title: Laryngeal electromyography: electrode guidance based on 3-dimensional magnetic resonance tomography images of the larynx.
abstract: OBJECTIVE
  Laryngeal electromyography (LEMG) is an important tool for the assessment of laryngeal nerve and muscle functioning. The purpose of the study was to determine electrode insertion angle and insertion depth for the various laryngeal muscles.
  
  
  METHODS
  Twenty-three cadaver larynges were examined with magnetic resonance tomography (MRT) and Materialize Interactive Medical Image Control System (Leuven, Belgium) 3-dimensional (3D) imaging software. Geometrical analysis was used to calculate the electrode insertion angles.
  
  
  RESULTS
  All laryngeal muscles could be identified and 3D visualized on MRT scans. Although the insertion angles were the same in male and female larynges, the insertion depth was significantly larger in male than in female larynges (P<0.05). Of particular clinical importance is the fact that the electrode has to be directed lateral and upward for the thyroarytenoid muscle but lateral and downward for the lateral cricoarytenoid muscle (insertion point=midline lower border of the thyroid).
  
  
  CONCLUSIONS
  This is the first study that analyzes electrode insertion angles and insertion depths for each laryngeal muscle using 3D imaging. We hope that the information gained from this study will help clinicians performing LEMG to localize the individual laryngeal muscles.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Division of Phoniatrics, University Hospital Basel, Basel, Switzerland. cstorck@uhbs.ch
authors.forename: Claudio
authors.initials: C
authors.lastname: Storck
authors.forename: Raphael
authors.initials: R
authors.lastname: Gehrer
authors.forename: Michael
authors.initials: M
authors.lastname: Hofer
authors.forename: Bernhard
authors.initials: B
authors.lastname: Neumayer
authors.forename: Rudolf
authors.initials: R
authors.lastname: Stollberger
authors.forename: Ralf
authors.initials: R
authors.lastname: Schumacher
authors.forename: Markus
authors.initials: M
authors.lastname: Gugatschka
authors.forename: Gerhard
authors.initials: G
authors.lastname: Friedrich
authors.forename: Markus
authors.initials: M
authors.lastname: Wolfensberger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D004576:Electromyography / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007830:Larynx / Q000033:anatomy & histology* / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged