Introduction
In this prospective study, we compared unilateral and bilateral thyroarytenoid muscle injections of Botulinum toxin (Dysport®) in 31 patients with adductor spasmodic dysphonia, who had undergone more than 5 consecutive Dysport® injections (either unilateral or bilateral) and had completed 5 concomitant self-rated efficacy and complication scores questionnaires related to the previous injections. We also developed a Neurophysiological Scoring (NPS) system which has utility in the treatment administration.