Relationships between respiratory and oromotor events differ between motor phenotypes in patients with obstructive sleep apnea.

Purpose: The present study investigated the relationship between sleep bruxism (SB) and obstructive sleep apnea (OSA) in relation to the sleep architecture. Methods: We conducted a cross-sectional study. Polysomnographic recordings were performed on 36 patients. Sleep, respiratory, and oromotor variables, such as rhythmic masticatory muscle activity (RMMA) and non-specific masticatory muscle activity (NSMA), were compared between OSA patients with or without SB. A correlation analysis of the frequency of respiratory and oromotor events in NREM and REM sleep was performed. The frequency of oromotor events following respiratory events was also assessed. Results: The proportion of REM sleep was higher in OSA patients with SB than in those without SB (p = 0.02). The apnea-hypopnea index (AHI) did not significantly differ between the two groups; however, AHI was approximately 8-fold lower during REM sleep in OSA patients with SB (p = 0.01) and the arousal threshold was also lower (p = 0.04). Although the RMMA index was higher in OSA patients with than in those without SB (p < 0.01), the NSMA index did not significantly differ. The percentage of RMMA following respiratory events was significantly higher in OSA patients with than in those without SB, whereas that of NSMA did not significantly differ. The frequency of oromotor events throughout the whole night positively correlated with AHI. However, regardless of the sleep state, AHI did not correlate with the RMMA index, but positively correlated with the NSMA index. Conclusion: In consideration of the limitations of the present study, the results obtained indicate that OSA patients with SB have a unique phenotype of OSA and also emphasize the distinct relationship of respiratory events with RMMA and NSMA.

Potential patient screening for late-onset Pompe disease in suspected sleep apnea: a rationale and study design for a Prospective Multicenter Observational Cohort Study in Japan (PSSAP-J Study).

BACKGROUND: Pompe disease is an autosomal recessive disorder caused by deficiency of the acid α-glucosidase (GAA) enzyme. GAA deficiency induces progressive glycogen accumulation which leads to weakness of the respiratory muscle including the diaphragm. Pompe disease is one of the few myopathies, for which an established therapy is available. Thus, earlier detection of potential late-onset Pompe disease (LOPD) and earlier intervention would have a significant clinical impact. PURPOSE: Our hypothesis is that sleep problems including sleep disordered breathing (SDB) and clinical symptoms may indicate an early stage of LOPD since decreased respiratory muscle activity generally first presents during sleep. Thus, the aims of this prospective, multicenter observational cohort study in Japan (PSSAP-J) are to demonstrate a higher prevalence of LOPD in a sleep lab-based population (primary outcome), and to identify predictive factors for LOPD from findings in diagnostic polysomnography (PSG) and clinical symptoms (secondary outcomes). METHODS: The study design is a prospective multicenter observational cohort study. Consecutive patients who present to sleep labs due to suspected SDB for an overnight PSG will be enrolled. All patients will be measured for creatine kinase, GAA activity, and if necessary, genetic analysis of GAA. Furthermore, chest X-ray, pulmonary function test, and arterial blood gas analysis will be collected. Then, prevalence and specific findings of LOPD will be assessed. RESULT: Congenital myopathy shows a shift from slow-deep to rapid-shallow breathing during transition from wakefulness to sleep accompanying a symptom of waking with gasping (actual further results are pending). DISCUSSION: The distribution in respiratory physiology between during wakefulness and sleep specific to LOPD may provide insights into early-stage detection. CLINICAL TRIAL REGISTRATION NUMBER: UMIN000039191, UMIN Clinical Trials Registry ( http://www.umin.ac.jp/ctr ).

Intraperitoneal injection of ginkgolide B, a major active compound of Ginkgo biloba, dose-dependently increases the amount of wake and decreases non-rapid eye movement sleep in C57BL/6 mice.

The terpene lactones of Ginkgo biloba extract, namely ginkgolides (A, B, and C) and bilobalide, possess antioxidant, anti-inflammatory, and neuroprotective effects. They are widely prescribed for the treatment of cerebral dysfunctions and neurological impairments. In addition, they demonstrate antagonistic action at the gamma-aminobutyric acid type A and glycine receptors, which are members of the ligand-gated ion channel superfamily. In the present study, the effects of ginkgolides (A, B, and C) and bilobalide on sleep in C57BL/6 mice were investigated. Ginkgolide B was found to dose-dependently increase the amount of wake and decrease that of non-rapid eye movement sleep without changes in the electroencephalography power density of each sleep/wake stage, core body temperature and locomotor activity for the first 6 h after intraperitoneal injection. Of note, the amount of wake after injection of 5 mg/kg of ginkgolide B showed a significant increase (14.9 %) compared with that of vehicle (P = 0.005). In contrast, there were no significant differences in the amount of sleep, core body temperature, and locomotor activity in the mice injected with ginkgolide A and C. Bilobalide briefly induced a decrease in locomotor activity but did not exert significant effects on the amounts of sleep and wake. The modes of action of the wake-enhancing effects of ginkgolide B are unknown. However, it may act through the antagonism of gamma-aminobutyric acid type A and glycine receptors because it is established that these inhibitory amino acids mediate sleep and sleep-related physiology. It is of interest to further evaluate the stimulant and awaking actions of ginkgolide B on the central nervous system in clinical and basic research studies.

Subjective oropharyngeal symptoms for abnormal swallowing in Japanese patients with obstructive sleep apnea syndrome: a descriptive questionnaire study.

OBJECTIVES: This study aimed to investigate the prevalence of clinical symptoms related to abnormal swallowing in a large sample of obstructive sleep apnea syndrome (OSAS) patients. METHODS: Oropharyngeal symptoms for abnormal swallowing were assessed by a self-administered questionnaire in 507 consecutive patients (females: 65, males: 442; mean age: 49.6 ± 12.6 years old) with clinical symptoms of OSAS, enrolled for cardiorespiratory evaluation. RESULTS: Overall, 16.2% of patients (82/507) had at least one symptom for abnormal swallowing and 6.3% (32/507) had two or more symptoms. The most frequent symptom was difficulty with coughing up phlegm during or after a meal (8.3%). Demographic, sleep, and clinical variables did not differ between the patients with and without abnormal symptoms. CONCLUSIONS: The results of the current study showed that 16% of middle-aged OSAS patients reported pharyngeal symptoms related to abnormal swallowing, regardless of the severity of OSAS.

Responsiveness of jaw motor activation to arousals during sleep in patients with obstructive sleep apnea syndrome.

OBJECTIVES: We aimed to characterize the association between jaw muscle contractions and respiratory events in patients with obstructive sleep apnea syndrome (OSAS) and to investigate the responsiveness of the contractions to respiratory events in comparison with that of leg muscles in terms of arousal types and sleep states. METHODS: Polysomnographic (PSG) recordings were performed in 19 OSAS patients (F/M: 2/17; 53.1 ± 13.7 years; AHI: 31.8 ± 19.9/h) with no concomitant sleep bruxism or other sleep-related movement disorders. Muscle contractions of unilateral masseter (MAS) and anterior tibialis (AT) muscles were scored during sleep in association with graded arousals (microarousals and awakenings) related or unrelated to apneahypopnea events. RESULTS: Arousals were scored for 68.2% and 52.3% of respiratory events during light NREM and REM sleep, respectively. Respiratory events with arousals were associated with longer event duration and/or larger transient oxygen desaturation than those without (ANOVAs: p < 0.05). Median response rates of MAS events to respiratory events were 32.1% and 18.9% during NREM and REM sleep. During two sleep states, MAS muscle was rarely activated after respiratory events without arousals, while its response rate increased significantly in association with the duration of arousals (Friedman tests: p < 0.001). A similar response pattern was found for AT muscle. Motor responsiveness of the two muscles to arousals after respiratory events did not differ from responsiveness to spontaneous arousals in two sleep stages. CONCLUSION: In patients with OSAS, the contractions of MAS and AT muscles after respiratory events can be nonspecific motor phenomena, dependent on the duration of arousals rather than the occurrence of respiratory events.

Negative association between self-reported jaw symptoms and apnea-hypopnea index in patients with symptoms of obstructive sleep apnea syndrome: a pilot study.

OBJECTIVES: Prior to oral appliance therapy for snoring and obstructive sleep apnea syndrome (OSAS), patients are screened for jaw symptoms (e.g., pain). However, the presence of jaw symptoms in a large spectrum of OSAS patients remains unknown. This study aimed to assess the distribution of subjective jaw symptoms in patients with symptoms of OSAS. METHODS: Five hundred and eleven consecutive patients (66 female, 445 male; mean age 49.6 ± 12.6 years) with clinical symptoms of OSAS were enrolled for cardiorespiratory evaluation. Self-administered questionnaires were used to assess jaw symptoms, tooth grinding and clenching during sleep, morning oral dryness, morning heartburn sensation, and pain in the neck and back. RESULTS: The mean apnea-hypopnea (AHI) index was 32.5 ± 30.6 per hour of sleep. Nineteen percent of patients (n = 96) reported at least one jaw symptom. The presence of jaw symptoms was more frequently reported by patients with AHI less than 15 (25 %) than those with AHI of 15 and more (15 %, p = 0.012). In the crude analyses, jaw symptoms were associated with tooth grinding, tooth clenching, morning oral dryness, morning heartburn sensation, and neck/back pain. Multiple logistic regression analysis confirmed that jaw symptoms were associated with AHI less than 15 (odds ratio (OR) 1.99, p = 0.009), tooth clenching (OR 1.79, p = 0.006), morning oral dryness (OR 2.17, p = 0.02), and neck/back pain (OR 1.99, p = 0.005). CONCLUSIONS: Jaw symptoms can be found in 19 % of patients with symptoms of OSAS and are more frequently reported in patients with lower AHI, a patient population for whom oral appliances are often prescribed.

[Case of exploding head syndrome].

Exploding head syndrome (EHS) attacks are characterized by the sensation of sudden loud banging noises, and are occasionally accompanied by the sensation of a flash light. Although these attacks in themselves are usually not painful, it is reported that EHS attacks may precede migraines and may be perceived as auras. A 53-year-old woman, with a 40-year history of fulgurating migraines, experienced 2 different types of EHS attacks. During most of the attacks, which were not painful, she heard sounds like someone yelling or cars passing by. Only 1 episode was accompanied with the sensation of a flash light and of sounds similar to those of an electrical short circuit. On the video-polysomnography, video-polysomnography showed 11 EHS attacks occurred during stage N1 and stage N2; these attacks were preceded by soft snoring. She also had moderate obstructive sleep apnea syndrome (Apnea Hypopnea Index: 16.7) for which an oral appliance was prescribed; the EHS attacks did not recur after this treatment. The pathophysiology of EHS is still unclear. A detailed analysis of PSG data may help in understanding the pathophysiology of this syndrome and also in the selection of therapeutic strategies.