Original article| Volume 93, ISSUE 11, P2000-2007, November 2012

Effects of Submental Neuromuscular Electrical Stimulation on Pharyngeal Pressure Generation

  • Frauke M. Heck
    Correspondence to Frauke M. Heck, MS, Boxhagener Straβe 42, 10245 Berlin, Germany
    Department of Communication Disorders, University of Canterbury, Van der Veer Institute for Parkinson's and Brain Research, Christchurch, New Zealand

    Department of Linguistics and Literature, University of Bielefeld, Bielefeld, Germany
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  • Sebastian H. Doeltgen
    Department of Communication Disorders, University of Canterbury, Van der Veer Institute for Parkinson's and Brain Research, Christchurch, New Zealand

    Neuromotor Plasticity and Development Research Group, School of Paediatrics and Reproductive Health, The University of Adelaide, Adelaide, SA, Australia
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  • Maggie-Lee Huckabee
    Department of Communication Disorders, University of Canterbury, Van der Veer Institute for Parkinson's and Brain Research, Christchurch, New Zealand
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Published:March 07, 2012DOI:


      Heck FM, Doeltgen SH, Huckabee M-L. Effects of submental neuromuscular electrical stimulation on pharyngeal pressure generation.


      To investigate the immediate and late effects of submental event-related neuromuscular electrical stimulation (NMES) on pharyngeal pressure generation during noneffortful and effortful saliva swallows.


      Before-after trial.


      Swallowing rehabilitation research laboratory.


      Sex-matched (N=20) healthy research volunteers.


      Participants received 80Hz NMES of 4-second duration to floor of mouth muscles that was time-locked to 60 volitional saliva swallows.

      Main Outcome Measures

      Manometry measures of peak pressures and duration of pressure events in the oropharynx, hypopharynx, and the upper esophageal sphincter (UES) were derived during execution of noneffortful and effortful saliva swallows. Measures were taken at baseline, during stimulation, and at 5-, 30-, and 60-minutes poststimulation.


      Baseline pharyngeal and UES pressures did not differ between stimulated and nonstimulated swallows. At 5- and 30-minutes poststimulation, peak pressure decreased at the hypopharyngeal and at the UES sensor during noneffortful swallows. The effect lasted up to an hour only in the hypopharynx. No changes in duration of pressure events were observed.


      Using this treatment paradigm, decreased peak amplitude in the hypopharynx up to an hour after treatment indicates a potential risk of decreased bolus flow associated with NMES. On the other hand, decreased UES relaxation pressure may facilitate bolus transit into the esophagus.

      Key Words

      List of Abbreviations:

      CPG (central pattern generator), EREstim (event-related stimulation), ICC (intraclass correlation coefficient), LTD (long-term depression), LTP (long-term potentiation), MEP (motor evoked potential), NMES (neuromuscular electrical stimulation), RM-ANOVA (repeated-measures analysis of variance), UES (upper esophageal sphincter)
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