Relationship between velopharyngeal dimensions and palatal
electromyography during progressive hypercapnia.
Launois, Sandrine H., Stacia Remsburg, Won Jae Yang, J. Woodrow Weiss.
Charles A. Dana Research Institute and the Harvard-Thorndike
Laboratory of Beth Israel Hospital, the Beth Israel Hospital Sleep
Disorders Center and the Department of Medicine, Beth Israel Hospital
and Harvard Medical School, Boston, MA 02215
APStracts 2:0431A, 1995.
To examine the contribution of specific palatal muscles to
velopharyngeal dimensions, we recorded EMG activity in the levator
veli palatini (LVP), the tensor veli palatini (TVP) and the
palatoglossus (PLG) while examining the velopharynx (VP) with
videoendoscopy in 8 awake normal adults. Simultaneous display of VP
images and airflow provided precise timing of events. Video images
and EMG signals were recorded during progressive hypercapnia. Every
tenth breath was analyzed. For each selected breath, VP area, antero
-posterior and lateral diameters and EMG activity were determined at 5
points: beginning, middle and end-inspiration (BI, MI and EI), middle
and end-expiration (ME and EE). VP measurements changed significantly
during the respiratory cycle. Although maximum area was measured at
EI or ME and minimum area at the beginning or end of the breath,
respiratory-related changes in VP measurements and EMG activity were
characterized by substantial inter- and intra-subject variability.
This variability is similar to velopharyngeal behavior during non
-respiratory tasks and suggests that upper airway patency is
determined by multiple factors.
Received 12 April 1995; accepted in final form 29 September 1995.
APS Manuscript Number A406-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95