Electrical stimulation of the lingual musculature in obstructive
sleep apnea.
Schwartz, Alan R., David W. Eisele, Anil Hari, Roy Testerman, Donald
Erickson, Philip L. Smith.
Division of Pulmonary & Critical Care Division, Department of
Medicine, Department of Otolaryngology, Johns Hopkins University,
Baltimore, MD 2122; Dept. Diagnostic Radiology, University Health
Center of Pittsburgh, Pittsburgh, PA; and Medtronic, Inc.,
Minneapolis, MN
APStracts 3:0115A, 1996.
The influence of lingual muscle activity on airflow dynamics in the
upper airway was examined in nine patients with obstructive sleep
apnea. Muscles that retract the tongue (hyoglossus and styloglossus)
and protrude the tongue (genioglossus) were selectively stimulated
electrically during sleep with fine wire electrodes placed
intramuscularly transorally. We confirmed that stimulation with 50 Hz
and 40 [mu]s pulse duration did not elicit changes in
electroencephalographic patterns or heart rate, or alter airflow
after the stimulation burst had ceased. The highest stimulus
intensity that did not arouse patients from sleep was then utilized
to examine the effect of lingual muscle recruitment on airflow
dynamics during steady-state periods of inspiratory airflow
limitation. When applying a stimulus burst during single
inspirations, maximal inspiratory airflow (Imax) decreased by 239 +/-
177 ml/s (p<0.05) during retractor stimulation, whereas Imax
increased by 217 +/- 93 ml/s during protrusor stimulation
(p<0.001) compared to breaths immediately before and after the
stimulated breath. When consecutive inspirations were stimulated
repeatedly, protrusor stimulation decreased the frequency of
obstructive breathing episodes in four patients breathing at 3.9 +/-
3.4 cmH2O (mean +/- S.D.) nasal pressure. The findings suggest that
stimulation of the lingual muscles can increase or decrease airflow,
depending on the specific muscles stimulated, without arousing
patients from sleep.
Received 10 August 1995; accepted in final form 7 February 1996.
APS Manuscript Number A877-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96