Age-Related Perioperative Neurocognitive Disorders: Experimental Models and Druggable Targets.

With the worldwide increase in life span, surgical patients are becoming older and have a greater propensity for postoperative cognitive impairment, either new onset or through deterioration of an existing condition; in both conditions, knowledge of the patient's preoperative cognitive function and postoperative cognitive trajectory is imperative. We describe the clinical utility of a tablet-based technique for rapid assessment of the memory and attentiveness domains required for executive function. The pathogenic mechanisms for perioperative neurocognitive disorders have been investigated in animal models in which excessive and/or prolonged postoperative neuroinflammation has emerged as a likely contender. The cellular and molecular species involved in postoperative neuroinflammation are the putative targets for future therapeutic interventions that are efficacious and do not interfere with the surgical patient's healing process.

Leisure-time sedentary behaviors are differentially associated with all-cause dementia regardless of engagement in physical activity.

Sedentary behavior (SB) is associated with cardiometabolic disease and mortality, but its association with dementia is currently unclear. This study investigates whether SB is associated with incident dementia regardless of engagement in physical activity (PA). A total of 146,651 participants from the UK Biobank who were 60 years or older and did not have a diagnosis of dementia (mean [SD] age: 64.59 [2.84] years) were included. Self-reported leisure-time SBs were divided into two domains: time spent watching television (TV) or time spent using a computer. A total of 3,507 individuals were diagnosed with all-cause dementia over a mean follow-up of 11.87 (±1.17) years. In models adjusted for a wide range of covariates, including time spent in PA, time spent watching TV was associated with increased risk of incident dementia (HR [95% CI] = 1.24 [1.15 to 1.32]) and time spent using a computer was associated with decreased risk of incident dementia (HR [95% CI] = 0.85 [0.81 to 0.90]). In joint associations with PA, TV time and computer time remained significantly associated with dementia risk at all PA levels. Reducing time spent in cognitively passive SB (i.e., TV time) and increasing time spent in cognitively active SB (i.e., computer time) may be effective behavioral modification targets for reducing risk of dementia regardless of engagement in PA.

Passage of exogeneous fine particles from the lung into the brain in humans and animals.

There are still significant knowledge gaps in understanding the intrusion and retention of exogeneous particles into the central nervous system (CNS). Here, we uncovered various exogeneous fine particles in human cerebrospinal fluids (CSFs) and identified the ambient environmental or occupational exposure sources of these particles, including commonly found particles (e.g., Fe- and Ca-containing ones) and other compositions that have not been reported previously (such as malayaite and anatase TiO2), by mapping their chemical and structural fingerprints. Furthermore, using mouse and in vitro models, we unveiled a possible translocation pathway of various inhaled fine particles from the lung to the brain through blood circulation (via dedicated biodistribution and mechanistic studies). Importantly, with the aid of isotope labeling, we obtained the retention kinetics of inhaled fine particles in mice, indicating a much slower clearance rate of localized exogenous particles from the brain than from other main metabolic organs. Collectively, our results provide a piece of evidence on the intrusion of exogeneous particles into the CNS and support the association between the inhalation of exogenous particles and their transport into the brain tissues. This work thus provides additional insights for the continued investigation of the adverse effects of air pollution on the brain.

Associations of serum uric acid variability with neuroimaging metrics and cognitive decline: a population-based cohort study.

BACKGROUND: The relationship between variation in serum uric acid (SUA) levels and brain health is largely unknown. This study aimed to examine the associations of long-term variability in SUA levels with neuroimaging metrics and cognitive function. METHODS: This study recruited 1111 participants aged 25-83 years from a multicenter, community-based cohort study. The SUA concentrations were measured every two years from 2006 to 2018. We measured the intraindividual SUA variability, including the direction and magnitude of change by calculating the slope value. The associations of SUA variability with neuroimaging markers (brain macrostructural volume, microstructural integrity, white matter hyperintensity, and the presence of cerebral small vessel disease) and cognitive function were examined using generalized linear models. Mediation analyses were performed to assess whether neuroimaging markers mediate the relationship between SUA variation and cognitive function. RESULTS: Compared with the stable group, subjects with increased or decreased SUA levels were all featured by smaller brain white matter volume (beta = - 0.25, 95% confidence interval [CI] - 0.39 to - 0.11 and beta = - 0.15, 95% CI - 0.29 to - 0.02). Participants with progressively increased SUA exhibited widespread disrupted microstructural integrity, featured by lower global fractional anisotropy (beta = - 0.24, 95% CI - 0.38 to - 0.10), higher mean diffusivity (beta = 0.16, 95% CI 0.04 to 0.28) and radial diffusivity (beta = 0.19, 95% CI 0.06 to 0.31). Elevated SUA was also associated with cognitive decline (beta = - 0.18, 95% CI - 0.32 to - 0.04). White matter atrophy and impaired brain microstructural integrity mediated the impact of SUA increase on cognitive decline. CONCLUSIONS: It is the magnitude of SUA variation rather than the direction that plays a critical negative role in brain health, especially for participants with hyperuricemia. Smaller brain white matter volume and impaired microstructural integrity mediate the relationship between increased SUA level and cognitive function decline. Long-term stability of SUA level is recommended for maintaining brain health and preventing cognitive decline.

Mind over Microbes: Investigating the Interplay between Lifestyle Factors, Gut Microbiota, and Brain Health.

BACKGROUND: The gut microbiota (GM) of the human body comprises several species of microorganisms. This microorganism plays a significant role in the physiological and pathophysiological processes of various human diseases. METHODS: The literature review includes studies that describe causative factors that influence GM. The GM is sensitive to various factors like circadian rhythms, environmental agents, physical activity, nutrition, and hygiene that together impact the functioning and composition of the gut microbiome. This affects the health of the host, including the psycho-neural aspects, due to the interconnectivity between the brain and the gut. Hence, this paper examines the relationship of GM with neurodegenerative disorders in the context of these aforesaid factors. CONCLUSION: Future studies that identify the regulatory pathways associated with gut microbes can provide a causal link between brain degeneration and the gut at a molecular level. Together, this review could be helpful in designing preventive and treatment strategies aimed at GM, so that neurodegenerative diseases can be treated.

Sleep Capital: Linking Brain Health to Wellbeing and Economic Productivity Across the Lifespan.

INTRODUCTION AND FRAMEWORK: Sleep capital contributes to individual and societal wellbeing, productivity, and economic outcomes and involves a novel aspect of brain capital. It encompasses the quality and quantity of sleep as integral components that influence cognitive abilities, mental and brain health, and physical health, affecting workplace productivity, learning, decision-making, and overall economic performance. Here, we bring a framework to understand the complex relationship between sleep quality, health, wellbeing, and economic productivity. Then we outline the multilevel impact of sleep on cognitive abilities, mental/brain health, and economic indicators, providing evidence for the substantial returns on investment in sleep health initiatives. Moreover, sleep capital is a key factor when considering brain health across the lifespan, especially for the aging population. DISCUSSION: We propose specific elements and main variables to develop specific indexes of sleep capital to address its impacts on health, wellbeing and productivity. CONCLUSION: Finally, we suggest policy recommendations, workplace interventions, and individual strategies to promote sleep health and brain capital. Investing in sleep capital is essential for fostering a healthier, happier, fairer and more productive society.

Relationship of Hoarding and Depression Symptoms in Older Adults.

Hoarding disorder (HD) is a debilitating neuropsychiatric condition that affects 2%-6% of the population and increases in incidence with age. Major depressive disorder (MDD) co-occurs with HD in approximately 50% of cases and leads to increased functional impairment and disability. However, only one study to date has examined the rate and trajectory of hoarding symptoms in older individuals with a lifetime history of MDD, including those with current active depression (late-life depression; LLD). We therefore sought to characterize this potentially distinct phenotype. We determined the incidence of HD in two separate cohorts of participants with LLD (n = 73) or lifetime history of MDD (n = 580) and examined the reliability and stability of hoarding symptoms using the Saving Inventory-Revised (SI-R) and Hoarding Rating Scale-Self Report (HRS), as well as the co-variance of hoarding and depression scores over time. HD was present in 12% to 33% of participants with MDD, with higher rates found in those with active depressive symptoms. Hoarding severity was stable across timepoints in both samples (all correlations >0.75), and fewer than 30% of participants in each sample experienced significant changes in severity between any two timepoints. Change in depression symptoms over time did not co-vary with change in hoarding symptoms. These findings indicate that hoarding is a more common comorbidity in LLD than previously suggested, and should be considered in screening and management of LLD. Future studies should further characterize the interaction of these conditions and their impact on outcomes, particularly functional impairment in this vulnerable population.

The COVID-19 pandemic and neurology: A survey on previous and continued restrictions for clinical practice, curricular training, and health economics.

BACKGROUND AND PURPOSE: The COVID-19 pandemic has significantly impacted health systems worldwide. Here, we assessed the pandemic's impact on clinical service, curricular training, and financial burden from a neurological viewpoint during the enforced lockdown periods and the assumed recovery by 2023. METHODS: An online 18-item survey was conducted by the European Academy of Neurology (EAN) NeuroCOVID-19 Task Force among the EAN community. The survey was online between February and March 2023. Questions related to general, demographic, clinical, work, education, and economic aspects. RESULTS: We collected 430 responses from 79 countries. Most health care professionals were aged 35-44 years, with >15 years of work experience. The key findings of their observations were as follows. (i) Clinical services were cut back in all neurological subspecialties during the most restrictive COVID-19 lockdown period. The most affected neurological subspecialties were services for patients with dementia, and neuromuscular and movement disorders. The levels of reduction and the pace of recovery were distinct for acute emergencies and in- and outpatient care. Recovery was slow for sleep medicine, autonomic nervous system disorders, neurorehabilitation, and dementia care. (ii) Student and residency rotations and grand rounds were reorganized, and congresses were converted into a virtual format. Conferences are partly maintained in a hybrid format. (iii) Affordability of neurological care and medication shortage are emerging issues. CONCLUSIONS: Recovery of neurological services up to spring 2023 has been incomplete following substantial disruption of neurological care, medical education, and health economics in the wake of the COVID-19 pandemic. The continued limitations for the delivery of neurological care threaten brain health and call for action on a global scale.

Brain health and national neurological societies: Results of the European Academy of Neurology survey on brain health awareness and areas of implementation for European countries.

BACKGROUND AND PURPOSE: The European Academy of Neurology (EAN) has adhered to the global plan for reducing the burden of neurological disorders and promoting brain health launched by the World Health Organisation (WHO), the WHO Intersectoral Global Action Plan on Epilepsy and Other Neurological Disorders. This study reports the results of an EAN survey among national neurological societies (NNSs) on their awareness of brain health policies. METHODS: The EAN survey on the current state of national brain health policies was conducted among the 47 presidents of the NNSs affiliated with the EAN, with the aim of developing the best strategy for close collaboration among stakeholders. RESULTS: From June 2023 to February 2024, 36/47 responses (77%) were collected. Among respondents, 67% were in contact with their Ministry of Health and 78% were aware of and in contact with one or more national neurological patient organisation, while 17% had no contacts with any association. Ninety-two percent declared a high to medium degree of awareness of the need to support brain health and of brain health plans and strategies in their country. CONCLUSIONS: Our findings suggest good awareness of the importance of brain health and of the strategies implemented at the national level among the EAN-affiliated NNSs and representatives. Efforts towards improvement may be directed towards cooperation between NNSs and political institutions, as well as patient organisations, to optimise brain and global public health and neurological care in each country.

European Academy of Neurology: First 10 years.

The European Academy of Neurology (EAN) was founded in May 2014 as the scientific society of all neurologists and all national neurological societies in Europe. The creation of EAN was based on the conscious decision of two predecessor societies (the European Federation of Neurological Societies and the European Neurological Society) to have a unique society for this continent with its 53 countries according to the World Health Organization and with the EU as the most important continental political decision level. In this report, the important milestones and the motivations of the decision-makers during the first 10 years are described. The development of the annual congress, the broad educational agenda, and the scientific groundwork including the European guidelines for the practise of neurology are described. Collaboration with and work for the national neurological societies is an important task for EAN. The political representation of neurology in Brussels and collaboration with the scientific societies of neighbouring medical disciplines and patient organizations are other major tasks on the agenda of the organization. EAN's goal is to reduce the burden of neurological diseases and to be the "home of neurology" in Europe for physicians, patients, and society. EAN communicates and interacts with its members, patients, partners, politicians, and the public through different channels. EAN is the owner of the scientifically independent European Journal of Neurology. EAN is based in Vienna, where its head office is located, but is also strongly represented in Brussels.

Towards new perspectives: A scoping review and meta-synthesis to redefine brain health for multiple sclerosis.

BACKGROUND AND PURPOSE: Research promoting the health of the brain has increased exponentially over the last decade. The importance of 'brain health' for multiple sclerosis (MS), as one example, is a high priority. However, as research into the concept increases, so does varied use of the term. METHODS: A scoping review, guided by the methodological framework of the Joanna Briggs Institute, was conducted to collate the evidence relating to brain health for MS. A comprehensive literature search incorporated six search strategies to retrieve both scientific and grey literature sources. All evidence sources were qualitatively charted and synthesized (meta-synthesis) according to their definition of brain health used, outcome measures and brain-healthy lifestyle elements. RESULTS: Seventy evidence sources (34 peer reviewed, 36 grey literature) were eligible for inclusion. Of these, just over half (n = 40, 57%) provided a definition of brain health. The most common definition alluded to the biomedical model of neurological reserve (n = 22, 55%), a self-remodelling theory described to retain optimal brain function. Twenty-nine outcome measures of brain health were identified, the most frequent being magnetic resonance imaging metrics (n = 25, 83%). Physical activity was the most prevalent brain-healthy lifestyle element (n = 44), followed by avoidance of smoking (n = 26) and diet (n = 24). CONCLUSIONS: Brain health should be considered a primary target for optimal disease and lifestyle management across the MS disease course. A working definition reflecting a shift from a medical lens towards broader biopsychosocial contexts that may influence brain health for people living with MS is proposed.

World Federation of Neurology.

BACKGROUND AND PURPOSE: To acknowledge the occasion of the 10th anniversary of the formation of the European Academy of Neurology (EAN), the World Federation of Neurology was invited to contribute its perspective on the formation of the EAN and its activities over the past decade. METHODS: This article is based on the experiences of the author in several functions with the European Union of Medical Specialists, the European Federation of Neurology and the European Neurological Society and with the World Federation of Neurology as a trustee since 2009. This article is supported by the author's own archive as well as by several publications. RESULTS: The formation of the EAN was influenced by the activities of the two main predecessor societies, the European Neurological Society and European Federation of Neurology, which left an imprint on the structure of the EAN. The newly formed EAN underwent rigorous structural and organizational changes and has been acting as a successful and independent regional society, expanding increasingly in worldwide activities. CONCLUSION: The EAN, with its 47 member countries, strong democratic leadership and structure, is an excellent example of a regional society with expanding global influence that uses its advocacy skills to influence and improve the structure of neurology in Europe.

Increasing awareness for dementia risk reduction through a public awareness campaign in Denmark: A pre-post study.

OBJECTIVE: It is estimated that about 40% of all dementia cases are potentially attributable to modifiable risk factors, but awareness of this is relatively lacking. METHODS: An 18-months nation-wide public awareness campaign on dementia risk reduction was rolled out in Denmark that combined a mass-media approach with an online risk assessment tool and knowledge bank targeting all inhabitants aged between 40 and 75 years. Campaign effects (increase in awareness and knowledge of modifiable dementia risk and protective factors) were assessed via online surveys in two independent random samples before (n = 1003) and after the campaign (n = 1076). RESULTS: After adjusting for differences in educational level between the two samples, there was no significant difference in awareness of dementia risk reduction between the pre-campaign (66.5% aware) and post-campaign (63.4% aware) sample (probit z = -0.08, p = 0.151). The number of correctly identified risk/protective factors was significantly higher in the post-campaign sample. After adjusting for potential confounding factors, self-reported exposure to the campaign was associated with more awareness, better recognition of risk/protective factors, more motivation for and actual implementation of lifestyle changes. CONCLUSIONS: This mass-media campaign did not increase overall awareness that dementia risk is partly modifiable. However, exposure to the campaign was associated with more awareness and willingness to take action to improve brain health. Future campaigns should tailor messages to specific subgroups to broaden the reach (e.g., males), co-create materials with the target group, and give special attention to the contribution of metabolic/cardiovascular risk factors to dementia risk.

Determinants of exercise adherence in sedentary middle-aged and older adults.

Regular exercise positively impacts neurocognitive health, particularly in aging individuals. However, low adherence, particularly among older adults, hinders the adoption of exercise routines. While brain plasticity mechanisms largely support the cognitive benefits of exercise, the link between physiological and behavioral factors influencing exercise adherence remains unclear. This study aimed to explore this association in sedentary middle-aged and older adults. Thirty-one participants underwent an evaluation of cortico-motor plasticity using transcranial magnetic stimulation (TMS) to measure changes in motor-evoked potentials following intermittent theta-burst stimulation (iTBS). Health history, cardiorespiratory fitness, and exercise-related behavioral factors were also assessed. The participants engaged in a 2-month supervised aerobic exercise program, attending sessions three times a week for 60 min each, totaling 24 sessions at a moderate-to-vigorous intensity. They were divided into Completers (n = 19), who attended all sessions, and Dropouts (n = 12), who withdrew early. Completers exhibited lower smoking rates, exercise barriers, and resting heart rates compared to Dropouts. For Completers, TMS/iTBS cortico-motor plasticity was associated with better exercise adherence (r = -.53, corrected p = .019). Exploratory hypothesis-generating regression analysis suggested that post-iTBS changes (ß = -7.78, p = .013) and self-efficacy (ß = -.51, p = .019) may predict exercise adherence (adjusted-R2 = .44). In conclusion, this study highlights the significance of TMS/iTBS cortico-motor plasticity, self-efficacy, and cardiovascular health in exercise adherence. Given the well-established cognitive benefits of exercise, addressing sedentary behavior and enhancing self-efficacy are crucial for promoting adherence and optimizing brain health. Clinicians and researchers should prioritize assessing these variables to improve the effectiveness of exercise programs.

Association Between Psychosocial Stress and Brain Aging: Results of the Population-Based Cohort Study of Health in Pomerania (SHIP).

OBJECTIVE: Recent studies suggest that psychosocial factors can have an impact on brain health. Yet, it is unclear whether psychosocial stress affects aging of the brain. The aim of the study was to investigate the association between psychosocial stress and brain aging. METHODS: Data from the German population-based cohort Study of Health in Pomerania (N=991; age range 20-78 years) were used to calculate a total psychosocial stress score by combining subscores from five domains: stress related to the living situation, the occupational situation, the social situation, danger experiences, and emotions. Associations with brain aging, indicated by an MRI-derived score quantifying age-related brain atrophy, were estimated by using regression models adjusted for age, gender, education, diabetes, problematic alcohol consumption, smoking, and hypertension. RESULTS: The relative risk ratio for advanced brain aging was 1.21 (95% CI=1.04-1.41) for stress related to emotions in fully adjusted models. The interactions between stress related to emotions and mental health symptoms were also significantly associated with advanced brain aging. The association between higher total psychosocial stress and brain aging was not statistically significant. CONCLUSIONS: These findings highlight that high stress related to emotions is associated with advanced brain aging. To protect brain health in older age, more research is needed to explore the role of emotional distress.

Family history of dementia and brain health in childhood and middle age: a prospective community-based study.

We aimed to determine the association of family history of dementia with structural brain measures and cognitive performance in childhood and mid-life adulthood. We studied 1,259 parents (mean age: 47.3 years, range 31.9-67.4) and 866 of their children (mean age [range] at brain MRI: 9.9 years [8.8-11.9], and for cognition: 13.5 years [12.6-15.8]) of the population-based Generation R Study. Parents filled in a questionnaire on family history, and both parents and children underwent cognitive assessment and neuroimaging. Of all participants, 109 parents (8.6%) reported a parental family history of dementia and 73 children (8.4%) had a grandparental history of dementia with mean age of dementia diagnosis in those affected 75 years (± 7.3). We observed no associations of dementia family history with cognitive ability in either parents or their children, except for worse Purdue pegboard in parents with a parental history of dementia, compared to those without (mean difference [95%CI]: -1.23 [-2.15; -0.31], test range: 21-52). In parents and children, neuroimaging measures did not differ significantly by family history. Results did not depend on age, sex, and APOE genotype. Family history of dementia was associated with worse manual dexterity in mid-life adulthood, but not with any other measures of cognitive ability or subclinical brain health in childhood and mid-life. These findings suggest that the association of family history with dementia risk is due chiefly to neurodegenerative rather than neurodevelopmental processes, and might first present with reduced motor skills.

Diabetes, brain health, and treatment gains in post-stroke aphasia.

In post-stroke aphasia, language improvements following speech therapy are variable and can only be partially explained by the lesion. Brain tissue integrity beyond the lesion (brain health) may influence language recovery and can be impacted by cardiovascular risk factors, notably diabetes. We examined the impact of diabetes on structural network integrity and language recovery. Seventy-eight participants with chronic post-stroke aphasia underwent six weeks of semantic and phonological language therapy. To quantify structural network integrity, we evaluated the ratio of long-to-short-range white matter fibers within each participant's whole brain connectome, as long-range fibers are more susceptible to vascular injury and have been linked to high level cognitive processing. We found that diabetes moderated the relationship between structural network integrity and naming improvement at 1 month post treatment. For participants without diabetes (n = 59), there was a positive relationship between structural network integrity and naming improvement (t = 2.19, p = 0.032). Among individuals with diabetes (n = 19), there were fewer treatment gains and virtually no association between structural network integrity and naming improvement. Our results indicate that structural network integrity is associated with treatment gains in aphasia for those without diabetes. These results highlight the importance of post-stroke structural white matter architectural integrity in aphasia recovery.

The role of multidisciplinary MS care teams in supporting lifestyle behaviour changes to optimise brain health among people living with MS: A qualitative exploration of clinician perspectives.

INTRODUCTION: Healthcare professionals have an important role in advocating for the adoption of a brain-healthy lifestyle for optimal multiple sclerosis (MS) care. Nonetheless, studies to date have mainly focussed on the consumer perspective. Herein, we aimed to explore the current practices of how healthcare professionals support protective, lifestyle-related behaviour changes to optimise brain health among people living with MS (plwMS), and their perspectives of professional roles. METHODS: Australian healthcare professionals were recruited via study advertisements, purposive and snowball sampling, to participate in an online, semi-structured and audio-recorded interview. Clinicians were eligible if they had a minimum of a tertiary Bachelor's degree and 12-months experience working with plwMS, access to the Internet and sufficient time to participant. An inductive, data-driven form of reflexive thematic analysis was undertaken before thematic categorisation of the quotes from transcripts. Data analysis was guided by the methods of Braun and Clark and the study's underpinnings drew on the constructs of the Social Cognitive Theory (SCT). RESULTS: Six physicians, 10 MS nurses, 18 allied health professionals, one exercise therapist and one alternative therapist were interviewed. Three primary themes encompassing the perceived role of healthcare professionals in supporting a brain-healthy lifestyle were identified: (1) the empowering role, (2) collaborative role and (3) communicative role. External factors/forces including time constraints, professional expertise, training and skill set, power dynamics, consumer readiness, health literacy, self-efficacy and motivation are at play, and affect how/when healthcare professionals may support behaviour change to optimise lifelong brain health for plwMS. CONCLUSION: Healthcare professionals recognise their critical role in encouraging and supporting the adoption of a brain-healthy lifestyle to optimise lifelong brain health for plwMS. However, discord is evident when they underestimate the complexity of translating knowledge of lifestyle-related behaviour change(s) into action. Greater awareness must be made in recognising and addressing the bidirectionality of external factors such as those in the SCT, that may influence how behaviour change occurs. PUBLIC CONTRIBUTION: Healthcare professionals volunteered to be interviewed as part of the data collection phase of this study.

Investigating the effects of indoor lighting on measures of brain health in older adults: protocol for a cross-over randomized controlled trial.

BACKGROUND: The worldwide number of adults aged 60 years and older is expected to double from 1 billion in 2019 to 2.1 billion by 2050. As the population lives longer, the rising incidence of chronic diseases, cognitive disorders, and behavioral health issues threaten older adults' health span. Exercising, getting sufficient sleep, and staying mentally and socially active can improve quality of life, increase independence, and potentially lower the risk for Alzheimer's disease or other dementias. Nonpharmacological approaches might help promote such behaviors. Indoor lighting may impact sleep quality, physical activity, and cognitive function. Dynamically changing indoor lighting brightness and color throughout the day has positive effects on sleep, cognitive function, and physical activity of its occupants. The aim of this study is to investigate how different indoor lighting conditions affect such health measures to promote healthier aging. METHODS: This protocol is a randomized, cross-over, single-site trial followed by an exploratory third intervention. Up to 70 older adults in independent living residences at a senior living facility will be recruited. During this 16-week study, participants will experience three lighting conditions. Two cohorts will first experience a static and a dynamic lighting condition in a cluster-randomized cross-over design. The static condition lighting will have fixed brightness and color to match lighting typically provided in the facility. For the dynamic condition, brightness and color will change throughout the day with increased brightness in the morning. After the cross-over, both cohorts will experience another dynamic lighting condition with increased morning brightness to determine if there is a saturation effect between light exposure and health-related measures. Light intake, sleep quality, and physical activity will be measured using wearable devices. Sleep, cognitive function, mood, and social engagement will be assessed using surveys and cognitive assessments. DISCUSSION: We hypothesize participants will have better sleep quality and greater physical activity during the dynamic lighting compared to the static lighting condition. Additionally, we hypothesize there is a maximal threshold at which health-outcomes improve based on light exposure. Study findings may identify optimal indoor lighting solutions to promote healthy aging for older adults. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05978934.

The acute influence of amateur boxing on dynamic cerebral autoregulation and cerebrovascular reactivity to carbon dioxide.

PURPOSE: The purpose of this study was to investigate the acute effect of head impacts, sustained over the course of three rounds of amateur boxing, on indices of cerebrovascular function. METHODS: Eighteen university amateur boxers (six female) completed three experimental trials in a randomised order; (1) three rounds of boxing (BOX), (2) an equivalent bout of pad boxing (where no blows to the head were sustained; PAD), and (3) a time-matched seated control trial (CON). Indices of cerebrovascular function were determined immediately before and 45 min after each trial. Specifically, dynamic cerebral autoregulation (dCA) was determined by considering the relationship between changes in cerebral blood velocity and mean arterial pressure during 5 min of squat-stand manoeuvres at 0.05 and 0.10 Hz. Cerebrovascular reactivity was determined using serial breath holding and hyperventilation attempts. RESULTS: Participants received an average of 40 ± 16 punches to the head during the BOX trial. Diastolic, mean and systolic dCA phase during squat stand manoeuvres at 0.05 Hz was lower after BOX compared to pre BOX (P ≤ 0.02, effect size (d) ≥ 0.74). No other alterations in dCA outcomes were observed at 0.05 or 0.10 Hz. The number of head impacts received during the BOX trial was associated with the change in systolic phase (r = 0.50, P = 0.03). No differences in cerebrovascular reactivity to breath holding or hyperventilation were observed. CONCLUSIONS: A typical bout of amateur boxing (i.e., three rounds) can subtly alter cerebral pressure-flow dynamics, and the magnitude of this change may be related to head impact exposure.