of both consistencies were created in 29 phases at an interval of 0.10 s (100 ms) over a 2.90-s duration. The timing of the motions of the hyoid bone, soft palate, and epiglottis; the opening and closing of the laryngeal vestibule, true vocal cords (TVC), and pharyngoesophageal segment; and the bolus movement were measured and compared between the two consistencies. The result showed differing patterns of bolus movement for thin and thick liquids. With thin liquids, the bolus reached the hypopharynx earlier and stayed in the hypopharynx longer than with thick liquids. Among events of laryngeal closure, only the timing of TVC closure differed significantly between the two consistencies. With thin liquids, TVC closure started earlier and lasted longer than with thick liquids. This TVC movement could reflect a response to the faster flow of thin liquids. The results suggest that bolus viscosity alters the temporal characteristics of swallowing, especially closure of the TVC.

Keywords

Swallowing Larynx Pharynx Vocal cords Computed tomography 320-ADCT Deglutition Deglutition disorders 

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Yoko Inamoto
    • 1
  • Eiichi Saitoh
    • 2
  • Sumiko Okada
    • 1
  • Hitoshi Kagaya
    • 2
  • Seiko Shibata
    • 2
  • Kikuo Ota
    • 1
  • Mikoto Baba
    • 2
  • Naoko Fujii
    • 3
  • Kazuhiro Katada
    • 3
  • Pattra Wattanapan
    • 4
  • Jeffrey B. Palmer
    • 5
  1. 1.Faculty of Rehabilitation, School of Health SciencesFujita Health UniversityToyoakeJapan
  2. 2.Department of Rehabilitation, School of MedicineFujita Health UniversityToyoakeJapan
  3. 3.Department of Radiology, School of MedicineFujita Health UniversityToyoakeJapan
  4. 4.Department of Rehabilitation Medicine, Faculty of MedicineKhon Kaen UniversityKhon KaenThailand
  5. 5.Department of Physical Medicine and Rehabilitation, Department of Otolaryngology-Head and Neck Surgery, and Center for Functional Anatomy and EvolutionJohns Hopkins UniversityBaltimoreUSA