Hemifacial spasm in sleep - A polysomnographic study.

Background: Polysomnography (PSG) studies in patients with facial dyskinesias are few. With regard to hemifacial spasm (HFS), one study reported the continuity of spasms during sleep which was not confirmed elsewhere using a PSG. Therefore, we sought to investigate abnormal facial movements during sleep in patients with HFS.

Methods: All patients have undergone PSG assessments. Facial spasms were recorded using an electromyography (EMG) and quantified according to the duration of the hyperkinetic episodes in each epoch of 60 s. Scores were compared between wakefulness and sleep as well as within the sleep stages. Number of arousals and their association with the EMG activity is also evaluated.

Results: Twelve patients with a mean age of 58 (35-76) years and disease duration of 7.8 (2-20) years were included in the study. In seven of them all sleep stages were detected. Facial spasms continued in sleep in all patients with a significant decrease compared to wakefulness (p < 0.001). No significant difference between non-REM and REM stages are found with regard to EMG activity (p = 0.35). On average, sleep was interrupted 5.9 (±2.8) times mostly in non-REM-II and least in REM sleep.

Conclusion: This study confirms the continuity of hyperkinetic movements of HFS during sleep despite a significant decrease compared to wakefulness causing increased arousals. These findings highlight the importance of assessing the sleep quality in patients with HFS.