Spasmodic dysphonia: a seven-year audit of dose titration and demographics in the Indian population

J Laryngol Otol. 2014 Jul;128(7):649-53. doi: 10.1017/S002221511400142X. Epub 2014 Jul 7.


Objectives: This study aimed to evaluate the demographics of spasmodic dysphonia in the Indian population and to analyse the optimum dose titration of botulinum toxin type A in this group. A comparative analysis with international studies was also performed.

Method: The study involved a retrospective analysis and audit of botulinum toxin type A dose titration in spasmodic dysphonia patients who visited our voice clinic between January 2005 and January 2012.

Results: The average total therapeutic dose required for patients with adductor spasmodic dysphonia was 4.2 U per patient per vocal fold (total 8.4 U per patient), and for patients with abductor spasmodic dysphonia, it was 4.6 U per patient.

Conclusion: Our audit revealed that 80 per cent of the spasmodic dysphonia patients were male, which contrasts dramatically with international studies, wherein around 80 per cent of spasmodic dysphonia patients were female. Our study also revealed a higher dose titration of botulinum toxin for the Indian spasmodic dysphonia population in both adductor and abductor spasmodic dysphonia cases.

MeSH terms

  • Botulinum Toxins, Type A / administration & dosage*
  • Clinical Audit / methods*
  • Dose-Response Relationship, Drug
  • Dysphonia / drug therapy*
  • Dysphonia / epidemiology
  • Dysphonia / physiopathology
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • India / epidemiology
  • Injections, Intramuscular
  • Laryngeal Muscles
  • Laryngismus / drug therapy*
  • Laryngismus / epidemiology
  • Laryngismus / physiopathology
  • Laryngoscopy
  • Male
  • Neuromuscular Agents / administration & dosage
  • Population Surveillance / methods*
  • Retrospective Studies
  • Time Factors
  • Vocal Cords
  • Voice Quality


  • Neuromuscular Agents
  • Botulinum Toxins, Type A