Safety and efficacy of clonazepam in patients with hemifacial spasm: A double-blind, randomized, placebo-controlled trial

Abstract

INTRODUCTION: Hemifacial spasm (HFS) is an involuntary intermittent twitching of the facial muscles. Medical and surgical treatments can be considered for HFS. Among medical treatments, clonazepam is a benzodiazepine used to treat epilepsy, psychiatric symptoms, and movement disorders. This study aimed to investigate the efficacy and safety of clonazepam for the treatment of HFS. METHODS: This randomized double-blind placebo-controlled trial prospectively enrolled patients with HFS aged 20-79 years. The patients were randomly assigned in a 1:1 ratio to receive either clonazepam (0.5 mg twice daily) or a placebo for 4 weeks. All participants underwent clinical assessment and laboratory tests at baseline and visit 2. The primary endpoint was the clinical global impression-improvement (CGI-I) score at visit 2. RESULTS: A total of 34 patients with HFS assessed for eligibility were enrolled between April 2015 and November 2016. Among them, two patients were withdrawn before randomization. Thus, the intention-to-treat analysis included 32 patients with HFS. The median CGI-I scores at visit 2 did not differ significantly between the clonazepam (3; range 1-6) and placebo (3.5; range 3-5) groups. In the safety analysis, only mild or no serious adverse events were observed. CONCLUSION: The results of this study demonstrated the safety of clonazepam in patients with HFS. However, clonazepam did not show a statistically significant effect on HFS. Further studies are needed to provide evidence of the clinical benefits in patients with HFS.