title: Prospective electromyographic evaluation of functional postthyroidectomy voice and swallowing symptoms.
abstract: BACKGROUND
  Voice and swallowing symptoms following thyroidectomy in the absence of any demonstration of laryngeal nerves injury are usually considered a functional outcome of uncomplicated operations, mainly related to scar formation and emotional reaction. They could be related to unapparent laryngeal nerve or cricothyroid (CT) muscle injuries detectable only by laryngeal electromyography (LEMG). We correlated such symptoms with LEMG patterns.
  
  
  METHODS
  A total of 33 consenting patients undergoing total thyroidectomy (TT) were enrolled. Video-strobolaryngoscopy (VSL), acoustic voice analysis (AVA), and maximum phonation time (MPT) were performed preoperatively and 3 months postoperatively. Subjective evaluation of voice (Voice Impairment Score, or VIS) and swallowing (Swallowing Impairment Score, or SIS) were obtained preoperatively and 1 and 3 months postoperatively. At 1 month postoperatively LEMG was performed examining thyroarytenoid (TA) and CT muscles to evaluate the inferior laryngeal nerve (ILN) and the external branch of the superior laryngeal nerve (EBSLN), respectively.
  
  
  RESULTS
  One patient experienced transient vocal cord palsy and was excluded. The remaining 32 patients completed the postoperative evaluation. No significant difference was found between preoperative and postoperative AVA and MPT parameters. Mean VIS was significantly worse than preoperatively 1 and 3 months after TT. No significant difference was found between preoperative and postoperative SIS. LEMG evaluation of TA muscle showed decreased voluntary activity and spontaneous fibrillation potentials in one patient. LEMG of the CT muscle did not reveal any sign of EBSLN injury.
  
  
  CONCLUSIONS
  Patients frequently complain of subjective symptoms early after TT. LEMG demonstrated the absence of subclinical laryngeal nerve injury in all but one patient, confirming their functional nature.
authors.affiliation: Department of Surgery, Division of General and Endocrine Surgery, Università Cattolica del Sacro Cuore, L.go A. Gemelli 8, Rome 00168, Italy.
authors.forename: Celestino P
authors.initials: CP
authors.lastname: Lombardi
authors.forename: Lucia
authors.initials: L
authors.lastname: D'Alatri
authors.forename: Maria R
authors.initials: MR
authors.lastname: Marchese
authors.forename: Daria
authors.initials: D
authors.lastname: Maccora
authors.forename: Mauro Lo
authors.initials: ML
authors.lastname: Monaco
authors.forename: Carmela
authors.initials: C
authors.lastname: De Crea
authors.forename: Marco
authors.initials: M
authors.lastname: Raffaelli
mesh_terms: D000328:Adult; D003680:Deglutition Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D004576:Electromyography; D005260:Female; D006801:Humans; D007821:Laryngeal Muscles / Q000294:innervation / Q000503:physiopathology*; D007828:Laryngoscopy; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D011446:Prospective Studies; D013965:Thyroidectomy; D014832:Voice Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology