Correlation between electromyography and quantitative ultrasonography of facial muscles in patients with facial palsy.

Introduction: In this study we correlated results of ultrasonographic muscle thickness and contractility with facial electromyography (EMG) in patients with unilateral peripheral acute or chronic facial palsy.

Methods: Two hundred twenty measurements of 4 facial muscles (frontalis, orbicularis oculi, zygomaticus, and orbicularis oris) were performed in 44 patients.

Results: Facial muscle thickness at rest and during muscle contraction correlated best with EMG insertional activity, and facial muscle contractility correlated with EMG voluntary activity.