Frozen versus Fresh Reconstituted Botox for Laryngeal. Dystonia

Abstract

Objectives. To compare the efficacy and side effects of fresh versus frozen reconstituted botulinum toxin type A (BTX-A) in the treatment of laryngeal dystonia. Methods. 43 patients, 30–70 years (mean 56.1±9.3) with adductor spasmodic dysphonia were randomly treated with fresh or refrozen reconstituted BTX-A (various duration ranging from one to eight weeks (mean 2.4±1.7)). Injections of BTX-A were guided using electromyography to the thyroarytenoid muscle bilaterally. Dose of medicine was adjusted per individual preference and ranged from 0.83 to 6 U per muscle. Efficacy of treatment was assessed by duration of action (number of weeks without spasms) and self-rated satisfaction of treatment using a 7 point Likert scale before every repeated injection. Side effects of breathiness and dysphagia were assessed. Data collection began after the patient’s third injection. Data analysis was performed on three randomly selected BTX-A injections for each type (fresh or frozen). [...].