Cognitive deficits in obstructive sleep apnea: Insights from a meta-review and comparison with deficits observed in COPD, insomnia, and sleep deprivation

Sex differences in the association of sleep spindle density and cognitive performance among community-dwelling middle-aged and older adults with obstructive sleep apnea

Recent studies have found associations between obstructive sleep apnea and cognitive decline. The underlying mechanisms are still unclear. Here, we investigate the associations between changes in micro-architecture, specifically sleep spindles, and cognitive function in community-dwelling middle-aged and older adults, some with obstructive sleep apnea, with a focus on sex differences. A total of 125 voluntary participants (mean age 66.0 ± 6.4 years, 64 females) from a larger cohort (participants of the Brain in Motion Studies I and II) underwent 1 night of in-home polysomnography and a neuropsychological battery (sleep and cognitive testing were conducted within 2 weeks of each other). A semi-automatic computerized algorithm was used to score polysomnography data and detect spindle characteristics in non-rapid eye movement Stages 2 and 3 in both frontal and central electrodes. Based on their apnea-hypopnea index, participants were divided into those with no obstructive sleep apnea (apnea-hypopnea index < 5 per hr, n = 21), mild obstructive sleep apnea (5 ≥ apnea-hypopnea index < 15, n = 47), moderate obstructive sleep apnea (15 ≥ apnea-hypopnea index < 30, n = 34) and severe obstructive sleep apnea (apnea-hypopnea index ≥ 30, n = 23). There were no significant differences in spindle characteristics between the four obstructive sleep apnea severity groups. Spindle density and percentage of fast spindles were positively associated with some verbal fluency measures on the cognitive testing. Sex might be linked with these associations. Biological sex could play a role in the associations between spindle characteristics and some verbal fluency measures. Obstructive sleep apnea severity was not found to be a contributing factor in this non-clinical community-dwelling cohort.

Obstructive Sleep Apnea Plasma-Derived Exosomes Mediate Cognitive Impairment Through Hippocampal Neuronal Cell Pyroptosis

OBJECTIVE

Obstructive sleep apnea (OSA) is associated with impaired cognitive function. Exosomes are secreted by most cells and play a role in OSA-associated cognitive impairment (CI). The aim of this study was to investigate whether OSA plasma-derived exosomes cause CI through hippocampal neuronal cell pyroptosis, and to identify exosomal miRNAs in OSA plasma-derived.

MATERIALS AND METHODS

Plasma-derived exosomes were isolated from patients with severe OSA and healthy comparisons. Daytime sleepiness and cognitive function were assessed using the Epworth Sleepiness Scale (ESS) and the Beijing version of the Montreal Cognitive Assessment Scale (MoCA). Exosomes were coincubated with mouse hippocampal neurons (HT22) cells to evaluate the effect of exosomes on pyroptosis and inflammation of HT22 cells. Meanwhile, exosomes were injected into C57BL/6 male mice via caudal vein, and then morris water maze was used to evaluate the spatial learning and memory ability of the mice, so as to observe the effects of exosomes on the cognitive function of the mice. Western blot and qRT-PCR were used to detect the expressions of Gasdermin D (GSDMD) and Caspase-1 to evaluate the pyroptosis level. The expression of IL-1β, IL-6, IL-18 and TNF-α was detected by qRT-PCR to assess the level of inflammation. Correlations of GSDMD and Caspase-1 expression with clinical parameters were evaluated using Spearman's rank correlation analysis. In addition, plasma exosome miRNAs profile was identified, followed by Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways.

RESULTS

Compared to healthy comparisons, body mass index (BMI), apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and ESS scores were increased in patients with severe OSA, while lowest oxygen saturation during sleep (LSaO2), mean oxygen saturation during sleep (MSaO2) and MoCA scores were decreased. Compared to the PBS group (NC) and the healthy comparison plasma-derived exosomes (NC-EXOS), the levels of GSDMD and Caspase-1 and IL-1β, IL-6, IL-18 and TNF-α were increased significantly in the severe OSA plasma-derived exosomes (OSA-EXOS) coincubated with HT22 cells. Compared to the NC and NC-EXOS groups, the learning and memory ability of mice injected with OSA-EXOS was decreased, and the expression of GSDMD and Caspase-1 in hippocampus were significantly increased, along with the levels of IL-1β, IL-6, IL-18 and TNF-α. Spearman correlation analysis found that clinical AHI in HCs and severe OSA patients was positively correlated with GSDMD and Caspase-1 in HT22 cells from NC-EXOS and OSA-EXOS groups, while negatively correlated with clinical MoCA. At the same time, clinical MoCA in HCs and severe OSA patients was negatively correlated with GSDMD and Caspase-1 in HT22 cells from NC-EXOS and OSA-EXOS groups. A unique exosomal miRNAs profile was identified in OSA-EXOS group compared to the NC-EXOS group, in which 28 miRNAs were regulated and several KEGG and GO pathways were identified.

CONCLUSIONS

The results of this study show a hypothesis that plasma-derived exosomes from severe OSA patients promote pyroptosis and increased expression of inflammatory factors in vivo and in vitro, and lead to impaired cognitive function in mice, suggesting that OSA-EXOS can mediate CI through pyroptosis of hippocampal neurons. In addition, exosome cargo from OSA-EXOS showed a unique miRNAs profile compared to NC-EXOS, suggesting that plasma exosome associated miRNAs may reflect the differential profile of OSA related diseases, such as CI.

Sleep apnea in schizophrenia: Estimating prevalence and impact on cognition

Undertreated medical illnesses can compound the disabling cognitive deficits of schizophrenia. Obstructive sleep apnea (OSA) impairs cognitive domains also affected by schizophrenia, is common, and is treatable. The effects of sleep apnea on cognition in schizophrenia, however, are not well understood. We estimated the prevalence of OSA in a previously characterized sample of 3942 Veterans with schizophrenia by self-report and with a predictive model to identify individuals at high risk for OSA. We then compared neuropsychological and functional capacity assessment results between those who reported OSA versus those who did not, and between those predicted to have OSA versus predicted to not have OSA. We expected that many Veterans not reporting sleep apnea would be predicted to have it, and that both reported and predicted sleep apnea would be associated with lower cognitive and functional performance. The reported prevalence of OSA in the sample was 14%, whereas 72% were predicted to be at high risk of OSA. Interestingly, participants who reported having OSA had better cognitive and functional capacity performance (p's < 0.001) compared to those who did not report OSA, particularly on speed of processing assessments (p < 0.001). Predicted OSA, by contrast, was associated with lower speed of processing, verbal learning and working memory test scores (p's < 0.001). One possible interpretation of these results is that people with higher cognitive capacity may be more likely to seek medical care, while those with cognitive impairments are at greater risk for having untreated co-occurring medical conditions that further compromise cognition.

Mind reading dysfunctions in patients with obstructive sleep apnoea: A neuropsychological approach

Obstructive sleep apnoea syndrome (OSAS) is a prevalent sleep-related breathing disorder that has been extensively studied for its effects on cognitive functions. However, little attention has been given to investigating Mind Reading (MR) skills in patients with OSAS. In this study, we employed a neuropsychological approach to thoroughly assess various facets of MR skills in patients with OSAS. Forty-two patients with untreated moderate or severe OSAS (AHI ≥15; 30 men, 12 women) and 16 healthy controls (7 men and 9 women), matched by age, were enrolled. To assess MR skills, we used: (i) The Story-based Empathy Task (SET), which includes three experimental conditions: identifying intentions (SET-IA), emotional states (SET-EA), and a control condition for inferring causality reactions (SET-CI); (ii) the Ekman 60 Faces Test (Ek60), which measures emotion recognition from facial expressions. Our findings revealed that patients with OSAS exhibit deficits in emotion-related MR skills, while their ability to make inferences about the cognitive states of social partners remains largely preserved. This finding corroborates previous evidence indicating that social cognition, particularly MR skills, may be one of the cognitive domains affected by OSAS. It emphasizes the significance of investigating social cognition and the relationship between MR skills and social functioning as a new and intriguing area of research in patients with OSAS.

Obstructive Sleep Apnea Among Patients with Mild Cognitive Impairment

Background

Obstructive sleep apnea (OSA) is associated with cognitive disorders, but little is known about prevalence of co-occurring OSA and mild cognitive impairment (MCI) as well as about co-occurring OSA and Alzheimer's disease (AD). Pathophysiological models integrating OSA, cognitive deficits and neurodegeneration remain speculative. Findings in this area could contribute to the knowledge about pathophysiological processes in cognitive disorders and neurodegenerative processes, be helpful for the diagnosis of cognitive disorders and provide approaches for the treatment of cognitive disorders.

Objective

Examining the prevalence of OSA and patterns of cognitive deficits as well as AD biomarker profiles associated with OSA in a cohort of 104 MCI patients.

Methods

Assessments used include: respiratory polygraphy, The Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD NB), Tau, phosphoTau181, amyloid-β-1-42/1-40, 18F-fluorodeoxyglucose positron emission tomography (F18-FDG-PET).

Results

Prevalence of OSA of any severity: 58,7% (Apnea Hypopnea Index (AHI)≥5/h), OSA in a moderate-to-severe extent (AHI≥15/h): 25%. Only 13.1% of MCI patients with OSA reported daytime sleepiness. MCI-OSA patients showed no specific neuropsychological pattern. Presence of OSA was not associated with specific AD biomarker profiles in the whole study group besides a positive association between AD positivity in an AD biomarker sub cohort.

Conclusions

OSA is highly prevalent in patients with MCI. It might often remain undiagnosed as only a small number of MCI-OSA patients report daytime sleepiness. OSA could contribute to MCI symptoms and even to AD pathology. Further research is needed to validate these findings and to investigate possible pathophysiological relationships between OSA and MCI as well as between OSA and AD.

Prevalence survey and psychometric measurement of vertigo and dizziness in individuals with obstructive sleep apnoea: A cross-sectional study

INTRODUCTION

This study aimed to evaluate the prevalence and psychometric properties of vertigo and dizziness in an obstructive sleep apnoea (OSA) population.

METHODS

Five hundred and twelve OSA patients and 53 controls were enroled. All eligible subjects were asked to complete the basic information questionnaire, the Chinese version of Vestibular Disorders Activities of Daily Living (VADL-C), the Dizziness Handicap Inventory (DHI) and the Activities-Specific Balance Confidence (ABC) scale.

RESULTS

Among 512 enroled OSA patients, a 22.46% (115) prevalence of vertigo and dizziness was found. The scores of the VADL-C, DHI and ABC of the study group were significantly worse (p < .001) than those of the control group, while the abnormal rates of the three scales in the study group were higher than those of the control group. In the study group, the results of the VADL-C were correlated with those of the DHI (r = .55, p < .001) and inversely correlated with those of the ABC (r = -.50, p < .001), and the results of the DHI were inversely correlated with those of the ABC (r = -.60, p < .001).

CONCLUSIONS

A high prevalence of vertigo and dizziness in the OSA population was detected. Psychometric results showed that vertigo and dizziness in OSA patients led to changes in activities of daily living, increased frequency of somatic symptoms, and reduced balance confidence. In the diagnosis and treatment of OSA patients, the occurrence of vertigo and dizziness is worth clinicians' attention.

Cognitive complaints in patients with untreated obstructive sleep apnea versus patients with neurological and respiratory diseases: prevalence, severity and risk factors

PURPOSE

Little is known about cognitive complaints (self-reported problems in cognitive functioning) in patients with Obstructive Sleep Apnea (OSA). We compared the prevalence and severity of cognitive complaints in patients with untreated OSA to patients with neurological and respiratory diseases. We also studied risk factors for cognitive complaints across these diseases, including OSA.

METHODS

We used a convenience sample to compare untreated OSA patients (N = 86) to patients with stroke (N = 166), primary brain tumor (N = 197) and chronic obstructive pulmonary disease (COPD, N = 204) on cognitive complaints (Cognitive Failure Questionnaire, CFQ), anxiety and depression (Hospital Anxiety and Depression Scale, HADS) and cognitive impairments using neuropsychological tests. We combined all patient groups (OSA, stroke, brain tumor and COPD) and studied potential risk factors (demographic variables, anxiety, depression and cognitive impairments) for cognitive complaints across all patient groups using regression analysis.

RESULTS

The prevalence of cognitive complaints was higher in OSA patients and complaints of forgetfulness and distractibility were more severe compared to stroke and primary brain tumor patients, but similar to or lower than COPD patients. Regression analysis for the combined sample of all patient groups showed that cognitive complaints were most strongly associated with symptoms of anxiety and depression.

CONCLUSION

A high rate of OSA reported clinically significant cognitive complaints, comparable to other respiratory and neurological patients. Symptoms of anxiety and depression are important risk factors for cognitive complaints in patients with various neurological and respiratory diseases. Future studies should examine the relation between anxiety, depression and cognitive complaints in patients with OSA.

General low alertness in people with obstructive sleep apnea

STUDY OBJECTIVES

In patients with obstructive sleep apnea (OSA), a previous study using a Go/No-Go task reported an average attention deficit. However, the temporal dynamics of such a deficit are unknown. Here, we investigated whether attention deficits in different subdomains increased as the test progressed. We also investigated the effect of target frequency and speed of stimulus presentation on performance.

METHODS

Twenty-seven untreated people with OSA and 27 age- and sex-matched controls underwent a 15-minute Go/No-Go task, divided into 6 blocks. Each block was subdivided into 3 different interstimulus intervals (1, 2, and 4 seconds). Three blocks had a low and three had a high target probability (20% and 80%, respectively). Reaction time (alertness), variability of reaction time (sustained attention), commission errors (response inhibition), and omission errors (focused attention) were measured.

RESULTS

Alertness was lower in the group with OSA compared with controls, as evidenced by a significantly higher average reaction time. This effect was seen from the start of the task and continued until the end but did not increase in test progression. The temporal pattern of intrinsic alertness deficits in patients with OSA was found to be independent of target frequency or interstimulus interval.

CONCLUSIONS

The primary attention problem in OSA is on the alertness subdomain irrespective of the number of required responses or speed of stimulus presentation. The present results support the notion that OSA is distinct from other neurological and psychiatric conditions, such as depression or chronic pain. The results also suggest significant concerns regarding daily life activities (eg, driving).

CITATION

de Souza Bezerra ML, van Duinkerken E, Simões E, Schmidt SL. General low alertness in people with obstructive sleep apnea. J Clin Sleep Med. 2024;20(5):689-698.

Neurometabolic and Brain Functional Alterations Associated with Cognitive Impairment in Patients with Myasthenia Gravis: A Combined 1H-MRS and fMRI Study

Whether patients with myasthenia gravis (MG) exhibit cognitive impairment is controversial. Also the underlying mechanisms are unknown. We aimed to investigate alterations in cognitive function, neurometabolite levels, and brain function in patients with MG and to explore the associations between abnormal regional brain functional activity, neurometabolite concentrations in the MPFC and left thalamus, and cognitive activity in patients with MG. Neuropsychological tests, proton magnetic resonance spectroscopy, and resting-state functional magnetic resonance imaging were performed on 41 patients with MG and 45 race-, sex-, age-, and education-matched healthy controls (HCs). The results suggest that MG is accompanied by cognitive decline, as indicated by global cognitive function, visual-spatial function, language, memory, abnormalities in regional brain functional activity, and neurometabolite alterations (including GABA, NAA, and Cho) in the medial prefrontal cortex (MPFC) and left thalamus. Cognitive impairment in patients with MG may be related to abnormal regional brain functional activity and changes in neurometabolites, and regional brain functional activity may be modulated by specific neurometabolites.

The effects of insufficient sleep and adequate sleep on cognitive function in healthy adults

STUDY OBJECTIVES

Although sleep affects a range of waking behaviors, the majority of studies have focused on sleep loss with relatively little attention on sustained periods of adequate sleep. The goal of this study was to use an experimental design to examine the effect of both of these sleep patterns on cognitive performance in healthy adults.

METHODS

This study used a randomized crossover design. Participants who regularly slept 7-9 hours/night completed two 6-week intervention conditions, adequate sleep (maintenance of habitual bed/wake times) and insufficient sleep (reduction in sleep of 1.5 hours relative to adequate sleep), separated by a 2-6weeks (median=43days) washout period. Cognitive functioning was evaluated at baseline and endpoint of each intervention using the NIH Toolbox Cognition Battery. General linear models contrasted scores following each condition to the baseline of the first condition; the baseline of the second condition was included to evaluate practice effects.

RESULTS

Sixty-five participants (age 35.9 ± 4.9years, 89% women, 52% non-White race/ethnicity) completed study procedures. There was improvement in performance on the List Sorting Working Memory task after the adequate sleep condition that exceeded practice effects. Cognitive performance after insufficient sleep did not reach the level expected with practice and did not differ from baseline. A similar pattern was found on the Flanker Inhibitory Control and Attention task.

CONCLUSIONS

These findings contribute to our understanding of the complex interplay between sleep and cognition and demonstrate that consistent, stable sleep of at least 7 hours/night improves working memory and response inhibition in healthy adults.

CLINICAL TRIAL REGISTRATION

The manuscript reports on data from two clinical trials: Impact of Sleep Restriction on Performance in Adults (URL: https://clinicaltrials.gov/ct2/show/NCT02960776, ID Number: NCT02960776) and Impact of Sleep Restriction in Women (URL: https://clinicaltrials.gov/ct2/show/NCT02835261, ID Number: NCT02835261).

Abnormal prefrontal functional network in adult obstructive sleep apnea: A resting-state fNIRS study

To assess prefrontal brain network abnormality in adults with obstructive sleep apnea (OSA), resting-state functional near infrared spectroscopy (rs-fNIRS) was used to evaluate 52 subjects, including 27 with OSA and 25 healthy controls (HC). The study found that patients with OSA had a decreased connection edge number, particularly in the connection between the right medial frontal cortex (MFG-R) and other right-hemisphere regions. Graph-based analysis also revealed that patients with OSA had a lower global efficiency, local efficiency, and clustering coefficient than the HC group. Additionally, the study found a significant positive correlation between the Montreal Cognitive Assessment (MoCA) score and both the connection edge number and the graph-based indicators in patients with OSA. These preliminary results suggest that prefrontal rs-fNIRS could be a useful tool for objectively and quantitatively assessing cognitive function impairment in patients with OSA.

Anterolateral advancement pharyngoplasty versus barbed reposition pharyngoplasty in patients with obstructive sleep apnea

OBJECTIVES

To compare functional outcomes and complication rates of anterolateral advancement pharyngoplasty (ALA) versus barbed reposition pharyngoplasty (BRP) in the treatment of obstructive sleep apnea patients with palatal and lateral pharyngeal wall collapse.

STUDY DESIGN

Prospective study.

SETTING

University hospitals.

SUBJECTS AND METHODS

Forty-six patients were included in this study. Patients were divided into two groups randomly, group 1 (23 cases) underwent anterolateral advancement pharyngoplasty and group 2 (23 cases) underwent barbed relocation pharyngoplasty. According to the following criteria: both sex, age between 18 and 65 years, body mass index ≤ 32 kg/m2, Friedman stage II or III, type I Fujita, nocturnal polysomnography study diagnostic for OSA, retropalatal and lateral pharyngeal wall collapse, diagnosis with flexible nasoendoscopy during a Muller's maneuver based on a 5-point scale and drug-induced sleep endoscopy. Patients who suffered from retroglossal airway collapse were rolled out.

RESULTS

Apnea-hypopnea index decreased from 27.50 ± 11.56 to 11.22 ± 7.63 (P ≤ .001) in group 1 and from 33.18 ± 10.94 to 12.38 ± 6.77 (P ≤ .001) in group 2. Retropalatal posterior airway space increased from 9.84 ± 1.29 mm to 21.48 ± 2.8 mm (P ≤ .001) in group 1 and increased from 10.26 ± 1.2 mm to 22.86 ± 2.62 mm (P ≤ .001) in group 2. Retropalatal space volume increased from 1.9 ± 0.68 cm3 to 2.75 ± 0.7 cm3 (P ≤ .001) in group 1 and increased from 1.96 ± 0.88 cm3 to 2.82 ± 0.83 cm3 (P ≤ .001) in group 2. Surgical success was 86.95% in group 1 compared to 82.6% in group 2.

CONCLUSIONS

Both techniques appear to be effective with a high surgical success rate in the treatment of OSA patients with retropalatal and lateral pharyngeal wall collapse.

Increased Flow Limitation During Sleep Is Associated With Increased Psychomotor Vigilance Task Lapses in Individuals With Suspected OSA

BACKGROUND

Impaired daytime vigilance is an important consequence of OSA, but several studies have reported no association between objective measurements of vigilance and the apnea-hypopnea index (AHI). Notably, the AHI does not quantify the degree of flow limitation, that is, the extent to which ventilation fails to meet intended ventilation (ventilatory drive).

RESEARCH QUESTION

Is flow limitation during sleep associated with daytime vigilance in OSA?

STUDY DESIGN AND METHODS

Nine hundred ninety-eight participants with suspected OSA completed a 10-min psychomotor vigilance task (PVT) before same-night in-laboratory polysomnography. Flow limitation frequency (percent of flow-limited breaths) during sleep was quantified using airflow shapes (eg, fluttering and scooping) from nasal pressure airflow. Multivariable regression assessed the association between flow limitation frequency and the number of lapses (response times > 500 ms, primary outcome), adjusting for age, sex, BMI, total sleep time, depression, and smoking status.

RESULTS

Increased flow limitation frequency was associated with decreased vigilance: a 1-SD (35.3%) increase was associated with 2.1 additional PVT lapses (95% CI, 0.7-3.7; P = .003). This magnitude was similar to that for age, where a 1-SD increase (13.5 years) was associated with 1.9 additional lapses. Results were similar after adjusting for AHI, hypoxemia severity, and arousal severity. The AHI was not associated with PVT lapses (P = .20). In secondary exploratory analysis, flow limitation frequency was associated with mean response speed (P = .012), median response time (P = .029), fastest 10% response time (P = .041), slowest 10% response time (P = .018), and slowest 10% response speed (P = .005).

INTERPRETATION

Increased flow limitation during sleep was associated with decreased daytime vigilance in individuals with suspected OSA, independent of the AHI. Flow limitation may complement standard clinical metrics in identifying individuals whose vigilance impairment most likely is explained by OSA.

The Effect of High-Altitude Hypoxia on Neuropsychiatric Functions

Liu, Bo, Minlan Yuan, Mei Yang, Hongru Zhu, and Wei Zhang. The effect of high-altitude hypoxia on neuropsychiatric functions. High Alt Med Biol. 25:26-41, 2024. Background: In recent years, there has been a growing popularity in engaging in activities at high altitudes, such as hiking and work. However, these high-altitude environments pose risks of hypoxia, which can lead to various acute or chronic cerebral diseases. These conditions include common neurological diseases such as acute mountain sickness (AMS), high-altitude cerebral edema, and altitude-related cerebrovascular diseases, as well as psychiatric disorders such as anxiety, depression, and psychosis. However, reviews of altitude-related neuropsychiatric conditions and their potential mechanisms are rare. Methods: We conducted searches on PubMed and Google Scholar, exploring existing literature encompassing preclinical and clinical studies. Our aim was to summarize the prevalent neuropsychiatric diseases induced by altitude hypoxia, the potential pathophysiological mechanisms, as well as the available pharmacological and nonpharmacological strategies for prevention and intervention. Results: The development of altitude-related cerebral diseases may arise from various pathogenic processes, including neurovascular alterations associated with hypoxia, cytotoxic responses, activation of reactive oxygen species, and dysregulation of the expression of hypoxia inducible factor-1 and nuclear factor erythroid 2-related factor 2. Furthermore, the interplay between hypoxia-induced neurological and psychiatric changes is believed to play a role in the progression of brain damage. Conclusions: While there is some evidence pointing to pathophysiological changes in hypoxia-induced brain damage, the precise mechanisms responsible for neuropsychiatric alterations remain elusive. Currently, the range of prevention and intervention strategies available is primarily focused on addressing AMS, with a preference for prevention rather than treatment.

The prevalence of obstructive sleep apnea in Japanese asthma patients

BACKGROUND

Obstructive sleep apnea (OSA) occurs more commonly in asthma patients than in the general population because these conditions share some comorbidities. In Japan, the prevalence of OSA in the general population is reported to be approximately 20%; however, few reports have described the prevalence of OSA in asthma patients. Furthermore, the characteristics of Japanese patients with OSA and asthma are not clear.

METHODS

Adult asthma patients were recruited from the outpatient departments of our institution between August 31, 2017, and March 31, 2019. In all included patients, the presence and severity of OSA were evaluated by the Epworth Sleepiness Scale (ESS) and a home sleep test (HST) using portable polysomnography (PSG). The rate of coexisting OSA in asthma patients and the characteristics of those patients according to the severity of OSA were investigated.

RESULTS

Fifty-three patients were included. OSA was detected in 36 (67.9%) patients (mild, n = 15; moderate, n = 14; and severe, n = 7). Patients with OSA had significantly higher body mass index, Brinkman index, apnea-hypopnea index (AHI), and 3% oxygen desaturation index (ODI) values in comparison to those without OSA, while the percentage of the predicted value of forced vital capacity (%FVC) and lowest SpO2 levels were significantly lower. As the severity of OSA increased, age, brain natriuretic peptide level, AHI, and 3%ODI increased, and in contrast, FVC, %FVC, forced expiratory volume in one second (FEV1), percentage of the predicted value of FEV1 (%FEV1), Epworth Sleepiness Scale (ESS), 3%ODI, and lowest SpO2 levels decreased. In particular, the fact that the ESS value was inversely correlated with the severity of OSA in our patients was different from the general characteristics of OSA. Moreover, the AHI value was negatively correlated with FVC, %FVC, FEV1, and %FEV1. BMI was the only independent factor for the presence of OSA, and for asthma severity (FEV1, % of predicted), there was a weak correlation with smoking history.

CONCLUSIONS

This is the first report to investigate the prevalence of OSA in Japanese asthma patients, using an HST. This study suggests that an HST should be performed in addition to the sleep interview for asthma patients with refractory disease, a low pulmonary function, advanced age, and high BMI because the more severe the OSA, the lower the ESS value may be.

Clinical Characteristics of Older Adults Seeking Hypoglossal Nerve Stimulation for the Treatment of Obstructive Sleep Apnea

OBJECTIVES

Obstructive sleep apnea (OSA) is a common sleep disorder with numerous clinical correlates. Although effective treatments abound, patient acceptance and adherence is low. Hypoglossal nerve stimulation (HNS) is a surgical treatment alternative for the treatment of OSA; however, the demographic and clinical characteristics of individuals seeking HNS are not well categorized. This study sought to determine the clinical characteristics of older adults seeking HNS for the treatment of OSA.

METHODS

Self-report questionnaires were administered to all patients older than 50 years seeking a HNS consultation at a large university medical center. Questionnaires included validated National Institutes of Health Patient-Reported Outcomes Measurement Information System (NIH PROMIS) measures of physical functioning, sleep-related impairment, cognitive abilities, depression, anxiety, and anger along with the Information extracted from electronic medical records included age, sex, race, and apnea-hypopnea index (AHI).

RESULTS

Patients included 113 adults (mean age 63.30 years, 57% male, 79% white) with severe OSA (AHI = 33.91, standard deviation = 20.63). Overall, 88% of patients reported elevated insomnia symptoms, 30% reported mild difficulty with physical functioning, and 36% indicated that they had experienced moderate-severe daytime impairments attributed to poor sleep. Additionally, we found 28% of sampled individuals reported moderate-severe depressive symptomology, over 19% reported moderate-severe anxiety, and over 17% reported moderate to severe anger issues. Approximately, 38% of the sample reported moderate to severe cognitive difficulties.

CONCLUSIONS

The aim of the study was to better understand the clinical characteristics of older patients with OSA seeking HNS treatment. Utilizing NIH PROMIS questionnaires, we identified unique clinical and psychosocial correlates in this sample, which included higher rates of insomnia symptoms, physical dysfunction, cognitive deficits, and depressive symptoms than the general population. Future studies will be needed to investigate these relationships more thoroughly and throughout the course of the treatment.

Sleep at high altitude: A bibliometric study and visualization analysis from 1992 to 2022

Background

As an important monitoring index for adaptation to hypoxia, sleep may reflect the adaptive state of the body at high altitudes. The literature has shown a link between altitude and sleep problems, and sleep changes have become a common problem for individuals at high altitudes, negatively impacting their physical and mental health. As research on high-altitude sleep has gained attention in recent years, the publishing volume has increased worldwide, necessitating a more comprehensive understanding of this field. This manuscript evaluates the key themes and emerging trends in high-altitude sleep over the past few decades and predicts future research directions.

Methods

Articles related to high-altitude sleep published from 1992 to 2022 were retrieved from the Web of Science Core Collection, and the relevant literature characteristics were extracted after the screening. Then, bibliometric analyses and visualizations were performed using Microsoft Excel, CiteSpace, VOSviewer, and an online analysis platform (http://bibliometric.com).

Results

A total of 1151 articles were retrieved, of which 368 were included in the analysis, indicating a gradually increasing trend. The United States, Switzerland, and China have made significant contributions in this field. Bloch KE from the University of Zurich was determined to be the most productive and academically influential author in this field. The highest-yielding journal was High Altitude Medicine & Biology. Initially, altitude training was the primary research topic. Currently, research focuses on sleep disorders and sleep apnea. In the coming years, keywords such as "sleep quality," "prevalence," and "obstructive sleep apnea" will attract more attention.

Conclusion

Our findings will assist scholars to better understand the intellectual structure and emerging trends in this field. Future developments in high-altitude sleep research are highly anticipated, particularly in terms of sleep quality at high altitudes and its associated prevalence. This research is also crucial for the improvement and treatment of symptoms during nocturnal sleep in patients with chronic hypoxia due to cardiopulmonary diseases at high altitudes.

Associations Between Sleep Spindle Metrics, Age, Education and Executive Function in Young Adult and Middle-Aged Patients with Obstructive Sleep Apnea

Purpose

This study aimed to investigate the association between sleep spindle metrics and executive function in individuals with obstructive sleep apnea (OSA). Furthermore, we examined the association of age and education on executive function.

Patients and Methods

A total of 230 (40.90 ± 8.83 years, F/M = 45/185) participants were enrolled. Overnight electroencephalogram (C3-M2) recording detected sleep spindles by a novel U-Net-type neural network that integrates temporal information with time-frequency images. Sleep spindle metrics, including frequency (Hz), overall density (events/min), fast density (events/min), slow density (events/min), duration (sec) and amplitude (µV), were measured. Executive function was assessed using standardized neuropsychological tests. Associations between sleep spindle metrics, executive function, and demographic factors were analyzed using multivariate linear regression.

Results

In fully adjusted linear regression models, higher overall sleep spindle density (TMT-A, B=-1.279, p=0.009; TMT-B, B=-1.813, p=0.008), fast sleep spindle density (TMT-A, B=-1.542, p=0.048; TMT-B, B=-2.187, p=0.036) and slow sleep spindle density (TMT-A, B=-1.731, p=0.037; TMT-B, B=-2.449, p=0.034) were associated with better executive function. And the sleep spindle duration both during N2 sleep time (TMT-A, B=-13.932, p=0.027; TMT-B, B=-19.001, p=0.034) and N3 sleep time (TMT-B, B=-29.916, p=0.009; Stroop-incongruous, B=-21.303, p=0.035) was independently associated with better executive function in this population. Additionally, age and education were found to be highly associated with executive function.

Conclusion

Specific sleep spindle metrics, higher overall density, fast density and slow density during N2 sleep time, and longer duration during N2 and N3 sleep time, are independent and sensitive indicators of better executive function in young adult and middle-aged patients with OSA. Further research is needed to explore the underlying mechanisms and clinical implications of these findings.

The Relation of Sleep Characteristics and Cognitive Impairment in Community-Dwelling Middle-Aged and Older Adults: Ardakan Cohort Study on Aging (ACSA)

Introduction

The rise in the elderly population has brought attention to mild cognitive impairment (MCI). Sleep disorders also affect many older adults, indicating an important area of research for disturbed sleep and faster brain aging. This population-based study aimed to investigate the association of several sleep indicators with cognitive performance.

Methods

This cross-sectional study focused on adults over 50 in the Ardakan Cohort Study on Aging (ACSA). MCI was evaluated using the Mini-Mental State Examination (MMSE) and the Abbreviated Mental Test score (AMTS) in literate and illiterate individuals. Sleep characteristics were collected using the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, and Berlin questionnaire. The logistic regression models were used to analyze the data.

Results

Overall, 3,380 literate and 1,558 illiterate individuals were included. In both groups, participants with MCI had a significantly higher PSQI global score (p < 0.05). Also, among the literate individuals, a significantly higher risk of having sleep-disordered breathing and poor sleep quality was observed in participants with MCI (p < 0.05). In illiterate individuals, higher sleep latency than 15 min increased odds of MCI (p < 0.05). However, after adjusting for all variables, only literate individuals with a sleep duration of more than 8 h had 66 percent increased odds of having MCI (p = 0.033).

Conclusion

Sleep duration might be associated with cognitive function in the older Iranian population. Our findings underscore the importance of considering sleep patterns in relation to cognitive health.

Evaluation of nocturnal apnea and airflow limitation as indicators for cognitive dysfunction in patients with chronic obstructive pulmonary disease/obstructive sleep apnea hypopnea syndrome overlap syndrome

OBJECTIVE

The aim of this study is to investigate how much intermittent hypoxemia and airflow limitation contribute to cognitive impairment in overlap syndrome (OS), which is the coexistence of two common diseases, obstructive sleep apnea hypopnea syndrome (OSAHS) and chronic obstructive pulmonary disease (COPD).

METHODS

We conducted a cross-sectional study of patients with OSAHS, COPD or OS, compared with normal controls, to determine the association between sleep apnea/pulmonary function-related indicators and cognitive dysfunction in individuals with OSAHS, COPD or OS.

RESULTS

A total of 157 participants were recruited. Both OSAHS and OS presented lower adjusted Montreal cognitive assessment (MoCA) scores compared with COPD group. In addition, the MoCA score was significantly lower in COPD group compared with control group. The incidence of cognitive impairment was 57.4% in OSAHS group, and 78% in OS group, which were significantly higher than COPD group (29%) and control group (8.8%). Furthermore, a broader range of cognitive domains were affected in OS group compared with OSAHS group. Elevated levels of oxygen desaturation index (ODI) and/or apnea hypopnea index (AHI) were positively correlated with increased Epworth sleeping scale (ESS) in OSAHS and OS. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and peak expiratory flow (PEF) were positively correlated with cognitive scores in OSAHS but not in OS. Serum level of hypoxia-inducible factor-1α (HIF-1α) was significantly higher in OS. Logistic regression identified ODI as an independent risk factor for cognitive impairment in OS, while severity of snoring and PEF were independent risk factors in OSAHS.

DISCUSSION

This study revealed significant cognitive impairment in OS, OSAHS and COPD. Sleep-related indicators are warranted in OS patients for detection, differentiation and grading of cognitive impairment, whereas pulmonary functions are warranted in OSAHS patients for detection and early intervention of cognitive impairment.

Obstructive sleep apnea during rapid eye movement sleep and cognitive performance in adults

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) during rapid eye movement (REM) sleep is often characterized with more frequent and lengthy breathing events and greater oxygen desaturation than during other sleep stages. Current evidence suggests an association between OSA and cognitive decline, however whether OSA during REM sleep plays a vital role in this link is understudied.

METHODS

A cross-sectional sample of 728 men and women (aged 59.1 ± 11.3 years) underwent a full night polysomnography for determining apnea-hypopnea index (AHI) and sleep stages. Trail Making Test (TMT) part A and B were conducted during the following day for assessing participants' cognitive function. Linear regression analyses were performed to test the possible association between AHI and AHI during REM sleep with TMT-A and B results. Similar analyses were carried out in a subsample involving participants aged ≥60 years with ≥30 min of REM sleep (n = 356).

RESULTS

Despite a slight difference in TMT-B between participants with and without OSA (AHI ≥5 vs AHI <5, β-coefficient: 4.83, 95 % CI: [-9.44, -0.22], P = 0.040), no other association between AHI or REM-AHI and TMT results were found in the full sample. In older participants (aged ≥60 years), a REM-AHI ≥5 events/hour was associated with longer time taken to finish TMT-A (vs REM-AHI <5 events/hour, 3.93, [0.96, 6.90], P = 0.010). There was no association between REM-AHI and time taken to finish TMT-B in older participants.

CONCLUSIONS

The results indicate that OSA during REM sleep may be of particular concern for attention-related cognitive function in older adults.

Evaluation of cognitive and psychomotor faculties in relation to mood-related symptoms under the conditions of sleep deprivation

Introduction

Deprivation of sleep (DS) has been associated with changes in mood and cognitive function, rapidly but transiently improving the severity of depression symptoms. However, it remains unclear whether there are differences in performance between DS responders and non-responders. The relationship between DS, mood, cognitive, and psychomotor function is also poorly understood.

Methods

Participants (n = 77) underwent a baseline assessment of sleep under the control of polysomnography (PSG). Later they were subjected to DS with actigraphy monitoring. Evaluation of mood as well as completing a battery of tests assessing cognitive functions and eye-hand coordination was conducted four times, pre/post PSG and DS. Participants were further divided into respondents (RE, n = 48) and non-respondents (NR, n = 29) depending on alleviation of depression symptoms severity following DS.

Results

All participants exhibited increased response speed to visual triggers after DS compared to baseline (p = 0.024). Psychomotor vigilance test (PVT) results remained intact in the RE, whereas it was increased in the NR (p = 0.008). Exposure time in the eye-hand coordination test improved in both groups, but total error duration was reduced only in RE individuals (p < 0.001, p = 0.009 for RE and NR, respectively). All subjects were more proficient at trail-making test (p ≤ 0.001 for Part 1 and 2 in all, NR, RE). Stroop test also improved regardless of mood changes after DS (p = 0.007, p = 0.008 for Part 1 and 2, respectively); cognitive interference remained at a similar level within groups (p = 0.059, p = 0.057 for NR and RE, respectively). A positive correlation was observed between the difference in PSG morning/DS morning depression severity and vigilance (R = 0.37, p = 0.001, R = 0.33, p = 0.005, for error duration eye-hand coordination test and PVT total average score, respectively).

Conclusion

RE tend to maintain or improve cognitive function after DS, oppositely to NR. Vigilance in particular might be tightly associated with changes in depression symptoms after DS. Future studies should examine the biological basis behind the response to sleep loss.

Effects of smoking on sleep architecture and ventilatory parameters including apneas: Results of the Tab-OSA study

Background

The interaction between smoking and sleep seems appears to be bidirectional, but few studies evaluated the impact of smoking and its cessation on objective sleep parameters. In this context, this new study aimed to assess the impact of smoking and its cessation on sleep architecture and on ventilatory sleep parameters, particularly the presence of sleep apnea syndrome (apnea-hypopnea index (AHI)≥15). Methods: Patients hospitalized for polysomnographic sleep exploration were compared according to their smoking status: active smokers (AS), former smokers (FS), non-smokers (NoNi). Psychiatric and non-psychiatric co-morbidities and treatment or substance use were taken into account in the analyses.

Results

A total of 170 participants were included (N = 37 FS, 39 AS, 86 NoNi). A significant decrease in the mean nocturnal O2 saturation was observed for FS and AS compared to NoNi. No differences were found regarding AHI. Regarding sleep architecture, we observed a significant decrease in the slow wave sleep duration for AS compared to NoNi, and interestingly not between FS and NoNi.

Conclusion

This study suggests that current smokers suffer from alterations in both sleep architecture and ventilatory parameters, the later appears to persist even after smoking cessation.

Association between myasthenia gravis and cognitive disorders: a PRISMA-compliant meta-analysis

OBJECTIVE

This meta-analysis assessed the association between myasthenia gravis (MG) and cognitive disorders.

METHODS

The PubMed, Web of Science, OVID, EMBASE, CNKI and Wanfang electronic databases were comprehensively searched from inception to October 2020 for relevant studies. The primary outcomes were scores of the cognitive function battery. A random effects model was used to evaluate the cognitive function of patients with MG.

RESULTS

Eight cross-sectional studies containing 381 patients and 220 healthy controls were included in this meta-analysis. In relation to global cognitive function, patients with MG performed significantly worse than healthy individuals (SMD = -0.4, 95% CI = -0.63 to -0.16, p < 0.001, I2 = 10%). Specifically, the impaired cognitive domains included language, visuospatial function, information processing, verbal immediate and delayed recall memory, visual immediate recall memory, and response fluency, while attention, executive function, and visual delayed recall memory were unimpaired. The patients with early-onset (SMD= -0.527, 95% CI = -0.855 to -0.199, p = 0.002) and generalized MG (SMD= -0.577, 95% CI = -1.047 to -0.107, p = 0.016) had poorer global cognitive performance than the healthy population.

CONCLUSIONS

Patients with MG may have cognitive disorders, including those associated with the domains of language, visuospatial function, information processing, verbal immediate and delayed recall memory, visual immediate recall memory and response fluency. Furthermore, the age of onset and disease severity may be associated with cognitive disorders in patients with MG.

Electroencephalographic slowdowns during sleep are associated with cognitive impairment in patients who have obstructive sleep apnea but no dementia

OBJECTIVES

To research the relationship between quantitative electroencephalogram (qEEG) and impaired cognitive function patients who have obstructive sleep apnea (OSA) but no dementia.

METHODS

Subjects who complained of snoring between March 2020 and April 2021 in the Sleep Medicine Center of Weihai Municipal Hospital were included. All subjects underwent overnight in-laboratory polysomnography (PSG) and were assessed using a neuropsychological scale. Standard fast fourier transform (FFT) was used to obtain the electroencephalogram (EEG) power spectral density curve, and to calculate the delta, theta, alpha, and beta relative power and the ratio between slow and fast frequencies. Binary logistic regression was used to assess the risk factors for cognitive impairment in patients who had OSA but no dementia. Correlation analysis was performed to determine the relationship between qEEG and cognitive impairment.

RESULTS

A total of 175 participants without dementia who met the inclusion criteria were included in this study. There were 137 patients with OSA, including 76 with mild cognitive impairment (OSA + MCI), 61 without mild cognitive impairment (OSA-MCI), and 38 participants without OSA (non-OSA). The relative theta power in the frontal lobe in stage 2 of non-rapid eye movement sleep (NREM 2) in OSA + MCI was higher than that in OSA-MCI (P = 0.038) and non-OSA (P = 0.018). Pearson correlation analysis showed that the relative theta power in the frontal lobe in NREM 2 was negatively correlated with Mini-Mental State Examination (MMSE) scores, Montreal Cognitive Assessment (MoCA) Beijing version scores, and MoCA subdomains scores (visual executive function, naming, attention, language, abstraction, delayed recall and orientation) outside language.

CONCLUSIONS

In patients who had OSA but no dementia, the EEG slower frequency power increased. The relative theta power in the frontal lobe in NREM 2 was associated with MCI of patients with OSA. These results suggest that the slowing of theta activity may be one of the neurophysiological changes in the early stage of cognitive impairment in patients with OSA.

Obstructive sleep apnea-related knowledge, attitude, experience, and behaviors among orthodontic professionals: a survey

PURPOSE

To assess obstructive sleep apnea (OSA)-related experience, knowledge, attitude, and behaviors among orthodontic professionals in China and identify factors associated with their knowledge levels, attitude toward referring, and self-confidence in the management of patients with OSA.

METHODS

An online cross-sectional survey was conducted using a 31-item questionnaire developed with a professional online survey tool ( www.wjx.cn ) and distributed via WeChat (Tencent, Shenzhen, China). Data were collected between January 16 and 23, 2022 and analyzed using the chi-square test, Fisher's exact test, and multivariate generalized estimation equations.

RESULTS

A total of 1760 professionals responded to the survey, and responses to 1611 questionnaires were valid. The average score of correct answers to the 15 OSA knowledge questions was 12.1 ± 2.0. Most of the professionals agreed that it was necessary to identify patients who might have OSA in practice. The top three sources for gaining knowledge of OSA according to the survey were classrooms and textbooks (76.3%), medical lectures (75.7%), and academic conferences (73.2%). The level of knowledge was significantly correlated with self-confidence in treatment (P < 0.001) and willingness to refer patients to otolaryngologists or clinicians of related disciplines (P < 0.001).

CONCLUSIONS

Most orthodontic professionals agreed that there was a need to identify patients with OSA and learn further about related problems. Treatment confidence and willingness of professionals to refer patients were related to the level of OSA knowledge. These findings suggest that promotion of OSA-related education may help improve the care of patients with OSA.

Abnormal dynamic functional connectivity in the hippocampal subregions of patients with untreated moderate-to-severe obstructive sleep apnea

OBJECTIVE

To investigate the dynamic change characteristics of dynamic functional connectivity (dFC) between the hippocampal subregions (anterior and posterior) and other brain regions in obstructive sleep apnoea (OSA) and its relationship with cognitive function, and to explore whether these characteristics can be used to distinguish OSA from healthy controls (HCs).

METHODS

Eighty-five patients with newly diagnosed moderate-to-severe OSA and 85 HCs were enrolled. All participants underwent resting-state functional magnetic resonance imaging (fMRI). The difference between dFC values between the hippocampal subregions and other brain regions in OSA patients and HCs was compared using the two-sample t tests. Correlation analyses were used to assess the relationship between dFC, clinical data, and cognitive functions in OSA patients. dFC values from different brain regions were used as classification features to distinguish between the two groups using a support vector machine.

RESULTS

Compared with HCs, the dFC values between the left anterior hippocampus and right culmen of the cerebellum anterior lobe, right anterior hippocampus and left lingual gyrus, and left posterior hippocampus and left precentral gyrus were significantly lower, and the dFC values between the left posterior hippocampus and precuneus were significantly higher in OSA patients. The dFC values between the left posterior hippocampus and the precuneus of OSA patients were associated with sleep-related indicators and Montreal Cognitive Assessment scores. Support vector machine analysis results showed that dFC values in different brain regions could distinguish OSA patients from HCs.

CONCLUSION

dFC patterns between the hippocampal subregions and other brain regions were altered in patients with OSA, including the cerebellum, default mode networks, sensorimotor networks, and visual function networks, which is possibly associated with cognitive decline. In addition, the dFC values of different brain regions could effectively distinguish OSA patients from HCs. These findings provide new perspectives on neurocognition in these patients.

Poor sleep is associated with deficits of attention in COPD patients

BACKGROUND

Poor sleep and attention deficits are common in COPD.

OBJECTIVES

To assess the relationship between self-reported poor sleep and attention deficits in COPD. We also studied the association between self-reported sleep and the attention tests with the objective characteristics of sleep.

METHODS

Fifty-nine COPD patients were prospectively studied. Self-reported sleep quality was assessed using the Pittsburgh sleep quality index (PSQI). Objective characteristics of sleep were assessed by actigraphy and polysomnography. Attention was evaluated with the Oxford sleep resistance test (OSLER) and the Psychomotor vigilance test (PVT).

RESULTS

28 (47 %) patients referred poor sleep (PSQI >5). In the OSLER test they showed earlier sleep onset than patients with good sleep, median (Interquartil range): 31.2 min (25.4-40) vs 40 min (28.5-40), p: 0.048. They also spent more time making errors: 4.5 % (0.6-7.6) of total test time vs 0.7 % (0.2-5.3), p: 0.048. In PVT, patients with poor sleep presented a greater dispersion of the reaction time values with a higher value in the slowest 10 % of the reactions, 828 (609-1667) msec. vs 708 (601-993) msec, p: 0.028. No association was found between self-reported poor sleep and objective sleep variables. We found no correlation between OSLER and PVT results and polysomnographic variables except between sleep efficiency and PVT response speed (β: 0.309, p: 0.018).

CONCLUSION

Self-reported poor sleep in COPD is associated with attention deficits. Sleep quality should be included in future studies of this facet of cognition in COPD, as well as to assess its potential usefulness as a therapeutic target.

Shedding light on neurofilament involvement in cognitive decline in obstructive sleep apnea and its possible role as a biomarker

Obstructive sleep apnea is one of the most common sleep disorders with a high estimated global prevalence and a large number of associated comorbidities in general as well as specific neuropsychiatric complications such as cognitive impairment. The complex pathogenesis and effects of the disorder including chronic intermittent hypoxia and sleep fragmentation may lead to enhanced neuronal damage, thereby contributing to neuropsychiatric pathologies. Obstructive sleep apnea has been described as an independent risk factor for several neurodegenerative diseases, including Alzheimer's disease and all-cause dementia. The influence of obstructive sleep apnea on cognitive deficits is still a topic of recent debate, and several mechanisms, including neurodegeneration and depression-related cognitive dysfunction, underlying this correlation are taken into consideration. The differentiation between both pathomechanisms of cognitive impairment in obstructive sleep apnea is a complex clinical issue, requiring the use of multiple and costly diagnostic methods. The studies conducted on neuroprotection biomarkers, such as brain-derived neurotrophic factors and neurofilaments, are recently gaining ground in the topic of cognition assessment in obstructive sleep apnea patients. Neurofilaments as neuron-specific cytoskeletal proteins could be useful non-invasive indicators of brain conditions and neurodegeneration, which already are observed in many neurological diseases leading to cognitive deficits. Additionally, neurofilaments play an important role as a biomarker in other sleep disorders such as insomnia. Thus, this review summarizes the current knowledge on the involvement of neurofilaments in cognitive decline and neurodegeneration in obstructive sleep apnea patients as well as discusses its possible role as a biomarker of these changes.

Older Age is Associated With Positional Obstructive Sleep Apnea

OBJECTIVES

Untreated obstructive sleep apnea (OSA) is associated with cognitive dysfunction; however studies report low adherence rates to standard continuous positive airway pressure (CPAP) treatment in the elderly. Positional OSA (p-OSA) is a subset that can be cured by positional therapy of avoiding supine sleep. However, there is no well-established criteria to identify patients who could benefit from positional therapy as an alternative or adjunct to CPAP. This study investigates if older age is related to p-OSA using different diagnostic criteria.

DESIGN

Cross-sectional study.

PARTICIPANTS

Participants aged 18 years old or more who underwent polysomnography for clinical reasons at University of Iowa Hospitals and Clinics over a 1-year period from July 2011 to June 2012 were enrolled retrospectively.

MEASUREMENT

P-OSA was defined as a high supine-position dependency of obstructive breathing events with potential resolution of OSA in nonsupine positions [high apnea-hypopnea index on supine positions (s-AHI)/ AHI on nonsupine positions (ns0AHI) combined with ns-AHI < 5/hour]. Different cutoff points (2, 3, 5, 10, 15, 20) were applied to determine a meaningful ratio of supine-position dependency of obstructions [s-AHI/ns-AHI]. We compared the proportion of patients with p-OSA between the older age group (≥65 years old) and the propensity score (PS)-matched (upto 1:4) younger age group (<65 years old) using logistic regression analyses.

RESULTS

In total, 346 participants were included. The older age group had a higher s-AHI/ns-AHI ratio than the younger age group (mean 31.6 [SD 66.2] versus 9.3 [SD 17.4], median 7.3 [interquartile range [IQR], 3.0-29.6) versus 4.1 (IQR, 1.9-8.7). After PS-matching, the older age group (n = 44) had higher proportion of those with a high s-AHI/ns-AHI ratio and ns-AHI< 5/hour compared with the younger age group (n = 164). (s-AHI/ns-AHI≥10: 54.6% versus 31.7%, OR 2.44 (95% CI, 1.22-4.90); s-AHI/ns-AHI≥15: 47.7% versus 26.2%, OR 2.24 (95% CI, 1.14-4.37); s-AHI/ns-AHI≥20: 40.9% versus 19.5%, OR 2.52 (95% CI, 1.22-5.20)) CONCLUSION: Older patients with OSA are more likely to have severe position dependent OSA, that is potentially more treatable with positional therapy. Thus, clinicians treating older, cognitively impaired geriatric patients unable to tolerate CPAP therapy should consider positional therapy as an adjunct or alternative.

Predicting mild cognitive impairment among Chinese older adults: a longitudinal study based on long short-term memory networks and machine learning

Background

Mild cognitive impairment (MCI) is a transitory yet reversible stage of dementia. Systematic, scientific and population-wide early screening system for MCI is lacking. This study aimed to construct prediction models using longitudinal data to identify potential MCI patients and explore its critical features among Chinese older adults.

Methods

A total of 2,128 participants were selected from wave 5-8 of Chinese Longitudinal Healthy Longevity Study. Cognitive function was measured using the Chinese version of Mini-Mental State Examination. Long- short-term memory (LSTM) and three machine learning techniques, including 8 sociodemographic features and 12 health behavior and health status features, were used to predict individual risk of MCI in the next year. Performances of prediction models were evaluated through receiver operating curve and decision curve analysis. The importance of predictors in prediction models were explored using Shapley Additive explanation (SHAP) model.

Results

The area under the curve values of three models were around 0.90 and decision curve analysis indicated that the net benefit of XGboost and Random Forest were approximate when threshold is lower than 0.8. SHAP models showed that age, education, respiratory disease, gastrointestinal ulcer and self-rated health are the five most important predictors of MCI.

Conclusion

This screening method of MCI, combining LSTM and machine learning, successfully predicted the risk of MCI using longitudinal datasets, and enables health care providers to implement early intervention to delay the process from MCI to dementia, reducing the incidence and treatment cost of dementia ultimately.

Obstructive sleep apnea in Parkinson's disease: A prevalent, clinically relevant and treatable feature

Parkinson's disease (PD) is a chronic neurodegenerative disease characterized by motor and non-motor symptoms, including obstructive sleep apnea (OSA), a common comorbid sleep disorder. The prevalence of OSA in PD is high, and its impact on quality of life, accident risk, and limited treatment options underscores the need for vigilant monitoring and effective interventions. OSA is observed in 20-70% of PD patients, whereas the general population exhibits a lower prevalence ranging from 2 to 14%. These discrepancies in prevalence may be attributed to differences in demographic characteristics, sample sizes with selection bias, and variations in scoring systems for apnea and hypopnea events used across different studies. This review highlights the potential pathogenesis of comorbid OSA in PD and provides an overview of ongoing clinical trials investigating interventions for this condition. Several mechanisms have been implicated in the development of OSA in PD, including intermittent hypoxemia, sleep fragmentation, alterations in the glymphatic system homeostasis, upper airway obstruction, and inflammation. Given the adverse effects of PD comorbid OSA, early intervention measures are crucial. It is imperative to conduct longitudinal studies and clinical trials to elucidate the pathogenesis and develop novel and effective interventions for OSA in PD patients. These efforts aim to delay the progression of PD, enhance patients' quality of life, and alleviate the burden on society and families.

Obstructive sleep apnea and dementia: A role to play?

A growing number of studies, in animal models and humans, have highlighted the link between sleep and Alzheimer's disease (AD) pathophysiology. Among sleep disorders, obstructive sleep apnea (OSA) appears to be a potentially interesting comorbidity, as it is highly prevalent in the middle-aged and elderly population, often associated with some cognitive impairment, associated with an increased risk of developing cognitive decline and dementia including AD, and indeed treatable. The association between OSA and cognition varies according to the studies, but OSA is more frequent in older people with AD than those who are cognitively normal. People with OSA suffer from daytime sleepiness, impaired cognitive function and an increased risk of developing mild cognitive impairment, dementia and AD than those without OSA. Finally, the literature suggests a link between OSA and AD biomarkers. Whether screening and treating OSA could have positive impact on the levels of AD biomarkers and slow or even prevent incident dementia remain to be investigated. It therefore seems essential to understand the role of OSA in the pathophysiology of AD, as there is still no effective treatment to slow or halt its progression. At present, treating the risk factors that can promote the development and/or worsening of AD represents a promising strategy for delaying or even thwarting the onset of symptoms.

Sleep electroencephalography biomarkers of cognition in obstructive sleep apnea

Obstructive sleep apnea has been associated with cognitive impairment and may be linked to disorders of cognitive function. These associations may be a result of intermittent hypoxaemia, sleep fragmentation and changes in sleep microstructure in obstructive sleep apnea. Current clinical metrics of obstructive sleep apnea, such as the apnea-hypopnea index, are poor predictors of cognitive outcomes in obstructive sleep apnea. Sleep microstructure features, which can be identified on sleep electroencephalography of traditional overnight polysomnography, are increasingly being characterized in obstructive sleep apnea and may better predict cognitive outcomes. Here, we summarize the literature on several major sleep electroencephalography features (slow-wave activity, sleep spindles, K-complexes, cyclic alternating patterns, rapid eye movement sleep quantitative electroencephalography, odds ratio product) identified in obstructive sleep apnea. We will review the associations between these sleep electroencephalography features and cognition in obstructive sleep apnea, and examine how treatment of obstructive sleep apnea affects these associations. Lastly, evolving technologies in sleep electroencephalography analyses will also be discussed (e.g. high-density electroencephalography, machine learning) as potential predictors of cognitive function in obstructive sleep apnea.

Obstructive sleep apnea and cognition: insights gleaned from bibliometric analysis

Objective

Obstructive sleep apnea (OSA) is associated with cognitive impairment. However, the broad trends of the research publications on OSA and cognition are unclear. This study aimed to investigate patterns of research on the relationship between OSA and cognitive function using bibliometric analysis and to identify future research directions by analyzing research trends and emerging hotspots in the field.

Methods

We searched Web of Science for relevant publications from 2003 to 2022 and conducted a bibliometric analysis of OSA and cognitive research using CiteSpace, R, and VOSviewer.

Results

A total of 1995 articles met the eligibility criteria for the analysis of OSA and cognition research. There was a notable increase in publications over time, with significant contributions from the United States, particularly Harvard University, leading to substantial academic impact. Gozal D emerged as the most prolific author (59 articles) and influential researcher (3,612 citations) in this field. Hotspot analysis revealed that investigating the pathological physiology and mechanisms of OSA-associated cognitive dysfunction is a recent area of focus, while burst detection analysis identified sleep quality and mild cognitive impairment as top investigation topics. The study by Canessa N published in the American Journal of Respiratory and Critical Care Medicine received the highest number of 77 citations.

Conclusion

Researchers are increasingly focusing on OSA and cognition. Currently, the majority of studies on OSA-related cognitive dysfunction are focused on correctable aspects of the condition. Future investigations into the pathology of OSA-induced cognitive impairment will facilitate more precise therapeutic interventions.

Alterations of Limbic Structure Volumes in Patients with Obstructive Sleep Apnea

OBJECTIVES

We investigated the change in limbic structure volumes and intrinsic limbic network in patients with obstructive sleep apnea (OSA) compared to healthy controls.

METHODS

We enrolled 26 patients with OSA and 30 healthy controls. They underwent three-dimensional T1-weighted magnetic resonance imaging (MRI) on a 3 T MRI scanner. The limbic structures were analyzed volumetrically using the FreeSurfer program. We examined the intrinsic limbic network using the Brain Analysis with Graph Theory program and compared the groups' limbic structure volumes and intrinsic limbic network.

RESULTS

There were significant differences in specific limbic structure volumes between the groups. The volumes in the right amygdala, right hippocampus, right hypothalamus, right nucleus accumbens, left amygdala, left basal forebrain, left hippocampus, left hypothalamus, and left nucleus accumbens in patients with OSA were lower than those in healthy controls (right amygdala, 0.102 vs. 0.113%, p = 0.004; right hippocampus, 0.253 vs. 0.281%, p = 0.002; right hypothalamus, 0.028 vs. 0.032%, p = 0.002; right nucleus accumbens, 0.021 vs. 0.024%, p = 0.019; left amygdala, 0.089 vs. 0.098%, p = 0.007; left basal forebrain, 0.020 vs. 0.022%, p = 0.027; left hippocampus, 0.245 vs. 0.265%, p = 0.021; left hypothalamus, 0.028 vs. 0.031%, p = 0.016; left nucleus accumbens, 0.023 vs. 0.027%, p = 0.002). However, there were no significant differences in network measures between the groups.

CONCLUSION

We demonstrate that the volumes of several limbic structures in patients with OSA are significantly lower than those in healthy controls. However, there are no alterations to the intrinsic limbic network. These findings suggest that OSA is one of the risk factors for cognitive impairments.

Relationship between Symptom Profiles and Endotypes among Patients with Obstructive Sleep Apnea: A Latent Class Analysis

Rationale: Obstructive sleep apnea (OSA) is a heterogeneous syndrome with various endotypic traits and symptoms. A link among symptoms, endotypes, and disease prognosis has been proposed but remains unsupported by empirical data. Objectives: To link symptom profiles and endotypes by clustering endotypic traits estimated using polysomnographic signals. Methods: We recruited 509 patients with moderate to severe OSA from a single sleep center. Polysomnographic data were collected between May 2020 and January 2022. Endotypic traits, namely arousal threshold, upper airway collapsibility, loop gain, and upper airway muscle compensation, were retrieved using polysomnographic signals during non-rapid eye movement periods. We used latent class analysis to group participants into endotype clusters. Demographic and polysomnographic parameter differences were compared between clusters, and associations between endotype clusters and symptom profiles were examined using logistic regression analyses. Results: Three endotype clusters were identified, characterized by high collapsibility/loop gain, low arousal threshold, and low compensation, respectively. Patients in each cluster exhibited similar demographic characteristics, but those in the high collapsibility/loop gain cluster had the highest proportion of obesity and severe oxygen desaturation observed in polysomnographic studies. The low compensation cluster was characterized by fewer sleepy symptoms and exhibited a lower rate of diabetes mellitus. Compared with the excessively sleepy group, disturbed sleep symptoms were associated with the low arousal threshold cluster (odds ratio, 1.89; 95% confidence interval, 1.16-3.10). Excessively sleepy symptoms were associated with the high collapsibility/loop gain cluster (odds ratio, 2.16; 95% confidence interval, 1.39-3.37) compared with the minimally symptomatic group. Conclusions: Three pathological endotype clusters were identified among patients with moderate to severe OSA, each exhibiting distinct polysomnographic characteristics and clinical symptom profiles.

The Abnormal Alternations of Brain Imaging in Patients with Chronic Obstructive Pulmonary Disease: A Systematic Review

Background

Cognitive impairment (CI) is an important extrapulmonary complication in patients with chronic obstructive pulmonary disease (COPD). Multimodal Neuroimaging Examination can display changes in brain structure and functions in patients with COPD.

Objective

The purpose of this systematic review is to provide an overview of the variations in brain imaging in patients with COPD and their potential relationship with CI. Furthermore, we aim to provide new ideas and directions for future research.

Methods

Literature searches were performed using the electronic databases PubMed, Scopus, and ScienceDirect. All articles published between January 2000 and November 2021 that met the eligibility criteria were included.

Results

Twenty of the 23 studies focused on changes in brain structure and function. Alterations in the brain's macrostructure are manifested in the bilateral frontal lobe, hippocampus, right temporal lobe, motor cortex, and supplementary motor area. The white matter microstructural changes initially appear in the bilateral frontal subcortical region. Regarding brain function, patients with COPD exhibited reduced frontal cerebral perfusion and abnormal alterations in intrinsic brain activity in the bilateral posterior cingulate cortex, precuneus, right lingual gyrus, and left anterior central gyrus. Currently, there is limited research related to brain networks.

Conclusion

CI in patients with COPD may present as a type of dementia different from Alzheimer's disease, which tends to manifest as frontal cognitive decline early in the disease. Further studies are required to clarify the neurobiological pathways of CI in patients with COPD from the perspective of brain connectomics based on the whole-brain system in the future.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Sleep quality mediates the relationship between systemic inflammation and neurocognitive performance

Background

Systemic inflammation is a significant mechanism underpinning adverse cognitive changes. Sleep quality is a crucial factor associated with systemic inflammation and neurocognitive health. Elevated levels of pro-inflammatory cytokines in the periphery help mark inflammation. With this background, we examined the relationship between systemic inflammation, subjective sleep quality, and neurocognitive performance in adults.

Method & Results

In 252 healthy adults, we measured the systemic inflammation reflected by serum levels of IL-6, IL-12, IL-18, TNF-α and IFN-γ, subjective sleep quality reflected by the global scores of the Pittsburgh Sleep Quality Index, and their neurocognitive performance measured by the Hong Kong Montreal Cognitive Assessment. We observed that neurocognitive performance was negatively related to IL-18 (p = 0.046) and positively related to sleep quality (p = 0.006). We did not observe significant associations between other cytokines and neurocognitive performance. Furthermore, we found that sleep quality as a mediator explained the relationship between IL-18 and neurocognitive performance depending on the levels of IL-12 (index of moderated mediation: 95% CI = [0.0047, 0.0664]). Better subjective sleep quality buffered the negative effect of IL-18 on neurocognitive performance when IL-12 was low (bootstrapping 95% CI: [- 0.0824, - 0.0018]). On the contrary, poor subjective sleep quality mediated the association between higher IL-18 and poorer neurocognitive performance when IL-12 was elevated (bootstrapping 95% CI: [0.0004, 0.0608]).

Conclusion & Implications

Our findings indicate that systemic inflammation was negatively associated with neurocognitive performance. Sleep quality regulated by IL-18/IL-12 axis activation could be a potential mechanism underpinning neurocognitive changes. Our results illustrate the intricate relationships between immune functioning, sleep quality and neurocognitive performance. These insights are essential to understand the potential mechanisms underpinning neurocognitive changes, paving the way for the development of preventive interventions for the risk of cognitive impairment.

The Relationship Between Cognitive Impairments and Sleep Quality Measures in Persistent Insomnia Disorder

Study Objectives

Persistent insomnia disorder (pID) is linked to neurocognitive decline and increased risk of Alzheimer's Disease (AD) in later life. However, research in this field often utilizes self-reported sleep quality data - which may be biased by sleep misperception - or uses extensive neurocognitive test batteries - which are often not feasible in clinical settings. This study therefore aims to assess whether a simple screening tool could uncover a specific pattern of cognitive changes in pID patients, and whether these relate to objective aspect(s) of sleep quality.

Methods

Neurocognitive performance (Montreal Cognitive Assessment; MoCA), anxiety/depression severity, and subjective sleep quality (Pittsburgh Sleep Quality Index: PSQI; Insomnia Severity Index: ISI) data were collected from 22 middle-aged pID patients and 22 good-sleepers. Patients underwent overnight polysomnography.

Results

Compared to good-sleepers, patients had lower overall cognitive performance (average: 24.6 versus 26.3 points, Mann-Whitney U = 136.5, p = <0.006), with deficits in clock drawing and verbal abstraction. In patients, poorer overall cognitive performance correlated with reduced subjective sleep quality (PSQI: r(42) = -0.47, p = 0.001; and ISI: r(42) = -0.43, p = 0.004), reduced objective sleep quality (lower sleep efficiency: r(20) = 0.59, p = 0.004 and less REM-sleep: r(20) = 0.52, p = 0.013; and increased sleep latency: r(20) = -0.57, p = 0.005 and time awake: r(20) = -0.59, p = 0.004). Cognitive performance was not related to anxiety/depression scores.

Conclusion

Using a simple neurocognitive screening tool, we found that pID patients showed cognitive deficiencies that related to both subjective/self-reported and objective/polysomnographic measures of sleep quality. Furthermore, these cognitive changes resembled those seen in preclinical non-amnestic AD, and thus could indicate incumbent neurodegenerative processes in pID. Interestingly, increased REM-sleep was correlated with better cognitive performance. However, whether REM-sleep is protective against neurodegeneration requires further investigation.

Pterostilbene mediates glial and immune responses to alleviate chronic intermittent hypoxia-induced oxidative stress in nerve cells

Chronic intermittent hypoxia (CIH) induces oxidative stress in the brain, causing sleep disorders. Herein, we investigated the role of pterostilbene (Pte) in CIH-mediated oxidative stress in the brain tissue. A CIH mouse model was constructed by alternately reducing and increasing oxygen concentration in a sealed box containing the mouse; brain tissue and serum were then collected after intragastric administration of Pte. Neurological function was evaluated through field experiments. The trajectory of the CIH mice to the central region initially decreased and then increased after Pte intervention. Pte increased the number of neuronal Nissl bodies in the hippocampus of CIH mice, upregulated the protein levels of Bcl-2, occludin, and ZO-1 as well as the mRNA and protein levels of cAMP-response element binding protein (CREB) and p-BDNF, and reduced the number of neuronal apoptotic cells, Bax protein levels, IBA-1, and GFAP levels. Simultaneously, Pte reversed the decreased levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and BDNF and increased levels of malondialdehyde (MDA) in the serum of CIH mice. Pte increased Th2 cells, Treg cells, IL-4, IL-10, and TGF-β1 levels and decreased Th1 cells, Th17 cells, IFN-γ, IL-6, and IL- 17A levels in activated BV2 cells and hippocampus in CIH mice. The protein levels of p-ERK1/2, TLR4, p-p38, p-p65, and Bax, apoptosis rate, MDA concentration, Bcl-2 protein level, cell viability, and SOD and GSH-PX concentrations decreased after the activation of BV2 cells. Pte inhibited gliocytes from activating T-cell immune imbalance through p-ERK signaling to alleviate oxidative stress injury in nerve cells.

Changes in Functional Connectivity of Hippocampal Subregions in Patients with Obstructive Sleep Apnea after Six Months of Continuous Positive Airway Pressure Treatment

Previous studies have shown that the structural and functional impairments of hippocampal subregions in patients with obstructive sleep apnea (OSA) are related to cognitive impairment. Continuous positive airway pressure (CPAP) treatment can improve the clinical symptoms of OSA. Therefore, this study aimed to investigate functional connectivity (FC) changes in hippocampal subregions of patients with OSA after six months of CPAP treatment (post-CPAP) and its relationship with neurocognitive function. We collected and analyzed baseline (pre-CPAP) and post-CPAP data from 20 patients with OSA, including sleep monitoring, clinical evaluation, and resting-state functional magnetic resonance imaging. The results showed that compared with pre-CPAP OSA patients, the FC between the right anterior hippocampal gyrus and multiple brain regions, and between the left anterior hippocampal gyrus and posterior central gyrus were reduced in post-CPAP OSA patients. By contrast, the FC between the left middle hippocampus and the left precentral gyrus was increased. The changes in FC in these brain regions were closely related to cognitive dysfunction. Therefore, our findings suggest that CPAP treatment can effectively change the FC patterns of hippocampal subregions in patients with OSA, facilitating a better understanding of the neural mechanisms of cognitive function improvement, and emphasizing the importance of early diagnosis and timely treatment of OSA.

Preliminary Development of a Brainwave Model for K1 Kickboxers Using Quantitative Electroencephalography (QEEG) with Open Eyes

K1 kickboxing fighting is characterised by high injury rates due to the low restrictions of fighting rules. In recent years, much attention has been paid to research on changes in brain function among athletes, including those in combat sports. One of the tools that are likely to help diagnose and assess brain function is quantitative electroencephalography (QEEG). Therefore, the aim of the present study was an attempt to develop a brainwave model using quantitative electroencephalography in competitive K1 kickboxers. A total of thirty-six male individuals were purposefully selected and then comparatively divided into two groups. The first group consisted of specialised K1 kickboxing athletes exhibiting a high level of sports performance (experimental group, n = 18, mean age: 29.83 ± 3.43), while the second group comprised healthy individuals not training competitively (control group, n = 18, mean age: 26.72 ± 1.77). Body composition assessment was performed in all participants before the main measurement process. Measurements were taken for kickboxers during the de-training period, after the sports competition phase. Quantitative electroencephalography of Delta, Theta, Alpha, sensimotor rhytm (SMR), Beta1 and Beta2 waves was performed using electrodes placed on nine measurement points (frontal: FzF3F4, central: CzC3C4, and parietal: PzP3P4) with open eyes. In the course of the analyses, it was found that the level of brain activity among the study population significantly differentiated the K1 formula competitors compared with the reference standards and the control group in selected measurement areas. For kickboxers, all results of the Delta amplitude activity in the area of the frontal lobe were significantly above the normative values for this wave. The highest value was recorded for the average value of the F3 electrode (left frontal lobe), exceeding the norm by 95.65%, for F4 by 74.45% and Fz by 50.6%, respectively. In addition, the Alpha wave standard value for the F4 electrode was exceeded by 14.6%. Normative values were found for the remaining wave amplitudes. Statistically significant differentiation of results, with a strong effect (d = 1.52-8.41), was shown for the activity of Delta waves of the frontal area and the central part of the parietal area (Fz,F3,F4,Cz-p < 0.001), Theta for the frontal area as well as the central and left parietal lobes (Fz,F3,F4-p < 0.001, Cz-p = 0.001, C3-p = 0.018; d = 1.05-3.18), Alpha for the frontal, parietal and occipital areas (for: Fz,F3-p < 0.001, F4-p = 0.036, Cz-p < 0.001, C3-p = 0.001, C4-p = 0.025, Pz-p = 0.010, P3-p < 0.001, P4-p = 0.038; d = 0.90-1.66), SMR for the central parietal and left occipital lobes (Cz-p = 0.043; d = 0.69, P3-p < 0.001; d = 1.62), Beta for the frontal area, occipital and central lobes and left parietal segment (Fz,F3-p < 0.001, F4-p = 0.008, Cz, C3, Pz, P3,P4-p < 0.001; d = 1.27-2.85) and Beta 2 for all measurement areas (Fz, F3, F4, Cz, C3, C4, Pz, P3, P4-p < 0.001; d = 1.90-3.35) among the study groups. Significantly higher results were shown in the kickboxer group compared to the control. In addition to problems with concentration or over-stimulation of neural structures, high Delta waves, with elevated Alpha, Theta and Beta 2 waves, can cause disorders in the limbic system and problems in the cerebral cortex.

Treatment of hypertension and obstructive sleep apnea counteracts cognitive decline in common neurocognitive disorders in diagnosis-related patterns

The aim of this study was to investigate the effect of arterial hypertension (AH) and of obstructive sleep apnea (OSA) on cognitive course in the neurocognitive disorder (NCD) cohort RIFADE which enrolled patients with NCD due to Alzheimer's disease (AD), vascular NCD (vNCD), and mixed NCD (AD + vNCD = mNCD). Multiple risk factors (RF), including AH and OSA, that contribute to the development of various kinds of dementia have been identified in previous studies. Studies that observed AH lacked investigation of long-term effects and did not isolate it from other RF. Studies involving OSA as a risk factor did not include participants with all stages of NCD. 126 subjects were screened for AH and OSA. Repeated cognitive measurements were performed with the DemTect as primary outcome and the clock drawing test as secondary outcome measure. 90 patients had AH (71.4%) and 40 patients had OSA (31.7%). RF-status had a significant effect on cognitive outcome in models with RF as single factors (AH p = 0.027, OSA p < 0.001), a 2-factor analysis with AH × OSA (AH as main factor p = 0.027) as well as a model including the 3 factors AH × OSA × diagnosis (p = 0.038). Similarly, a 3-factor model was significant for the clock-drawing test, whereas single factor-models remained insignificant. AH and OSA appear to be risk factors in common NCD and cognitive decline can be mitigated by treatment of these RF.

Obstructive Sleep Apnea - Influence on the Cardiovascular System and Cognition

Kardiovaskuläre und kognitive Erkrankungen sind ebenso wie die obstruktive Schlafapnoe sehr häufige Krankheiten mit einer erheblichen Beeinträchtigung der Lebensqualität und einer deutlichen sozioökonomischen Bedeutung. Die Auswirkungen einer unbehandelten obstruktiven Schlafapnoe (OSA) auf das kardiovaskuläre und kognitive Erkrankungsrisiko und die Therapieeffekte einer OSA sind für die meisten kardiovaskulären und kognitiven Folgeerkrankungen wissenschaftlich nachgewiesen. Für die klinische Praxis besteht ein deutlicher Bedarf nach mehr Interdisziplinarität. Aus schlafmedizinischer Sicht müssen bei der Therapieindikation das individuelle kardiovaskuläre und kognitive Risiko berücksichtigt und kognitive Erkrankungen bei der Beurteilung der Therapieintoleranz und residuellen Symptomatik beachtet werden. Aus internistischer Sicht sollte bei Patienten mit schlecht einstellbarem Hypertonus, Vorhofflimmern, koronarer Herzkrankheit und Schlaganfall die Abklärung einer OSA in die Diagnostik integriert werden. Bei Patienten mit milder kognitiver Beeinträchtigung, Alzheimer-Krankheit und Depression können sich die typischen Symptome wie Fatigue, Tagesmüdigkeit und Reduktion der kognitiven Leistungen mit OSA-Symptomen überschneiden. Die Diagnostik einer OSA sollte in die Abklärung dieser Krankheitsbilder integriert werden, da eine Therapie der OSA die kognitiven Beeinträchtigungen reduzieren und die Lebensqualität verbessern kann.

SENP1 modulates chronic intermittent hypoxia-induced inflammation of microglia and neuronal injury by inhibiting TOM1 pathway

Chronic intermittent hypoxia (CIH) is a characteristic pathophysiological change of obstructive sleep apnea syndrome (OSAS). Inflammation of microglia induced by CIH, plays a vital role in OSAS-associated cognitive dysfunction. SUMO-specific proteases 1 (SENP1) has been implicated in tumor inflammatory microenvironment and cells migration. However, the role of SENP1 in CIH-induced neuroinflammation remains unknown. We aimed to investigate the effect of SENP1 on neuroinflammation and neuronal injury. After the preparation of SENP1 overexpression microglia and SENP1 knockout mouse, CIH microglia and mice were established using an intermittent hypoxia device. Results showed that CIH reduced the level of SENP1 and TOM1, induced the SUMOylation of TOM1, and promoted microglial migration, neuroinflammation, neuronal amyloid-beta 42 (Aβ₄₂) deposition and apoptosis in vitro and in vivo. After SENP1 overexpression in vitro, the enhanced SUMOylation of TOM1 was inhibited; the level of TOM1 and microglial migration were enhanced; neuroinflammation, neuronal Aβ₄₂ deposition and apoptosis were significantly reduced. However, the administration of siRNA-TOM1 suppressed microglial migration, neuroinflammation, neuronal Aβ₄₂ deposition and apoptosis. After SENP1 knockout in vivo, the SUMOylation enhancement of TOM1 was accelerated, microglial migration was inhibited. Neuroinflammation, neuronal Aβ₄₂ deposition and apoptosis, cognitive impairment was significantly exacerbated. Overall, the results demonstrated that SENP1 promoted microglial migration by alleviating the de-SUMOylation of TOM1, thus contributing to attenuate neuroinflammation, neuronal Aβ₄₂ deposition and neuronal apoptosis induced by CIH.

A Review of Neurological Symptoms in Long COVID and Clinical Management

Long COVID is a clinical diagnosis generally referring to the persistence or development of new symptoms, affecting multiple organ systems after SARS-CoV-2 COVID-19 infection. Long COVID is thought to affect ∼20% of people after infection, including all age ranges and severity of infection. Fatigue, postexertional malaise, and respiratory and cardiac symptoms are commonly described. Neurological symptoms such as cognitive changes, sensory disturbances, headaches, and dysautonomia are common as well. The underlying pathophysiology remains unclear but immune dysregulation, autoimmunity, persistent viral reservoirs, and microvascular dysfunction have been implicated. As there are no tests at this time to diagnose long COVID, work-up should be focused on assessing reversible or treatable causes of symptoms. Furthermore, no treatments for long COVID currently exist, and management remains focused on a multimodal approach and symptom management, with many people showing improvement in symptoms over time.

Mentation Tracks Severity but not Oxygenation in Obstructive Sleep Apnea

There is a rough consensus, after decades of research, that obstructive sleep apnea (OSA) is associated with mild cognitive impairments, especially in areas of executive functioning (EF), attention/working memory (A/WM), episodic memory (EM), and speed of speed of information processing (SIP). However, there is less consensus as to whether apnea severity matters for these impairments, which sleep variables matter most to which cognitive domains, whether common OSA comorbidities contribute to these determinations, or whether the apparent associations are really artifacts of these comorbidities. In this study, 40 participants with OSA submitted to polysomnography and to neuropsychological assessment with an expanded Halstead-Reitan Test Battery. Aggregates of tests to cover the four cognitive domains mentioned above were linearly regressed on the apnea-hypopnea index (AHI), the nadir of oxygen saturation (NOS), and hypertension and diabetes mellitus (scored present or absent). The AHI predicted both EF (p = .015; sr2 = .13) and A/WM (p = .023; sr2 = 11) in the primary analyses, and EM (p = .027; sr2 = .10) in the secondary analyses. Thus, AHI may affect EF, A/WM and perhaps EM beyond NOS and beyond two of OSA's most common comorbidities. Implications of these findings are discussed here.