Sleep apnea and the risk of dementia: A systematic review and meta-analysis

Comparative efficacy of non-pharmacological interventions for adults with sleep apnea: A systematic review and network meta-analysis

BACKGROUND

Sleep apnea is associated with cardiovascular risk, work productivity, occupational/traffic accidents, and quality-of-life (QoL); however uncertainty exists regarding optimal treatment. We performed a systematic review on the efficacy of non-pharmacological interventions for adults with sleep apnea.

METHOD

We searched MEDLINE, Scopus, Virtual-Health-Library and Web-of-Science through June 2023 for parallel/cross-over randomized trials on adults with sleep apnea (apnea-hypopnea-index>5 events/hour). Study selection, data extraction and risk-of-bias assessment were performed in duplicate, followed by frequentist network meta-analyses.

RESULTS

Ultimately, 197 unique trials were included (15,931 patients; mean age 51.4 years; 78.9 % male) assessing 25 treatments. Positive Airway Pressure (PAP) (alone or combined with health behaviour modification) consistently improved more apnea-hypopnea-index or daytime sleepiness and physical/mental QoL in obstructive sleep apnea (OSA) patients compared to all other interventions but was not always well-tolerated. Mandibular advancement devices (MAD) yielded the greatest improvement in depression, while also improving objective/subjective apnea-outcomes, and physical/mental QoL-albeit less than PAP and less for moderate/severe cases. Acupuncture, health behaviour modifications, surgical maxillomandibular advancement, minor oral surgery, oropharyngeal training, oxygen supplementation, or electrical neurostimulation might improve apnea-related outcomes, but weak evidence exists. Finally, electrical neurostimulation performed best for central sleep apnea and PAP performed best for positional OSA. Confidence in the network meta-analysis estimates was low due to non-adherence issues that was rarely directly assessed in included trials with objective measures.

CONCLUSION

PAP (alone or with co-interventions) performed best for the treatment of adult OSA patients regardless of disease severity. For patients not tolerating PAP, MADs might be a good alternative, but confer smaller improvements overall. However, adherence issues and the heterogenous response increase the complexity of OSA treatment.

Impact of sleep apnea on alzheimer's disease in relation to sex: an 8-year longitudinal follow-up study of a nationwide cohort

BACKGROUND

We aimed to investigate the association between sleep apnea and incident dementia (dementia of the Alzheimer type [DAT] and vascular dementia) and whether differences in the effects of sleep apnea on dementia depend on sex. Furthermore, we sought to determine whether obesity affects the sex-specific relationship between sleep apnea and dementia.

METHODS

We used de-identified data on patients with sleep apnea and a control group aged ≥ 50 years from the Korean National Health Insurance Service. After propensity score matching to balance age and sex between the patient and control groups, 30,111 individuals with sleep apnea (patient group) and 121,528 individuals without sleep apnea (control group) were included. To investigate the impact of sleep apnea on the development of dementia, we used Cox proportional hazards regression after controlling for potential confounders.

RESULTS

Sleep apnea was predictive of developing DAT in both women (hazard ratio [HR] = 1.30, 95% confidence interval [CI] 1.16-1.44, p < 0.001) and men (HR = 1.13, 95% CI 1.03-1.24, p = 0.012). The adverse effects of sleep apnea on DAT were more prominent in women than in men (p = 0.015 for sleep apnea×sex). Furthermore, obesity affected the sex-specific relationship between sleep apnea and DAT. Specifically, the adverse effects of obese sleep apnea on the DAT were more pronounced in women than in men (p = 0.002 for obese sleep apnea×sex). In contrast, there were no differences in the effects of non-obese sleep apnea on DAT between women and men (p = 0.667 for non-obese sleep apnea×sex).

CONCLUSIONS

Our results highlight sex differences in the adverse effects of sleep apnea on DAT. Furthermore, these results suggest that sex-specific strategies for controlling sleep apnea are necessary to prevent DAT.

Brain health services for the secondary prevention of cognitive impairment and dementia: Opportunities, challenges, and the business case for existing and future facilities

A European Task Force has recently developed and published the concept and protocols for the setup of the innovative health offer of Brain Health Services for the secondary prevention of dementia and cognitive impairment (dBHS). dBHS are outpatient health care facilities where adult persons can find an assessment of their risk of developing cognitive impairment and dementia, have their risk level and contributing factors communicated using appropriate language supported by adequate communication tools, can decide to participate to programs for personalized risk reduction if at higher risk, and benefit from cognitive enhancement interventions. This health offer is distinct from that of currently active memory clinics. The ultimate aim of dBHS is to extend healthy life, free from cognitive impairment. Here, we (i) discuss the pertinent opportunities and challenges for those persons who want to benefit from dBHS, professionals, and wider society, (ii) describe the concepts, protocols, organizational features, and patient journeys of some currently active dBHS in Europe, and (iii) argue in favor of the business case for dBHS in Europe.

Obstructive sleep apnea is a common diagnosis in patients admitted at the memory clinic: Please screen for it!

Obstructive sleep apnea (OSA) affects a large portion of middle-aged and older adults. It has been linked to increased risk of cognitive decline and Alzheimer's disease. OSA can impair cognitive performance and patients with cognitive complaints can frequently present with this sleep disorder. Although instruments able for correctly screening patients with cognitive impairment and OSA exist, there is no evidence about utility and feasibility of their use in the memory clinics. The study by Lam et al. showed that, in case of impossibility of performing polysomnography-that is the gold standard for OSA diagnosis, pulse oximetry can represent a good instrument for screening patients with cognitive impairment for OSA, and they do not advice for using sleep interview or STOP-Bang questionnaire for screening this sleep disorder.

Obstructive sleep apnoea syndrome and future risk of dementia among individuals managed in UK general practice

BACKGROUND

Obstructive sleep apnoea syndrome (OSAS) has been recognised as a potential risk factor for cognitive decline, yet its precise relationship with dementia remains uncertain. This study aimed to determine the risk of dementia among individuals with and without OSAS.

METHODS

Data derived from 2.3 million adults (aged ≥18 years) were extracted from the Clinical Practice Research Datalink (2000-2022), a nationally representative primary care electronic health records database in the UK. 193 600 individuals with OSAS were propensity score-matched to 536 701 individuals without OSAS. Cox proportional hazard regression models were applied to quantify the risk of developing all-cause dementia, vascular dementia and Alzheimer's disease between individuals with and without OSAS.

RESULTS

With a median follow-up of 4.0 (IQR 1.8-7.5) years, 2802 and 6211 individuals developed all-cause dementia in those with and without OSAS, corresponding to crude incidence rates of 2.47 and 2.34 per 1000 person-years, respectively. The presence of OSAS was associated with higher risks of all-cause dementia (adjusted HR (aHR) 1.12, 95% CI 1.07 to 1.17), vascular dementia (1.29, 95% CI 1.19 to 1.41) and unchanged risk of Alzheimer's disease (1.07, 95% CI 0.99 to 1.16). Individuals with OSAS who had received continuous positive airway pressure (CPAP) treatment exhibited a similar risk of all-cause dementia as their matched counterparts (0.99, 95% CI 0.74 to 1.32).

CONCLUSION

OSAS is associated with higher risks of all-cause dementia and some of its subtypes. Further investigation is needed to investigate the clinical benefits of screening for cognitive impairment in people with OSAS and to further evaluate the impact of CPAP on cognitive decline and dementia risk.

The cumulative impact of type 2 diabetes and obstructive sleep apnoea on cardiovascular, liver, diabetes-related and cancer outcomes

AIM

A bidirectional relationship exists between obstructive sleep apnoea (OSA) and type 2 diabetes (T2D). We aimed to examine the cumulative impact of having both OSA and T2D on patient outcomes, relative to having either condition alone.

MATERIALS AND METHODS

Using TriNetX, a global federated research network (n = 128 million), we undertook two retrospective cohort studies, using time-to-event analysis. Analysis 1 compared OSA with T2D versus OSA alone; analysis 2 compared T2D with OSA versus T2D alone. Propensity score matching using greedy nearest neighbour (calliper 0.1) balanced the cohorts (1:1) for significant covariates. Primary outcomes were cardiovascular, liver, diabetes-related (microvascular) and cancer events over 1-5 years.

RESULTS

Analysis 1 (n = 179 688): A codiagnosis of T2D/OSA significantly increased risk of all-cause mortality (hazard ratio [HR] 1.52; confidence interval [CI]: 1.48, 1.57), dementia (HR 1.19; CI: 1.12, 1.26), liver (HR 2.20; CI: 1.77, 2.73), pancreatic (HR 1.62; CI: 1.35, 1.93), colon, renal and endometrial cancers; all cardiovascular, microvascular and liver related outcomes versus OSA alone over 1-5 5 years following OSA diagnosis. Analysis 2 (n = 240 094): A codiagnosis of OSA/T2D significantly increased the risk of peripheral (HR 1.39; CI: 1.36, 1.43) and autonomic (HR 1.63; CI: 1.51, 1.75) neuropathy; retinopathy (HR 1.13; CI: 1.09, 1.18), CKD (HR 1.21; CI: 1.18, 1.23); all cardiovascular and liver outcomes; all-cause mortality and several obesity related cancers versus T2D alone.

CONCLUSIONS

T2D significantly potentiates risk of cardiovascular, malignancy and liver-related outcomes in individuals with OSA. OSA, in individuals with T2D, significantly potentiates risk of cardiovascular disease, malignancy, death and several microvascular complications (retinopathy, CKD, peripheral/autonomic neuropathy).

Prevalence of prediabetes according to sleep apnea status

AIM

The association between obstructive sleep apnea (OSA) and prediabetes using the STOP-Bang questionnaire remains unknown. We aimed to investigate the prevalence of prediabetes among people based on their sleep apnea status.

METHODS

This cross-sectional study included 10131 Korean adults without diabetes with information of STOP-Bang scores, drawn from the dataset of the Korea National Health and Nutrition Examination Survey 2019-2021. Prediabetes was defined in three subsets: only by fasting blood glucose (FBG) (FBG 100-125 mg/dL, HbA1c <5.7 %), only by HbA1c (FBG <100 mg/dL, HbA1c 5.7-6.4 %) or by both. We used multivariable logistic regression to assess the odds ratio (OR) and 95 % confidence intervals (CIs) for prediabetes.

RESULTS

A total of 3828 subjects reported a STOP-Bang score of ≥ 3, which shows increased risk of OSA. Multivariable-adjusted OR (95 % CI) showed that a STOP-Bang score ≥ 3 was associated with prediabetes meeting both FBG and HbA1c criteria (OR 1.06; 95 % CI 1.01-1.12). This association was statistically significant among women, particularly postmenopausal women (OR 1.20, 95 % CI 1.10-1.30; OR 1.21, 95 % CI 1.11-1.32, respectively).

CONCLUSION

In Korean general population, a significant correlation between higher OSA risk and prediabetes was observed, especially in postmenopausal women.

Obstructive sleep apnea and polysomnographic predictors of neuropsychological performance two years after injury in a prospective cohort of adults with traumatic brain injury

Objective: Obstructive sleep apnea (OSA) has been associated with structural and functional brain changes and cognitive impairment in sleep clinic samples. Persons with traumatic brain injury (TBI) are at increased risk of OSA compared to community samples, and many experience chronic cognitive disability. However, the impact of OSA on cognitive outcome after TBI is unknown. The purpose of this study was to examine the relationship between polysomnographic sleep parameters on neuropsychological performance 2 years following TBI. We hypothesized that oxygen desaturation, sleep fragmentation, and sleep depth would predict neuropsychological performance. Method: Participants (N = 123) were persons with moderate-to-severe TBI who underwent Type 1 Polysomnography during acute neurorehabilitation. At 2 years post-TBI, participants completed telephone-based neuropsychological testing (the Brief Test of Adult Cognition by Telephone). General linear models were fit to investigate the relationship between sleep parameters and neuropsychological performance, controlling for demographics and posttraumatic amnesia. Results: When controlling for demographics, injury characteristics, and other sleep parameters, greater percent of Stage 1 sleep time predicted poorer cognitive performance (Overall BTACT composite, p = 0.0078, ηp2 = 6.6%; Verbal Memory composite, p = 0.0407, ηp2 = 3.9%; Executive Function composite, p = 0.0215, ηp2 = 4.9%). Oxygen desaturation, cortical arousals, Stage 3 sleep, and the obstructive apnea-hypopnea index were not significantly associated with cognitive outcome. Conclusions: Reduced sleep depth was associated with cognitive outcome in persons with TBI; these findings require replication. Future research should examine whether improving sleep (e.g. increasing deep sleep) during acute recovery can improve cognitive recovery following TBI.

The Neurologist's Role in Promoting Brain Health: Emerging Issues in Neurology

Neurologic conditions are a leading cause of morbidity and mortality within the United States and worldwide. Brain health is a global concern, and the American Academy of Neurology's Brain Health Initiative promises to drive progress in this field over the next decades. Neurologists with detailed training and insight into brain function are uniquely positioned to apply emerging preventive health data to promote healthy brain development and maintain optimal brain function throughout the lifespan. The neurologist's role in promoting brain health is also vital in patients with active neurologic disease, in whom preventive measures may reduce recurrence or slow progression of disease and may enhance quality of life and overall function. In this Emerging Issues in Neurology article, we present the factors that may protect brain function and frame a practical approach to screening assessments and preventive interventions that neurology clinicians may consider to improve the brain health of patients at all life stages.

Assessing the impact of apnea duration on the relationship between obstructive sleep apnea and hearing loss

OBJECTIVES

The relationship between obstructive sleep apnea (OSA) and hearing loss (HL) remains uncertain. This study aimed to investigate the relationship between OSA and HL, and to identify which factors play a key role.

METHODS

A retrospective review was conducted of 90 subjects diagnosed with OSA. These subjects underwent overnight polysomnography (PSG) and pure-tone audiometry at a single institution from February 2014 to November 2023. Hearing evaluations involved the comparison of OSA subjects with a non-OSA group, identified through national data utilizing the STOP-BANG questionnaire (SBQ) and age-sex 1:1 matching. Subsequently, individuals with OSA were categorized into HL and non-HL groups. Comparisons were made to ascertain differences in PSG parameters, followed by regression analysis to assess their actual impact.

RESULTS

The OSA group exhibited elevated hearing thresholds across all frequencies compared to the non-OSA group. Furthermore, classification of OSA subjects into the HL and non-HL groups revealed a statistically significant increase in apnea duration in the HL group for all-frequency and high-frequency cases (p = 0.038, 0.006). Multiple linear regression analysis, adjusting for age and sex, revealed a significant influence of apnea duration on HL in both all-frequency and high-frequency cases (ß = 0.404, p = 0.002; ß = 0.425, p = 0.001).

CONCLUSION

These findings underscore the significant association between OSA and reduced auditory function, with apnea duration standing out as a crucial factor contributing to hearing loss. Our results suggest that prolonged apnea duration may be a marker of chronic hypoxic damage in patients with OSA, further clarifying its potential role in the development of hearing loss.

Chinese herbal medicine for obstructive sleep apnoea: a systematic review with meta-analysis

PURPOSE

Chinese Herbal Medicine (CHM) may have a place in the treatment of obstructive sleep apnoea (OSA), but the evidence has not been systematically assessed. The objective of this study is to evaluate the evidence for the effectiveness of CHM for OSA.

METHODS

CENTRAL, EMBase, PubMed, CINAHL, CNKI, Wanfang and Chongqing VIP were searched from database inception to the 13th of August 2023. Randomised-controlled trials in which the effect of CHM on sleep variables was tested in the treatment of OSA were selected. The primary outcomes of this review and meta-analysis were the apnoea hypopnoea index (AHI) measured with polysomnography.

RESULTS

A total of 58 studies, involving 4,590 participants, were included. The meta-analysis showed that CHM reduced AHI more significantly than placebo (mean difference = -7.10 events/hour, 95% CI = -11.95, -2.25, P < 0.01, 7 studies, 583 participants) and the combination of CHM and Continuous Positive Airway Pressure (CPAP) more effective than CPAP alone (mean difference = -4.71 events/hour, 95% CI = -5.62, -3.80, P < 0.001, 28 studies, 2,267 participants). CHM improved sleepiness, quality of life, body weight, oxidative biomarkers, inflammatory biomarkers, cognitive function, blood pressure and respiratory function.

CONCLUSION

Our results suggest that CHM, alone and as an adjunct treatment, can improve various aspects of OSA and its comorbidities and is therefore a viable therapeutic option for OSA.

Next generation brain health: transforming global research and public health to promote prevention of dementia and reduce its risk in young adult populations

Efforts to prevent dementia can benefit from precision interventions delivered to the right population at the right time; that is, when the potential to reduce risk is the highest. Young adults (aged 18-39 years) are a neglected population in dementia research and policy making despite being highly exposed to several known modifiable risk factors. The risk and protective factors that have the biggest effect on dementia outcomes in young adulthood, and how these associations differ across regions and groups, still remain unclear. To address these uncertainties, the Next Generation Brain Health team convened a multidisciplinary expert group representing 15 nations across six continents. We identified several high-priority modifiable factors in young adulthood and devised five key recommendations for promoting brain health, ranging from individual to policy levels. Increasing research and policy focus on brain health across the life course, inclusive of younger populations, is the next crucial step in the efforts to prevent dementia at the global level.

Systemic determinants of brain health in ageing

Preservation of brain health is a worldwide priority. The traditional view is that the major threats to the ageing brain lie within the brain itself. Consequently, therapeutic approaches have focused on protecting the brain from these presumably intrinsic pathogenic processes. However, an increasing body of evidence has unveiled a previously under-recognized contribution of peripheral organs to brain dysfunction and damage. Thus, in addition to the well-known impact of diseases of the heart and endocrine glands on the brain, accumulating data suggest that dysfunction of other organs, such as gut, liver, kidney and lung, substantially affects the development and clinical manifestation of age-related brain pathologies. In this Review, a framework is provided to indicate how organ dysfunction can alter brain homeostasis and promote neurodegeneration, with a focus on dementia. We delineate the associations of subclinical dysfunction in specific organs with dementia risk and provide suggestions for public health promotion and clinical management.

A Longitudinal Study Investigating Whether Chronic Rhinosinusitis Influences the Subsequent Risk of Developing Dementia

Background/Objectives: Numerous studies have explored the association between chronic rhinosinusitis (CRS) and cognitive decline. However, whether CRS is an independent risk factor for the development of dementia remains unclear. Thus, this retrospective cohort study sought to examine the potential association between CRS and increased incidence and risk of dementia by utilizing a representative population-based cohort dataset. Methods: In this study, we identified 2126 patients with CRS aged >55 years and matched them with 8504 controls to assess the incidence and risk of dementia. Results: We found that the incidence of all-cause dementia in CRS patients was 0.125 per 1000 person-years. The risk of developing all-cause dementia events (adjusted hazard ratio [HR] = 1.0, 95% confidence interval = 0.8-1.3) also did not differ significantly between the control group and the CRS group, irrespective of the CRS phenotype. Subgroup analysis also showed no increased adjusted HR for developing Alzheimer's disease (0.9, 0.7-1.2), Parkinson's disease (0.9, 0.5-1.4), and other types of dementia (1.0, 0.7-1.4) in the CRS group compared to the control group. Conclusions: Therefore, the present study demonstrated that patients over 55 years of age with CRS did not exhibit an increased incidence or risk of dementia compared to individuals without CRS.

Sex-specific dementia risk in known or suspected obstructive sleep apnea: a 10-year longitudinal population-based study

Study Objectives

To evaluate sex-specific associations between known or suspected obstructive sleep apnea (OSA) and dementia risk over 10 years among older women and men.

Methods

This study included 18 815 women and men age 50+ years (dementia-free at baseline) who participated in the Health and Retirement Study (HRS), a nationally representative cohort of US adults. Presence of OSA was defined by self-reported diagnosis or key HRS items that correspond to elements of a validated OSA screening tool (STOP-Bang). Incident dementia cases were identified using a validated, HRS-based algorithm derived from objective cognitive assessments. Survey-weighted regression models based on pseudo-values were utilized to estimate sex- and age-specific differences in cumulative incidence of dementia by OSA status.

Results

Data from 18 815 adults were analyzed, of which 9% of women and 8% of men (weighted proportions) met criteria for incident dementia. Known/suspected OSA was more prevalent in men than in women (weighted proportions 68% vs. 31%). Unadjusted sex-stratified analyses showed that known/suspected OSA was associated with higher cumulative incidence of dementia across ages 60-84 years for women and men. By age 80, relative to adults without known/suspected OSA, the cumulative incidence of dementia was 4.7% higher (CI 2.8%, 6.7%) for women with known/suspected OSA, and 2.5% (CI 0.5%, 4.5%) for men with known/suspected OSA, respectively. Adjusted associations between age-specific OSA and cumulative incidence of dementia attenuated for both women and men but remained statistically significant.

Conclusions

OSA contributes to dementia risk in older adults, particularly women. This study illuminates the impact of a potentially modifiable yet frequently overlooked risk factor for dementia onset.

Nasal lymphatic obstruction of CSF drainage as a possible cause of Alzheimer's disease and dementia

Alzheimer's disease, the most common form of dementia among older adults, slowly destroys memory and thinking skills. In recent years, scientists have made tremendous progress in understanding Alzheimer's disease, still, they do not yet fully understand what causes the disease. This article proposes a novel etiology for Alzheimer's disease. Our hypothesis developed from a review of nuclear medicine scans, in which the authors observed a significant increase in nasal turbinate vasodilation and blood pooling in patients with hypertension, sleep apnea, diabetes and/or obesity, all risk factors for Alzheimer's disease. The authors propose that nasal turbinate vasodilation and resultant blood pooling lead to the obstruction of normal nasal lymphatic clearance of cerebrospinal fluid and its waste products from the brain. The nasal turbinate vasodilation, due to increased parasympathetic activity, occurs alongside the well-established increased sympathetic activity of the cardiovascular system as seen in patients with hypertension. The increased parasympathetic activity is likely due to an autonomic imbalance secondary to the increase in worldwide consumption of highly processed food associated with dysregulation of the glucose regulatory system. The authors' hypothesis offers a novel mechanism and a new paradigm for the etiology of Alzheimer's disease and helps explain the rapid worldwide rise in the disease and other dementias which are expected to double in the next 20 years. This new paradigm provides compelling evidence for the modulation of the parasympathetic nervous system as a novel treatment strategy for Alzheimer's disease and other degenerative brain diseases, specifically targeting nasal turbinate lymphatic flow.

Alzheimer's disease and sleep disorders: A bidirectional relationship

Alzheimer's disease (AD) is the most prevalent dementia, pathologically featuring abnormal accumulation of amyloid-β (Aβ) and hyperphosphorylated tau, while sleep, divided into rapid eye movement sleep (REM) and nonrapid eye movement sleep (NREM), plays a key role in consolidating social and spatial memory. Emerging evidence has revealed that sleep disorders such as circadian disturbances and disruption of neuronal rhythm activity are considered as both candidate risks and consequence of AD, suggesting a bidirectional relationship between sleep and AD. This review will firstly grasp basic knowledge of AD pathogenesis, then highlight macrostructural and microstructural alteration of sleep along with AD progression, explain the interaction between accumulation of Aβ and hyperphosphorylated tau, which are two critical neuropathological processes of AD, as well as neuroinflammation and sleep, and finally introduce several methods of sleep enhancement as strategies to reduce AD-associated neuropathology. Although theories about the bidirectional relationship and relevant therapeutic methods in mice have been well developed in recent years, the knowledge in human is still limited. More studies on how to effectively ameliorate AD pathology in patients by sleep enhancement and what specific roles of sleep play in AD are needed.

Specific and cumulative infection burden and mild cognitive impairment and dementia: A population-based study

Infection by pathogenic microbes is widely hypothesized to be a risk factor for the development of neurocognitive disorders and dementia, but evidence remains limited. We analyzed the association of seropositivity to 11 common pathogens and cumulative infection burden with neurocognitive disorder (mild cognitive impairment and dementia) in a population-based cohort of 475 older individuals (mean age = 67.6 y) followed up over 3-5 years for the risk of MCI-dementia. Specific seropositivities showed a preponderance of positive trends of association with MCI-dementia, including for Plasmodium, H. pylori, and RSV (p < 0.05), as well as Chickungunya, HSV-2, CMV and EBV (p > 0.05), while HSV-1 and HHV-6 showed equivocal or no associations, and Dengue and VZV showed negative associations (p < 0.05) with MCI-dementia. High infection burden (5 + cumulated infections) was significantly associated with an increased MCI-dementia risk in comparison with low infection burden (1-3 cumulative infections), adjusted for age, sex, and education. Intriguingly, for a majority (8 of 11) of pathogens, levels of antibody titers were significantly lower in those with MCI-dementia compared to cognitive normal individuals. Based on our observations, we postulate that individuals who are unable to mount strong immunological responses to infection by diverse microorganisms, and therefore more vulnerable to infection by greater numbers of different microbial pathogens or repeated infections to the same pathogen in the course of their lifetime are more likely to develop MCI or dementia. This hypothesis should be tested in more studies.

Promoting identification of obstructive sleep apnea among patients with psychiatric conditions

ABSTRACT

Obstructive sleep apnea (OSA) is prevalent but remains underdiagnosed and undertreated. Recognizing OSA in patients with psychiatric disorders can be challenging due to the conditions' overlapping symptoms. To aid primary care NPs in identifying OSA among patients with psychiatric disorders, this article examines overlapping symptoms and outlines diagnostic reasoning. It also provides an overview of the anatomy and neurotransmitters involved in OSA, as well as OSA-specific screening tools and risk stratification, to promote the condition's identification among this population.

Analysis of sleep apnea research with a special focus on the use of positron emission tomography as a study tool

The quality of sleep plays a significant role in determining human well-being, and studying sleep and sleep disorders using various methods can aid in the prevention and treatment of diseases. Positron emission tomography (PET) is a noninvasive and highly sensitive medical imaging technique that has been widely adopted in the clinic. This review article provides data on research activity related to sleep and sleep apnea and discusses the use of PET in investigating sleep apnea and other sleep disorders. We conducted a statistical analysis of the number of original research articles published on sleep and sleep apnea between 1965 and 2021 and found that there has been a dramatic increase in publications since 1990. The distribution of contributing countries and regions has also undergone significant changes. Although there is an extensive body of literature on sleep research (256,399 original research articles during 1965-2021), PET has only been used in 54 of these published studies, indicating a largely untapped area of research. Nonetheless, PET is a useful tool for identifying connections between sleep disorders and pathological changes in various diseases, including neurological, metabolic, and cardiovascular disorders, as well as cancer. To facilitate the broader use of PET in sleep apnea research, further studies are needed in both clinical and preclinical settings.

The Cost-Effectiveness of Sleep Apnea Management: A Critical Evaluation of the Impact of Therapy on Health Care Costs

TOPIC IMPORTANCE

OSA is a widespread condition that significantly affects both health and health-related quality of life (HRQoL). If left untreated, OSA can lead to accidents, decreased productivity, and medical complications, resulting in significant economic burdens including the direct costs of managing the disorder. Given the constraints on health care resources, understanding the cost-effectiveness of OSA management is crucial. A key factor in cost-effectiveness is whether OSA therapies reduce medical costs associated with OSA-related complications.

REVIEW FINDINGS

Treatments for OSA have been shown to enhance HRQoL, particularly for symptomatic patients with moderate or severe disease. Economic studies also have demonstrated that these treatments are highly cost-effective. However, although substantial empirical evidence shows that untreated OSA is associated with increased medical costs, uncertainty remains about the impact of OSA treatment on these costs. Randomized controlled trials of positive airway pressure (PAP) therapy have failed to demonstrate cost reductions, but the studies have had important limitations. Observational studies suggest that PAP therapy may temper increases in costs, but only among patients who are highly adherent to treatment. However, the healthy adherer effect is an important potential source of bias in these studies.

SUMMARY

OSA management is cost-effective, although uncertainties persist regarding the therapy's impact on medical costs. Future studies should focus on reducing bias, particularly the healthy adherer effect, and addressing other confounding factors to clarify potential medical cost savings. Promising avenues to further understanding include using quasiexperimental designs, incorporating more sophisticated characterization of OSA severity and symptoms, and leveraging newer technologies (eg, big data, wearables, and artificial intelligence).

Sleep Disordered Breathing and Neurocognitive Disorders

Sleep-disordered breathing (SDB), which includes conditions such as obstructive sleep apnea (OSA) and central sleep apnea (CSA), is an independent risk factor for cerebral small vessel disease (CSVD), stroke, heart failure, arrhythmias, and other cardiovascular disorders. The influence of OSA on brain structure and cognitive function has become an essential focus in the heart-brain axis, given its potential role in developing neurocognitive abnormalities. In this review, we found that OSA plays a significant role in the cardio-neural pathway that leads to the development of cerebral small vessel disease and neurocognitive decline. Although data is still limited on this topic, understanding the critical role of OSA in the heart-brain axis could lead to the utilization of imaging modalities to simultaneously identify early signs of pathology in both organ systems based on the known OSA-driven pathological pathways that result in a disease state in both the cardiovascular and cerebrovascular systems. This narrative review aims to summarize the current link between OSA and neurocognitive disorders, cardio-neural pathophysiology, and the treatment options available for patients with OSA-related neurocognitive disorders.

Assessing Risk Factors for Cognitive Decline Using Electronic Health Record Data: A Scoping Review

Background

The data and information contained within electronic health records (EHR) provide a rich, diverse, longitudinal view of real-world patient histories, offering valuable opportunities to study antecedent risk factors for cognitive decline. However, the extent to which such records' data have been utilized to elucidate the risk factors of cognitive decline remains unclear.

Methods

A scoping review was conducted following the PRISMA guideline, examining articles published between January 2010 and April 2023, from PubMed, Web of Science, and CINAHL. Inclusion criteria focused on studies using EHR to investigate risk factors for cognitive decline. Each article was screened by at least two reviewers. Data elements were manually extracted based on a predefined schema. The studied risk factors were classified into categories, and a research gap was identified.

Results

From 1,593 articles identified, 80 were selected. The majority (87.5%) were retrospective cohort studies, with 66.3% using datasets of over 10,000 patients, predominantly from the US or UK. Analysis showed that 48.8% of studies addressed medical conditions, 31.3% focused on medical interventions, and 17.5% on lifestyle, socioeconomic status, and environmental factors. Most studies on medical conditions were linked to an increased risk of cognitive decline, whereas medical interventions addressing these conditions often reduced the risk.

Conclusions

EHR data significantly enhanced our understanding of medical conditions, interventions, lifestyle, socioeconomic status, and environmental factors related to the risk of cognitive decline.

Cerebral perfusion is not impaired in persons with moderate obstructive sleep apnoea when awake

PURPOSE

It is well established that, together with a multitude of other adverse effects on health, severe obstructive sleep apnoea causes reduced cerebral perfusion and, in turn, reduced cerebral function. Less clear is the impact of moderate obstructive sleep apnoea (OSA). Our aim was to determine if cerebral blood flow is impaired in people diagnosed with moderate OSA.

METHODS

Twenty-four patients diagnosed with moderate OSA (15 ≤ apnoea-hypopnea index (AHI) < 30) were recruited (aged 32-72, median 59 years, 10 female). Seven controls (aged 42-73 years, median 62 years, 4 female) with an AHI < 5 were also recruited. The OSA status of all participants was confirmed at baseline by unattended polysomnography and they had an MRI arterial-spin-labelling scan of cerebral perfusion.

RESULTS

Neither global perfusion nor voxel-wise perfusion differed significantly between the moderate-OSA and control groups. We also compared the average perfusion across three regional clusters, which had been found in a previous study to have significant perfusion differences with moderate-severe OSA versus control, and found no significant difference in perfusion between the two groups. The perfusions were also very close, with means of 50.2 and 51.8 mL/100 g/min for the moderate-OSAs and controls, respectively, with a negligible effect size (Cohen's d = 0.10).

CONCLUSION

We conclude that cerebral perfusion is not impaired in people with moderate OSA and that cerebral flow regulatory mechanisms can cope with the adverse effects which occur in moderate OSA. This is an important factor in clinical decisions for prescription of continuous positive airway pressure therapy (CPAP).

The role of cardiovascular health and vascular events in the relationship between excessive daytime sleepiness and dementia risk

Many studies suggest a relationship between excessive daytime sleepiness (EDS) and dementia incidence, but the underlying mechanisms remain uncertain. The study aimed to investigate the role of cardiovascular burden in the relationship between EDS and dementia incidence over a 12-year follow-up in community-dwelling older adults. We performed analyses on 6171 subjects (aged ≥65 years) free of dementia and vascular disease at baseline. Participants self-reported EDS at baseline and an expert committee validated both prevalent and incident dementia. We defined cardiovascular burden by a low Cardiovascular Health score, constructed using the American Heart Association metrics, and incident vascular events. To explore the potential role of the cardiovascular burden in the relationship between EDS and dementia, we conducted mediation analyses with inverse odds ratio-weighted estimation, using multivariable-adjusted proportional hazard Cox and logistic regression models. Subjects with EDS had a higher risk of all-cause dementia (hazard ratio [HR] 1.39, 95% confidence interval [CI] 1.13-1.69) and dementia with vascular component (DVC) (HR 2.14, 95% CI 1.30-3.51), but not Alzheimer's disease (HR 1.18, 95% CI 0.93-1.51). Cardiovascular burden explained 5% (95% CI 4.1-5.2) and 11% (95% CI 9.7-11.3) of the relationship between EDS and all-cause dementia and DVC, respectively. These findings confirm that EDS may be implicated in the development of dementia and indicate a weaker than expected role of cardiovascular burden in the relationship between EDS and DVC.

The effect of pharyngeal structures on the severity of obstructive sleep apnea

BACKGROUND/OBJECTIVE

Obstructive sleep apnea (OSA) is characterized by complete or partial cessation of breathing during sleep. The tongue is suggested as a possible anatomical site causing airway obstruction. However, the role of other pharyngeal structures in the development of OSA remains unclear. We designed a study using both the apnea-hypopnea index (AHI) and the oxygen saturation measurements to assess the severity of OSA. We aimed to identify critical anatomical structures of the upper airway that correlate with the severity of OSA and to evaluate the utility of magnetic resonance imaging (MRI) markers to detect possible OSA in patients without overt symptoms.

MATERIALS AND METHODS

The study included participants referred to the neurology outpatient clinic from the check-up unit. Participants were grouped as controls, mild, moderate, or severe OSA according to the AHI. A cranial MRI with a field of view (FOV) encompassing the upper airway structures was obtained from all participants. The areas of the tongue and the uvula were measured on the sagittal images by drawing the boundaries of the tissues manually. The posterior air space (PAS) area was evaluated from regions of interest in five parallel planes.

RESULTS

Of 105 participants, 30 were controls, 27 had mild, 25 had moderate, and 23 had severe OSA. The moderate and severe OSA groups did not differ in oxygen saturation levels during sleep. Therefore, patients with moderate and severe OSA were combined into one group (moderate/severe OSA). The area of the tongue was significantly larger in the moderate/severe OSA group compared to the control group. Both the tongue and the uvula areas showed a significant positive correlation with the AHI.

CONCLUSION

Our findings suggest that the tongue and uvula have prominent roles in the severity of OSAS. It may be useful to measure these structures with MRI to screen for at-risk individuals without overt OSA symptoms.

Prospective cohort study of long-term neurological outcomes in retired elite athletes: the Advanced BiomaRker, Advanced Imaging and Neurocognitive (BRAIN) Health Study protocol

INTRODUCTION

Although limited, recent research suggests that contact sport participation might have an adverse long-term effect on brain health. Further work is required to determine whether this includes an increased risk of neurodegenerative disease and/or subsequent changes in cognition and behaviour. The Advanced BiomaRker, Advanced Imaging and Neurocognitive Health Study will prospectively examine the neurological, psychiatric, psychological and general health of retired elite-level rugby union and association football/soccer players.

METHODS AND ANALYSIS

400 retired athletes will be recruited (200 rugby union and 200 association football players, male and female). Athletes will undergo a detailed clinical assessment, advanced neuroimaging, blood testing for a range of brain health outcomes and neuropsychological assessment longitudinally. Follow-up assessments will be completed at 2 and 4 years after baseline visit. 60 healthy volunteers will be recruited and undergo an aligned assessment protocol including advanced neuroimaging, blood testing and neuropsychological assessment. We will describe the previous exposure to head injuries across the cohort and investigate relationships between biomarkers of brain injury and clinical outcomes including cognitive performance, clinical diagnoses and psychiatric symptom burden.

ETHICS AND DISSEMINATION

Relevant ethical approvals have been granted by the Camberwell St Giles Research Ethics Committee (Ref: 17/LO/2066). The study findings will be disseminated through manuscripts in clinical/academic journals, presentations at professional conferences and through participant and stakeholder communications.

Clinical Outcomes and Tau Pathology in Retired Football Players: Associations With Diagnosed and Witnessed Sleep Apnea

Background and Objectives

Obstructive sleep apnea (SA) is common in older men and a contributor to negative cognitive, psychiatric, and brain health outcomes. Little is known about SA in those who played contact sports and are at increased risk of neurodegenerative disease(s) and other neuropathologies associated with repetitive head impacts (RHI). In this study, we investigated the frequency of diagnosed and witnessed SA and its contribution to clinical symptoms and tau pathology using PET imaging among male former college and former professional American football players.

Methods

The sample included 120 former National Football League (NFL) players, 60 former college players, and 60 asymptomatic men without exposure to RHI (i.e., controls). Diagnosed SA was self-reported, and all participants completed the Mayo Sleep Questionnaire (MSQ, informant version), the Epworth Sleepiness Scale (ESS), neuropsychological testing, and tau (flortaucipir) PET imaging. Associations between sleep indices (diagnosed SA, MSQ items, and the ESS) and derived neuropsychological factor scores, self-reported depression (Beck Depression Inventory-II [BDI-II]), informant-reported neurobehavioral dysregulation (Behavior Rating Inventory of Executive Function-Adult Version [BRIEF-A] Behavioral Regulation Index [BRI]), and tau PET uptake, were tested.

Results

Approximately 36.7% of NFL players had diagnosed SA compared with 30% of the former college football players and 16.7% of the controls. Former NFL players and college football players also had higher ESS scores compared with the controls. Years of football play was not associated with any of the sleep metrics. Among the former NFL players, diagnosed SA was associated with worse Executive Function and Psychomotor Speed factor scores, greater BDI-II scores, and higher flortaucipir PET standard uptake value ratios, independent of age, race, body mass index, and APOE ε4 gene carrier status. Higher ESS scores correlated with higher BDI-II and BRIEF-A BRI scores. Continuous positive airway pressure use mitigated all of the abovementioned associations. Among the former college football players, witnessed apnea and higher ESS scores were associated with higher BRIEF-A BRI and BDI-II scores, respectively. No other associations were observed in this subgroup.

Discussion

Former elite American football players are at risk of SA. Our findings suggest that SA might contribute to cognitive, neuropsychiatric, and tau outcomes in this population. Like all neurodegenerative diseases, this study emphasizes the multifactorial contributions to negative brain health outcomes and the importance of sleep for optimal brain health.

Associations of sleep disorders with all-cause MCI/dementia and different types of dementia - clinical evidence, potential pathomechanisms and treatment options: A narrative review

Due to worldwide demographic change, the number of older persons in the population is increasing. Aging is accompanied by changes of sleep structure, deposition of beta-amyloid (Aß) and tau proteins and vascular changes and can turn into mild cognitive impairment (MCI) as well as dementia. Sleep disorders are discussed both as a risk factor for and as a consequence of MCI/dementia. Cross-sectional and longitudinal population-based as well as case-control studies revealed sleep disorders, especially sleep-disorderded breathing (SDB) and excessive or insufficient sleep durations, as risk factors for all-cause MCI/dementia. Regarding different dementia types, SDB was especially associated with vascular dementia while insomnia/insufficient sleep was related to an increased risk of Alzheimer's disease (AD). Scarce and still inconsistent evidence suggests that therapy of sleep disorders, especially continuous positive airway pressure (CPAP) in SDB, can improve cognition in patients with sleep disorders with and without comorbid dementia and delay onset of MCI/dementia in patients with sleep disorders without previous cognitive impairment. Regarding potential pathomechanisms via which sleep disorders lead to MCI/dementia, disturbed sleep, chronic sleep deficit and SDB can impair glymphatic clearance of beta-amyloid (Aß) and tau which lead to amyloid deposition and tau aggregation resulting in changes of brain structures responsible for cognition. Orexins are discussed to modulate sleep and Aß pathology. Their diurnal fluctuation is suppressed by sleep fragmentation and the expression suppressed at the point of hippocampal atrophy, contributing to the progression of dementia. Additionally, sleep disorders can lead to an increased vascular risk profile and vascular changes such as inflammation, endothelial dysfunction and atherosclerosis which can foster neurodegenerative pathology. There is ample evidence indicating that changes of sleep structure in aging persons can lead to dementia and also evidence that therapy of sleep disorder can improve cognition. Therefore, sleep disorders should be identified and treated early.

Impact of Sleep Disorders and Disturbed Sleep on Brain Health: A Scientific Statement From the American Heart Association

Accumulating evidence supports a link between sleep disorders, disturbed sleep, and adverse brain health, ranging from stroke to subclinical cerebrovascular disease to cognitive outcomes, including the development of Alzheimer disease and Alzheimer disease-related dementias. Sleep disorders such as sleep-disordered breathing (eg, obstructive sleep apnea), and other sleep disturbances, as well, some of which are also considered sleep disorders (eg, insomnia, sleep fragmentation, circadian rhythm disorders, and extreme sleep duration), have been associated with adverse brain health. Understanding the causal role of sleep disorders and disturbances in the development of adverse brain health is complicated by the common development of sleep disorders among individuals with neurodegenerative disease. In addition to the role of sleep disorders in stroke and cerebrovascular injury, mechanistic hypotheses linking sleep with brain health and biomarker data (blood-based, cerebrospinal fluid-based, and imaging) suggest direct links to Alzheimer disease-specific pathology. These potential mechanisms and the increasing understanding of the "glymphatic system," and the recognition of the importance of sleep in poststroke recovery, as well, support a biological basis for the indirect (through the worsening of vascular disease) and direct (through specific effects on neuropathology) connections between sleep disorders and brain health. Given promising evidence for the benefits of treatment and prevention, sleep disorders and disturbances represent potential targets for early treatment that may improve brain health more broadly. In this scientific statement, we discuss the evidence supporting an association between sleep disorders and disturbances and poor brain health ranging from stroke to dementia and opportunities for prevention and early treatment.

Association Between Sleep Quantity and Quality in Early Adulthood With Cognitive Function in Midlife

BACKGROUND AND OBJECTIVE

Growing evidence supports an association between sleep quality and risk of dementia. However, little is known about whether objectively measured sleep duration and quality influence cognition in midlife, a period of importance for understanding the direction of the association between sleep and dementia. We examined the association between sleep duration and quality, measured when participants were in their mid-30s to late 40s, and midlife cognition assessed 11 years later among Black and White adults.

METHODS

As part of the Coronary Artery Risk Development in Young Adults cohort study, sleep duration and quality were assessed objectively using wrist actigraphy and subjectively by Pittsburgh Sleep Quality Index (PSQI) at 2003-2005. During 2015-2016, we evaluated midlife cognition using the Digit Symbol Substitution Test (DSST), Stroop test, Rey Auditory Verbal Learning Test, Montreal Cognitive Assessment (MoCA), and Letter Fluency and Category Fluency tests. We used multivariable logistic regression to examine the association between sleep parameters and poor cognitive performance, which was defined as a score that was >1 SD below the mean score.

RESULTS

The 526 participants (58% women and 44% Black) had a mean age of 40.1 ± 3.6 years at baseline, a mean sleep duration of 6.1 ± 1.1 hours, and mean sleep fragmentation index (calculated as the sum of the percentage of time spent moving and the percentage of immobile periods ≤1 minute) of 19.2 ± 8.1%, and 239 (45.6%) participants reported poor sleep as defined by a PSQI global score of >5. After adjustment for demographics, education, smoking, body mass index, depression, physical activity, hypertension, and diabetes, those in the highest vs lowest tertile of sleep fragmentation index had over twice the odds of having poor cognitive performance (>1 SD below the mean) on the DSST (odds ratio [OR] = 2.97; 95% CI 1.34-6.56), fluency (OR = 2.42; 95% CI 1.17-5.02), and MoCA test (OR = 2.29; 95% CI 1.06-4.94). The association between sleep fragmentation and cognitive performance did not differ by race or sex. Objective sleep duration or subjective sleep quality was not associated with cognition in midlife.

DISCUSSION

Actigraphy-measured high sleep fragmentation rather than sleep duration was associated with worse cognition among middle-aged Black and White men and women. Sleep quality is important for cognitive health even as early as midlife.

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.

Sleep Disorders in Patients with Neurologic Disease

OBJECTIVE

This article provides an overview of the growing body of evidence showing bidirectional relationships between sleep and various neurologic disorders.

LATEST DEVELOPMENTS

Mounting evidence demonstrates that disrupted sleep can negatively impact various neurologic disease processes, including stroke, multiple sclerosis, epilepsy, neuromuscular disorders including amyotrophic lateral sclerosis, and headache syndromes. Abnormal sleep can also be a precursor to Alzheimer disease and neurodegenerative disease states such as Parkinson disease and dementia with Lewy bodies. Interventions to improve sleep and treat obstructive sleep apnea may play a vital role in preventing neurologic disease development and progression.

ESSENTIAL POINTS

Sleep disorders are common among patients with neurologic disorders. To provide comprehensive care to patients with neurologic conditions, neurologists must ask patients about sleep issues that may warrant further diagnostic testing, treatment, and sleep medicine referral when indicated.

Examining later-in-life health risks associated with sport-related concussion and repetitive head impacts: a systematic review of case-control and cohort studies

OBJECTIVE

Concern exists about possible problems with later-in-life brain health, such as cognitive impairment, mental health problems and neurological diseases, in former athletes. We examined the future risk for adverse health effects associated with sport-related concussion, or exposure to repetitive head impacts, in former athletes.

DESIGN

Systematic review.

DATA SOURCES

Search of MEDLINE, Embase, Cochrane, CINAHL Plus and SPORTDiscus in October 2019 and updated in March 2022.

ELIGIBILITY CRITERIA

Studies measuring future risk (cohort studies) or approximating that risk (case-control studies).

RESULTS

Ten studies of former amateur athletes and 18 studies of former professional athletes were included. No postmortem neuropathology studies or neuroimaging studies met criteria for inclusion. Depression was examined in five studies in former amateur athletes, none identifying an increased risk. Nine studies examined suicidality or suicide as a manner of death, and none found an association with increased risk. Some studies comparing professional athletes with the general population reported associations between sports participation and dementia or amyotrophic lateral sclerosis (ALS) as a cause of death. Most did not control for potential confounding factors (eg, genetic, demographic, health-related or environmental), were ecological in design and had high risk of bias.

CONCLUSION

Evidence does not support an increased risk of mental health or neurological diseases in former amateur athletes with exposure to repetitive head impacts. Some studies in former professional athletes suggest an increased risk of neurological disorders such as ALS and dementia; these findings need to be confirmed in higher quality studies with better control of confounding factors.

PROSPERO REGISTRATION NUMBER

CRD42022159486.

Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport-Amsterdam, October 2022

For over two decades, the Concussion in Sport Group has held meetings and developed five international statements on concussion in sport. This 6th statement summarises the processes and outcomes of the 6th International Conference on Concussion in Sport held in Amsterdam on 27-30 October 2022 and should be read in conjunction with the (1) methodology paper that outlines the consensus process in detail and (2) 10 systematic reviews that informed the conference outcomes. Over 3½ years, author groups conducted systematic reviews of predetermined priority topics relevant to concussion in sport. The format of the conference, expert panel meetings and workshops to revise or develop new clinical assessment tools, as described in the methodology paper, evolved from previous consensus meetings with several new components. Apart from this consensus statement, the conference process yielded revised tools including the Concussion Recognition Tool-6 (CRT6) and Sport Concussion Assessment Tool-6 (SCAT6, Child SCAT6), as well as a new tool, the Sport Concussion Office Assessment Tool-6 (SCOAT6, Child SCOAT6). This consensus process also integrated new features including a focus on the para athlete, the athlete's perspective, concussion-specific medical ethics and matters related to both athlete retirement and the potential long-term effects of SRC, including neurodegenerative disease. This statement summarises evidence-informed principles of concussion prevention, assessment and management, and emphasises those areas requiring more research.

The effect of sleep disorders on dementia risk in patients with traumatic brain injury: A large-scale cohort study

Introduction

We investigated the association between sleep disorders (SDs) and incident dementia in adults with traumatic brain injury (TBI).

Methods

Adults with a TBI between 2003 and 2013 were followed until incident dementia. Sleep disorders at TBI were predictors in Cox regression models, controlling for other dementia risks.

Results

Over 52 months, 4.6% of the 712,708 adults (59% male, median age 44, <1% with SD) developed dementia. An SD was associated with a 26% and a 23% of increased risk of dementia in male and female participants (hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.11-1.42 and HR 1.23, 95% CI 1.09-1.40, respectively). In male participants, SD was associated with a 93% increased risk of early-onset dementia (HR 1.93, 95% CI 1.29-2.87); this did not hold in female participants (HR 1.38, 95% CI 0.78-2.44).

Discussion

In a province-wide cohort, SDs at TBI were independently associated with incident dementia. Clinical trials testing sex-specific SD care after TBI for dementia prevention are timely.

Highlights

TBI and sleep disorders are linked to each other, and to dementia.It is unclear if sleep disorders pose a sex-specific dementia risk in brain injury.In this study, presence of a sleep disorder increased dementia risk in both sexes.The risk differed by type of sleep disorder, which differed between the sexes.Sleep disorder awareness and care in persons with brain injury is vital for dementia prevention.

An Alternative View of Familial Alzheimer's Disease Genetics

Probabilistic and parsimony-based arguments regarding available genetics data are used to propose that Hardy and Higgin's amyloid cascade hypothesis is valid but is commonly interpreted too narrowly to support, incorrectly, the primacy of the amyloid-β peptide (Aβ) in driving Alzheimer's disease pathogenesis. Instead, increased activity of the βCTF (C99) fragment of AβPP is the critical pathogenic determinant altered by mutations in the APP gene. This model is consistent with the regulation of APP mRNA translation via its 5' iron responsive element. Similar arguments support that the pathological effects of familial Alzheimer's disease mutations in the genes PSEN1 and PSEN2 are not exerted directly via changes in AβPP cleavage to produce different ratios of Aβ length. Rather, these mutations likely act through effects on presenilin holoprotein conformation and function, and possibly the formation and stability of multimers of presenilin holoprotein and/or of the γ-secretase complex. All fAD mutations in APP, PSEN1, and PSEN2 likely find unity of pathological mechanism in their actions on endolysosomal acidification and mitochondrial function, with detrimental effects on iron homeostasis and promotion of "pseudo-hypoxia" being of central importance. Aβ production is enhanced and distorted by oxidative stress and accumulates due to decreased lysosomal function. It may act as a disease-associated molecular pattern enhancing oxidative stress-driven neuroinflammation during the cognitive phase of the disease.

Association of a History of Sleep Disorder With Risk of Mild Cognitive Impairment and Alzheimer's Disease Dementia

OBJECTIVE

We explored whether a history of sleep disorder affected a current diagnosis of cognitive impairment and clinical conversion in a non-demented elderly population.

METHODS

Comprehensive clinical data collected as part of the Alzheimer's Disease Neuroimaging Initiative (ADNI) was analyzed. A history of sleep disorder was recorded in the recent ADNI medical database. Standard clinical and neuropsychological tests were performed both at baseline and follow-up visit. Multiple logistic regression analysis was performed after adjusting for age, sex, education, apolipoprotein E ε4 status, vascular risk score, body mass index, Geriatric Depression Scale score, and use of sleeping pills.

RESULTS

A total of 391 cognitively normal individuals, 303 with early mild cognitive impairment (MCI) and 364 with late MCI were included. Sleep disorder history was significantly associated with an increased risk of MCI but not with clinical conversion. A history of insomnia or obstructive sleep apnea (OSA) significantly increased the risk of MCI, but only an OSA history predicted progression to Alzheimer's disease (AD) dementia.

CONCLUSION

Our findings suggest that a sleep disorder history usefully aids early detection of cognitive impairment and emphasize that such sleep disorder, particularly OSA, is important as potential target for AD prevention.