title: Laryngeal electromyography findings of vocal fold immobility in patients after radiotherapy for nasopharyngeal carcinoma.
abstract: BACKGROUND
  The clinical features of vocal fold immobility (VFI) after radiotherapy for nasopharyngeal carcinoma (NPC) have seldom been reported.
  
  
  METHODS
  We retrospectively reviewed laryngeal electromyography (LEMG) and tumor study findings to elucidate the common clinical features of patients who presented with VFI after radiotherapy for NPC. The LEMG signals obtained from the cricothyroid and thyroarytenoid muscles were used to confirm superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN) injury.
  
  
  RESULTS
  The medical records of 13 patients were reviewed and 11 of them had evidence of RLN injury. Six of the 11 patients also had SLN injury, indicating possible vagus nerve (VN) injury. Two patients had cricoarytenoid joint fixation without evidence of nerve injury. None of the nerve injuries were caused by skull base recurrence or tumor metastasis.
  
  
  CONCLUSIONS
  VFI is usually caused by nerve injury, but it is not a malignant sign of tumor recurrence or metastasis.
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Hsieh
authors.forename: Ming-Hong
authors.initials: MH
authors.lastname: Chang
authors.forename: Chen-Chi
authors.initials: CC
authors.lastname: Wang
mesh_terms: D000368:Aged; D002277:Carcinoma; D004576:Electromyography; D005260:Female; D006784:Hospitals, Teaching; D006787:Hospitals, Veterans; D006801:Humans; D061224:Laryngeal Nerve Injuries / Q000209:etiology*; D008297:Male; D016347:Medical Records Systems, Computerized; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000532:radiotherapy*; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects*; D061226:Recurrent Laryngeal Nerve Injuries / Q000209:etiology; D012189:Retrospective Studies; D013624:Taiwan; D014826:Vocal Cord Paralysis / Q000209:etiology*
keywords: laryngeal electromyography; nasopharyngeal carcinoma; nerve paralysis; radiotherapy; vocal fold immobility