Role of Cannabinoid CB1 Receptor in Object Recognition Memory Impairment in Chronically Rapid Eye Movement Sleep-deprived Rats / 中国医学科学杂志(英文版)

Objective We aimed to investigate whether antagonism of the cannabinoid CB1 receptor (CB1R) could affect novel object recognition (NOR) memory in chronically rapid eye movement sleep-deprived (RSD) rats.Methods The animals were examined for recognition memory following a 7-day chronic partial RSD paradigm using the multiple platform technique. The CB1R antagonist rimonabant (1 or 3 mg/kg, i.p.) was administered either at one hour prior to the sample phase for acquisition, or immediately after the sample phase for consolidation, or at one hour before the test phase for retrieval of NOR memory. For the reconsolidation task, rimonabant was administered immediately after the second sample phase.Results The RSD episode impaired acquisition, consolidation, and retrieval, but it did not affect the reconsolidation of NOR memory. Rimonabant administration did not affect acquisition, consolidation, and reconsolidation; however, it attenuated impairment of the retrieval of NOR memory induced by chronic RSD.Conclusions These findings, along with our previous report, would seem to suggest that RSD may affect different phases of recognition memory based on its duration. Importantly, it seems that the CB1R may, at least in part, be involved in the adverse effects of chronic RSD on the retrieval, but not in the acquisition, consolidation, and reconsolidation, of NOR memory.

Enfermedad de Willis-Ekbom a propósito de un caso / Willis-Ekbom's disease a case report

Los trastornos del sueño REM, son de alta prevalencia en nuestro medio, se manifiestan por lo general en comorbilidad con trastornos afectivos como la ansiedad y la depresión. Dependiendo de la sintomatología del paciente la afectación puede afectar su calidad de vida, en nuestro medio son frecuentes las crisis de pánico y trastornos del sueño reconocidos culturalmente como provenientes de embrujos o maleficios, que al no ser tratados con buenos resultados, buscan una respuesta en el ámbito médico postergando la intervención en el caso evaluado. El presente caso describe los síntomas experimentados por un adulto de sexo masculino, con un cuadro que impresiona por su descripción sintomatológica de origen netamente urológico, que fue valorado en integridad con sus respectivos resultados laboratoriales y de gabinete es referido a diferentes especialidades y finalmente a psiquiatría donde se llega a la conclusión diagnostica de enfermedad de Willis-Ekbom, trastorno del sueño REM y Trastorno de ansiedad generalizada con crisis de pánico, se realiza tratamiento específico, con resultados favorables y seguimientos periódicos. Se presenta el caso clínico de un paciente de sexo masculino de 61 años como se describe en la presentación.

REM sleep disorders, are of high prevalence in our environment, are usually manifested in comorbidity with affective disorders such as anxiety and depression. Depending on the symptomatology of the patient, the affectation can affect their quality of life, in our environment there are frequent panic crises and sleep disorders culturally recognized as coming from spells or curses, which, when not being treated with good results, seek an answer in the medical field postponing the intervention in the case evaluated. The present case describes the symptoms experienced by a male adult, with a picture that impresses with his symptomatic description of a purely urological origin, which was assessed in integrity with their respective laboratory and laboratory results. It refers to different specialties and finally to psychiatry. where the diagnostic conclusión of Willis-Ekbom disease, REM sleep disorder and generalized anxiety disorder with panic crisis is reached, specific treatment is performed, with favorable results and periodic follow-up.

Unveiling sleep mysteries: neurobiology of dreaming / Revelando mistérios do sono: neurobiologia dos sonhos

Dreaming is the result of the mental activity of rapid eye movement (REM) sleep stage, and less commonly of non-REM sleep. Dreams offer unique insights into the patients' brains, minds, and emotions. Based on neurophysiological and neuroimaging studies, the biological core of dreaming stands on some brain areas activated or inactivated. Dream abnormalities in neurological disorders include a reduction / cessation of dreaming, an increase in dream frequency, changes in dream contents and accompaniments, and the occurrence of dreamlike experiences (hallucinations) mainly during the wake-sleep/sleep-wake transitions. Dream changes can be associated with several neurological conditions, and the unfolding of biological knowledge about dream experiences can also have significance in clinical practice. Regarding the dream importance in clinical neurological management, the aim of this paper encompasses a summary of sleep stages, dreams neurobiology including brain areas involved in the dreams, memory, and dreams, besides Dreams in the aging people and neurodegenerative disorders.

Sonhar é o resultado da atividade mental do estágio do sono de movimento rápido dos olhos (REM) e, menos comumente, do sono não-REM. Os sonhos oferecem informações únicas sobre o cérebro, a mente e as emoções dos pacientes. Com base em estudos neurofisiológicos e de neuroimagem, o núcleo biológico do sonho está em algumas áreas do cérebro ativadas ou inativadas. As anormalidades do sonho nos distúrbios neurológicos incluem uma redução / cessação do sonho, um aumento na frequência do sonho, alterações nos conteúdos e acompanhamentos do sonho e a ocorrência de experiências semelhantes ao sonho (alucinações), principalmente durante as transições de vigília-sono / sono-vigília. As mudanças do sonho podem estar associadas a várias condições neurológicas, e o desenvolvimento do conhecimento biológico sobre as experiências do sonho também pode ter significado na prática clínica. Com relação à importância do sonho no manejo neurológico clínico, o objetivo deste artigo é resumir os estágios do sono, a neurobiologia dos sonhos, incluindo as áreas do cérebro envolvidas nos sonhos, a memória e os sonhos, além dos sonhos nos idosos e nos distúrbios neurodegenerativos.

Unveiling sleep mysteries: functions / Revelando mistérios do sono: funções

Sleep occupies roughly one-third of human lives, yet it is still not entirely scientifically clear about its purpose or function. However, the latest research achievement concluded that sleeping has much more effect on the brain than formerly believed. Much of these studies are about the effects of sleep deprivation, and the glymphatic pathway initially identified in the rodent brain. In this paper, it is presented some of the theories about sleep functions, besides a review of some physiologic function of sleep. Now, it is accepted that sleep is involved with cleaning the brain toxins, physical restoration, information processing and recall, regulation, besides strengthening the immune system. Sleep implies in a neuronal activity markedly different along with its phases. It is regulated by two parallel mechanisms, homeostatic and circadian. Besides, the sleep-waking cycle involves diverse brain circuits and neurotransmitters and their interaction is explained using a flip-flop model. Several theories may help clarify the reasons human beings spend an important part of their lives sleeping such as those of Inactivity, Energy Conservation, Restorative, and Brain Plasticity. Recently, it was emphasized the importance of the glymphatic system that is a waste clearence system that acts mainly during sleep support efficient removal of soluble proteins and metabolites from the central nervous system. Indeed, sleep meet the needs of higher brain functions along with basic vital processes.

O sono ocupa cerca de um terço da vida humana, mas ainda não é totalmente claro cientificamente o seu propósito ou função. No entanto, a mais recente pesquisa concluiu que dormir tem muito mais efeito no cérebro do que se pensava anteriormente. Muitos desses estudos são sobre os efeitos da privação do sono e o sistema glinfático inicialmente identificada no cérebro de roedores. Neste artigo, são apresentadas algumas das teorias sobre as funções do sono, além de uma revisão de algumas funções fisiológicas do sono. Agora, aceita-se que o sono esteja envolvido com a limpeza de toxinas cerebrais, restauração física, processamento e memorização de informações, regulação do humor, além de fortalecer o sistema imunológico. O sono implica em uma atividade neuronal marcadamente diferente ao longo de suas fases. É regulado por dois mecanismos paralelos, homeostático e circadiano. Além disso, o ciclo de vigília envolve diversos circuitos cerebrais e neurotransmissores e sua interação é explicada por meio de um modelo de flip-flop. Várias teorias podem ajudar a esclarecer as razões pelas quais o ser humano passa uma parte importante de suas vidas dormindo, como as de inatividade, conservação de energia, restauração e plasticidade cerebral. Recentemente, enfatizou-se a importância do sistema glinfático agir principalmente durante o sono, que é um sistema de eliminação de resíduos para apoiar a remoção eficiente de proteínas e metabólitos solúveis do sistema nervoso central. De fato, o sono atende às necessidades de funções cerebrais superiores, juntamente com processos vitais básicos.

Recent Updates on Narcolepsy and Hypersomnia / 신경정신의학

Narcolepsy is a chronic neurological sleep disorder caused by hypocretin neuron loss, resulting in excessive daytime sleepiness, disturbed nocturnal sleep, and intrusions of aspects of rapid eye movement sleep in wakefulness, such as cataplexy, sleep paralysis, and hypnopompic/hypnagogic hallucinations. Narcolepsy disrupts the maintenance and orderly occurrence of the wake and sleep stages. Cataplexy is a highly specific symptom of narcolepsy, but many other symptoms can be observed in a variety of sleep disorders. The diagnosis of narcolepsy type 1 requires a history of excessive daytime sleepiness and one of the following : 1) a low cerebrospinal fluid hypocretin-1 level or 2) cataplexy and a positive multiple sleep latency test result. The diagnosis of narcolepsy type 2 requires a history of excessive daytime sleepiness and a positive mean sleep-latency test result. The mean sleep-latency test must be preceded by nighttime polysomnography to exclude other sleep disorders and to document adequate sleep. The mean sleep-latency test result can be falsely positive in other sleep disorders, such as shift work, sleep apnea, or sleep deprivation, and it is influenced by age, sex, and puberty. Modafinil and armodafinil can reduce the excessive daytime sleepiness without many of the side effects associated with older stimulants. Although there is no cure for narcolepsy, the treatments are often effective and include both behavioral and pharmacologic approaches.

Effective Continuous Positive Airway Pressure Changes Related to Sleep Stage and Body Position in Obstructive Sleep Apnea during Upward and Downward Titration: An Experimental Study

Alzheimer's disease and sleep disturbances: a review / Doença de Alzheimer e distúrbios do sono: uma revisão

ABSTRACT The association between Alzheimer's disease (AD) and sleep disturbances has received increasing scientific attention in the last decades. However, little is known about the impact of sleep and its disturbances on the development of preclinical AD stages, such as mild cognitive impairment. This review describes the evolution of knowledge about the potential bidirectional relationships between AD and sleep disturbances exploring recent large prospective studies and meta-analyses and studies of the possible mechanisms through which sleep and the neurodegenerative process could be associated. The review also makes a comprehensive exploration of the sleep characteristics of older people, ranging from cognitively normal individuals, through patients with mild cognitive impairment, up to the those with dementia with AD.

RESUMO A associação entre Doença de Alzheimer (DA) e distúrbios do sono vem recebendo atenção crescente nas últimas décadas. No entanto, pouco se sabe sobre o impacto do sono e suas alterações no desenvolvimento de estágios pré-clínicos da doença, como é o caso do Comprometimento Cognitivo Leve (CCL). Esta revisão descreve a evolução do conhecimento sobre as relações potencialmente bidirecionais entre DA e distúrbios do sono, explorando grandes estudos prospectivos e meta-análises, assim como estudos dos possíveis mecanismos da associação entre o sono e as doenças neurodegenerativas. Também revisamos amplamente as características do sono de pessoas idosas, incluindo indivíduos cognitivamente normais, com CCL e com demência por DA.

Effects of Light on Daytime Sleep in 12 Hours Night Shift Workers: A Field Study

OBJECTIVES: Night shift workers suffer from sleep and daytime disturbances due to circadian misalignment. To investigate the role of environmental light in daytime sleep following 12 h-night shift work. METHODS: We enrolled 12 h-shift female nurses working at one university-affiliated hospital (n=10, mean age 26.6 years, shift work duration 3.8 years). This is a cross-over study to compare sleep between under light exposure (30 lux) and in the dark (<5 lux) following 12 h-night duty. Two sessions of experiments were underwent and the interval between sessions was about a month. Psychomotor vigilance test (PVT) had performed on awakening from sleep at each session and sleep-wake pattern had been monitored by actigraphy throughout the study period. Daytime sleep was also compared with night sleep of age-and gender matched daytime workers (n=10). RESULTS: Sleep parameters and PVT scores were not different between two light conditions. Activities during sleep seemed to be more abundant under 30 lux condition than in the dark, which was not significant. Compared to night sleep, daytime sleep of shift workers was different in terms of rapid eye movement (REM) sleep. Three shift workers showed sleep onset REM sleep and first REM sleep period was the longest during daytime sleep. CONCLUSIONS: Unexpectedly, daytime sleep of 12 h night shift workers was well-maintained regardless of light exposure. Early occurrence of REM sleep and shorter sleep latency during daytime sleep suggest that shift workers meet with misalignment of circadian rhythm as well as increased homeostatic sleep pressure drive.

A Case of Rapid Eye Movement Sleep-Related Bradyarrhythmia Syndrome with Severe Obstructive Sleep Apnea Syndrome

A close relationship has emerged between obstructive sleep apnea (OSA) and cardiac arrhythmia. However, transient sinus arrest or atrioventricular (AV) conduction disturbance during rapid eye movement (REM) sleep was rarely reported. This sleep stage specific arrhythmia has been referred to as REM sleep-related bradyarrhythmia syndrome. The differential diagnosis between OSA-related arrhythmia and REM sleep-related bradyarrhythmia syndrome is important in determining the treatment strategy for the underlying disease and its complication, especially in patient with a history of OSA. Here, we report a case with both REM sleep-related AV block and severe OSA, whose REM sleep-related AV block was not improved with continuous positive airway pressure treatment.

Nonmotor and Dopamine Transporter Change in REM Sleep Behavior Disorder by Olfactory Impairment

OBJECTIVE: It is unclear whether the decline in dopamine transporters (DAT) differs among idiopathic rapid eye movement sleep behavior disorder (iRBD) patients with different levels of olfactory impairment. This study aimed to characterize DAT changes in relation to nonmotor features in iRBD patients by olfactory loss. METHODS: This prospective cohort study consisted of three age-matched groups: 30 polysomnography-confirmed iRBD patients, 30 drug-naïve Parkinson's disease patients, and 19 healthy controls without olfactory impairment. The iRBD group was divided into two groups based on olfactory testing results. Participants were evaluated for reported prodromal markers and then underwent 18F-FP-CIT positron emission tomography and 3T MRI. Tracer uptakes were analyzed in the caudate, anterior and posterior putamen, substantia nigra, and raphe nuclei. RESULTS: Olfactory impairment was defined in 38.5% of iRBD patients. Mild parkinsonian signs and cognitive functions were not different between the two iRBD subgroups; however, additional prodromal features, constipation, and urinary and sexual dysfunctions were found in iRBD patients with olfactory impairment but not in those without. Tracer uptake showed significant group differences in all brain regions, except the raphe nuclei. The iRBD patients with olfactory impairment had uptake reductions in the anterior and posterior putamen, caudate, and substantia nigra (p < 0.016 in all, adjusted for age), which ranged from 0.6 to 0.8 of age-normative values. In contrast, those without olfactory impairment had insignificant changes in all regions ranging above 0.8. CONCLUSION: There was a clear distinction in DAT loss and nonmotor profiles by olfactory status in iRBD.

Sleep stage estimation method using a camera for home use

Recent studies have developed simple techniques for monitoring and assessing sleep. However, several issues remain to be solved for example high-cost sensor and algorithm as a home-use device. In this study, we aimed to develop an inexpensive and simple sleep monitoring system using a camera and video processing. Polysomnography (PSG) recordings were performed in six subjects for four consecutive nights. Subjects' body movements were simultaneously recorded by the web camera. Body movement was extracted by video processing from the video data and fi ve parameters were calculated for machine learning. Four sleep stages (WAKE, LIGHT, DEEP and REM) were estimated by applying these fi ve parameters to a support vector machine. The overall estimation accuracy was 70.3 ± 11.3% with the highest accuracy for DEEP (82.8 ± 4.7%) and the lowest for LIGHT (53.0 ± 4.0%) compared with correct sleep stages manually scored on PSG data by a sleep technician. Estimation accuracy for REM sleep was 68.0 ± 6.8%. The kappa was 0.19 ± 0.04 for all subjects. The present non-contact sleep monitoring system showed suffi cient accuracy in sleep stage estimation with REM sleep detection being accomplished. Low-cost computing power of this system can be advantageous for mobile application and modularization into home-device.

Does Rapid Eye Movement Sleep Aggravate Obstructive Sleep Apnea?

OBJECTIVES.: To investigate the apnea-hypopnea index (AHI) according to the sleep stage in more detail after control of posture. METHODS.: Patients who underwent nocturnal polysomnography between December 2007 and July 2018 were retrospectively evaluated. Inclusion criteria were as follows: age >18 years, sleep efficacy >80%, and patients who underwent polysomnography only in the supine position (100% of the time). Patients were classified into different groups according to the methods: the first, rapid eye movement (REM)-dominant group (AHIREM/AHINREM >2), non-rapid eye movement (NREM)-dominant group (AHINREM/AHIREM >2), and non-dominant group; and the second, light sleep group (AHIN1N2>AHISWS) and slow wave sleep (SWS) group (AHISWS>AHIN1N2). RESULTS.: A total of 234 patients (mean age, 47.4±13.9 years) were included in the study. There were 108 patients (46.2%) in the REM-dominant group, 88 (37.6%) in the non-dominant group, and 38 (16.2%) in the NREM-dominant group. The AHI was significantly higher in the NREM-dominant group than in the REM-dominant group (32.9±22.9 events/hr vs. 18.3±9.5 events/hr, respectively). There were improvements in the AHI from stage 1 to SWS in NREM sleep with the highest level in REM sleep. A higher AHISWS than AHIN1N2 was found in 16 of 234 patients (6.8%); however, there were no significant predictors of these unexpected results except AHI. CONCLUSION.: Our results demonstrated the highest AHI during REM sleep stage in total participants after control of posture. However, there were 16.2% of patients showed NREM-dominant pattern (AHINREM/AHIREM >2) and 6.8% of patients showed higher AHISWS than AHIN1N2. Therefore, each group might have a different pathophysiology of obstructive sleep apnea (OSA), and we need to consider this point when we treat the patients with OSA.

Prediction of Obstructive Sleep Apnea Based on Respiratory Sounds Recorded Between Sleep Onset and Sleep Offset

OBJECTIVES: To develop a simple algorithm for prescreening of obstructive sleep apnea (OSA) on the basis of respiratorysounds recorded during polysomnography during all sleep stages between sleep onset and offset. METHODS: Patients who underwent attended, in-laboratory, full-night polysomnography were included. For all patients, audiorecordings were performed with an air-conduction microphone during polysomnography. Analyses included allsleep stages (i.e., N1, N2, N3, rapid eye movement, and waking). After noise reduction preprocessing, data were segmentedinto 5-s windows and sound features were extracted. Prediction models were established and validated with10-fold cross-validation by using simple logistic regression. Binary classifications were separately conducted for threedifferent threshold criteria at apnea hypopnea index (AHI) of 5, 15, or 30. Prediction model characteristics, includingaccuracy, sensitivity, specificity, positive predictive value (precision), negative predictive value, and area under thecurve (AUC) of the receiver operating characteristic were computed. RESULTS: A total of 116 subjects were included; their mean age, body mass index, and AHI were 50.4 years, 25.5 kg/m2, and23.0/hr, respectively. A total of 508 sound features were extracted from respiratory sounds recorded throughoutsleep. Accuracies of binary classifiers at AHIs of 5, 15, and 30 were 82.7%, 84.4%, and 85.3%, respectively. Predictionperformances for the classifiers at AHIs of 5, 15, and 30 were AUC, 0.83, 0.901, and 0.91; sensitivity, 87.5%,81.6%, and 60%; and specificity, 67.8%, 87.5%, and 94.1%. Respective precision values of the classifiers were89.5%, 87.5%, and 78.2% for AHIs of 5, 15, and 30. CONCLUSION: This study showed that our binary classifier predicted patients with AHI of ≥15 with sensitivity and specificityof >80% by using respiratory sounds during sleep. Since our prediction model included all sleep stage data, algorithmsbased on respiratory sounds may have a high value for prescreening OSA with mobile devices.

Alteraciones del sueño y bruxismo / Sleep alterations and bruxism

El sueño es un requerimiento biológico para la vida, sus alteraciones o su ausencia pueden disminuir la calidad de vida, el estado anímico y funcional, afectando seriamente la salud. Un sueño placentero y reparador implica cursar por facetas de profundidad diversa y actividad neuronal compleja. En este artículo se intentan explicar las generalidades del proceso del sueño y algunos de sus trastornos que lo relacionan con aumento de la actividad de los músculos masticatorios (bruxismo). Son presentados aspectos clínicos y neuronales que inducen a un incremento de microdespertares como alteración del sueño, estimulando bruxismo nocturno y bruxismo asociado a apnea nocturna. Son discutidas las posibles relaciones bidireccionales entre bruxismo diurno y nocturno secundarias a modifi caciones en la cantidad y calidad del proceso del sueño. De la misma manera, son sugeridas algunas consideraciones semiológicas y nosológicas para el mejor manejo y control del bruxismo asociado a las alteraciones del sueño, bajo el diagnóstico, atención y supervisión de equipos de atención multi- e interdisciplinarios (AU)

Sleep is a biological requirement for life, its alterations or privation thereof may reduce a person's quality of life, his or her state of mind and physical functions, which signifi cantly aff ects their health. Pleasant and repairing sleep implies going through variable deepness sleep stages, and a complex neuronal activity. This article intends to explain the generalities of the sleep process and certain disorders, particularly those in connection with the activity of the mastication muscles (bruxism). Clinical and neuronal aspects are presented inducing an increase in micro-awakenings such as sleep alterations stimulating nocturnal and bruxism associated with sleep apnea. Bidirectional connections between diurnal and nocturnal bruxism are argued as secondary to changes in the amount and quality of the sleep process. In the same manner, certain considerations associated to semiology and nosology of the diverse bruxism manifestations are considered for the better handling and control of the bruxism associated with sleep alterations under the diagnosis attention and supervision of multi- and interdisciplinary teams (AU)

Linalool Ameliorates Memory Loss and Behavioral Impairment Induced by REM-Sleep Deprivation through the Serotonergic Pathway

Rapid eye movement (REM) sleep has an essential role in the process of learning and memory in the hippocampus. It has been reported that linalool, a major component of Lavandula angustifolia, has antioxidant, anti-inflammatory, and neuroprotective effects, along with other effects. However, the effect of linalool on the cognitive impairment and behavioral alterations that are induced by REM-sleep deprivation has not yet been elucidated. Several studies have reported that REM-sleep deprivation-induced memory deficits provide a well-known model of behavioral alterations. In the present study, we examined whether linalool elicited an anti-stress effect, reversing the behavioral alterations observed following REM-sleep deprivation in mice. Furthermore, we investigated the underlying mechanism of the effect of linalool. Spatial memory and learning memory were assessed through Y maze and passive avoidance tests, respectively, and the forced swimming test was used to evaluate anti-stress activity. The mechanisms through which linalool improves memory loss and behavioral alterations in sleep-deprived mice appeared to be through an increase in the serotonin levels. Linalool significantly ameliorated the spatial and learning memory deficits, and stress activity observed in sleep-deprived animals. Moreover, linalool led to serotonin release, and cortisol level reduction. Our findings suggest that linalool has beneficial effects on the memory loss and behavioral alterations induced by REM-sleep deprivation through the regulation of serotonin levels.

The Feasibility for Whole-Night Sleep Brain Network Research Using Synchronous EEG-fMRI / 수면정신생리

OBJECTIVES: Synchronous electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) has been used to explore sleep stage dependent functional brain networks. Despite a growing number of sleep studies using EEG-fMRI, few studies have conducted network analysis on whole night sleep due to difficulty in data acquisition, artifacts, and sleep management within the MRI scanner. METHODS: In order to perform network analysis for whole night sleep, we proposed experimental procedures and data processing techniques for EEG-fMRI. We acquired 6–7 hours of EEG-fMRI data per participant and conducted signal processing to reduce artifacts in both EEG and fMRI. We then generated a functional brain atlas with 68 brain regions using independent component analysis of sleep fMRI data. Using this functional atlas, we constructed sleep level dependent functional brain networks. RESULTS: When we evaluated functional connectivity distribution, sleep showed significantly reduced functional connectivity for the whole brain compared to that during wakefulness. REM sleep showed statistically different connectivity patterns compared to non-REM sleep in sleep-related subcortical brain circuits. CONCLUSION: This study suggests the feasibility of exploring functional brain networks using sleep EEG-fMRI for whole night sleep via appropriate experimental procedures and signal processing techniques for fMRI and EEG.

Case of a 19-Year-Old Male with Nocturnal Groaning (Catathrenia) / 수면정신생리

Catathrenia is a rare sleep disease characterized by monotonous groaning sounds that appear to be related with prolonged expiration, commonly experienced during rapid eye movement (REM) sleep. Catathrenia is also known as nocturnal groaning or sleep-related groaning and is currently categorized as a sleep-related breathing disorder. We present a rare case of a 19-year-old male with nocturnal groaning during non-REM sleep. We suggest that if catathrenia is suspected, polysomnography should be utilized to differentiate it from various sleep disorders such as snoring, central sleep apnea, sleep talking, parasomnia, and sleep-related movement disorders.

Apnoeic and Hypopnoeic Load in Obstructive Sleep Apnoea: Correlation with Epworth Sleepiness Scale

<p><b>INTRODUCTION</b>Patients with obstructive sleep apnoea (OSA) often present with excessive daytime sleepiness (EDS) as measured by the Epworth Sleepiness Scale (ESS). However, the relationship between EDS and OSA severity as measured by the apnoea-hypopnoea index (AHI) remains inconsistent. We hypothesise that this may be due to the usage and equal weightage of apnoea and hypopnoea events used in determining AHI and that apnoea and hypopnoea load as measured by their total durations may be a better metric to use. We sought to investigate if apnoea or hypopnoea load can display better correlation with ESS.</p><p><b>MATERIALS AND METHODS</b>Retrospective analysis of 821 patients with AHI ≥5, who underwent in-laboratory polysomnogram for suspected OSA from January 2015-December 2015, was performed. Objective factors on polysomnogram were correlated with ESS.</p><p><b>RESULTS</b>ESS was correlated with age (r = -0.148, <0.001), number of apnoeas (r = 0.096, = 0.006), apnoea load (r = 0.102, = 0.003), apnoea index (r = 0.075, = 0.032), number of desaturations (r = 0.081, = 0.020), minimum SpO (r = -0.071, = 0.041), time SpO <85% (r = 0.075, = 0.031) and REM sleep duration (r = 0.099, = 0.004). Linear regression analysis found age ( <0.001), apnoea load ( = 0.005), REM ( = 0.021) and stage 1 sleep duration ( = 0.042) as independent factors correlated to ESS. The apnoea load calculated using duration in apnoea correlate with ESS in patients with severe OSA by AHI criteria compared to the mild category.</p><p><b>CONCLUSION</b>AHI does not correlate with ESS. Younger age, longer apnoea, stage 1 and REM sleep were independently related to higher ESS though the correlations were weak. Apnoea load should be taken into account when determining OSA severity.</p>

Effect of Rapid Eye Movement Sleep Behavior Disorder on Obstructive Sleep Apnea Severity and Cognition of Parkinson's Disease Patients / 中华医学杂志(英文版)

<p><b>Background</b>Rapid eye movement (REM) sleep behavior disorder (RBD) and obstructive sleep apnea (OSA) are the most common sleep disorders in Parkinson's disease (PD). The aim of this study was to identify whether RBD could alleviate OSA severity in PD patients and its effect on cognitive impairment.</p><p><b>Methods</b>From February 2014 to May 2017, we recruited 174 PD patients from the Second Affiliated Hospital of Soochow University, all of whom underwent polysomnography (PSG). We collected clinical data, PSG results, and compared information between patients with and without RBD or OSA by analysis of covariance. We also investigated the effect of these sleep disorders on cognitive impairment using linear regression.</p><p><b>Results</b>We grouped participants as follows: PD only (n = 53), PD + OSA (n = 29), PD + RBD (n = 61), and PD + RBD + OSA (n = 31). Minimum oxygen saturation (SaO) during whole sleep and in REM sleep was higher in PD + RBD + OSA patients than that in PD + OSA patients. PD + RBD patients had worse Mini-Mental Status Examination and Montreal Cognitive Assessment (MoCA) scores than those in the PD group (P < 0.001), especially in visuospatial/executive, attention, and memory functions. The PD + OSA group performed worse than the PD group in the delayed recall domain. After adjusting for age, sex, body mass index, education, disease severity, and other sleep disorders, MoCA was negatively associated with OSA (β = -0.736, P = 0.043) and RBD (β = -2.575,P < 0.001). The severity of RBD (tonic/phasic electromyography activity) and OSA (apnea-hypopnea index/oxygen desaturation index/minimum SaO) were also associated with MoCA. The adjusted β values of RBD-related parameters were higher than that for OSA.</p><p><b>Conclusions</b>We found that RBD alleviated OSA severity; however, RBD and OSA together exacerbated PD cognitive impairment. Further studies are needed to evaluate whether OSA treatment can improve cognition in PD.</p>