Dementia and COVID-19, a Bidirectional Liaison: Risk Factors, Biomarkers, and Optimal Health Care

The risk of cognitive decline and dementia in older adults diagnosed with COVID-19: A systematic review and meta-analysis

BACKGROUND

Cognitive impairment can be caused by infections with various pathogens, including SARS-CoV-2. Research has yet to determine the true incidence and course of cognitive impairment in older adults following COVID-19. Furthermore, research has theorised that COVID-19 is associated with dementia progression and diagnosis but this association has yet to be fully described.

METHODS

A systematic review was registered in Prospero and conducted on the databases PubMed, Embase, Ovid, CENTRAL and Cochrane Library. Studies reporting cognitive impairment and dementia outcomes in post-acute and post-COVID-19 patients aged ≥65 years, and which included control data, were included in this review.

RESULTS

15,124 articles were identified by the search strategy. After eliminating duplicate titles and completing title, abstracts and full-text review, 18 studies were included comprising of 412,957 patients with COVID-19 (46.63 % male) and 411,929 patients without COVID-19 (46.59 % male). The overall mean Montreal Cognitive Assessment (MoCA) score in COVID-19 patients was 23.34 out of 30 (95 % CI [22.24, 24.43]). indicating cognitive impairment. The overall proportion of patients identified as having new onset cognitive impairment was 65 % (95 % CI [44,81]). Subgroup analyses indicated that time since infection significantly improves overall MoCA score and reduces proportion of patients with cognitive impairment.

CONCLUSION

This study indicates that cognitive impairment may be an important sequela of COVID-19. Further research with adequate sample sizes is warranted regarding COVID-19's association with new-onset dementia and dementia progression, and the effect of repeat infections. There is a need for development of diagnostic and management protocols for COVID-19 patients with cognitive impairment.

Long Coronavirus Disease and the Brain: Molecular Neuroimaging Insights into Neurologic and Psychiatric Sequelae

The coronavirus disease 2019 (COVID-19) pandemic has led to a variety of health challenges, with "long COVID" emerging as a widespread and debilitating post-acute syndrome among a considerable number of infected patients. This PET review synthesizes current evidence of the neurologic and psychiatric sequelae of COVID. This review also explores the pathophysiological mechanisms of these results, including astrocyte dysfunction and glutamate dysregulation, as well as the multimodal comparison to MR imaging findings. The findings underscore the potential for long-term brain injury. Additionally, the authors discuss the role of advanced imaging multimodal techniques in diagnosing, monitoring, and guiding treatment strategies for long COVID.

Memory complaints after COVID-19: a potential indicator of primary cognitive impairment or a correlate of psychiatric symptoms?

Cognitive impairment and symptoms of psychiatric disorders have been reported frequently as features of post-acute sequelae of SARS-CoV-2 infection. This study aims to investigate subjective memory complaints in COVID-19 survivors and determine if these are more strongly associated with objective cognitive impairment related to sequelae of SARS-CoV-2 infection or with symptoms of psychiatric conditions. A total of 608 COVID-19 survivors were evaluated in-person 6-11 months after hospitalization, with 377 patients assigned to a "no subjective memory complaint (SMC)" group and 231 patients assigned to an SMC group based on their Memory Complaint Scale scores. Follow-up evaluations included an objective cognitive battery and scale-based assessments of anxiety, depression, and post-traumatic stress symptoms. We found the perception of memory impairment in COVID-19 survivors to be more strongly associated to core symptoms of psychiatric conditions rather than to primary objective cognitive impairment. Univariate analysis indicated significant differences between the "no SMC" and SMC groups, both for the psychiatric symptom evaluations and for the cognitive evaluations (p < 0.05); however, the psychiatric symptoms all had large partial eta-squared values (ranging from 0.181 to 0.213), whereas the cognitive variables had small/medium partial eta-squared values (ranging from 0.002 to 0.024). Additionally, multiple regression analysis indicated that only female sex and depressive and post-traumatic stress symptoms were predictors of subjective memory complaints. These findings may help guide clinical evaluations for COVID-19 survivors presenting with memory complaints while also serving to expand our growing understanding of the relationship between COVID-19, subjective memory complaints, and the risk of cognitive decline.

Management of patients with neurological diseases considering post-pandemic coronavirus disease 2019 (COVID-19) related risks and dangers - An updated European Academy of Neurology consensus statement

BACKGROUND AND PURPOSE

In October 2020, the European Academy of Neurology (EAN) consensus statement for management of patients with neurological diseases during the coronavirus disease 2019 (COVID-19) pandemic was published. Due to important changes and developments that have happened since then, the need has arisen to critically reassess the original recommendations and address new challenges.

METHODS

In step 1, the original items were critically reviewed by the EAN COVID-19 Task Force. In addition, new recommendations were defined. In step 2, an online survey with the recommendations forged in step 1 was sent to the Managing Groups of all Scientific and Coordinating Panels of EAN. In step 3, the final set of recommendations was made.

RESULTS

In step 1, out of the original 36 recommendations, 18 were judged still relevant. They were edited to reflect the advances in knowledge and practice. In addition, 21 new recommendations were formulated to address the new knowledge and challenges. In step 2, out of the 39 recommendations sent for the survey, nine were approved as they were, whilst suggestions for improvement were given for the rest. In step 3, the recommendations were further edited, and some new items were formed to accommodate the participants' suggestions, resulting in a final set of 41 recommendations.

CONCLUSION

This revision of the 2020 EAN Statement provides updated comprehensive and structured guidance on good clinical practice in people with neurological disease faced with SARS-CoV-2 infection. It now covers the issues from the more recent domains of COVID-19-related care, vaccine complications and post-COVID-19 conditions.

Association of diabetes mellitus with dementia- and non-dementia-related mortality amongst women: a secondary competing risks analysis of the California Teachers Study

BACKGROUND AND PURPOSE

The prevalence of dementia is rapidly increasing. Attempts to further understand modifiable risk factors such as diabetes mellitus (DM) are urgently needed to inform public health policies for prevention. Thus, the objective of the current study was to assess the relationship between DM and risk of dementia and non-dementia mortality amongst women in the California Teachers Study prospective cohort.

METHODS

Women (n = 124,509) aged 22-104 years at baseline were included. DM was ascertained from self-reported questionnaires and hospital-linked records. Dementia-related deaths were ascertained from state and national records. Competing risk regression models were used to estimate cause-specific hazard ratios and 95% confidence intervals for the association of DM with dementia- and non-dementia-related mortality.

RESULTS

There were 10,511 total DM cases and 3625 deaths due to dementia over a mean of 21.3 years of follow-up. Fully adjusted cause-specific hazard ratios of the association with DM were 2.26 (2.01, 2.55) for dementia-related and 1.97 (1.89, 2.05) for the competing risk of non-dementia-related mortality. This association was strongest amongst participants with incident DM, younger age at baseline and higher alcohol consumption or who were overweight.

CONCLUSIONS

In the California Teachers Study, women with DM had increased risk of mortality due to both dementia and non-dementia causes; however, the risk of mortality due to dementia was elevated compared to non-dementia causes only amongst participants with incident DM.

Long COVID in Brain Health Research: A Call to Action

The COVID-19 pandemic has brought attention to the long-term consequences of the virus, particularly the persistent symptoms that characterize long COVID. This syndrome, which can last for months after the initial infection, includes a range of neurological and neuropsychiatric manifestations that have significant implications for brain health and dementia research. This review explores the current understanding of long COVID's cognitive, neurological, and psychiatric symptoms and their potential impact on brain stimulation and neuroimaging studies. It argues that researchers must adapt their study designs and screening processes to account for the confounding effects of long COVID and ensure the accuracy and reliability of their findings. To advance the understanding of this condition and its long-term effects on brain health, the review proposes a series of strategies, including the development of standardized screening tools, the investigation of underlying mechanisms, and the identification of risk factors and protective factors. It also emphasizes the importance of collaborative research efforts and international data sharing platforms in accelerating the pace of discovery and developing targeted interventions for individuals with long COVID. As the prevalence of this condition continues to grow, it is imperative that the neuroscience community comes together to address this challenge and support those affected by long COVID.

The association between memory, COVID-19 testing, and COVID-19 incidence in middle-aged and older adults: a prospective analysis of the CLSA

We investigated the association between pre-COVID-19 memory function and (a) receipt of a COVID-19 test and (b) incidence of COVID-19 using the COVID-19 Questionnaire Study (CQS) of the Canadian Longitudinal Study on Aging (CLSA). The CQS included 28,565 middle-aged and older adults. We regressed receipt of a COVID-19 test on participants' immediate and delayed recall memory scores and re-ran the regression models with COVID-19 incidence as the outcome. All regression models were adjusted for sociodemographic, lifestyle, and health covariates. In the analytical sample (n = 21,930), higher delayed recall memory (better memory) was significantly associated with lower COVID-19 incidence. However, this association was not significant for immediate recall memory. Immediate and delayed recall memory were not associated with receipt of a COVID-19 test. Health policymakers and practitioners may viewmemory status as a potential risk for COVID-19. Memory status may not be a barrier to COVID-19 testing.

Viral Infections, Are They a Trigger and Risk Factor of Alzheimer's Disease?

Alzheimer's Disease (AD), a progressive and debilitating condition, is reported to be the most common type of dementia, with at least 55 million people believed to be currently affected. Many causation hypotheses of AD exist, yet the intriguing link between viral infection and its possible contribution to the known etiology of AD has become an attractive focal point of research for the field and a challenging study task. In this review, we will explore the historical perspective and milestones that led the field to investigate the viral connection to AD. Specifically, several viruses such as Herpes Simplex Virus 1 (HSV-1), Zika virus (ZIKV), and severe cute respiratory syndrome coronavirus 2 (SARS-CoV-2), along with several others mentioned, include the various viruses presently considered within the field. We delve into the strong evidence implicating these viruses in the development of AD such as the lytic replication and axonal transport of HSV-1, the various mechanisms of ZIKV neurotropism through the human protein Musashi-1 (MSI1), and the spread of SARS-CoV-2 through the transfer of the virus through the BBB endothelial cells to glial cells and then to neurons via transsynaptic transfer. We will also explore beyond these mere associations by carefully analyzing the potential mechanisms by which these viruses may contribute to AD pathology. This includes but is not limited to direct neuronal infections, the dysregulation of immune responses, and the impact on protein processing (Aβ42 and hyperphosphorylated tau). Controversies and challenges of the virus-AD relationship emerge as we tease out these potential mechanisms. Looking forward, we emphasize future directions, such as distinct questions and proposed experimentations to explore, that the field should take to tackle the remaining unanswered questions and the glaring research gaps that persist. Overall, this review aims to provide a comprehensive survey of the past, present, and future of the potential link between viral infections and their association with AD development while encouraging further discussion.

Chatbot-Mediated Learning For Caregiving Relatives of People With Dementia: Empirical Findings and Didactical Implications For Mulitprofessional Health Care

Purpose

Supporting family caregivers is a major challenge for the healthcare system. The first points of contact are physicians, nurses and social services, which are not easily accessible. For this reason, an information platform has been developed to provide information for family caregivers caring for people with dementia at home. The aim of this article is to provide an insight into the didactic design of this platform.

Sample and Methods

A didactic concept was developed based on didactic target group analysis and interviews with caring relatives (n=6).

Results

The didactic concept of the digital platform takes into account the characteristics of family caregivers as learners, such as time constraints and reciprocity. Therefore two different learning paths, a long and a short version, are offered. Reciprocity is supported by information which are related to individual characteristics of the caring relation. This is made possible by an adaptation of the didactic method "anchored instructions": Family caregivers experience a problematic caring situation. They use the platform and central concepts related to this situation are offered as anchors. In chatbot mediated learning, these concepts are identified and, ideally, relevant information is provided in a short version. These concepts are displayed as a learning map and must be proactively selected. Chatbot mediated learning has the advantage that matching concepts are offered as a pre-selection. Especially for inexperienced carers who are not familiar with the concepts, this learning path seems to be suitable.

Conclusion

The combination of learning through the "Information for Relatives" website and CML seems to meet all needs. In order to promote learner motivation, the chatbot should not only offer the identified concept, but also those related to this concept, in order to link new knowledge in one's own knowledge network.

Unravelling the connection between COVID-19 and Alzheimer's disease: a comprehensive review

Currently, there exists a limited comprehension regarding the correlation between COVID-19 and Alzheimer's disease (AD). To elucidate the interrelationship and its impact on outcomes, a comprehensive investigation was carried out utilising time-unrestricted searches of reputable databases such as Scopus, PubMed, Web of Science, and Google Scholar. Our objective was to evaluate the impact of various medical conditions on severe COVID-19-related events. We focused on identifying and analysing articles that discussed the clinical characteristics of COVID-19 patients, particularly those pertaining to severe events such as ICU admission, mechanical ventilation, pneumonia, mortality and acute respiratory distress syndrome (ARDS) a serious lung condition that causes low blood oxygen. Through careful data analysis and information gathering, we tried to figure out how likely it was that people with conditions, like AD, would have serious events. Our research investigated potential mechanisms that link AD and COVID-19. The ability of the virus to directly invade the central nervous system and the role of ACE-2 receptors were investigated. Furthermore, the OAS1 gene served as the genetic link between AD and COVID-19. In the context of COVID-19, our findings suggest that individuals with AD may be more susceptible to experiencing severe outcomes. Consequently, it is crucial to provide personalised care and management for this demographic. Further investigation is required to attain a comprehensive comprehension of the intricate correlation between Alzheimer's disease and COVID-19, as well as its ramifications for patient outcomes.

Outcomes of COVID-19-Associated Hospitalizations in Geriatric Patients with Dementia in the United States: A Propensity Score Matched Analysis

Previous studies have convincingly demonstrated the negative impact of dementia on overall health outcomes. In the context of the COVID-19 pandemic, there is burgeoning evidence suggesting a possible association between dementia and adverse outcomes, however the relationship has not been conclusively established. We conducted a retrospective cohort study involving 816,960 hospitalized COVID-19 patients aged 65 or older from the 2020 national inpatient sample. The cohort was bifurcated into patients with dementia (n = 180,845) and those without (n = 636,115). Multivariate regression and propensity score matched analyses (PSM) assessed in-hospital mortality and complications. We observed that COVID-19 patients with dementia had a notably higher risk of in-hospital mortality (23.1% vs. 18.6%; aOR = 1.2 [95% CI 1.1-1.2]). This elevated risk persisted even after PSM. Interestingly, dementia patients had a reduced risk of several acute in-hospital complications, including liver failure and sudden cardiac arrest. Nevertheless, they had longer hospital stays and lower total hospital charges. Our findings conclusively demonstrate that dementia patients face a heightened risk of mortality when hospitalized with COVID-19 but are less likely to experience certain complications. This complexity underscores the urgent need for individualized care strategies for this vulnerable group.

Associations between cohort derived dementia and COVID-19 serological diagnosis among older Black adults in rural South Africa

Objectives

This study investigates the association between cohort derived dementia and serologically confirmed SARS-CoV-2 infection, an underexplored phenomena in low-and middle-income countries. Examining this relationship in a rural South African community setting offers insights applicable to broader healthcare contexts.

Methods

Data were collected from Black South Africans in the Mpumalanga province who participated in the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa. Cohort derived dementia was developed using a predictive model for consensus-based dementia diagnosis. Multinomial logistic regression models estimated the association between predicted dementia probability in 2018 and SARS-CoV-2 infection risk in 2021, controlling for demographics, socioeconomic status, and comorbidities.

Results

Fifty-two percent of the tested participants had serologically confirmed SARS-CoV-2 infections. In the fully adjusted model, cohort derived dementia was significantly associated with over twice the risk of serological diagnosis of COVID-19 (RRR = 2.12, p = 0.045).

Conclusion

Complying with COVID-19 prevention recommendations may be difficult for individuals with impaired cognitive functioning due to their symptoms. Results can inform community-based public health initiatives to reduce COVID-19 transmission among South Africa's rapidly aging population.

Revealing Molecular Patterns of Alzheimer's Disease Risk Gene Expression Signatures in COVID-19 Brains

Background

Various virus infections are known to predispose to Alzheimer's disease (AD), and a linkage between COVID-19 and AD has been established. COVID-19 infection modulates the gene expression of the genes implicated in progression of AD.

Objective

Determination of molecular patterns and codon usage and context analysis for the genes that are modulated during COVID-19 infection and are implicated in AD was the target of the study.

Methods

Our study employed a comprehensive array of research methods, including relative synonymous codon usage, Codon adaptation index analysis, Neutrality and parity analysis, Rare codon analyses, and codon context analysis. This meticulous approach was crucial in determining the molecular patterns present in genes up or downregulated during COVID-19 infection.

Results

G/C ending codons were preferred in upregulated genes while not in downregulated genes, and in both gene sets, longer genes have high expressivity. Similarly, T over A nucleotide was preferred, and selection was the major evolutionary force in shaping codon usage in both gene sets. Apart from stops codons, codons CGU - Arg, AUA - Ile, UUA - Leu, UCG - Ser, GUA - Val, and CGA - Arg in upregulated genes, while CUA - Leu, UCG - Ser, and UUA - Leu in downregulated genes were present below the 0.5%. Glutamine-initiated codon pairs have high residual values in upregulated genes. Identical codon pairs GAG-GAG and GUG-GUG were preferred in both gene sets.

Conclusions

The shared and unique molecular features in the up- and downregulated gene sets provide insights into the complex interplay between COVID-19 infection and AD. Further studies are required to elucidate the relationship of these molecular patterns with AD pathology.

The impact of aging and oxidative stress in metabolic and nervous system disorders: programmed cell death and molecular signal transduction crosstalk

Life expectancy is increasing throughout the world and coincides with a rise in non-communicable diseases (NCDs), especially for metabolic disease that includes diabetes mellitus (DM) and neurodegenerative disorders. The debilitating effects of metabolic disorders influence the entire body and significantly affect the nervous system impacting greater than one billion people with disability in the peripheral nervous system as well as with cognitive loss, now the seventh leading cause of death worldwide. Metabolic disorders, such as DM, and neurologic disease remain a significant challenge for the treatment and care of individuals since present therapies may limit symptoms but do not halt overall disease progression. These clinical challenges to address the interplay between metabolic and neurodegenerative disorders warrant innovative strategies that can focus upon the underlying mechanisms of aging-related disorders, oxidative stress, cell senescence, and cell death. Programmed cell death pathways that involve autophagy, apoptosis, ferroptosis, and pyroptosis can play a critical role in metabolic and neurodegenerative disorders and oversee processes that include insulin resistance, β-cell function, mitochondrial integrity, reactive oxygen species release, and inflammatory cell activation. The silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), AMP activated protein kinase (AMPK), and Wnt1 inducible signaling pathway protein 1 (WISP1) are novel targets that can oversee programmed cell death pathways tied to β-nicotinamide adenine dinucleotide (NAD+), nicotinamide, apolipoprotein E (APOE), severe acute respiratory syndrome (SARS-CoV-2) exposure with coronavirus disease 2019 (COVID-19), and trophic factors, such as erythropoietin (EPO). The pathways of programmed cell death, SIRT1, AMPK, and WISP1 offer exciting prospects for maintaining metabolic homeostasis and nervous system function that can be compromised during aging-related disorders and lead to cognitive impairment, but these pathways have dual roles in determining the ultimate fate of cells and organ systems that warrant thoughtful insight into complex autofeedback mechanisms.

Effects of COVID-19 on cognition and brain health

COVID-19 is associated with a range of neurological, cognitive, and mental health symptoms both acutely and chronically that can persist for many months after infection in people with long-COVID syndrome. Investigations of cognitive function and neuroimaging have begun to elucidate the nature of some of these symptoms. They reveal that, although cognitive deficits may be related to brain imaging abnormalities in some people, symptoms can also occur in the absence of objective cognitive deficits or neuroimaging changes. Furthermore, cognitive impairment may be detected even in asymptomatic individuals. We consider the evidence regarding symptoms, cognitive deficits, and neuroimaging, as well as their possible underlying mechanisms.

Direct impact of 2 years of COVID-19 on chronic disease patients: a population-based study in a large hard-hit Italian region

OBJECTIVES

We aimed to provide a region-wide comprehensive account of the direct effects of COVID-19 on chronic disease patients, in terms of disease incidence, severity and mortality, over a 2-year pandemic period (2020-2021).

DESIGN

Population-based retrospective study.

SETTING/PARTICIPANTS

Adult patients, affected by at least 1 of 32 prevalent chronic conditions, residing in the Emilia-Romagna Region in Italy, during the years 2020 (N=1 791 189, 47.7% of the overall adult regional population) and 2021 (N=1 801 071, 47.8%).

RESULTS

COVID-19 incidence among chronic disease patients was 4.1% (74 067 cases) in 2020 and 7.3% (126 556 cases) in 2021, varying across pathologies, with obesity and dementia showing the highest incidence. Hospitalisation rate for pneumonia or acute respiratory distress syndrome among SARS-CoV-2-positive patients was 15.4%. COVID-19-related excess mortality, that is, deaths from COVID-19 as either main or contributing (1.5% of the total) cause of death, was observed during the three pandemic waves, with observed/expected death ratios ranging from +38% (March 2020) to +11% (December 2021). Increased risks of both COVID-19-related hospitalisation and death were associated with male gender, elderly age and many pre-existing pathologies, including cardiovascular, cerebrovascular and respiratory diseases, neurological and psychiatric disorders, and metabolic dysfunctions. The higher the number of concomitant pathologies, the greater the risk of COVID-19-related adverse outcomes: the likelihood of hospitalisation and death more than doubled for people with more than two comorbidities, compared with those with one underlying condition.

CONCLUSIONS

This study presents a thorough and up-to-date quantification of the direct impact of COVID-19 on chronic disease patients. The results obtained are particularly relevant considering that people with pre-existing chronic conditions accounted for almost all cases of COVID-19-related hospitalisation (82.6%) and death (91.5%) in a vast region of Italy, among the hardest hit by the pandemic.

Retinal Microvasculature Image Analysis Using Optical Coherence Tomography Angiography in Patients with Post-COVID-19 Syndrome

Several optical coherence tomography angiography (OCT-A) studies have demonstrated retinal microvascular changes in patients post-SARS-CoV-2 infection, reflecting retinal-systemic microvasculature homology. Post-COVID-19 syndrome (PCS) entails persistent symptoms following SARS-CoV-2 infection. In this study, we investigated the retinal microvasculature in PCS patients using OCT-angiography and analysed the macular retinal nerve fibre layer (RNFL) and ganglion cell layer (GCL) thickness via spectral domain-OCT (SD-OCT). Conducted at the Manchester Royal Eye Hospital, UK, this cross-sectional study compared 40 PCS participants with 40 healthy controls, who underwent ophthalmic assessments, SD-OCT, and OCT-A imaging. OCT-A images from the superficial capillary plexus (SCP) were analysed using an in-house specialised software, OCT-A vascular image analysis (OCTAVIA), measuring the mean large vessel and capillary intensity, vessel density, ischaemia areas, and foveal avascular zone (FAZ) area and circularity. RNFL and GCL thickness was measured using the OCT machine's software. Retinal evaluations occurred at an average of 15.2 ± 6.9 months post SARS-CoV-2 infection in PCS participants. Our findings revealed no significant differences between the PCS and control groups in the OCT-A parameters or RNFL and GCL thicknesses, indicating that no long-term damage ensued in the vascular bed or retinal layers within our cohort, providing a degree of reassurance for PCS patients.

Neuroinflammation in Alzheimer's Disease: A Potential Role of Nose-Picking in Pathogen Entry via the Olfactory System?

Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by progressive cognitive decline and memory impairment. Many possible factors might contribute to the development of AD, including amyloid peptide and tau deposition, but more recent evidence suggests that neuroinflammation may also play an-at least partial-role in its pathogenesis. In recent years, emerging research has explored the possible involvement of external, invading pathogens in starting or accelerating the neuroinflammatory processes in AD. In this narrative review, we advance the hypothesis that neuroinflammation in AD might be partially caused by viral, bacterial, and fungal pathogens entering the brain through the nose and the olfactory system. The olfactory system represents a plausible route for pathogen entry, given its direct anatomical connection to the brain and its involvement in the early stages of AD. We discuss the potential mechanisms through which pathogens may exploit the olfactory pathway to initiate neuroinflammation, one of them being accidental exposure of the olfactory mucosa to hands contaminated with soil and feces when picking one's nose.

Hippocampal alterations after SARS-CoV-2 infection: A systematic review

SARS-CoV-2 infection produces a wide range of symptoms. Some of the structural changes caused by the virus in the nervous system are found in the medial temporal lobe, and several neuropsychological sequelae of COVID-19 are related to the function of the hippocampus. The main objective of the systematic review is to update and further analyze the existing evidence of hippocampal and related cortices' structural and functional alterations due to SARS-CoV-2 infection. Both clinical and preclinical studies that used different methodologies to explore the effects of this disease at different stages and grades of severity were considered, besides exploring related cognitive and emotional symptomatology. A total of 24 studies were identified by searching in SCOPUS, Web Of Science (WOS), PubMed, and PsycInfo databases up to October 3rd, 2022. Thirteen studies were performed in clinical human samples, 9 included preclinical animal models, 3 were performed post-mortem, and 1 included both post-mortem and preclinical samples. Alterations in the hippocampus were detected in the acute stage and after several months of infection. Clinical studies revealed alterations in hippocampal connectivity and metabolism. Memory alterations correlated with altered metabolic profiles or changes in grey matter volumes. Hippocampal human postmortem and animal studies observed alterations in neurogenesis, dendrites, and immune response, besides high apoptosis and neuroinflammation. Preclinical studies reported the viral load in the hippocampus. Olfactory dysfunction was associated with alterations in brain functionality. Several clinical studies revealed cognitive complaints, neuropsychological alterations, and depressive and anxious symptomatology.

Assessment of COVID-19 lockdown effect on early Alzheimer Disease progression

INTRODUCTION

Recently, many aspects of daily life have changed due to the COVID-19 pandemic. Patients with Alzheimer Disease (AD) could be more vulnerable to those daily life changes as experts expected. Mainly, the lockdown involved reduced social contact and cognitive stimulation. So, it could affect the AD expression, increasing the patients' disabilities development.

OBJECTIVE

The aim of this study is to evaluate the effect of COVID-19 lockdown on cognitive impairment progression in early AD patients.

METHODOLOGY

The participants were patients with mild cognitive impairment due to AD (MCI-AD) from the Neurology Unit (La Fe Hospital), who were neuropsychologically evaluated (cognitive impairment, daily activity tests) twice over 2 years. They were classified into a case group (n = 21), evaluated before and after lockdown condition, and a control group (n = 20), evaluated entirely before the lockdown condition.

RESULTS

All the participants showed increasing cognitive impairment and functional deterioration over the 2-year period of evaluation (p < 0.05). However, a faster worsening was not observed as a consequence of the COVID-19 pandemic and the lockdown condition. In fact, the statistical significance observed between the two study groups for daily life activities showed that the worsening was even lesser in the group evaluated under the lockdown condition.

CONCLUSION

Medium-term effects of COVID-19 lockdown could not involve an acceleration of the cognitive decline in MCI-AD patients in a 2-year evaluation period. In addition, the least worsening observed for daily living activities in the case group was probably due to the change in routines. Therefore, the common assumption of cognitive worsening of AD progression due to the lockdown in comparison with normal disease progression was not demonstrated in this study, at least for MCI-AD cases. However, more longitudinal studies are required to evaluate long-term effects in these patients.

Caregiver Experience of Tele-dementia Care for Older Veterans

BACKGROUND

For the 5 million persons living with dementia (PLWD) in the USA, telemedicine may improve access to specialty care from their homes.

OBJECTIVE

To elicit informal caregiver perceptions of tele-dementia care provided during COVID-19.

DESIGN

Qualitative, observational study using grounded theory.

PARTICIPANTS

Informal caregivers aged 18 + who cared for an older adult who received tele-dementia services at two major VA healthcare systems participated in 30-60-min semi-structured telephone interviews.

INTERVENTIONS

Interviews were designed using Fortney's Access to Care model.

MAIN MEASURES

Thirty caregivers (mean age = 67, SD = 12, 87% women) were interviewed.

KEY RESULTS

Five major themes were (1) Tele-dementia care avoids routine disruption and pre-visit stress; (2) Transportation barriers to in-person visits include not only travel logistics but navigating the sequelae of dementia and comorbid medical conditions. These include cognitive, behavioral, physical, and emotional challenges such as balance issues, incontinence, and agitation in traffic; (3) Tele-dementia care saves time and money and improves access to specialists; (4) Tele-dementia facilitated communication between caregiver and provider without hindering communication between PLWD and provider; and (5) Caregivers described ideal future dementia care as a combination of virtual and in-person modalities with in-home help, financial and medical support, and dementia-sensitive caregiver access. Caregivers interviewed saved 2.6 h ± 1.5 h (range: 0.5 to 6 h) of travel time. Multiple caregivers described disruption of routines as difficult in PLWD and appreciated the limited preparation and immediate return to routine post telemedicine visit as positives.

CONCLUSIONS

Caregivers found tele-dementia care convenient, comfortable, stress reducing, timesaving, and highly satisfactory. Caregivers would prefer a combination of in-person and telemedicine visits, with an opportunity to communicate with providers privately. This intervention prioritizes care for older Veterans with dementia who have high care needs and are at higher risk for hospitalization than their same age counterparts without dementia.

COVID-19 as a polymorphic inflammatory spectrum of diseases: a review with focus on the brain

There appear to be huge variations and aberrations in the reported data in COVID-19 2 years now into the pandemic. Conflicting data exist at almost every level and also in the reported epidemiological statistics across different regions. It is becoming clear that COVID-19 is a polymorphic inflammatory spectrum of diseases, and there is a wide range of inflammation-related pathology and symptoms in those infected with the virus. The host's inflammatory response to COVID-19 appears to be determined by genetics, age, immune status, health status and stage of disease. The interplay of these factors may decide the magnitude, duration, types of pathology, symptoms and prognosis in the spectrum of COVID-19 disorders, and whether neuropsychiatric disorders continue to be significant. Early and successful management of inflammation reduces morbidity and mortality in all stages of COVID-19.

A Transformer-Based Model Trained on Large Scale Claims Data for Prediction of Severe COVID-19 Disease Progression

In situations like the COVID-19 pandemic, healthcare systems are under enormous pressure as they can rapidly collapse under the burden of the crisis. Machine learning (ML) based risk models could lift the burden by identifying patients with a high risk of severe disease progression. Electronic Health Records (EHRs) provide crucial sources of information to develop these models because they rely on routinely collected healthcare data. However, EHR data is challenging for training ML models because it contains irregularly timestamped diagnosis, prescription, and procedure codes. For such data, transformer-based models are promising. We extended the previously published Med-BERT model by including age, sex, medications, quantitative clinical measures, and state information. After pre-training on approximately 988 million EHRs from 3.5 million patients, we developed models to predict Acute Respiratory Manifestations (ARM) risk using the medical history of 80,211 COVID-19 patients. Compared to Random Forests, XGBoost, and RETAIN, our transformer-based models more accurately forecast the risk of developing ARM after COVID-19 infection. We used Integrated Gradients and Bayesian networks to understand the link between the essential features of our model. Finally, we evaluated adapting our model to Austrian in-patient data. Our study highlights the promise of predictive transformer-based models for precision medicine.

Cognitive Aspects of COVID-19

PURPOSE OF REVIEW

Since the beginning of the coronavirus disease 2019 pandemic, many lasting neurological sequelae including cognitive impairment have been recognized as part of the so-called long COVID syndrome. This narrative review summarizes the cognitive aspects of COVID-19.

RECENT FINDINGS

Studies have consistently identified attention, memory, and executive functions as the cognitive domains most often affected by COVID-19 infection. Many studies have also reported neuroimaging, biofluid, and neurophysiological abnormalities that could potentially reflect the pathophysiological aspects of post-COVID cognitive impairment. While patients suffering from dementia have an elevated risk of COVID-19 infection, increasing evidence has also indicated that COVID-19 infection may increase the risks of Alzheimer's disease, suggesting bidirectional relationships. Post-COVID cognitive dysfunction is a pervasive and multifaceted problem and we are surely in our infancy of understanding. Future elucidation into the long-term effects, mechanisms, and therapies will depend on a concerted effort from clinicians, researchers, patients, and policy-makers alike.

COVID-19 and neurological disorders: what might connect Parkinson's disease to SARS-CoV-2 infection

SARS-CoV-2 infection leading to Coronavirus disease 19 (COVID-19) rapidly became a worldwide health emergency due to its elevated infecting capacity, morbidity, and mortality. Parkinson’s disease (PD) is the second most common neurodegenerative disorder and, nowadays the relationship between SARS-CoV-2 outbreak and PD reached a great interest. Apparently independent one from the other, both diseases share some pathogenetic and clinical features. The relationship between SARS-CoV-2 infection and PD is complex and it depends on the direction of the association that is which of the two diseases comes first. Some evidence suggests that SARS-CoV-2 infection might be a possible risk factor for PD wherein the exposure to SARS-CoV-2 increase the risk for PD. This perspective comes out from the increasing cases of parkinsonism following COVID-19 and also from the anatomical structures affected in both COVID-19 and early PD such as olfactory bulb and gastrointestinal tract resulting in the same symptoms such as hyposmia and constipation. Furthermore, there are many reported cases of patients who developed hypokinetic extrapyramidal syndrome following SARS-CoV-2 infection although these would resemble a post-encephalitic conditions and there are to date relevant data to support the hypothesis that SARS-CoV-2 infection is a risk factor for the development of PD. Future large, longitudinal and population-based studies are needed to better assess whether the risk of developing PD after COVID-19 exists given the short time span from the starting of pandemic. Indeed, this brief time-window does not allow the precise estimation of the incidence and prevalence of PD after pandemic when compared with pre-pandemic era. If the association between SARS-CoV-2 infection and PD pathogenesis is actually putative, on the other hand, vulnerable PD patients may have a greater risk to develop COVID-19 being also more prone to develop a more aggressive disease course. Furthermore, PD patients with PD showed a worsening of motor and non-motor symptoms during COVID-19 outbreak due to both infection and social restriction. As well, the worries related to the risk of being infected should not be neglected. Here we summarize the current knowledge emerging about the epidemiological, pathogenetic and clinical relationship between SARS-CoV-2 infection and PD.

Cellular Metabolism: A Fundamental Component of Degeneration in the Nervous System

It is estimated that, at minimum, 500 million individuals suffer from cellular metabolic dysfunction, such as diabetes mellitus (DM), throughout the world. Even more concerning is the knowledge that metabolic disease is intimately tied to neurodegenerative disorders, affecting both the central and peripheral nervous systems as well as leading to dementia, the seventh leading cause of death. New and innovative therapeutic strategies that address cellular metabolism, apoptosis, autophagy, and pyroptosis, the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), growth factor signaling with erythropoietin (EPO), and risk factors such as the apolipoprotein E (APOE-ε4) gene and coronavirus disease 2019 (COVID-19) can offer valuable insights for the clinical care and treatment of neurodegenerative disorders impacted by cellular metabolic disease. Critical insight into and modulation of these complex pathways are required since mTOR signaling pathways, such as AMPK activation, can improve memory retention in Alzheimer's disease (AD) and DM, promote healthy aging, facilitate clearance of β-amyloid (Aß) and tau in the brain, and control inflammation, but also may lead to cognitive loss and long-COVID syndrome through mechanisms that can include oxidative stress, mitochondrial dysfunction, cytokine release, and APOE-ε4 if pathways such as autophagy and other mechanisms of programmed cell death are left unchecked.

Cerebral hypoperfusion in post-COVID-19 cognitively impaired subjects revealed by arterial spin labeling MRI

Cognitive impairment is one of the most prevalent symptoms of post Severe Acute Respiratory Syndrome COronaVirus 2 (SARS-CoV-2) state, which is known as Long COVID. Advanced neuroimaging techniques may contribute to a better understanding of the pathophysiological brain changes and the underlying mechanisms in post-COVID-19 subjects. We aimed at investigating regional cerebral perfusion alterations in post-COVID-19 subjects who reported a subjective cognitive impairment after a mild SARS-CoV-2 infection, using a non-invasive Arterial Spin Labeling (ASL) MRI technique and analysis. Using MRI-ASL image processing, we investigated the brain perfusion alterations in 24 patients (53.0 ± 14.5 years, 15F/9M) with persistent cognitive complaints in the post COVID-19 period. Voxelwise and region-of-interest analyses were performed to identify statistically significant differences in cerebral blood flow (CBF) maps between post-COVID-19 patients, and age and sex matched healthy controls (54.8 ± 9.1 years, 13F/9M). The results showed a significant hypoperfusion in a widespread cerebral network in the post-COVID-19 group, predominantly affecting the frontal cortex, as well as the parietal and temporal cortex, as identified by a non-parametric permutation testing (p < 0.05, FWE-corrected with TFCE). The hypoperfusion areas identified in the right hemisphere regions were more extensive. These findings support the hypothesis of a large network dysfunction in post-COVID subjects with cognitive complaints. The non-invasive nature of the ASL-MRI method may play an important role in the monitoring and prognosis of post-COVID-19 subjects.

Pathogenic mechanisms of post-acute sequelae of SARS-CoV-2 infection (PASC)

COVID-19, with persistent and new onset of symptoms such as fatigue, post-exertional malaise, and cognitive dysfunction that last for months and impact everyday functioning, is referred to as Long COVID under the general category of post-acute sequelae of SARS-CoV-2 infection (PASC). PASC is highly heterogenous and may be associated with multisystem tissue damage/dysfunction including acute encephalitis, cardiopulmonary syndromes, fibrosis, hepatobiliary damages, gastrointestinal dysregulation, myocardial infarction, neuromuscular syndromes, neuropsychiatric disorders, pulmonary damage, renal failure, stroke, and vascular endothelial dysregulation. A better understanding of the pathophysiologic mechanisms underlying PASC is essential to guide prevention and treatment. This review addresses potential mechanisms and hypotheses that connect SARS-CoV-2 infection to long-term health consequences. Comparisons between PASC and other virus-initiated chronic syndromes such as myalgic encephalomyelitis/chronic fatigue syndrome and postural orthostatic tachycardia syndrome will be addressed. Aligning symptoms with other chronic syndromes and identifying potentially regulated common underlining pathways may be necessary for understanding the true nature of PASC. The discussed contributors to PASC symptoms include sequelae from acute SARS-CoV-2 injury to one or more organs, persistent reservoirs of the replicating virus or its remnants in several tissues, re-activation of latent pathogens such as Epstein-Barr and herpes viruses in COVID-19 immune-dysregulated tissue environment, SARS-CoV-2 interactions with host microbiome/virome communities, clotting/coagulation dysregulation, dysfunctional brainstem/vagus nerve signaling, dysautonomia or autonomic dysfunction, ongoing activity of primed immune cells, and autoimmunity due to molecular mimicry between pathogen and host proteins. The individualized nature of PASC symptoms suggests that different therapeutic approaches may be required to best manage specific patients.

Pathogenic mechanisms of post-acute sequelae of SARS-CoV-2 infection (PASC)

COVID-19, with persistent and new onset of symptoms such as fatigue, post-exertional malaise, and cognitive dysfunction that last for months and impact everyday functioning, is referred to as Long COVID under the general category of post-acute sequelae of SARS-CoV-2 infection (PASC). PASC is highly heterogenous and may be associated with multisystem tissue damage/dysfunction including acute encephalitis, cardiopulmonary syndromes, fibrosis, hepatobiliary damages, gastrointestinal dysregulation, myocardial infarction, neuromuscular syndromes, neuropsychiatric disorders, pulmonary damage, renal failure, stroke, and vascular endothelial dysregulation. A better understanding of the pathophysiologic mechanisms underlying PASC is essential to guide prevention and treatment. This review addresses potential mechanisms and hypotheses that connect SARS-CoV-2 infection to long-term health consequences. Comparisons between PASC and other virus-initiated chronic syndromes such as myalgic encephalomyelitis/chronic fatigue syndrome and postural orthostatic tachycardia syndrome will be addressed. Aligning symptoms with other chronic syndromes and identifying potentially regulated common underlining pathways may be necessary for understanding the true nature of PASC. The discussed contributors to PASC symptoms include sequelae from acute SARS-CoV-2 injury to one or more organs, persistent reservoirs of the replicating virus or its remnants in several tissues, re-activation of latent pathogens such as Epstein-Barr and herpes viruses in COVID-19 immune-dysregulated tissue environment, SARS-CoV-2 interactions with host microbiome/virome communities, clotting/coagulation dysregulation, dysfunctional brainstem/vagus nerve signaling, dysautonomia or autonomic dysfunction, ongoing activity of primed immune cells, and autoimmunity due to molecular mimicry between pathogen and host proteins. The individualized nature of PASC symptoms suggests that different therapeutic approaches may be required to best manage specific patients.

Relationship between Reaction Times and Post-COVID-19 Symptoms Assessed by a Web-Based Visual Detection Task

Long-COVID is a clinical condition in which patients affected by SARS-CoV-2 usually report a wide range of physical and cognitive symptoms from 3 to 6 months after the infection recovery. The aim of the current study was to assess the link between self-reported long-COVID symptoms and reaction times (RTs) in a self-administered Visual Detection Task (VDT) in order to identify the predictor symptoms of the slowing in reaction times to determine attention impairment. In total, 362 participants (age (mean ± S.D.: 38.56 ± 13.14); sex (female-male: 73.76-26.24%)) responded to a web-based self-report questionnaire consisting of four sections: demographics, disease-related characteristics, and medical history questions. The final section consisted of a 23 item 5-point Likert-scale questionnaire related to long-term COVID-19 symptoms. After completing the questionnaire, subjects performed a VDT on a tablet screen to assess reaction times (RTs). An exploratory factorial analysis (EFA) was performed on the 23 long-COVID symptom questions, identifying 4 factors (cognition, behavior, physical condition, presence of anosmia and/or ageusia). The most important predictors of RTs were cognition and physical factors. By dissecting the cognitive and physical factors, learning, visual impairment, and headache were the top predictors of subjects' performance in the VDT. Long-COVID subjects showed higher RTs in the VDT after a considerable time post-disease, suggesting the presence of an attention deficit disorder. Attention impairment due to COVID-19 can be due to the presence of headaches, visual impairments, and the presence of cognitive problems related to the difficulty in learning new activities. The link between the slowing of reaction times and physical and cognitive symptoms post-COVID-19 suggests that attention deficit disorder is caused by a complex interaction between physical and cognitive symptoms. In addition, the study provides evidence that RTs in a VDT represent a reliable measure to detect the presence of long-COVID neurological sequelae.

Dementia and psychotropic medications are associated with significantly higher mortality in geriatric patients hospitalized with COVID-19: data from the StockholmGeroCovid project

BACKGROUND

Dementia and psychotropic medications are discussed as risk factors for severe/lethal outcome of the coronavirus disease 2019 (COVID-19). We aimed to explore the associations between the presence of dementia and medication use with mortality in the hospitalized and discharged patients who suffered from COVID-19.

METHODS

We conducted an open-cohort observational study based on electronic patient records from nine geriatric care clinics in the larger Stockholm area, Sweden, between February 28, 2020, and November 22, 2021. In total, we identified 5122 hospitalized patients diagnosed with COVID-19, out of which 762 (14.9%) patients had concurrent dementia and 4360 (85.1%) were dementia-free. Patients' age, sex, baseline oxygen saturation, comorbidities, and medication prescription (cardiovascular and psychotropic medication) were registered at admission. The hazard ratios (HRs) with 95% confidence intervals (CIs) of in-hospital, 30-day, 90-day, 365-day post-discharge, and overall mortality during the follow-up were obtained. Then, the associations of dementia and medication use with mortality were determined using proportional hazards regression with time since entry as a time scale.

RESULTS

After adjustment, dementia was independently associated with 68% higher in-hospital mortality among COVID-19 patients compared to patients who were dementia-free at admission [HRs (95% CI) 1.68 (1.37-2.06)]. The increase was consistent post-discharge, and the overall mortality of dementia patients was increased by 59% [1.59 (1.40-1.81)]. In addition, the prescription of antipsychotic medication at hospital admission was associated with a 70% higher total mortality risk [1.70 (1.47-1.97)].

CONCLUSIONS

The clinical co-occurence of dementia and COVID-19 increases the short- and long-term risk of death, and the antipsychotics seem to further the risk increase. Our results may help identify high-risk patients in need of more specialized care when infected with COVID-19.

The current state of artificial intelligence-augmented digitized neurocognitive screening test

The cognitive screening test is a brief cognitive examination that could be easily performed in a clinical setting. However, one of the main drawbacks of this test was that only a paper-based version was available, which restricts the test to be manually administered and graded by medical personnel at the health centers. The main solution to these problems was to develop a potential remote assessment for screening individuals with cognitive impairment. Currently, multiple studies have been adopting artificial intelligence (AI) technology into these tests, evolving the conventional paper-based neurocognitive test into a digitized AI-assisted neurocognitive test. These studies provided credible evidence of the potential of AI-augmented cognitive screening tests to be better and provided the framework for future studies to further improve the implementation of AI technology in the cognitive screening test. The objective of this review article is to discuss different types of AI used in digitized cognitive screening tests and their advantages and disadvantages.

The future of neurology after the COVID-19 pandemic according to neurology residents

BACKGROUND

The ongoing COVID-19 pandemic has resulted in significant changes in the delivery of neurological disease care and in neurology training in academic departments.

OBJECTIVE

We aimed to investigate how neurology residents viewed the future of neurology after the COVID-19 pandemic with regard to three main aspects: (i) organization of neurological activity, (ii) patient care, and (iii) funding availability for neurological diseases.

METHODS

We surveyed Italian neurology residents in order to investigate how they viewed the future of neurology after the COVID-19 pandemic.

RESULTS

Responses were collected from 254 residents who reported: a high risk of reduction of hospital neurological beds, of worsening of the quality of neurological patient management, and of lack of funding for neurological care and research.

CONCLUSION

The survey results demonstrate the views of future neurologists regarding the direction of neurology after the COVID-19 emergency. It is important to focus on these aspects in order to adapt neurology training to the societal changes introduced by the pandemic, and to safeguard the essential role of neurology in the management and prevention of chronic degenerative illnesses and emergencies.

Cognition Before and After COVID-19 Disease in Older Adults: An Exploratory Study

BACKGROUND

Older age is a major risk factor for severe COVID-19 disease which has been associated with a variety of neurologic complications, both acutely and chronically.

OBJECTIVE

We sought to determine whether milder COVID-19 disease in older vulnerable individuals is also associated with cognitive and behavioral sequelae.

METHODS

Neuropsychological, behavioral, and clinical outcomes before and after contracting COVID-19 disease, were compared in members of two ongoing longitudinal studies, the Arizona APOE Cohort and the national Alzheimer's Disease Research Center (ADRC).

RESULTS

152 APOE and 852 ADRC cohort members, mean age overall roughly 70 years, responded to a survey that indicated 21 APOE and 57 ADRC members had contracted COVID-19 before their ensuing (post-COVID) study visit. The mean interval between test sessions that preceded and followed COVID was 2.2 years and 1.2 years respectively for the APOE and ADRC cohorts. The magnitude of change between the pre and post COVID test sessions did not differ on any neuropsychological measure in either cohort. There was, however, a greater increase in informant (but not self) reported cognitive change in the APOE cohort (p = 0.018), but this became nonsignificant after correcting for multiple comparisons.

CONCLUSION

Overall members of both cohorts recovered well despite their greater age-related vulnerability to more severe disease.

Video Call Usage in Older Adults With or Without Dementia Impacted by the COVID-19 Pandemic

The usage of video calls for social connection generally increased during the COVID-19 pandemic. It remains unclear, how individuals with dementia (IWD), many of who already experienced isolation in their care settings, use and perceive video calls, what barriers and benefits exist, and how the COVID-19 pandemic impacted their use of video calls. An online survey was conducted to healthy older adults (OA) and people surrounding IWD as proxies. Both OA and IWD showed increased use of video calls after COVID-19 and the severity of dementia was not correlated with the video call usage among IWD during this period. Both groups perceived significant benefits in using video calls. However, IWD exhibited more difficulties and barriers to using them compared to OA. Given the perceived benefits of video calls to the quality of life in both populations, education and support by family, caregivers, or healthcare professionals are necessary for them.

The impact of the COVID-19 pandemic on mortality in people with dementia without COVID-19: a systematic review and meta-analysis

INTRODUCTION

Significant mortality amongst vulnerable populations, such as people living with dementia, might go undetected during pandemic conditions due to refocus of care efforts. There is an urgent need to fully evaluate the pandemic impact on mortality amongst people living with dementia in order to facilitate future healthcare reforms and prevent deaths. The purpose of this study was to determine whether there was any significant difference in mortality amongst people with dementia without COVID-19 during the COVID-19 pandemic compared to previous years.

METHODS

A literature search was conducted in 5 databases. The relative risk ratio and confidence interval was used to estimate the change in mortality rates amongst people with dementia during the COVID-19 pandemic. The I2 value was used to assess heterogeneity, publication bias, and sensitivity analyses were performed.

RESULTS

Pooled analysis of 11 studies showed that mortality amongst people living with dementia was significantly increased during the COVID-19 pandemic for people with dementia without COVID-19. Mortality risk increased by 25% during the time period studied. Subgroup analysis was not performed due the low number of included studies.

CONCLUSIONS

The results of this study suggest that people with dementia had a significant increased mortality during the pandemic even if they did not have COVID-19. People with dementia should participate in efforts that reduce general social spread and pandemic impact on healthcare system such as vaccinations, mask mandates, and testing. These results have clinical implications as preventing direct COVID-19 infection is not enough to adequately protect people living with dementia from increased mortality. Measures to limit social spread of infections and help support patients should also be a focus for clinicians. Further research should focus on the identification of mechanisms and other explanations for increased mortality as well as contributing factors such as living in care homes and differences between countries with various pandemic strategies.

The Effect of Computer-Assisted Cognitive Remediation Therapy on Cognitive Function, Social Function and Quality of Life in Patients with Vascular Dementia

OBJECTIVE

Our study aimed to investigate the effects of computer-assisted cognitive remediation therapy (CCRT) on cognitive function, social function and quality of life in patients with vascular dementia (VD).

METHODS

Ninety-eight patients with VD were treated with CCRT in four 45-minute sessions per week over a course of 40 sessions to exercise four cognitive functions, including flexibility, working memory, plan execution and social cognition. The Mini-Mental State Examination (MMSE), Social Disability Screening Schedule (SDSS), Personal and Social Performance Scale (PSP), and Generic Quality of Life Inventory-74 (GQOL-74) were used to assess before and after treatment.

RESULTS

(1) The scores of orientation (5.60 ± 1.35), calculation (2.20 ± 0.79), verbal ability (7.10 ± 0.36), spatial ability (0.78 ± 0.42), immediate memory (2.42 ± 0.53), short-term memory (1.17 ± 0.78) and MMSE (23.36 ± 2.98) were all improved after treatment (P < 0.05) compared with those before treatment; (2) The scores of SDSS, PSP and Activities of Daily Living (ADL) after treatment were 8.23 ± 0.94, 81.36 ± 14.23, and 32.7 ± 12.1, and all of which improved (P < 0.05); (3) The scores of physical health were 68.24 ± 7.44, mental health were 69.75 ± 7.15, social function were 69.08 ± 7.43, material life were 37.46 ± 4.85 and the total score were 230.79 ± 9.56, all of which improved (P < 0.05).

CONCLUSION

For patients with VD, CCRT can improve their cognitive function, social function, daily life ability and quality of life.

Cognitive Behavioral Psychotherapy after COVID-19: Opportunities and Prospects

This article reviews domestic and foreign studies on cognitive behavioral therapy techniques in treating cognitive disorders in former COVID-19 patients. Coronavirus-induced cognitive disorders include damage to the nervous system as a result of respiratory distress syndrome, cytokine storm, cerebral vascular thrombosis, direct exposure to SARS-Cov2, and inadequate immune response. Concomitant mental illnesses include autistic disorders, dementia, cognitive decline, eating disorders, suicidal behavior, anxiety, depression, post-traumatic stress, insomnia, etc. Diagnostic methods usually take into account a complex violation of mental activities, e.g., short memory span, attention deficiency, slow thinking, and various affective disorders. As a result, diagnostic methods can be divided into several areas: neuropsychological diagnostics of cognitive functions (MMSE, MOCA, FAB), identification of inadequate attitudes and behavior (WCQ, SPB, DAS), identification of violations of daily activity (The Barthel Scale), identification of psychological and psychiatric issues (Hospital Anxiety and Depression Scale, State-Trait Anxiety Inventory, Hamilton Rating Scale for Depression). Psychological care for former COVID-19 patients relies on some basic principles. Cognitive behavioral psychotherapy techniques aim at correcting cognitive distortions, teaching relaxation and self-regulation, improving problem-solving skills, and restoring cognitive functions. 

Why antidiabetic drugs are potentially neuroprotective during the Sars-CoV-2 pandemic: The focus on astroglial UPR and calcium-binding proteins

We are living in a terrifying pandemic caused by Sars-CoV-2, in which patients with diabetes mellitus have, from the beginning, been identified as having a high risk of hospitalization and mortality. This viral disease is not limited to the respiratory system, but also affects, among other organs, the central nervous system. Furthermore, we already know that individuals with diabetes mellitus exhibit signs of astrocyte dysfunction and are more likely to develop cognitive deficits and even dementia. It is now being realized that COVID-19 incurs long-term effects and that those infected can develop several neurological and psychiatric manifestations. As this virus seriously compromises cell metabolism by triggering several mechanisms leading to the unfolded protein response (UPR), which involves endoplasmic reticulum Ca2+ depletion, we review here the basis involved in this response that are intimately associated with the development of neurodegenerative diseases. The discussion aims to highlight two aspects-the role of calcium-binding proteins and the role of astrocytes, glial cells that integrate energy metabolism with neurotransmission and with neuroinflammation. Among the proteins discussed are calpain, calcineurin, and sorcin. These proteins are emphasized as markers of the UPR and are potential therapeutic targets. Finally, we discuss the role of drugs widely prescribed to patients with diabetes mellitus, such as statins, metformin, and calcium channel blockers. The review assesses potential neuroprotection mechanisms, focusing on the UPR and the restoration of reticular Ca2+ homeostasis, based on both clinical and experimental data.

Long COVID, neuropsychiatric disorders, psychotropics, present and future

Long COVID refers to the lingering symptoms which persist or appear after the acute illness. The dominant long COVID symptoms in the two years since the pandemic began (2020-2021) have been depression, anxiety, fatigue, concentration and cognitive impairments with few reports of psychosis. Whether other symptoms will appear later on is not yet known. For example, dopamine-dependent movement disorders generally take many years before first symptoms are seen. Post-stroke depression and anxiety may explain many of the early long COVID cases. Hemorrhagic, hypoxic and inflammatory damages of the central nervous system, unresolved systematic inflammation, metabolic impairment, cerebral vascular accidents such as stroke, hypoxia from pulmonary damages and fibrotic changes are among the major causes of long COVID. Glucose metabolic and hypoxic brain issues likely predispose subjects with pre-existing diabetes, cardiovascular or lung problems to long COVID as well. Preliminary data suggest that psychotropic medications may not be a danger but could instead be beneficial in combating COVID-19 infection. The same is true for diabetes medications such as metformin. Thus, a focus on sigma-1 receptor ligands and glucose metabolism is expected to be useful for new drug development as well as the repurposing of current drugs. The reported protective effects of psychotropics and antihistamines against COVID-19, the earlier reports of reduced number of sigma-1 receptors in post-mortem schizophrenic brains, with many antidepressant and antipsychotic drugs being antihistamines with significant affinity for the sigma-1 receptor, support the role of sigma and histamine receptors in neuroinflammation and viral infections. Literature and data in all these areas are accumulating at a fast rate. We reviewed and discussed the relevant and important literature.

Adult Vaccination as a Protective Factor for Dementia: A Meta-Analysis and Systematic Review of Population-Based Observational Studies

Background

Common vaccinations may have impacts on dementia risk, but current evidence is inconsistent. We therefore investigated the association between vaccinations and dementia risk by systematic review and meta-analysis approach.

Methods

We conducted an extensive search of PubMed, Embase, Cochrane Library, and Web of Science to identify studies that compared the risk of dementia in vaccinated versus unvaccinated populations. The adjusted hazard ratio (HR) and corresponding 95% confidence intervals (CIs) were pooled as measures.

Results

Of the 9124 records initially retrieved, 17 studies with 1857134 participants were included in our analysis. The overall pooled results showed that vaccinations were associated with a 35% lower dementia risk (HR=0.65, 95% CI: 0.60-0.71, Poverall effect < 0.001; I2 = 91.8%, Pheterogeneity<0.001). All types of vaccination were associated with a trend toward reduced dementia risk, with rabies (HR=0.43), tetanus & diphtheria & pertussis (Tdap) (HR=0.69), herpes zoster (HR=0.69), influenza (HR=0.74), hepatitis A (HR=0.78), typhoid (HR=0.80), and hepatitis B (HR=0.82) vaccinations being significant. Individuals with more full vaccination types and more annual influenza vaccinations were less likely to develop dementia. Gender and age had no effect on this association.

Conclusion

Routine adult vaccinations are associated with a significant reduction in dementia risk and may be an effective strategy for dementia prevention. Further research is needed to elucidate the causal effects of this association and the underlying mechanisms.

Dementia Clinical Care in Relation to COVID-19

PURPOSE OF REVIEW

This review discusses the complex relationship between COVID-19 and dementia and how the pandemic has affected the management of patients with dementia. This population resulted particularly susceptible to SARS-CoV-2 infection and its effects and also to the negative effects of the measures taken worldwide to control the spread of the virus.

RECENT FINDINGS

Patients with dementia were at increased risk for COVID-19 compared to patients without dementia, and diagnosis of dementia represents an independent risk factor for hospitalization in COVID-19 patients. Mortality due to SARS-CoV2 infection in subjects with dementia is 2-5 times higher than in the general population. Cognitive impairment and delirium have been described in COVID-19 survivors. SARS-COV2 pandemic exacerbates the vulnerability of dementia patients and their caregivers, due to the morbidity and mortality from COVID-19, the indirect effects of the pandemic on the social supports, and the effects on healthcare system on which they depend.

SUMMARY

The COVID-19 pandemic requires people with dementia to move from traditional models of health care to innovative models for home care, to support caregivers' burden, and to improve long term care.

Metabolic correlates of olfactory dysfunction in COVID-19 and Parkinson's disease (PD) do not overlap

Purpose

Hyposmia is a common feature of COVID-19 and Parkinson’s disease (PD). As parkinsonism has been reported after COVID-19, a link has been hypothesized between SARS-CoV2 infection and PD. We aimed to evaluate brain metabolic correlates of isolated persistent hyposmia after mild-to-moderate COVID-19 and to compare them with metabolic signature of hyposmia in drug-naïve PD patients.

Methods

Forty-four patients who experienced hyposmia after SARS-COV2 infection underwent brain [¹⁸F]-FDG PET in the first 6 months after recovery. Olfaction was assessed by means of the 16-item “Sniffin’ Sticks” test and patients were classified as with or without persistent hyposmia (COVID-hyposmia and COVID-no-hyposmia respectively). Brain [¹⁸F]-FDG PET of post-COVID subgroups were compared in SPM12. COVID-hyposmia patients were also compared with eighty-two drug-naïve PD patients with hyposmia. Multiple regression analysis was used to identify correlations between olfactory test scores and brain metabolism in patients’ subgroups.

Results

COVID-hyposmia patients (n = 21) exhibited significant hypometabolism in the bilateral gyrus rectus and orbitofrontal cortex with respect to COVID-non-hyposmia (n = 23) (p < 0.002) and in middle and superior temporal gyri, medial/middle frontal gyri, and right insula with respect to PD-hyposmia (p < 0.012). With respect to COVID-hyposmia, PD-hyposmia patients showed hypometabolism in inferior/middle occipital gyri and cuneus bilaterally. Olfactory test scores were directly correlated with metabolism in bilateral rectus and medial frontal gyri and in the right middle temporal and anterior cingulate gyri in COVID-hyposmia patients (p < 0.006) and with bilateral cuneus/precuneus and left lateral occipital cortex in PD-hyposmia patients (p < 0.004).

Conclusion

Metabolic signature of persistent hyposmia after COVID-19 encompasses cortical regions involved in olfactory perception and does not overlap metabolic correlates of hyposmia in PD.

Primary Palliative Care in Dementia

Primary palliative care is a fundamental aspect of high-quality care for patients with a serious illness such as dementia. The clinician caring for a patient and family suffering with dementia can provide primary palliative care in numerous ways. Perhaps the most important aspects are high quality communication while sharing a diagnosis, counseling the patient through progression of illness and prognostication, and referral to hospice when appropriate. COVID-19 presents additional risks of intensive care requirement and mortality which we must help patients and families navigate. Throughout all of these discussions, the astute clinician must monitor the patient's decision making capacity and balance respect for autonomy with protection against uninformed consent. Excellent primary palliative care also involves discussion of deprescribing medications of uncertain benefit such as long term use of cholinesterase inhibitors and memantine and being vigilant in the monitoring of pain with its relationship to behavioral disturbance in patients with dementia. Clinicians should follow a standardized approach to pain management in this vulnerable population. Caregiver burden is high for patients with dementia and comprehensive care should also address this burden and implement reduction strategies. When these aspects of care are particularly complex or initial managements strategies fall short, palliative care specialists can be an important additional resource not only for the patient and family, but for the care team struggling to guide the way through a disease with innumerable challenges.

Monoclonal Human Antibodies That Recognise the Exposed N and C Terminal Regions of the Often-Overlooked SARS-CoV-2 ORF3a Transmembrane Protein

ORF3a has been identified as a viroporin of SARS-CoV-2 and is known to be involved in various pathophysiological activities including disturbance of cellular calcium homeostasis, inflammasome activation, apoptosis induction and disruption of autophagy. ORF3a-targeting antibodies may specifically and favorably modulate these viroporin-dependent pathological activities. However, suitable viroporin-targeting antibodies are difficult to generate because of the well-recognized technical challenge associated with isolating antibodies to complex transmembrane proteins. Here we exploited a naïve human single chain antibody phage display library, to isolate binders against carefully chosen ORF3a recombinant epitopes located towards the extracellular N terminal and cytosolic C terminal domains of the protein using peptide antigens. These binders were subjected to further characterization using enzyme-linked immunosorbent assays and surface plasmon resonance analysis to assess their binding affinities to the target epitopes. Binding to full-length ORF3a protein was evaluated by western blot and fluorescent microscopy using ORF3a transfected cells and SARS-CoV-2 infected cells. Co-localization analysis was also performed to evaluate the "pairing potential" of the selected binders as possible alternative diagnostic or prognostic biomarkers for COVID-19 infections. Both ORF3a N and C termini, epitope-specific monoclonal antibodies were identified in our study. Whilst the linear nature of peptides might not always represent their native conformations in the context of full protein, with carefully designed selection protocols, we have been successful in isolating anti-ORF3a binders capable of recognising regions of the transmembrane protein that are exposed either on the "inside" or "outside" of the infected cell. Their therapeutic potential will be discussed.

Unwanted Exacerbation of the Immune Response in Neurodegenerative Disease: A Time to Review the Impact

The COVID-19 pandemic imposed a series of behavioral changes that resulted in increased social isolation and a more sedentary life for many across all age groups, but, above all, for the elderly population who are the most vulnerable to infections and chronic neurodegenerative diseases. Systemic inflammatory responses are known to accelerate neurodegenerative disease progression, which leads to permanent damage, loss of brain function, and the loss of autonomy for many aged people. During the COVID-19 pandemic, a spectrum of inflammatory responses was generated in affected individuals, and it is expected that the elderly patients with chronic neurodegenerative diseases who survived SARSCoV-2 infection, it will be found, sooner or later, that there is a worsening of their neurodegenerative conditions. Using mouse prion disease as a model for chronic neurodegeneration, we review the effects of social isolation, sedentary living, and viral infection on the disease progression with a focus on sickness behavior and on the responses of microglia and astrocytes. Focusing on aging, we discuss the cellular and molecular mechanisms related to immunosenescence in chronic neurodegenerative diseases and how infections may accelerate their progression.