Tongue Biting Event in Patients with Sleep-Related Facial Mandibular Myoclonus: A Case Series Study

Abstract

Gengyao Hu,1,* Yuanhang Pan,1,* Na Yuan,1,* Zhixian Yang,2 Xiuyu Shi,3 Sha Ma,4 Shan Li,4 Xiaohua Hou,5 Fei Liu,5 Dongmei Li,6 Junxiang Bao,7 Yonghong Liu1 1Department of Neurology, Xijing Hospital, Fourth Military Medical University (Air Force Medical University), Xi’an, People’s Republic of China; 2Department of Pediatrics, Peking University First Hospital, Beijing, People’s Republic of China; 3Department of Pediatrics, Chinese People’s Liberation Army General Hospital, Beijing, People’s Republic of China; 4Department of Neurology, The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, Yunnan, People’s Republic of China; 5Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, People’s Republic of China; 6Department of Dentistry for Special Services, Fourth Military Medical University (Air Force Medical University), Xi’an, People’s Republic of China; 7Department of Aerospace Hygiene, Fourth Military Medical University (Air Force Medical University), Xi’an, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yonghong Liu, Email [email protected]: Sleep-related facial mandibular myoclonus (SRFMM) remains rare in clinical practice. The aim of this study was to provide a comprehensive understanding of the electroclinical manner, therapeutic regimen, and prognosis of SRFMM.Methods: Twenty-three patients who were diagnosed with SRFMM by clinical manifestation, video-electroencephalography (EEG) and electromyography over bilateral masseter and temporalis muscles were enrolled. Clinical and electrophysiological evaluation as well as follow-up information were recorded and analyzed.Results: The cohort involved 4 infants and 19 adults with a mean onset age of 43.5 years for SRFMM, among whom 19 were male. Twenty-one patients complained of tongue injuries and disturbed night-time sleep. SRFMM in 4 patients were ascribed to oral aripiprazole, brainstem ischemia and brain trauma. In 62 SRFMM episodes, 93.5% occurred in NREM sleep and 6.5% in REM sleep, and all events were associated with EEG arousals. In 13 patients with or without clonazepam, the motor events gradually disappeared, and the rest turned to be sporadic.Conclusion: SRFMM is a characteristic parasomnia manifested by tongue biting and accompanying facial mandibular myoclonus, leading to disrupted sleep. Besides adults, infants can also experience SRFMM with spontaneous remission. Most patients respond well to clonazepam, eventually with favorable prognosis.Keywords: sleep-related facial mandibular myoclonus, tongue biting, movement disorder, SRFMM

Keywords

• sleep-related facial mandibular myoclonus
• tongue biting
• movement disorder.