title: Sleep bruxism is related to decreased inhibitory control of trigeminal motoneurons, but not with reticulobulbar system.
abstract: Sleep bruxism (SB) is a stereotyped movement disorder characterized by grinding or clenching of the teeth during sleep. We aimed to understand the abnormal networks related to the excitability of masticatory pathways in patients with SB. Eleven patients with SB and age- and gender-matched 20 healthy subjects were prospectively enrolled in our study. The masseter inhibitory reflex (MIR) after electrical stimulation and auditory startle reaction (ASR) were examined. For MIR responses, durations of early and late silent period (SP) were shorter and the degree of suppression of SPs was significantly lower in SB group in comparison to those obtained in healthy subjects. The ASR responses even of the masseter muscle, however, were similar between patients with SB and healthy individuals. Abnormal MIR provides support for the decreased inhibitory control of the central masticatory circuits in SB whereas normal ASR suggests the integrity and normal functioning of brainstem pathways mediating startle reaction. Although the sample size is small, our results are in line with previous findings and suggest an abnormally decreased inhibition in trigeminal motoneurons to masseter muscle rather than reticulobulbar pathways in patients with SB.
authors.affiliation: Department of Neurology, Dr. Lütfi Kırdar Kartal Training and Researching Hospital, Istanbul, Turkey.
authors.forename: Rahşan
authors.initials: R
authors.lastname: İnan
authors.affiliation: Department of Neurology, Cerrahpasa School of Medicine, Istanbul Unıversity, Istanbul, Turkey.
authors.forename: Gülçin Benbir
authors.initials: GB
authors.lastname: Şenel
authors.affiliation: Neurology Department, School of Medicine, Bahcesehir University, Istanbul, Turkey.
authors.forename: Figen
authors.initials: F
authors.lastname: Yavlal
authors.affiliation: Department of Neurology, Cerrahpasa School of Medicine, Istanbul Unıversity, Istanbul, Turkey.
authors.forename: Derya
authors.initials: D
authors.lastname: Karadeniz
authors.affiliation: Department of Neurology, Cerrahpasa School of Medicine, Istanbul Unıversity, Istanbul, Turkey. draysegulgunduz@yahoo.com.
authors.forename: Ayşegül
authors.initials: A
authors.lastname: Gündüz
authors.affiliation: Department of Neurology, Cerrahpasa School of Medicine, Istanbul Unıversity, Istanbul, Turkey.
authors.forename: Meral E
authors.initials: ME
authors.lastname: Kızıltan
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology*; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D017286:Polysomnography; D012018:Reflex / Q000502:physiology; D012021:Reflex, Abnormal / Q000502:physiology*; D013216:Reflex, Startle / Q000502:physiology; D020186:Sleep Bruxism / Q000503:physiopathology*; D055815:Young Adult
keywords: Auditory startle reaction; Brainstem excitability; Bruxism; Masseter inhibitory reflex