Association of masticatory muscle activity with sleep arousal and other concomitant movements during sleep

Associations between abnormal sleep behavior and indoor environmental risk factors among children with a chronic cough in Wuxi, China: a cross-sectional study

BACKGROUND

Indoor environmental factors, such as pet ownership, presence of cockroaches, mattress quality, fuel usage (gas or electricity), use of biomass for cooking and heating, exposure to tobacco smoke or household molds can significantly affect the sleep quality of children with chronic cough. However, data regarding the effects of indoor environmental conditions on sleep in this population are limited. This study aimed to assess the prevalence of abnormal sleep behaviors and to establish associations between indoor environmental factors and sleep behaviors among children with chronic cough in Wuxi, China.

METHODS

A cross-sectional design was employed in this study, involving children aged 3-18 years. Data on sociodemographic factors, allergies, home environmental exposures, and sleep characteristics of the participants were collected using paper-based questionnaires. The association between indoor environmental factors and sleep behaviors in children with chronic cough was analyzed using logistic regression models.

RESULTS

The findings demonstrated that the prevalence of chronic cough among children in Wuxi was 15.50%. The chronic cough group exhibited a significantly higher incidence of eczema, wheezing, rhinitis, food allergy, and nasosinusitis than the non-chronic cough group. In addition, children with chronic cough also tended to have a family history of sleep disorders and adenoid hypertrophy (P < 0.01). After adjusting for confounding factors, a significant association was observed between bruxism (teeth grinding) and chronic cough (sometimes: odds ratio [OR] = 1.04; confidence interval [CI] = 1.01-1.08; always: OR = 1.11; CI = 1.04-1.19; P < 0.01). Among children with chronic cough, recent home decoration was associated with sleepwalking (OR = 1.04; CI = 1.00-1.07; P < 0.05), mold exposure was associated with bruxism (OR = 1.15; CI = 1.0-1.31; P < 0.05), and carpet use at home was associated with apnea (OR = 1.09; CI = 1.02-1.17; P < 0.05), twitching during sleep (OR = 1.13; CI = 1.00-1.27; P < 0.01) and morning headache (OR = 1.14; CI = 1.05-1.23; P < 0.01).

CONCLUSION

Children with chronic cough are more prone to some abnormal sleep behaviors than children without chronic cough. Household decoration within a year, household mold exposure, and carpet use were all significantly positively associated with abnormal sleep behaviors in children with chronic cough. Our study provides novel insights into the impact of the indoor environment on children's sleep and the occurrence of chronic cough, offering guidance for tailored health promotion programs for families.

Associations between sleep bruxism and other sleep-related disorders in adults: a systematic review

OBJECTIVE

Systematic reviews on sleep bruxism (SB) as a comorbid condition of other sleep-related disorders are lacking. Such reviews would contribute to the insight of sleep clinicians into the occurrence of SB in patients with other sleep-related disorders, and into the underlying mechanisms of such comorbid associations. This systematic review aimed: 1. to determine the prevalence of SB in adults with other sleep-related disorders; and 2. to determine the associations between SB and other sleep-related disorders, and to explain the underlying mechanisms of these associations.

METHODS

A systematic search on SB and sleep-related disorders was performed in PubMed, Embase, Cochrane Library, and Web of Science to identify eligible studies published until May 15, 2020. Quality assessment was performed using the Risk of Bias Assessment tool for Non-randomized Studies.

RESULTS

Of the 1539 unique retrieved studies, 37 articles were included in this systematic review. The prevalence of SB in adult patients with obstructive sleep apnea, restless leg syndrome, periodic limb movement during sleep, sleep-related gastroesophageal reflux disease, REM behavior disorder (RBD), and sleep-related epilepsy was higher than that in the general population. The specific mechanisms behind these positive associations could not be identified.

CONCLUSIONS

SB is more prevalent in patients with the previously mentioned disorders than in the general population. Sleep arousal may be a common factor with which all the identified disorders are associated, except RBD and Parkinson's disease. The associations between SB and these identified sleep-related disorders call for more SB screening in patients with the abovementioned sleep-related disorders.

A lack of specific motor patterns between rhythmic/non-rhythmic masticatory muscle activity and bodily movements in sleep bruxism

Purpose The aims of the present study were to investigate the temporal relationships between jaw and bodily movements and clarify motor processes in the genesis of rhythmic masticatory muscle activity (RMMA) in sleep bruxism (SB).Methods Video-polysomnography recordings were obtained from ten subjects with SB (mean age: 23.4 ± 1.6 years) and ten matched normal controls (CTL) (mean age: 24.4 ± 3.2 years). RMMA and nonspecific masseter activity (NSMA) were scored in association with bodily movements in the leg, arm, head, and trunk using electromyography and video recordings. The relationship between oromotor episodes and bodily movements was assessed in terms of sleep stage distributions and temporal relationships. Cardiac changes preceding oromotor episodes in stage N2 were assessed.Results Approximately 80% of RMMA and NSMA were associated with movements in one or more body sites. RMMA and NSMA were more frequently associated with movements of the leg (70-75%) and arm (40-55%) than movements of the head (17-22%) and trunk (5-25%). The relationship between oromotor episodes and bodily movements did not significantly differ among sleep stages. Oromotor episodes and bodily movements did not show a consistent temporal pattern in the SB and CTL groups. Regardless of the temporal relationship between oromotor episodes and bodily movements, the mean heart rate significantly increased by 5 beats before the onset of oromotor episodes.Conclusions No specific temporal motor patterns were found between RMMA and bodily movements. RMMA and NSMA represent a repertoire of arousal-related autonomic motor responses during sleep.

Sleep Bruxism: An Integrated Clinical View

The vision of adult sleep bruxism (SB) has changed over time. Thus, among the most important concomitant factors of SB noted are the pathophysiological aspect, namely sleep arousal, obstructive sleep apnea, gastroesophageal pH/gastroesophageal reflux disease, and the use or abuse of certain substances. The aim of this article was to review the main clinically relevant pathophysiological SB-associated factors and a proposal for a diagnostic process.