Association of Infection-Related Hospitalization With Cognitive Impairment Among Nursing Home Residents

Potentially Avoidable Hospitalizations Among Historically Marginalized Nursing Home Residents

Importance

Nursing home (NH) transfers to hospitals are common and have been associated with cognitive decline; approximately 45% of NH hospital transfers are potentially avoidable hospitalizations (PAHs).

Objective

To determine PAH incidence for historically marginalized NH residents with severe cognitive impairment compared with non-Hispanic White residents.

Design, Setting, and Participants

This cross-sectional study merged 2018 Centers for Medicaid & Medicare Services datasets and LTCFocus, a public dataset on US NH care, for US NH residents aged 65 years and older who had a hospitalization. Analyses were performed from January to May 2022.

Exposure

Race and ethnicity of NH residents.

Main Outcomes and Measures

Racial and ethnic differences in resident-level annual rates of PAHs were estimated for residents with and without severe cognitive impairment (measured using the Cognitive Function Scale), controlling for resident characteristics, comorbidities, dual eligibility, and time at risk. PAHs were defined as NH hospital transfers that resulted from neglectful NH care or for which NH treatment would have been appropriate.

Results

Of 2 098 385 NH residents nationwide included in the study, 7151 (0.3%) were American Indian or Alaska Native, 39 873 (1.9%) were Asian, 229 112 (10.9%) were Black or African American, 99 304 (4.7%) were Hispanic, 2785 (0.1%) were Native Hawaiian or Pacific Islander, 1 713 670 (81.7%) were White, and 6490 (0.3%) were multiracial; 1 355 143 (64.6%) were female; 128 997 (6.2%) were severely cognitively impaired; and the mean (SD) age was 81.8 (8.7) years. PAH incidence rate ratios (IRRs) were significantly greater for residents with severe cognitive impairment compared with those without. In unadjusted analyses comparing historically marginalized residents with severe cognitive impairment vs non-Hispanic White residents with severe cognitive impairment, American Indian or Alaska Native residents had a 49% higher PAH incidence (IRR, 1.49 [95% CI, 1.10-2.01]), Black or African American residents had a 64% higher incidence (IRR, 1.64 [95% CI, 1.48-1.81]), and Hispanic residents had a 45% higher incidence (IRR, 1.45 [95% CI, 1.29-1.62]). Higher incidences persisted for historically marginalized residents with severe cognitive impairment vs non-Hispanic White residents with severe cognitive impairment in adjusted analyses. Asian residents had a 24% higher PAH incidence (IRR, 1.24 [95% CI, 1.06-1.45]), Black or African American residents had a 48% higher incidence (IRR, 1.48 [95% CI, 1.36-1.60]), and Hispanic residents had a 27% higher incidence (IRR, 1.27 [95% CI, 1.16-1.39]).

Conclusions and Relevance

In this cross-sectional study of PAHs, compared with non-Hispanic White NH residents, historically marginalized residents had increased PAH incidence. In the presence of severe cognitive impairment, incidence rates increased significantly compared with rates for residents without severe cognitive impairment. These results suggest that identification of residents with severe cognitive impairment and proper NH care may help prevent further cognitive decline by avoiding PAHs.

Sex-Biased Expression and Response of microRNAs in Neurological Diseases and Neurotrauma

Neurological diseases and neurotrauma manifest significant sex differences in prevalence, progression, outcome, and therapeutic responses. Genetic predisposition, sex hormones, inflammation, and environmental exposures are among many physiological and pathological factors that impact the sex disparity in neurological diseases. MicroRNAs (miRNAs) are a powerful class of gene expression regulator that are extensively involved in mediating biological pathways. Emerging evidence demonstrates that miRNAs play a crucial role in the sex dimorphism observed in various human diseases, including neurological diseases. Understanding the sex differences in miRNA expression and response is believed to have important implications for assessing the risk of neurological disease, defining therapeutic intervention strategies, and advancing both basic research and clinical investigations. However, there is limited research exploring the extent to which miRNAs contribute to the sex disparities observed in various neurological diseases. Here, we review the current state of knowledge related to the sexual dimorphism in miRNAs in neurological diseases and neurotrauma research. We also discuss how sex chromosomes may contribute to the miRNA sexual dimorphism phenomenon. We attempt to emphasize the significance of sexual dimorphism in miRNA biology in human diseases and to advocate a gender/sex-balanced science.

Infection, Inflammation, and Poststroke Cognitive Impairment

BACKGROUND

Infection and inflammation are dementia risk factors in population-based cohorts; however, studies in stroke are scarce. We determined the prevalence of infection after stroke and routinely measured inflammatory biomarkers during hospitalization and their associations with acute and 6-month cognitive impairment.

METHODS AND RESULTS

A prospective stroke cohort completed the Oxford Cognitive Screen at ≤2 weeks and 6 months after stroke. Infection, inflammatory markers (C-reactive protein, white cell count, and neutrophil/lymphocyte ratio), and systemic inflammatory response syndrome were ascertained throughout admission with electronic patient records supplemented by hand searches. Associations with acute and 6-month global and domain-specific cognitive impairment were analyzed using multivariable regression, adjusting for demographic/vascular factors and stroke severity. Among 255 patients (mean age, 73.9 [SD, 12.6] years; 46.3% women; mean education, 12.6 [SD, 3.7] years; median National Institutes of Health Stroke Scale score 5 [range, minimum-maximum, 0-30]), infection was present in 90 patients (35.3%) at mean 4.4 (SD, 6.9) days after stroke, consisting predominantly of pneumonia (47/90; 52%) and urinary tract infection (39/90; 43%). Admission white cell count was elevated in 25.1% (n=64; mean, 9.5×109/L [SD, 3.2×109/L]), C-reactive protein in 41.2% (n=105; mean, 27.5 [SD, 50.9 mg/L]), neutrophil/lymphocyte ratio in 55.7% (n=97; mean, 5.5 [SD, 4.5]), and systemic inflammatory response syndrome in 26.6% (n=53 [45.2%] positive during hospitalization). Infection was associated with acute and 6-month poststroke cognitive impairment (P<0.05adj) with stronger associations acutely for severe infection (infection+systemic inflammatory response syndrome; P=0.03adj). Acute language, executive function and attention domain impairments, and 6-month number processing impairment were associated with infection (P<0.05adj). No significant relationships were found for any biomarker and cognitive impairment.

CONCLUSIONS

Infection and elevations in routinely measured inflammatory biomarkers are common following stroke; however, only infection is associated with poststroke cognitive impairment, suggesting that increases in these biomarkers may be nonspecific. Infection may present a tractable target for reducing poststroke cognitive impairment.

HLA-C*07:01 and HLA-DQB1*02:01 protect against white matter hyperintensities and deterioration of cognitive function: A population-based cohort study

BACKGROUND

Neuroinflammation and aberrant immune regulation are increasingly implicated in the pathophysiology of white matter hyperintensities (WMH), an imaging marker of cerebrovascular pathologies and predictor of cognitive impairment. The role of human leukocyte antigen (HLA) genes, critical in immunoregulation and associated with susceptibility to neurodegenerative diseases, in WMH pathophysiology remains unexplored.

METHODS

We performed association analyses between classical HLA alleles and WMH volume, derived from MRI scans of 38 302 participants in the UK Biobank. To identify independent functional alleles driving these associations, we conducted conditional forward stepwise regression and lasso regression. We further investigated whether these functional alleles showed consistent associations with WMH across subgroups characterized by varying levels of clinical determinants. Additionally, we validated the clinical relevance of the identified alleles by examining their association with cognitive function (n = 147 549) and dementia (n = 460 029) in a larger cohort.

FINDINGS

Four HLA alleles (DQB1*02:01, DRB1*03:01, C*07:01, and B*08:01) showed an association with reduced WMH volume after Bonferroni correction for multiple comparisons. Among these alleles, DQB1*02:01 exhibited the most significant association (β = -0.041, 95 % CI: -0.060 to -0.023, p = 1.04 × 10-5). Forward selection and lasso regression analyses indicated that DQB1*02:01 and C*07:01 primarily drove this association. The protective effect against WMH conferred by DQB1*02:01 and C*07:01 persisted in clinically relevant subgroups, with a stronger effect observed in older participants. Carrying DQB1*02:01 and C*07:01 was associated with higher cognitive function, but no association with dementia was found.

INTERPRETATION

Our population-based findings support the involvement of immune-associated mechanisms, particularly both HLA class I and class II genes, in the pathogenesis of WMH and subsequent consequence of cognitive functions.

Timing of Goals of Care Discussions in Nursing Homes: A Systematic Review

OBJECTIVES

Discussions between health professionals and nursing home (NH) residents or their families about the current or future goals of health care may be associated with better outcomes at the end of life (EOL), such as avoidance of unwanted interventions or death in hospital. The timing of these discussions varies, and it is possible that their influence on EOL outcomes depends on their timing. This study synthesized current evidence concerning the timing of goals of care (GOC) discussions in NHs and its impact on EOL outcomes.

DESIGN

Systematic review.

SETTING AND PARTICIPANTS

Adult populations in NH settings.

METHODS

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines. We searched PubMed, Embase, and Cumulative Index of Nursing and Allied Health from January 2000 to September 2022. We included studies that examined timing of GOC discussions in NHs, were peer-reviewed, and published in English. Quality of the studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

Screening of 1930 abstracts yielded 149 papers that were evaluated for eligibility. Of the 18 articles, representing 16 distinct studies that met review criteria, 12 evaluated the timing of advance directives. There was variation in the timing of GOC discussions and compared with discussions that occurred within a month of death, earlier discussions (eg, at the time of facility admission) were associated with lower rates of hospitalization at the EOL and lower health care costs.

CONCLUSIONS AND IMPLICATIONS

The timing of GOC discussions in NHs varies and evidence suggests that late discussions are associated with poorer EOL outcomes. The benefits of goal-concordant care may be enhanced by earlier and more frequent discussions. Future studies should examine the optimal timing for GOC discussions in the NH population.

The role of geriatric syndromes in predicting unplanned hospitalizations: a population-based study using Minimum Data Set for Home Care

BACKGROUND

The predictive accuracies of screening instruments for identifying home-dwelling old people at risk of hospitalization have ranged from poor to moderate, particularly among the oldest persons. This study aimed to identify variables that could improve the accuracy of a Minimum Data Set for Home Care (MDS-HC) based algorithm, the Detection of Indicators and Vulnerabilities for Emergency Room Trips (DIVERT) Scale, in classifying home care clients' risk for unplanned hospitalization.

METHODS

In this register-based retrospective study, factors associated with hospitalization among home care clients aged ≥ 80 years in the City of Tampere, Finland, were analyzed by linking MDS-HC assessments with hospital discharge records. MDS-HC determinants associated with hospitalization within 180 days after the assessment were analyzed for clients at low (DIVERT 1), moderate (DIVERT 2-3) and high (DIVERT 4-6) risk of hospitalization. Then, two new variables were selected to supplement the DIVERT algorithm. Finally, area under curve (AUC) values of the original and modified DIVERT scales were determined using the data of MDS-HC assessments of all home care clients in the City of Tampere to examine if addition of the variables related to the oldest age groups improved the accuracy of DIVERT.

RESULTS

Of home care clients aged ≥ 80 years, 1,291 (65.4%) were hospitalized at least once during the two-year study period. Unplanned hospitalization occurred following 15.9%, 22.8%, and 33.9% MDS-HC assessments with DIVERT group 1, 2-3 and 4-6, respectively. Infectious diseases were the most common diagnosis within each DIVERT groups. Many MDS-HC variables not included in the DIVERT algorithm were associated with hospitalization, including e.g. poor self-rated health and old fracture (other than hip fracture) (p 0.001) in DIVERT 1; impaired cognition and decision-making, urinary incontinence, unstable walking and fear of falling (p < 0.001) in DIVERT 2-3; and urinary incontinence, poor self-rated health (p < 0.001), and decreased social interaction (p 0.001) in DIVERT 4-6. Adding impaired cognition and urinary incontinence to the DIVERT algorithm improved sensitivity but not accuracy (AUC 0.64 (95% CI 0.62-0.65) vs. 0.62 (0.60-0.64) of the original DIVERT). More admissions occurred among the clients with higher scores in the modified than in the original DIVERT scale.

CONCLUSIONS

Certain geriatric syndromes and diagnosis groups were associated with unplanned hospitalization among home care clients at low or moderate risk level of hospitalization. However, the predictive accuracy of the DIVERT could not be improved. In a complex clinical context of home care clients, more important than existence of a set of risk factors related to an algorithm may be the various individual combinations of risk factors.

Hospital-Acquired Infection at Time of Stroke and Cognitive Decline: The Cardiovascular Health Study

Introduction Hospital-acquired infections (HAIs) after stroke are associated with additional morbidity and mortality, but whether HAIs increase long-term cognitive decline in stroke patients is unknown. We hypothesized that older adults with incident stroke with HAI experience faster cognitive decline than those having stroke without HAI and those without stroke. Methods We performed a longitudinal analysis in the population-based prospective Cardiovascular Health Study. Medicare-eligible participants aged >65 years with and without incident stroke had cognition assessed annually. HAIs were assessed by hospital discharge codes. Global cognitive function was assessed annually by Modified Mini-Mental State Examination (3MSE) and executive function by Digit Symbol Substitution Test (DSST). We used linear mixed models to estimate the mean decline and 95% confidence intervals (95% CI) for 3MSE and DSST scores by incident stroke and HAI status, adjusted for demographics and vascular risk factors. Results Among 5,443 participants >65 years without previous history of stroke, 393 participants had stroke with HAI (SI), 766 had a stroke only (SO), and 4,284 had no stroke (NS) throughout a maximum 9-year follow-up. For 3MSE, compared with NS participants, SO participants had a similar adjusted mean decline (additional 0.08 points/year, 95%CI -0.15, 0.31), while SI participants had a more rapid decline (additional 0.28 points/year, 95%CI 0.16, 0.40). Adjusted mean decline was 0.20 points/year faster (95%CI -0.05, 0.45) among SI than SO participants. For DSST, compared with NS participants, SO participants had a faster adjusted mean decline (additional 0.17 points/year (95%CI 0.003, 0.33), as did SI participants (additional 0.27 points/year (95%CI 0.19, 0.35). Conclusion Stroke, when accompanied by HAI, leads to a faster long-term decline in cognitive ability than in those without stroke. The clinical and public health implications of the effect of infection on post-stroke cognitive decline warrant further attention.

Sepsis exacerbates Alzheimer's disease pathophysiology, modulates the gut microbiome, increases neuroinflammation and amyloid burden

While our understanding of the molecular biology of Alzheimer's disease (AD) has grown, the etiology of the disease, especially the involvement of peripheral infection, remains a challenge. In this study, we hypothesize that peripheral infection represents a risk factor for AD pathology. To test our hypothesis, APP/PS1 mice underwent cecal ligation and puncture (CLP) surgery to develop a polymicrobial infection or non-CLP surgery. Mice were euthanized at 3, 30, and 120 days after surgery to evaluate the inflammatory mediators, glial cell markers, amyloid burden, gut microbiome, gut morphology, and short-chain fatty acids (SCFAs) levels. The novel object recognition (NOR) task was performed 30 and 120 days after the surgery, and sepsis accelerated the cognitive decline in APP/PS1 mice at both time points. At 120 days, the insoluble Aβ increased in the sepsis group, and sepsis modulated the cytokines/chemokines, decreasing the cytokines associated with brain homeostasis IL-10 and IL-13 and increasing the eotaxin known to influence cognitive function. At 120 days, we found an increased density of IBA-1-positive microglia in the vicinity of Aβ dense-core plaques, compared with the control group confirming the predictable clustering of reactive glia around dense-core plaques within 15 μm near Aβ deposits in the brain. In the gut, sepsis negatively modulated the α- and β-diversity indices evaluated by 16S rRNA sequencing, decreased the levels of SCFAs, and significantly affected ileum and colon morphology in CLP mice. Our data suggest that sepsis-induced peripheral infection accelerates cognitive decline and AD pathology in the AD mouse model.

Identifying predictors of cognitive decline in long-term care: a scoping review

BACKGROUND

Cognitive impairment can cause social, emotional, and financial burdens on individuals, caregivers, and healthcare providers. This is especially important in settings such as long-term care (LTC) homes which largely consist of vulnerable older adults. Thus, the objective of this study is to review and summarize current research examining risk factors of cognitive decline in older adults within LTC.

METHODS

This scoping review includes primary observational research studies assessing within-person change in cognition over time in LTC or equivalent settings in high resource countries. A mean participant age of ≥ 65 years was required. Searches were conducted in Medline, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and PyscInfo on June 27th, 2022 and included articles published during or after the year 2000. Title, abstract, and full-text screening was performed by two independent reviewers using Covidence. Specific predictors along with their associated relation with cognitive decline were extracted by a team of reviewers into a spreadsheet.

RESULTS

Thirty-eight studies were included in this review. The mean sample size was 14 620. Eighty-seven unique predictors were examined in relation to cognitive decline. Dementia was the most studied predictor (examined by 9 of 38 studies), and the most conclusive, with eight of those studies identifying it as a risk factor for cognitive decline. Other predictors that were identified as risk factors included arterial stiffness (identified by 2 of 2 studies), physical frailty (2 of 2 studies), sub-syndromal delirium (2 of 2 studies), and undergoing the first wave of COVID-19 lockdowns (2 of 2 studies). ADL independence was the most conclusive protective factor (3 of 4 studies), followed by social engagement (2 of 3 studies). Many remaining predictors showed no association and/or conflicting results.

CONCLUSIONS

Dementia was the most common risk factor, while ADL independence was the most common protective factor associated with cognitive decline in LTC residents. This information can be used to stratify residents by risk severity and provide better personalized care for older adults through the targeted management of cognitive decline.

Longitudinal impact of distinct infection trajectories on all-cause mortality of older people in Taiwan: a retrospective, nationwide, population-based study

BACKGROUND

Infectious diseases are the leading cause of deaths in adults aged 65 years or older. Studies of adverse infection outcomes have been limited to specific infections and acute episodes and have not investigated longitudinal trends of cumulative infections. We aimed to identify distinct trajectories of longitudinal infection episodes in older adults and to assess their corresponding risk of all-cause mortality.

METHODS

In this retrospective cohort study, we included people aged 65 years or older who were admitted to hospital between Jan 1 and Dec 31, 2011, with one of the following infections: urinary tract, pneumonia, sepsis, cellulitis, cholecystitis, peritonitis, endocarditis, and meningitis. Participants were identified from Taiwan's National Health Insurance Research Database. We analysed infection episodes on a quarterly basis during a 5-year period (2011-15) and used group-based trajectory modelling to identify distinct trajectories. We examined the associations between infection trajectories and all-cause mortality using Kaplan-Meier curves and the Cox proportional hazard model.

FINDINGS

Among 79 666 eligible older adults, we identified four distinct infection trajectories over the 5-year follow-up: infrequent (58 619 [73·6%]), increasing (9746 [12·2%]), decreasing (9069 [11·4%]), and frequent (2232 [2·8%]). Compared with people with infrequent infections, the adjusted hazard ratios for all-cause mortality were 2·96 (95% CI 2·82-3·11) in participants with frequent infections, 2·15 (2·09-2·22) in those with increasing infections, and 1·85 (1·80-1·91) in those with decreasing infections.

INTERPRETATION

Older adults with multiple infection episodes, irrespective of type, pathogens, and distinct infection pattern, had greater risk of all-cause mortality compared with those with infrequent infections. Further research to define the overall infection burden in older adults is needed for risk stratification and to inform prevention strategies.

FUNDING

The Interdisciplinary Research Center for Healthy Longevity of National Yang Ming Chiao Tung University from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education, the National Science and Technology Council, and the Ministry of Science and Technology in Taiwan.

Acute and long-term cognitive impairment following sepsis: mechanism and prevention

INTRODUCTION

Sepsis is a severe host response to infection, which induces both acute and long-term cognitive impairment. Despite its high incidence following sepsis, the underlying mechanisms remain elusive and effective treatments are not available clinically.

AREA COVERED

This review focuses on elucidating the pathological mechanisms underlying cognitive impairment following sepsis. Specifically, the authors discuss the role of systemic inflammation response, blood-brain barrier disruption, neuroinflammation, mitochondrial dysfunction, neuronal dysfunction, and Aβ accumulation and tau phosphorylation in cognitive impairment after sepsis. Additionally, they review current strategies to ameliorate cognitive impairment.

EXPERT OPINION

Potential interventions to reduce cognitive impairment after sepsis include earlier diagnosis and effective infection control, hemodynamic homeostasis, and adequate brain perfusion. Furthermore, interventions to reduce inflammatory response, reactive oxygen species, blood-brain barrier disruption, mitochondrial dysfunction, neuronal injury or death could be beneficial. Implementing strategies to minimize delirium, sleep disturbance, stress factors, and immobility are also recommended. Furthermore, avoiding neurotoxins and implementing early rehabilitation may also be important for preventing cognitive impairment after sepsis.

Sex, sepsis and the brain: defining the role of sexual dimorphism on neurocognitive outcomes after infection

Sexual dimorphisms exist in multiple domains, from learning and memory to neurocognitive disease, and even in the immune system. Male sex has been associated with increased susceptibility to infection, as well as increased risk of adverse outcomes. Sepsis remains a major source of morbidity and mortality globally, and over half of septic patients admitted to intensive care are believed to suffer some degree of sepsis-associated encephalopathy (SAE). In the short term, SAE is associated with an increased risk of in-hospital mortality, and in the long term, has the potential for significant impairment of cognition, memory, and acceleration of neurocognitive disease. Despite increasing information regarding sexual dimorphism in neurologic and immunologic systems, research into these dimorphisms in sepsis-associated encephalopathy remains critically understudied. In this narrative review, we discuss how sex has been associated with brain morphology, chemistry, and disease, sexual dimorphism in immunity, and existing research into the effects of sex on SAE.

Targeting the microbiota-mitochondria crosstalk in neurodegeneration with senotherapeutics

Neurodegenerative diseases are a group of age-related disorders characterized by a chronic and progressive loss of function and/or structure of synapses, neurons, and glial cells. The etiopathogenesis of neurodegenerative diseases is characterized by a complex network of intricately intertwined pathophysiological processes that are still not fully understood. Safe and effective disease-modifying treatments are urgently needed, but still not available. Accumulating evidence suggests that gastrointestinal dyshomeostasis and microbial dysbiosis might play an important role in neurodegeneration by acting as either primary or secondary pathophysiological factors. The research on the role of microbiota in neurodegeneration is in its early phase; however, accumulating evidence suggests that dysbiosis might promote neurodegenerative diseases by disrupting mitochondrial function and inducing mitochondrial dysfunction-associated senescence (MiDAS), possibly due to bidirectional crosstalk based on the common evolutionary origin of mitochondria and bacteria. Cellular senescence is an onco-supressive homeostatic mechanism that results in an irreversible cell cycle arrest upon exposure to noxious stimuli. Senescent cells resist apoptosis via senescent cell anti-apoptotic pathways (SCAPs) and transition into a state known as senescence-associated secretory phenotype (SASP) that generates a cytotoxic proinflammatory microenvironment. Cellular senescence results in the adoption of a detrimental vicious cycle driven by dysbiosis, mitochondrial dysfunction, inflammation, and oxidative stress - a pathophysiological positive feedback loop that results in neuroinflammation and neurodegeneration. Detrimental effects of MiDAS might be prevented and abolished by mitochondria-targeted senotherapeutics, a group of drugs specifically designed to alleviate senescence by inhibiting SCAPs (senolytics), or inhibiting SASP (senomorphics).

Memory, Attention, and Concentration Dysfunction Post-COVID-19 Among College Students in Saudi Arabia: A Case-Control Study

Introduction Multiple studies have demonstrated the multi-systemic involvement of COVID-19, and among all of these systems, there is mounting evidence that COVID-19 is linked to neurocognitive impairment, particularly when neurological symptoms are present. Our aim is to study the concept of cognitive dysfunction post-COVID-19 among college students in Saudi Arabia and its potential effect on their academic performance.  Methods A population-based, observational case-control study was conducted across the Kingdom of Saudi Arabia, from May 2022 to September 2022. A total of 2,150 eligible students have completed the study questionnaire. An exact 776 (36.1%) of them had COVID-19 infection (group 1), while 1,374 (63.9%) students had not (group 2). The sample population was college-enrolled students from 18 to 28 years old, with a mean age of 21.3 for group 1 and 20.8 for group 2. Both groups were handed the same data collection tool to establish whether the COVID-19 survivors had cognitive deficits more than the control group. Results There was no significant difference between the two groups regarding their bio-demographic data, study methods, or vaccination rate. However, both Neurological Fatigue and Big Five Inventory score were significantly higher among infected students, comparable to non-infected students. A negative relation was found between the infected students' neurological fatigue (rho=-0.14), cognitive failure (rho=-0.10), and depression and anxiety scale with their GPA (rho=0.03). Contrarily, infected students showed a positive relationship between their GPA and the Big Five Inventory (rho=0.13) and Short Grit Scale (rho=0.14). Also, there was a significant inverse relation between students' apathy motivation with their Big Five Inventory. Likewise, there was an inverse relation between their neurological fatigue, cognitive failure, and apathy motivation with their Short Grit Scale. Conclusion We demonstrated that college students who have survived COVID-19 infection mostly complain of cognitive impairment, even though most of them have no comorbidities or psychological disorders.

Are infections associated with cognitive decline and neuroimaging outcomes? A historical cohort study using data from the UK Biobank study linked to electronic health records

While there is growing evidence of associations between infections and dementia risk, associations with cognitive impairment and potential structural correlates of cognitive decline remain underexplored. Here we aimed to investigate the presence and nature of any associations between common infections, cognitive decline and neuroimaging parameters. The UK Biobank is a large volunteer cohort (over 500,000 participants recruited aged 40-69) with linkage to primary and secondary care records. Using linear mixed effects models, we compared participants with and without a history of infections for changes in cognitive function during follow-up. Linear regression models were used to investigate the association of infections with hippocampal and white matter hyperintensity (WMH) volume. 16,728 participants (median age 56.0 years [IQR 50.0-61.0]; 51.3% women) had baseline and follow-up cognitive measures. We found no evidence of an association between the presence of infection diagnoses and cognitive decline for mean correct response time (slope difference [infections versus no infections] = 0.40 ms, 95% CI: -0.17-0.96 per year), visual memory (slope difference 0.0004 log errors per year, 95% CI: -0.003-0.004, fluid intelligence (slope difference 0.007, 95% CI: -0.010-0.023) and prospective memory (OR 0.88, 95% CI: 0.68-1.14). No evidence of an association was found between infection site, setting or frequency and cognitive decline except for small associations on the visual memory test. We found no association between infections and hippocampal or WMH volume. Limitations of our study include selection bias, potential practice effects and the relatively young age of our cohort. Our findings do not support a major role for common midlife infections in contributing to cognitive decline for this cohort. Further research is warranted in individuals with more severe infections, for infections occurring later in life.

Influence of age and sex on microRNA response and recovery in the hippocampus following sepsis

Sepsis, defined as a dysregulated host immune response to infection, is a common and dangerous clinical syndrome. The excessive host inflammatory response can induce immediate and persistent cognitive decline, which can be worse in older individuals. Sex-specific differences in the outcome of infectious diseases and sepsis appear to favor females. We employed a murine model to examine the influence of age and sex on the brain's microRNA (miR) response following sepsis. Young and old mice of both sexes underwent cecal ligation and puncture (CLP) with daily restraint stress. Expression of hippocampal miR was examined in age- and sex-matched controls at 1 and 4 days post-CLP. Few miR were modified in a similar manner across age or sex and these few miR were generally associated with neuroprotection against inflammation. Similar to previous work examining transcription, young females exhibited a better recovery of the miR profile from day 1 to day 4, relative to young males and old females. For young males and all female groups, the initial response mainly involved a decrease in miR expression. In contrast, old males exhibited only upregulated miR on day 1 and day 4 and many of the miR upregulated on day 1 and day 4 were linked to neurodegeneration, increased neuroinflammation, and cognitive impairment. The results emphasize age and sex differences in epigenetic mechanisms that likely contribute to susceptibility or resilience to cognitive impairment due to sepsis.

Spotlight on non-motor symptoms and Covid-19

The Coronavirus Disease 2019 (Covid-19) pandemic has profoundly affected the quality of life (QoL) and health of the general population globally over the past 2 years, with a clear impact on people with Parkinson's Disease (PwP, PD). Non-motor symptoms have been widely acknowledged to hold a vital part in the clinical spectrum of PD, and, although often underrecognized, they significantly contribute to patients' and their caregivers' QoL. Up to now, there have been numerous reports of newly emerging or acutely deteriorating non-motor symptoms in PwP who had been infected by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), while some of these symptoms, like fatigue, pain, depression, anxiety and cognitive impairment, have also been identified as part of the long-COVID syndrome due to their persistent nature. The subjacent mechanisms, mediating the appearance or progression of non-motor symptoms in the context of Covid-19, although probably multifactorial in origin, remain largely unknown. Such mechanisms might be, at least partly, related solely to the viral infection per se or the lifestyle changes imposed during the pandemic, as many of the non-motor symptoms seem to be prevalent even among Covid-19 patients without PD. Here, we summarize the available evidence and implications of Covid-19 in non-motor PD symptoms in the acute and chronic, if applicable, phase of the infection, with a special reference on studies of PwP.

Cognitive Trajectories Following Acute Infection in Older Patients With and Without Cognitive Impairment: An 1-Year Follow-Up Study

Introduction: Dementia is a known risk factor for both delirium and acute systemic infections which may also play a significant role in promoting or accelerating neurodegenerative disease. Infections are both the main causes of hospitalization of dementia patients and can be a major precipitant of delirium but currently it is not possible to predict the risk of cognitive decline in older patients exposed to acute infection. Objectives: We aimed to determine the level of cognitive change at 1-year follow up in individuals with different patterns of cognitive function (dementia, delirium, delirium superimposed on dementia) at the time of their hospitalization due to a systemic infection and to correlate these cognitive patterns with clinical status variables. Methods: We recruited 53 hospitalized geriatric patients with a systemic infection, and we collected 12-months follow up data for 34 patients. These patients were classified in four groups: no cognitive impairment (controls-C), delirium only (D), dementia only (Dem), and delirium superimposed to dementia (DD). Cognitive performance was measured by change in score on the Montreal Cognitive Assessment (MoCA) and delirium was identified using Confusion Assessment Measure (CAM). We examined performance on the MoCA in the first year after hospitalization, controlling for demographic characteristics, coexisting medical conditions, and type of infection. Results: For the 34 patients to whom follow-up data was available, delirium presence in individuals with prior dementia (DD group) was associated with a negative mean change score of 3-point (p < 0.02) at 1 year follow up, whereas dementia patients without delirium had a mean change score of 1.5-point lower at 12-months (p = 0.04), when comparing follow-up and baseline MoCA scores. Cognitively healthy patients did not significantly decrease their MoCA score at follow-up (p = 0.15). MoCA and NPI scores during hospitalization were significantly correlated with the level of cognitive decline in the four groups (r = 0.658, p < 0.01 and r = 0.439, p = 0.02, respectively). Conclusions: Premorbid dementia and delirium superimposed on dementia during hospitalization in older patients with acute infections predict cognitive decline at 1 year following admission. Taken together, our findings suggest a pathophysiological interaction between neurodegenerative changes, acute infection, and delirium.