Inspiratory co-activation of genioglossus enlarges the retroglossal
space in laryngectomized humans.
Kobayashi, I., A. Perry, J. Rhymer, B. Wuyam, P. Hughes, K. Murphy, J.
A. Innes, J. Mcivor, A. D. Cheesman, and A. Guz.
Department of Medicine, Speech Therapy, Radiology and Ear Nose and
Throat Surgery, Charing Cross and Westminster Medical School, London,
U.K.; and Department of Medicine, Tokai University School of
Medicine, Isehara, Japan
APStracts 2:0548A, 1995.
To investigate the relationship between the electrical activity of
genioglossus (GG-EMG) and associated tongue movement, 7
laryngectomized subjects, breathing through a tracheal stoma (without
pressure or flow change in the upper airway) were studied supine.
Tongue movement, using lateral fluoroscopy, and GG-EMG, expressed as
% of maximum voluntary GG activation, were monitored simultaneously
during (i) spontaneous inspiration (SI), (ii) resistive loaded
inspiration (LI) and (iii) rapid inspiration (RI). Tongue position
during each maneuver was compared with its position during
spontaneous expiration. Peak GG-EMG during the three maneuvers were
significantly different from each other (SI: 5.4 + 1.6, LI: 11.9 +
1.8, RI: 51.6 + 9.4 (SE) % respectively). Associated forward movement
of the posterior aspect of the tongue was minimum during SI; however,
significant movement was observed during LI and this was increased
during RI; significant covariance existed between peak GG activation
and this movement. GG co-activation with inspiration enlarges the
glossopharyngeal airway particularly in its caudal part. In subjects
with intact upper airways, this activation may protect or enhance
upper airway patency in an effort-dependent manner.
Received 12 August 1994; accepted in final form 4 December 1995.
APS Manuscript Number A846-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 December 95