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

ABSTRACT 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. The correlation was much higher at >14 days after onset of facial palsy. The orbicularis oris, followed by the frontalis muscle, showed the best correlation between ultrasound and EMG. Conclusions Quantitative ultrasound of facial muscles helps confirm the results of facial EMG and is of particular additional value in the first 14 days after onset when the reliability of EMG is low. Muscle Nerve 53 : 755–761, 2016