A Double-Blind, Placebo-Controlled Study of Appropriate Site of Botulinum Toxin Therapy in Hemifacial Spasm.

Introduction: Hemifacial spasm (HFS) is a condition causing poor quality of life. Treatment with botulinum toxin A (BTX) injection is effective. Only one randomized controlled trial with a single-blind fashion has evaluated if oral injection is needed in HFS.