title: Selective intraoperative stimulation of the human larynx.
abstract: OBJECTIVE
  Laryngeal contraction normally entails activation of mutually cooperative intrinsic laryngeal muscles (ILMs). Unfortunately, standard stimulating methods do not completely mimic the normal ongoing synchrony between the muscles. We submit that this problem can be addressed by modifying the stimulating waveform.
  
  
  METHODS
  This study extends prior canine research to the human using quasitrapezoidal (QT) currents instead of standard square waves, which while valuable incompletely express normal ILM interactions.
  
  
  METHODS
  In two patients undergoing laryngectomy for cancer, the recurrent laryngeal nerve on the uninvolved side received QT pulses (4 Hz, 60-2,000 μA, 100-500 μs width, 0-500-μs decay) via a bipolar cuff electrode. Pairs of needle electrodes placed into the posterior cricoarytenoideus (PCA), lateral cricoarytenoideus (LCA), and thyroarytenoideus (TA) were used to record electromyography amplitudes, and waveforms were analyzed by a specially designed computer program.
  
  
  RESULTS
  With activity from square waves serving as control, we observed statistically significant (P < .05) shifts in mutual relationships among PCA, LCA, and TA for an array of specific QT configurations.
  
  
  CONCLUSIONS
  Our preliminary data on selective ILM manipulation offer promise for improved dynamic control of faulty laryngeal contraction patterns.
authors.affiliation: Saint Vincent Charity Medical Center, MetroHealth Medical Center, and the Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA. mbron@prodigy.net
authors.forename: Michael
authors.initials: M
authors.lastname: Broniatowski
authors.forename: Sharon
authors.initials: S
authors.lastname: Grundfest-Broniatowski
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Hahn
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Hadley
authors.forename: Dustin J
authors.initials: DJ
authors.lastname: Tyler
authors.forename: Harvey M
authors.initials: HM
authors.lastname: Tucker
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000601:surgery*; D004558:Electric Stimulation / Q000295:instrumentation / Q000379:methods*; D004567:Electrodes, Implanted; D005500:Follow-Up Studies; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D007821:Laryngeal Muscles / Q000294:innervation* / Q000502:physiology; D007822:Laryngeal Neoplasms / Q000473:pathology / Q000601:surgery*; D007825:Laryngectomy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D010865:Pilot Projects; D012494:Sampling Studies; D016896:Treatment Outcome