title: Vocal fold paralysis following radiotherapy for nasopharyngeal carcinoma: laryngeal electromyography findings.
abstract: Laryngeal electromyography was used to study the pattern of neurological injury in three patients with unilateral vocal fold paralysis following radiotherapy for nasopharyngeal carcinoma. The thyroarytenoid and cricothyroid muscles were assessed to give an indication of recurrent and superior laryngeal nerve function. Two patients demonstrated both recurrent and superior laryngeal neuropathy suggesting injury at the skull base. The other patient had only recurrent laryngeal neuropathy indicating more distal involvement. Subclinical neuropathic changes were seen in two cases on the side contralateral to the vocal fold paralysis. These patients may be at increased risk of developing bilateral vocal fold paralysis and potentially life-threatening airway obstruction. Long-term follow-up is recommended for such patients, especially if medialization thyroplasty is being considered. This is the first report describing the use of electromyography to determine the pattern of nerve injury in patients with vocal fold paralysis following head and neck radiotherapy.
authors.affiliation: Department of Otolaryngology, Singapore General Hospital, Singapore. dpclau@hotmail.com
authors.forename: David P C
authors.initials: DP
authors.lastname: Lau
authors.forename: Yew-Long
authors.initials: YL
authors.lastname: Lo
authors.forename: Joseph
authors.initials: J
authors.lastname: Wee
authors.forename: Nam-Guan
authors.initials: NG
authors.lastname: Tan
authors.forename: Wong-Kein
authors.initials: WK
authors.lastname: Low
mesh_terms: D002277:Carcinoma / Q000532:radiotherapy*; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007823:Laryngeal Nerves / Q000503:physiopathology; D007830:Larynx / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D011878:Radiotherapy / Q000009:adverse effects*; D012189:Retrospective Studies; D014826:Vocal Cord Paralysis / Q000209:etiology* / Q000503:physiopathology*