Treatment efficacy of electromyography versus fiberscopy-guided botulinum toxin injection in adductor spasmodic dysphonia patients: a prospective comparative study

ScientificWorldJournal. 2014:2014:327928. doi: 10.1155/2014/327928. Epub 2014 Oct 14.


Introduction: This study prospectively evaluates and compares the treatment efficacy of botulinum toxin injection under electromyography guidance (EMG group) and percutaneous botulinum toxin injection under flexible fiberscopic guidance (fiberscopy group).

Methods: Thirty patients with adductor spasmodic dysphonia (ADSD), who had never received treatment, were randomly allocated into EMG- or fiberscopy-guided botulinum toxin injections between March 2008 and February 2010. We assessed acoustic and aerodynamic voice parameters, and the voice handicap index (VHI) before injection and at 1, 3, and 6 months after injection.

Results: The mean total dosage of botulinum toxin was similar for both groups: 1.7 ± 0.5 U for the EMG group and 1.8 ± 0.4 U for the fiberscopy group (P > 0.05). There were no significant differences in outcomes between the two groups in either the duration of effectiveness or complications such as breathy voice and aspiration.

Conclusion: Botulinum toxin injection under fiberscopic guidance is a viable alternative to EMG-guided botulinum toxin injection for the treatment of adductor spasmodic dysphonia when EMG equipment is unavailable.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Botulinum Toxins, Type A / administration & dosage*
  • Dysphonia / drug therapy*
  • Dysphonia / pathology
  • Electromyography*
  • Female
  • Humans
  • Laryngeal Muscles / drug effects*
  • Laryngeal Muscles / pathology
  • Male
  • Middle Aged
  • Treatment Outcome


  • Botulinum Toxins, Type A