title: Liquid-type Botulinum Toxin Type A in Adductor Spasmodic Dysphonia: A Prospective Pilot Study.
abstract: OBJECTIVE
  Botulinum toxin (BTX) has been widely used to treat adductor spasmodic dysphonia (ADSD). Most commercially available forms of BTX require reconstitution before use, which may increase the risk of contamination and requires careful titration. Recently, a liquid-type BTX type A (BTX-A) has been developed, which should simplify the procedure and enhance its efficacy. Herein, we present a prospective pilot study to investigate the efficacy and safety of liquid-type BTX-A in the treatment of ADSD.
  
  
  METHODS
  Twenty-six consecutive liquid-type BTX-A injections were performed in 12 patients with ADSD. We included as a control group 34 consecutive patients with ADSD who had previously undergone 52 vocal fold injection procedures with freeze-dried-type BTX-A.
  
  
  RESULTS
  All patients in both groups had improvement of symptoms related to ADSD and period of normal voice. Most patients experienced breathiness, and the onset time, the peak response time, and the duration of breathiness were similar in both groups. The duration of effect (days) was 96.96 ± 18.91 and 77.38 ± 18.97 in the freeze-dried-type and the liquid-type groups, and the duration of benefit (days) was 80.02 ± 18.24 and 62.69 ± 19.73 in the freeze-dried-type and the liquid-type groups. To compare the efficacy between the freeze-dried-type and the liquid-type BTX-A, the sessions of the unilateral vocal fold injection were included and were categorized as group A (1 ~ 2 units BTX-A) and group B (2 ~ 3 units BTX-A), according to the dose per vocal fold. There was no significant difference of effect time between freeze-dried-type and liquid-type BTX-A groups. No adverse events related to BTX or vocal fold injection were reported.
  
  
  CONCLUSIONS
  Liquid-type BTX-A is safe and effective for the treatment of spasmodic dysphonia. With the advantages of simple preparation, storage, and reuse and animal protein-free constituents, liquid-type BTX-A may be a good option in the treatment of spasmodic dysphonia.
authors: Department of Otorhinolaryngology-Head and Neck Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea; Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University School of Medicine, Yangsan, Republic of Korea. Electronic address: chawonjae@gmail.com.
authors: Wonjae
authors: W
authors: Cha
authors: Department of Otorhinolaryngology-Head and Neck Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea.
authors: Jeon Yeob
authors: JY
authors: Jang
authors: Department of Otorhinolaryngology-Head and Neck Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea; Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University School of Medicine, Yangsan, Republic of Korea.
authors: Soo-Geun
authors: SG
authors: Wang
authors: Department of Otorhinolaryngology-Head and Neck Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea.
authors: Ji-Heon
authors: JH
authors: Kang
authors: Department of Otorhinolaryngology-Head and Neck Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea.
authors: Min-Gyu
authors: MG
authors: Jo
mesh_terms: D065087:Acetylcholine Release Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects / Q000737:chemistry; D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage* / Q000009:adverse effects / Q000737:chemistry; D016022:Case-Control Studies; D004339:Drug Compounding; D055154:Dysphonia / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D005612:Freeze Drying; D006801:Humans; D007267:Injections; D008297:Male; D008875:Middle Aged; D019999:Pharmaceutical Solutions; D010865:Pilot Projects; D011446:Prospective Studies; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome; D014827:Vocal Cords / Q000187:drug effects* / Q000503:physiopathology; D014833:Voice Quality / Q000187:drug effects*
chemical_list: D065087:Acetylcholine Release Inhibitors; D019999:Pharmaceutical Solutions; D019274:Botulinum Toxins, Type A
keywords: Botulinum toxin; Focal dystonia; Liquid-type; Spasmodic dysphonia; Vocal fold injection