title: Laryngeal electromyography and prognosis of unilateral vocal fold paralysis--a long-term prospective study.
abstract: OBJECTIVE
  To confirm the value of using laryngeal electromyography (LEMG) to predict the long-term prognosis of unilateral vocal fold paralysis (UVFP), and elucidate the adequate timing of LEMG.
  
  
  METHODS
  Prospective cohort prognosis study.
  
  
  METHODS
  The LEMG data of 84 patients with UVFP were prospectively collected, and 81 patients received follow-up at least 6 months after symptom onset. If the paralyzed vocal fold had <20% recruitment reduction during phonation compared to the normal vocal fold signals, and absence of fibrillation when the patient was silent, the prognosis was considered to be good (negative finding). Otherwise, the prognosis was considered to be poor (positive finding). The association between UVFP outcome and LEMG prognostic rules and the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of LEMG were calculated.
  
  
  RESULTS
  The mean duration of LEMG after symptom onset was 3.7 months, and follow-up after symptoms onset was 18.4 months. Sixty-six of 71 patients with a positive finding had persistent UVFP; four of 10 patients with a negative finding recovered vocal fold motion. LEMG results were significantly associated with the outcome of UVFP (P = .007). The overall accuracy, sensitivity, specificity, PPV, and NPV of LEMG were 86.4%, 91.7%, 44.4%, 93.0%, and 40.0%, respectively. When LEMG was done more than 2 months after symptom onset, the PPV was 97.9%.
  
  
  CONCLUSIONS
  LEMG has a high PPV in predicting the long-term outcome of UVFP patients with poor prognosis. Permanent laryngeal framework surgery is feasible if patients have positive findings at least 2 months after symptom onset.
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan; School of Speech Language Pathology & Audiology, Chung-Shan Medical University, Taichung, Taiwan; Department of Otolaryngology-Head & Neck Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Chen-Chi
authors.initials: CC
authors.lastname: Wang
authors.forename: Ming-Hong
authors.initials: MH
authors.lastname: Chang
authors.forename: Armando
authors.initials: A
authors.lastname: De Virgilio
authors.forename: Rong-San
authors.initials: RS
authors.lastname: Jiang
authors.forename: Hsiu-Chin
authors.initials: HC
authors.lastname: Lai
authors.forename: Ching-Ping
authors.initials: CP
authors.lastname: Wang
authors.forename: Shang-Heng
authors.initials: SH
authors.lastname: Wu
authors.forename: Shih-An
authors.initials: SA
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004576:Electromyography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012008:Recurrence; D018570:Risk Assessment; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D014826:Vocal Cord Paralysis / Q000175:diagnosis* / Q000628:therapy; D055815:Young Adult
keywords: Fibrillation; laryngeal electromyography; prognosis; recruitment reduction; vocal fold paralysis