title: Laryngeal elevation by selective stimulation of the hypoglossal nerve.
abstract: OBJECTIVE
  Laryngeal elevation protects the airway and assists opening of the esophagus during swallowing. The GH, thyrohyoid, and MH muscles provide a majority of this elevatory motion. This study applied functional electrical stimulation to the XII/C1 nerve complex using a nerve cuff electrode to determine the capabilities of neural stimulation to induce laryngeal elevation.
  
  
  METHODS
  Multi-contact FINE electrodes were implanted onto the XII/C1 nerve complex at locations proximal and distal to the thyrohyoid branching point in five anesthetized canines. Motion of the thyroid cartilage and the hyoid bone was recorded during stimulation of nerve cuffs and intramuscular electrodes.
  
  
  RESULTS
  Nerve stimulation induced 260% more laryngeal elevation than intramuscular stimulation (18.8 mm versus 5.2 mm, p ≪ 0.01), and 228% higher velocity (143.8 versus 43.9 mm s(-1), p ≪ 0.01). While stimulation at all cuff and electrode locations elevated the larynx, only the proximal XII/C1 nerve cuff significantly elicited both thyroid-hyoid approximation and hyoid elevation. In all proximal XII/C1 nerve cuffs (n = 7), stimulation was able to obtain selectivity of greater than 75% of at least one elevatory muscle.
  
  
  CONCLUSIONS
  These results support the hypothesis that an implanted neural interface system can produce increased laryngeal elevation, a significant protective mechanism of deglutition.
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland OH, USA.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Hadley
authors.forename: Ilya
authors.initials: I
authors.lastname: Kolb
authors.forename: Dustin J
authors.initials: DJ
authors.lastname: Tyler
mesh_terms: D000818:Animals; D003679:Deglutition / Q000502:physiology*; D004285:Dogs; D004558:Electric Stimulation / Q000379:methods*; D007002:Hypoglossal Nerve / Q000502:physiology*; D007830:Larynx / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*