Possible Treatment for Focal Laryngeal Dystonia Revealed at MDS Conference

Results of a double-blind, placebo-controlled, randomized cross-over study presented at the 2024 International Congress of Parkinson’s Disease and Movement Disorders suggest that sodium oxybate (SO) may be an effective treatment for some people with focal laryngeal dystonia (LD). This phase 2b study included investigators from the Dystonia and Speech Motor Control Laboratory at Harvard Medical School and enlisted 106 participants with LD who were stratified into 2 groups: those whose symptoms were responsive to alcohol (EtOH+) and those whose symptoms were unaffected by alcohol (EtOH-).

Key Findings

• Efficacy in EtOH+ Patients: SO significantly reduced voice symptoms in EtOH+ LD patients compared with those assigned to placebo.
• Symptom Improvement: 64% of EtOH+ patients experienced a 40.8% improvement in symptoms.
• Broad Effectiveness: The treatment showed similar benefits across all forms of LD, including adductor, abductor, and dystonic voice tremor.
• Duration of Effect: Symptom improvement peaked at 40 minutes post-intake and gradually decreased over 300 minutes.

Safety Profile

• No significant changes in cognitive function, suicidality, or vital signs were observed.
• Mild, transient side effects such as daytime sleepiness, dizziness, and nausea were common.