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. Author manuscript; available in PMC: 2012 Oct 18.
Published in final edited form as: Semin Speech Lang. 2012 Jul 31;33(3):203–216. doi: 10.1055/s-0032-1320040

Table 1.

Published Studies of the Immediate Physiological Effects of Surface Electrical Stimulation in a Healthy and Patient Population

Immediate effects of e-stim in a healthy population (Single application)
References Study Type Subjects/etiology Evaluation techniques Treatment groups Authors conclusion Outcome measures Follow-up post intervention
Humbert et al, 2008 prospective 27 subjects (mean age: 39.2yrs, range: 23–57yrs)

  1. Vocal fold position - FEES

 Pseudorandomised for 4 different placement of VitalStim® with additional submental placements

NMES fixed 80 Hz, pulse duration 700 μs

in Groups with randomised placements (ABC OR CBA):

  1. A :placements 1, 1 superior, 2, 2 superior, 2 inferior

  2. B: 3B, 3B superior

  3. C: 3A, 3A right, submental

  1. placement 3BS significant reduction in vocal fold angle (p=0.031) by 2,8 degrees

  2. no correlation of change in vocal fold angle and changes in motion of hyolaryngeal complex from data by Humbert et al, 2006

 Physiological Immediate results
Humbert et al, 2006 prospective pseudo- randomised 29 subjects (mean age: 39.5yrs, range: 20–60yrs)

  1. Movement of Hyolaryngeal complex at rest and swallowing (VFS)

  2. NIH-Swallowing Safety Scale

 Pseudorandomised for 4 different placement of VitalStim® with additional submental placements

NMES fixed 80 Hz, pulse duration 700 μs

‘ON’ state in random order :

  1. rest

  2. during swallows (5ml bolus)

  1. REST: Significant Descent of laryngeal and hyoid bone (placement 3B) (p<0.0001)

    significant differences between placements 3B and 3B superior and placement 2 superior and 2 inferior (p<0.0001, respectively)

  2. STIM during swallows: Significant reduction of peak laryngeal elevation (p=0.012) and hyoid bone (p<0.0005), sig. less safe

  3. stimulated swallows significant less safe than the non-stimulated (p=0.0275)

 Physiological Immediate results
Immediate effects of e-stim in patients (Single application)
References Study Type Subjects/etiology Evaluation techniques Treatment groups Authors conclusion Outcome measures Follow-up post intervention
Ludlow et al, 2007 Cohort-Case series 8/11 patients (mixed aetiology); 6 months stable pharyngeal dysphagia (stroke patients); rest patients: 2 years persistent dysphagia

  1. NIHSS Swallowing Safety Scale

  2. Penetration/aspiration scale

  3. Hyoid bone movement (x,y) on VFS

 Intensities used:

  1. No stimulation

  2. maximum tolerated level stimulation

  3. sensory threshold stimulation

‘ON’ state in random order :

  1. before swallows

  2. during swallows

  3. after swallows

  1. active NMES at rest lowered hyoid bone (y axis) (p=0.016)

  2. lower threshold NMES during swallowing changed NIHSSS significantly (p=0.025)

  3. no significant change for maximum tolerated level during swallowing

  4. no significant correlation between severity of dypshagia and changes in swallowing with stimulation

  5. correlation of NIHSSS improvement and degree of hyoid bone depression during motor stimulation at rest(p=0.006)

  6. active stimulation descends hyoid, opposite to movement for swallowing

 Physiological Immediate results