Adductor Respiratory Laryngeal Dystonia (Dystonic Respiratory Stridor): Clinical Characterization and Response to Botulinum Toxin Therapy: A Single Centre Experience

BACKGROUND: Adductor respiratory laryngeal dystonia (ARLD) is a rare focal dystonia with vocal fold closure during inspiration leading to stridor and dyspnoea. OBJECTIVES: To characterize clinical features and outcomes of patients with ARLD at a tertiary movement disorders center. METHODS: A retrospective cohort study was conducted of patients with adductor respiratory laryngeal dystonia attending a botulinum toxin injection clinic. RESULTS: Nineteen patients were identified. Most were female (94.7%). Mean age of onset was 51.9 years (range 39-89). Comorbid movement disorders included laryngeal dystonia, cervical dystonia, blepharospasm, dystonic tremor, and Parkinson's disease. Median time from symptom onset to diagnosis was 3.0 years (IQR 2.0-15.0). 92.8% of injections with botulinum toxin were effective, although 46.2% were associated with adverse events. CONCLUSIONS: ARLD is associated with diagnostic delay. Symptoms of stridor alongside other movement disorders may provide clues. Treatment with botulinum toxin is effective, though careful dosing is required.