Localized injections of botulinum toxin for the treatment of focal laryngeal dystonia (spastic dysphonia)

Abstract
Spastic dysphonia is a condition producing a strain-strangle phonation. We have previously classified most of these patients as having focal laryngeal dystonia, a disorder of central motor processing. The initial success of recurrent nerve section in many of these patients has been followed by recurrence of symptoms in months to years. Bilateral involvement of the vocal cords with hyperfunction of the nonparalyzed vocal cord could explain these failures. Injection of botulinum toxin (BOTOX) has been effective treatment for many focal dystonias. We have treated more than 100 patients with dystonia including five with laryngeal dystonia. All of the patients laryngeal had dramatic improvement after 48 to 72 hours; benefit lasted 3 to 9 months for each injection period. BOTOX injection can be performed on awake, ambulatory patients. Bilateral treatment and titration of dose can achieve the desired degree of weakness.