title: Laryngeal electromyography-guided hyaluronic acid vocal fold injection for unilateral vocal fold paralysis: a prospective long-term follow-up outcome report.
abstract: OBJECTIVE
  Unilateral vocal fold paralysis (UVFP) is a common voice disorder that may cause glottal closure insufficiency with hoarseness of voice. Laryngeal electromyography (LEMG)-guided hyaluronic acid vocal fold (VF) injection has been proposed as a treatment option to improve glottal closure with a satisfactory short-term effect. To our knowledge, this study reports the first long-term follow-up result of this treatment modality.
  
  
  OBJECTIVE
  To present the long-term treatment results of LEMG-guided hyaluronic acid VF injection for UVFP.
  
  
  METHODS
  Prospective study of the treatment results of 74 patients who received LEMG-guided hyaluronic acid VF injection for UVFP at a tertiary referral medical center from March 2010 to February 2013.
  
  
  METHODS
  In the office-based procedure, 1.0 mL of hyaluronic acid was injected via a 26-gauge monopolar injectable needle electrode into paralyzed thyroarytenoid muscles by LEMG guidance.
  
  
  METHODS
  Various glottal closure evaluations such as normalized glottal gap area, maximal phonation time, phonation quotient, mean airflow rate, perceptual GRBAS (grade, roughness, breathiness, asthenia, strain) scale, and Voice Handicap Index were compared before and after injection using the nonparametric Wilcoxon signed rank test within 1 month, at 6 months, and at the last follow-up examination.
  
  
  RESULTS
  Sixty patients had been followed up for at least 6 months. Forty-four patients received only 1 injection, and 16 patients received repeated injections (2 injections for 13 patients and 3 for 3 patients). All the glottal closure parameters improved significantly (P < .001) within 1 month, at 6 months, and at the last follow-up examination, with a mean (SD) of 17.4 (8.9) months. At the last follow-up examination, the mean (SD) normalized glottal gap area was significantly reduced from 7.9 (5.7) to 0.6 (1.6). Mean (SD) maximal phonation time was significantly prolonged from 4.6 (3.8) seconds to 12.1 (7.4) seconds. Mean (SD) phonation quotient was significantly reduced from 647 (508) mL/s to 277 (212) mL/s. Mean (SD) airflow rate was significantly reduced from 445 (338) mL/s to 175 (145) mL/s. When all the GRBAS scale parameters improved, the mean (SD) Voice Handicap Index score was significantly reduced from 76 (22) to 38 (30) (all P < .001).
  
  
  CONCLUSIONS
  Of the 74 patients in this study, 44 (60%) who received a single injection and 16 (22%) who received repeated injections did not require another treatment after long-term follow-up. Laryngeal electromyography-guided hyaluronic acid VF injection is an option for treating UVFP with satisfactory results.
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan2School of Speech Language Pathology & Audiology, Chung-Shan Medical University, Taichung, Taiwan3Department of Otolaryngology-Head & Neck Surgery, Taichung Veterans General Hospital, Taichu.
authors.forename: Chen-Chi
authors.initials: CC
authors.lastname: Wang
authors.affiliation: Department of Neurology, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Ming-Hong
authors.initials: MH
authors.lastname: Chang
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Taichung Veterans General Hospital, Taichung, Taiwan5School of Medicine, Chung-Shan Medical University, Taichung, Taiwan.
authors.forename: Rong-San
authors.initials: RS
authors.lastname: Jiang
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Hsiu-Chin
authors.initials: HC
authors.lastname: Lai
authors.affiliation: Department of Sensory Organs, ENT Section, Sapienza University of Rome, Rome, Italy.
authors.forename: Armando
authors.initials: A
authors.lastname: De Virgilio
authors.affiliation: School of Speech Language Pathology & Audiology, Chung-Shan Medical University, Taichung, Taiwan3Department of Otolaryngology-Head & Neck Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Ching-Ping
authors.initials: CP
authors.lastname: Wang
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Shang-Heng
authors.initials: SH
authors.lastname: Wu
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan3Department of Otolaryngology-Head & Neck Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Shi-An
authors.initials: SA
authors.lastname: Liu
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan3Department of Otolaryngology-Head & Neck Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Kai-Li
authors.initials: KL
authors.lastname: Liang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D007273:Injections, Intramuscular / Q000379:methods; D007821:Laryngeal Muscles; D008297:Male; D008875:Middle Aged; D010699:Phonation; D011446:Prospective Studies; D055675:Viscosupplements / Q000008:administration & dosage*; D014826:Vocal Cord Paralysis / Q000188:drug therapy*; D014833:Voice Quality; D055815:Young Adult
chemical_list: D055675:Viscosupplements; D006820:Hyaluronic Acid