title: Electromyography-Guided Botulinum Toxin Injection Into the Cricothyroid Muscles in Bilateral Vocal Fold Abductor Paralysis.
abstract: OBJECTIVE
  Bilateral vocal fold abductor paralysis (BVFAP) both deteriorates quality of life and may cause life-threatening respiratory problems. The aim of this study was to reduce respiratory symptoms in BVFAP patients using cricothyroid (CT) botulinum toxin (BTX) injection.
  
  
  METHODS
  Before and 2 weeks and 4 months after bilateral BTX injection into the CT muscles under electromyography; alterations in respiratory, acoustic, aerodynamic and quality of life parameters were evaluated in BVFAP patients with respiratory distress. For the respiratory evaluation modified Borg scale and spirometry, for the voice and aerodynamic evaluations Voice Handicap Index-30 (VHI-30), GRBAS, acoustic analysis (sound pressure level, F0, jitter%, shimmer%, noise-to-harmonic ratio) and maximum phonation time and for the quality of life assessment Short Form-36 (SF-36) form were used.
  
  
  RESULTS
  All patients were female with a mean age of 47±8.1 years. There was a mean time of 11.8±5.5 (minimum 2, maximum 23) months between BVFAP development and BTX injection. In all cases, other than one case with unknown aetiology, the cause of vocal fold paralysis was prior thyroid surgery. In total 18.6±3.1 units of BTX were applied to the CTs. In the preinjection period, and the 2nd week and 4th month after injection, the Borg dyspnea scale was 7.3/5.3/5.0, FIV1 (forced inspiratory volume in one second) was 1.7/1.7/1.8 L, peak expiratory flow (PEF) was 1.4/1.7/2.1 L/sec, maximum phonation time was 7.0/6.4/6.2 seconds and VHI-30 was 63.2/52.2/61.7 respectively. There was no significant alteration in acoustic analysis parameters. Many of the patients reported transient dysphagia within the first week. There were insignificant increases in SF-36 sub-scale values.
  
  
  CONCLUSIONS
  After BTX injection, improvements in the mean Borg score, PEF and FIV1 values and SF-36 sub-scale scores showed the restricted success of this approach. This modality may be kept in mind as a transient treatment option for patients refused persistent tracheotomy or ablative airway surgeries.
authors.affiliation: Department of Otolaryngology, Adnan Menderes University Medical School, Aydin, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Sahin
authors.affiliation: Department of Neurology, Ege University Medical School, Izmir, Turkey.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Aydogdu
authors.affiliation: Department of Otolaryngology, Ege University Medical School, Izmir, Turkey.
authors.forename: Serdar
authors.initials: S
authors.lastname: Akyildiz
authors.affiliation: Department Chest Diseases, Ege University Medical School, Izmir, Turkey.
authors.forename: Munevver
authors.initials: M
authors.lastname: Erdinc
authors.affiliation: Department of Otolaryngology, Ege University Medical School, Izmir, Turkey.
authors.forename: Kerem
authors.initials: K
authors.lastname: Ozturk
authors.affiliation: Department of Otolaryngology, Ege University Medical School, Izmir, Turkey.
authors.forename: Fatih
authors.initials: F
authors.lastname: Ogut
keywords: Bilateral Vocal Fold Paralysis; Botulinum Toxin; Cricothyroid Muscle