A COMPARISON OF THE EFFICACY OF UNILATERAL VERSUS BILATERAL BOTULINUMTOXIN INJECTIONS IN THE TREATMENT OF ADDUCTOR SPASMODIC DYSPHONIA

The current treatment of choice of adductor spasmodic dysphonia due to focal dystonia is thyroarytenoid-vocalis injection of botulinum toxin type A (Botox). Botox exerts its effect by presynaptic motor endplate blockade, preventing the release of acetylcholine and causing muscle paresis. Botox treatment protocols vary. Some centres perform unilater al injections, whereas others treat both cords. Our hypothesis is that unilateral injections may reduce the severity of whisper voice and as piration side effects in the early two to three weeks after treatment. The purpose of this study, therefore, is to compare the efficacy of u nilateral versus bilateral Botox injections in the treatment of adduct or spasmodic dysphonia in terms of duration of effect versus the side effects of breathiness and swallowing difficulties. This study present s data from a retrospective chart review and a prospective telephone i nterview of all patients receiving bilateral and unilateral Botox inje ctions.