TECHNIQUE FOR INJECTION OF BOTULINUM TOXIN THROUGH THE FLEXIBLE NASOLARYNGOSCOPE

A new endoscopic method of injecting botulinum toxin into the thyroary tenoid muscles for treatment of adductor spasmodic dysphonia was evalu ated. Twelve patients with adductor spasmodic dysphonia were given inj ections in the thyroarytenoid muscle under video visualization with a flexible catheter needle that was passed through the working channel o f a flexible nasolaryngoscope. Six patients received unilateral inject ions, and six received bilateral injections. Preinjection and postinje ction speech samples were compared by use of spectrographic analysis. Significant decreases in voice breaks and sentence duration were found after treatment with both unilateral and bilateral injections. Patien t interviews and diaries documented the reported degree and duration o f symptom reduction. All 12 patients reported that the injections were of significant benefit and that the endoscopic procedure was tolerabl e. We concluded that this is a safe and effective technique for inject ing botulinum toxin into laryngeal muscles for treatment of spasmodic dysphonia.