Use of Botulinum Toxin in Patients with Laryngeal Dystonia and Vocal Tremor

Abstract

Introduction: Laryngeal movement disorders, such as laryngeal dystonia (LD), essential voice tremor (EVT), and dystonic voice tremor (DVT) cause vocal instability, affecting func- tionality and quality of life. Although there is no curative treatment, laryngeal botulinum toxin (BT) injections are the standard therapy. Objective: To characterize the population of patients with LD, DVT and EVT and assess the outcomes of laryngeal BT injections. Mate­rial and Methods: A retrospective cohort study was conducted. Medical records of patients with LD, DVT, and EVT evaluated at the Voice Unit between January 2013 and July 2024 were reviewed. Biodemographic, clinical, and treatment data were collected. Patients treated with BT completed a self-reported vocal symptoms survey, including the Voice Handicap Index (VHI-10). Descriptive and comparative statistical analyses were performed. Results: Sixty-six patients were included (mean age: 60 years, 84,9% female). Diagnoses included LD (56.1%), DVT (12.1%), and EVT (31.8%). The most common LD subtype was ad­ductor LD (97.8%). Of the total cohort, 40 patients were prescribed BT treatment, and 35 received it at our center, totaling 133 injections, mostly administered via the cricothyroid approach. Vocal quality, vocal effort and VHI-10 scores significantly improved after treat- ment (P < 0.0001). Breathy voice was reported in 100% of cases, and dysphagia with solids and liquids in 21.7% and 60.1%, respectively. Conclusion: Laryngeal BT injection is a safe and effective treatment for patients with LD, DT, and EVT, improving self-perceived across all diagnoses and improving voice quality and reducing vocal effort in LD and DLT.