Is sleep bruxism in obstructive sleep apnea only an oral health related problem?

BACKGROUND: The etiology of sleep bruxism in obstructive sleep apnea (OSA) patients is not yet fully clarified. This prospective clinical study aimed to investigate the connection between probable sleep bruxism, electromyographic muscle tone, and respiratory sleep patterns recorded during polysomnography. METHODS: 106 patients with OSA (74 males, 31 females, mean age: 56.1 ± 11.4 years) were divided into two groups (sleep bruxism: SB; no sleep bruxism: NSB). Probable SB were based on the AASM criteria: self-report of clenching/grinding, orofacial symptoms upon awakening, abnormal tooth wear and hypertrophy of the masseter muscle. Both groups underwent clinical examination for painful muscle symptoms aligned with Temporomandibular Disorders Diagnostic Criteria (DC/TMD), such as myalgia, myofascial pain, and headache attributed to temporomandibular disorder. Additionally, non-complaint positive muscle palpation and orofacial-related limitations (Jaw Functional Limited Scale-20: JFLS-20) were assessed. A one-night polysomnography with electromyographic masseter muscle tone (EMG) measurement was performed. Descriptive data, inter-group comparisons and multivariate logistic regression were calculated. RESULTS: OSA patients had a 37.1% prevalence of SB. EMG muscle tone (N1-N3, REM; P = 0.001) and the number of hypopneas (P = 0.042) were significantly higher in the sleep bruxism group. While measures like apnea-hypopnea-index (AHI), respiratory-disturbance-index (RDI), apnea index (AI), hypopnea-index (HI), number of arousals, and heart rate (1/min) were elevated in sleep bruxers, the differences were not statistically significant. There was no difference in sleep efficiency (SE; P = 0.403). Non-complaint masseter muscle palpation (61.5%; P = 0.015) and myalgia (41%; P = 0.010) were significant higher in SB patients. Multivariate logistic regression showed a significant contribution of EMG muscle tone and JFLS-20 to bruxism risk. CONCLUSION: Increased EMG muscle tone and orofacial limitations can predict sleep bruxism in OSA patients. Besides, SB patients suffer more from sleep disorder breathing. Thus, sleep bruxism seems to be not only an oral health related problem in obstructive apnea. Consequently, interdisciplinary interventions are crucial for effectively treating these patients. TRIAL REGISTRATION: The study was approved by the Ethics Committee of Philipps-University Marburg (reg. no. 13/22-2022) and registered at the "German Clinical Trial Register, DRKS" (DRKS0002959).

[Analysis of Snoring in Patients with Obstructive Sleep Apnea (OSA) by Polysomnography and LEOSound]. / Die Analyse von Schnarchen bei Patienten mit obstruktiver Schlafapnoe (OSA) anhand von Polysomnographie und LEOSound.

INTRODUCTION: Snoring was monitored in patients with obstructive sleep apnea (OSA) using the LEOSound-Monitor and simultaneously polysomnographic (PSG) recording. In obstructive apneas snoring is normally apparent after apnea termination and the beginning of ventilation. We wanted to know how often obstructive apneas are terminated by ventilation in combination with snoring. METHODS AND INTENTION: In 40 patients with OSA (AHI > 15/h) simultaneous polysomnographic recordings were performed amongst long-term respiratory sound monitoring using the LEOSound monitor. Patients' average age was 57±11 years. Average weight was 100±19 kg by a mean body mass index (BMI) of 33±7 kg/m2. 12 out of 40 recordings had to be rejected for further analysis because of artifacts. Snoring recorded by polysomnography was compared with snoring monitored by LEOSound. RESULTS: 3778 obstructive apnea episodes were monitored. LEOSound identified snoring in 1921 (51,0%), polysomnography in 2229 (58,8%) obstructive apneas. Only in one patient there was a higher difference in snoring episodes between PSG and LEOSound. DISCUSSION: In nearly 60% of obstructive apnea events we found snoring during apnea-terminating hyperpnoea. LEOSound is a good diagnostic tool to monitor snoring. It is necessary to clarify why only 60% of all obstructive events/hyperpnoea develop snoring. From a pathophysiological point of view opening of collapsed upper airway should lead in a very high percentage to turbulences in airstream and committed snoring.

Repurposing CPAP machines as stripped-down ventilators.

The worldwide shortage of medical-grade ventilators is a well-known issue, that has become one of the central topics during the COVID-19 pandemic. Given that these machines are expensive and have long lead times, one approach is to vacate them for patients in critical conditions while patients with mild to moderate symptoms are treated with stripped-down ventilators. We propose a mass-producible solution that can create such ventilators with minimum effort. The central part is a module that can be attached to CPAP machines and repurpose them as low-pressure ventilators. Here, we describe the concept and first measurements which underline the potential of our solution. Our approach may serve as a starting point for open-access ventilator technologies.

[Analysis of Snoring in Patients with Obstructive Sleep Apnea (OSA) by Polysomnography and LEOSound]. / Die Analyse von Schnarchen bei Patienten mit obstruktiver Schlafapnoe (OSA) anhand von Polysomnografie und LEOSound.

INTRODUCTION: Snoring was monitored in patients with obstructive sleep apnea (OSA) using the LEOSound-Monitor and simultaneously polysomnographic (PSG) recording. In obstructive apneas snoring is normally apparent after apnea termination and the beginning of ventilation. We wanted to know how often obstructive apneas are terminated by ventilation in combination with snoring. METHODS AND INTENTION: In 40 patients with OSA (AHI > 15/h) simultaneous polysomnographic recordings were performed amongst long-term respiratory sound monitoring using the LEOSound monitor. Patients' average age was 57 ±â€Š11 years. Average weight was 100 ±â€Š19 kg by a mean body  mass  index (BMI) of 33 ±â€Š7 kg/m2. 12 out of 40 recordings had to be rejected for further analysis because of artifacts. Snoring recorded by polysomnography was compared with snoring monitored by LEOSound. RESULTS: 3778 obstructive apnea episodes were monitored. LEOSound identified snoring in 1921 (51,0 %), polysomnography in 2229 (58,8 %) obstructive apneas. Only in one patient there was a higher difference in snoring episodes between PSG and LEOSound. DISCUSSION: In nearly 60 % of obstructive apnea events we found snoring during apnea-terminating hyperpnoea. LEOSound is a good diagnostic tool to monitor snoring. It is necessary to clarify why only 60 % of all obstructive events/hyperpnoea develop snoring. From a pathophysiological point of view opening of collapsed upper airway should lead in a very high percentage to turbulences in airstream and committed snoring.

Validation of semiautomatic scoring of REM sleep without atonia in patients with RBD.

OBJECTIVE/BACKGROUND: To evaluate REM sleep without atonia (RSWA) in REM sleep behavior disorder (RBD) several automatic algorithms have been developed. We aimed to validate our algorithm (Mayer et al., 2008) in order to assess the following: (1). capability of the algorithm to differentiate between RBD, night terror (NT), somnambulism (SW), Restless legs syndrome (RLS), and obstructive sleep apnea (OSA), (2). the cut-off values for short (SMI) and long muscle activity (LMI), (3). which muscles qualify best for differential diagnosis, and (4). the comparability of RSWA and registered movements between automatic and visual analysis of videometry. PATIENTS/METHODS: RSWA was automatically scored according to Mayer et al., 2008 in polysomnographies of 20 RBD, 10 SW/NT, 10 RLS and 10 OSA patients. Receiver operating characteristic (ROC) curves were used to determine the sensitivity and specificity of SMI and LMI. Independent samples were calculated with t-tests. Boxplots were used for group comparison. The comparison between motor events by manual scoring and automatic analysis were performed with "Visual Basic for Applications" (VBA) for every hundredth second. RESULTS: Our method discriminates RBD from SW/NT, OSA and RLS with a sensitivity of 72.5% and a specificity of 86.7%. Automatic scoring identifies more movements than visual video scoring. Mentalis muscle discriminates the sleep disorders best, followed by FDS, which was only recorded in SW/NT. Cut-off values for RSWA are comparable to those found by other groups. CONCLUSION: The semi-automatic RSWA scoring method is capable to confirm RBD and to discriminate it with moderate sensitivity from other sleep disorders.

[Apnea Detection by Means of Respiratory Sound Recordings and Polysomnography - A Comparative Study]. / Ein Vergleich der Apnoeerkennung bei Patienten mit obstruktiver Schlafapnoe (OSA) anhand von Atemgeräuschaufzeichnungen und Polysomnografie.

Introduction In this study, recognition of apnoeas by means of polysomnography (PSG) and nocturnal respiratory sound recordings in patients with obstructive sleep apnoea (OSA) was analyzed and compared. Methods In 45 patients with OSA requiring treatment (AHI > 15/h), concomitant polysomnographic recordings and long term respiratory sound recordings by means of LEOSound were performed. Patients' average age was 58 ±â€Š12 years (mean ± standard deviation), average BMI was 33 ±â€Š7 kg/m2. Audio-visual apnoea detection by LEOSound was compared to polysomnographic apnoea detection. Increased artifact rate due to dislocation of microphones led to rejection of 11 out of 45 recordings for detailed analysis. Results Comparison of apnea detection by audio-visual analysis and polysomnography yielded a median of 164 apneas for LEOSound recordings and 158 apneas for PSG. Median apnoea index (AI) was calculated to be 20/h for respiratory sounds recording and 21/h for PSG. The correlation of apnea indices from acoustic long term registration and PSG was 0.939 (p < 0.001). Discussion Acoustic long term registration of primary and secondary respiratory sounds is also capable to recognize apnoeas. Exact differentiation between apnoeas and hypopnoeas is only possible in a limited fashion.

[Obstructive sleep apnea in neurological diseases: specially as a risk factor for stroke]. / Obstruktive Schlafapnoe bei neurologischen Erkrankungen: Speziell als Risikofaktor für Schlaganfall.

Neurological diseases are frequently associated with sleep-related breathing disorders. In contrast patients with obstructive sleep apnea (OSA) suffer more often from cerebrovascular and cardiovascular diseases. Epidemiological studies have shown that OSA is common among patients with stroke, arterial hypertension or cardiovascular disease. In particular apnea-associated arterial hypertension, atrial fibrillation, activation of the sympathetic nervous system, recurrent hypoxemia and vascular inflammatory response should be considered as risk factors for the vascular system. Early diagnosis and treatment of sleep-related breathing disorders in neurological diseases are required to reduce the risk of subsequent cerebrovascular and cardiovascular diseases.

ECG signal analysis for the assessment of sleep-disordered breathing and sleep pattern.

The diagnosis of sleep-disordered breathing (SDB) usually relies on the analysis of complex polysomnographic measurements performed in specialized sleep centers. Automatic signal analysis is a promising approach to reduce the diagnostic effort. This paper addresses SDB and sleep assessment solely based on the analysis of a single-channel ECG recorded overnight by a set of signal analysis modules. The methodology of QRS detection, SDB analysis, calculation of ECG-derived respiration curves, and estimation of a sleep pattern is described in detail. SDB analysis detects specific cyclical variations of the heart rate by correlation analysis of a signal pattern and the heart rate curve. It was tested with 35 SDB-annotated ECGs from the Apnea-ECG Database, and achieved a diagnostic accuracy of 80.5%. To estimate sleep pattern, spectral parameters of the heart rate are used as stage classifiers. The reliability of the algorithm was tested with 18 ECGs extracted from visually scored polysomnographies of the SIESTA database; 57.7% of all 30 s epochs were correctly assigned by the algorithm. Although promising, these results underline the need for further testing in larger patient groups with different underlying diseases.

[Measuring sleep duration and sleep quality]. / Messung von Schlafdauer und Schlafqualität.

Restorative functions of sleep are of special interest for sleep medicine. For the assessment of these restorative functions, various parameters are taken into account, among which sleep duration and sleep quality play the most important roles. Both terms are essential for sleep perception, expressing the subjective satisfaction of the individual with the time spent asleep. In recent decades, sleep medicine and sleep research have developed methods for the assessment of both objective and subjective dimensions of sleep. Among subjective methods, taking of the medical history focusing on the patient's sleep is important. Standardized and validated questionnaires play a supportive role. Objective methods are, for example, estimation of the sleep-wake cycle by means of actigraphy and polygraphy. Especially in multimorbid patients, polysomnography is still the gold standard method for diagnostics. An important approach during recent years is shifting from bothering overnight examinations into less disturbing procedures for patients that include performing ambulatory, outpatient examinations in the patients' home rather than inpatient surveillance within sleep centers.

Pattern of skeletal muscle involvement in primary dysferlinopathies: a whole-body 3.0-T magnetic resonance imaging study.

OBJECTIVES AND METHODS: Mutations in the gene encoding dysferlin cause limb girdle muscular dystrophy type 2B (LGMD2B), distal Miyoshi myopathy (MM), and a rare form of distal anterior compartment myopathy. To study the correlations between clinical manifestations and muscle imaging changes we conducted a 3.0-T magnetic resonance imaging (MRI) study in six German patients with primary dysferlinopathies defined by absence of dysferlin expression in muscle (MM, n = 3; LGMD2B, n = 2; hyperCKemia without clinical symptoms, n = 1). RESULTS: Patients with manifest myopathy had widespread muscular pathology. In analogy to previous imaging studies, we confirmed an involvement of the anterior and posterior thigh compartments and a predominant involvement of posterior lower legs. However, our whole-body MRI study further provided evidence of signal alterations in the glutei, erector spinae and shoulder girdle muscles. Correlation of clinical findings with imaging demonstrated the potential of MRI to detect subclinical muscle pathology. CONCLUSIONS: Whole-body 3.0-T MRI is a non-invasive method to demonstrate various degrees of skeletal muscle alterations and disease progression in muscular dystrophies. Furthermore, whole-body high-field MRI may serve as a helpful diagnostic tool in differentiating primary dysferlinopathies from other forms of LGMD and distal myopathies.

Analysis of sleep fragmentation and sleep structure in patients with sleep apnea and normal volunteers.

Sleep disorders have a high prevalence. Sleep disorders are recognized first by the complaint of nonrestorative sleep. A quantification of the disorder is done by the investigation in a sleep laboratory. The investigation in the sleep laboratory examines the EEG, EOG and EMG to derive sleep stages. This is a labor intensive sleep scoring after the polysomnography investigation. Usually the time course of the sleep stages is quantified in terms of percentages of stages related to total sleep time and the latencies for the individual stages. The additional feature of transitions between sleep stages and the disruption of sleep, which corresponds to periods of wakefulness during sleep are not evaluated systematically. We have evaluated these transitions using a statistical approach. We have detected systematic differences in the distributions o sleep stages and wake states during sleep. This differences were investigates in normal subjects and patients with sleep apnea. Then these differences were investigated in different species. The difference in the distributions can be explained only by fundamentally different regulation of sleep and wakefulness.

Ambulatory recording of sleep apnea using peripheral arterial tonometry.

Sleep related breathing disorders are common. A reliable diagnosis with relatively simple and portable methods is still needed. One approach is to make use of autonomous nervous system changes which accompany disordered breathing during sleep. The peripheral arterial tonometry (PAT) determines the peripheral arterial vascular tone using a plethysmographic method on the finger. The peripheral arterial tone is modulated by sympathetic activity, by peripheral blood pressure, and by the peripheral resistance of the vessels. We investigate a new ambulatory recording device which uses PAT, oximetry and actigraphy in order to detect sleep apnea. For this purpose we performed a comparative study on 21 patients referred to our sleep laboratory due to suspected sleep apnea. Of these 17 valid recordings were compared. The Watch-PAT was used in parallel with cardiorespiratory polysomnography and the validity was determined. The new system is able to detect apneas and hypopneas with a high reliability (r=0.89). It is very sensitive to arousals (r=0.77). Since arousal are not specific to sleep apnea the specificity of the new system could not be finally clarified in this study. We conclude that the new system is very well suited to perform control studies in patients with sleep apnea which are under therapy and require regular follow-up investigations to maintain a high CPAP compliance.

[Comorbidity in narcoleptic patients]. / Untersuchung zur Komorbidität bei Narkolepsiepatienten.

BACKGROUND AND OBJECTIVE: Narcolepsy is a rare disease which remains undiagnosed in 90 %. The international literature so far has paid little attention to comorbid disorders. PATIENTS AND METHODS: In preparation for a German Narcolepsy Register this pilot study evaluated data from hospital records of 106 narcolepsy patients (60 men, 46 women, 8-83 years, mean 45.1 years) retrospectively emphasising comorbid diseases. RESULTS: The parasomnias sleepwalking and nightmares were 6 times as frequent as in the general population. With respect to the HLA findings the extremely high frequency of REM behavior disorder contributes to the assumption of a common pathomechanism. Obstructive sleep apnea and periodic limb movement disorder (PLMD) occurred much less than described in literature, while the results on obesity, headache and depression are in line with published findings. CONCLUSION: Diagnosis of one of these comorbid disorders should always be followed by thorough investigation for symptoms of narcolepsy i. e. excessive daytime sleepiness, sleep attacks and cataplexy.

Sleep atlas and multimedia database.

The ENN sleep atlas and database was set up on a dedicated server connected to the internet thus providing all services such as WWW, ftp and telnet access. The database serves as a platform to promote the goals of the European Neurological Network, to exchange patient cases for second opinion between experts and to create a case-oriented multimedia sleep atlas with descriptive text, images and video-clips of all known sleep disorders. The sleep atlas consists of a small public and a large private part for members of the consortium. 20 patient cases were collected and presented with educational information similar to published case reports. Case reports are complemented with images, video-clips and biosignal recordings. A Java based viewer for biosignals provided in EDF format was installed in order to move free within the sleep recordings without the need to download the full recording on the client.

Assignment of the human serotonin 4 receptor gene (HTR4) to the long arm of chromosome 5 (5q31-q33).

In the present study, we report the chromosomal localization of the human 5-HT4 receptor gene (HTR4) by the analysis of somatic cell hybrids. Based upon genomic sequences of the HTR4 gene, a primer set was selected that reacted with human genomic DNA but not mouse or hamster genomic DNA. Using monochromosomal hybrid cell lines of the NIGMS Mapping Panel 2 we localized the HTR4 gene to human chromosome 5. To confirm the localization on chromosome 5 and to further sublocalize the HTR4 gene, the radiation hybrid panel RH3 was similarly analysed. Significant linkage was obtained to genetic marker D5S2654. This localizes the HTR4 gene to human chromosome 5q31-q33.