Cognitive dysfunction after covid-19

Animal Models for Long COVID: Current Advances, Limitations, and Future Directions

Long COVID (LC) represents a chronic, systemic, and often disabling condition that poses a significant ongoing threat to public health. Foundational scientific studies are needed to unravel the underlying mechanisms, with the ultimate goal of developing effective preventative and therapeutic strategies. Therefore, there is an urgent demand for animal models that can accurately replicate the clinical features of LC. This review integrates clinical epidemiological data to summarize the pathological changes in extrapulmonary systems involved in LC. Additionally, it critically examines the capacity of existing animal models, including nonhuman primates, genetically modified mice, and Syrian hamsters, to exhibit enduring postinfection symptoms that align with human clinical manifestations, and identifies key areas requiring further development. The objective is to offer insights that will aid in the development of next-generation animal models, thereby accelerating our understanding of how acute respiratory viral infections transition into chronic conditions, and ensuring preparedness for future pandemics.

SARS-CoV-2 Nsp7 plays a role in cognitive dysfunction by impairing synaptic plasticity

It has been reported that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can result in long-term neurological symptoms such as cognitive dysfunction, however the specific mechanisms underlying this phenomenon remain unclear. Initially, we confirmed a reduction in the level of synaptic proteins in SH-SY5Y neurons following SARS-CoV-2 infection. SARS-CoV-2 Nsps are crucial for the efficient replication of the virus and play important roles in the interaction between virus and host cell. Nsps screening experiments implied that Nsp7 is able to reduce the level of synapsin-1. Furthermore, overexpression of Nsp7 in SH-SY5Y cells and mouse primary neurons demonstrated that Nsp7 could decrease the levels of synaptic proteins without affecting neuronal viability. Moreover, C57BL/6 mice receiving AAV-GFP-Nsp7 injections into the ventral hippocampus displayed impaired memory ability, along with reduced dendritic spine density and synaptic protein levels. Mechanistic investigations suggested that Nsp7-induced mitochondrial damage led to ROS production and ATP levels decreasing in neurons. Additional experiments employing the ROS inhibitor NAC demonstrated that Nsp7 suppressed the expression of synaptic proteins via ROS inducing, implicating mitochondrial dysfunction in synaptic plasticity impairment and subsequent cognitive dysfunction. Our findings underscore the crucial role of SARS-CoV-2 Nsp7 in cognitive dysfunction, which is potentially mediated through impaired synaptic plasticity via mitochondrial damage. This study enhances our understanding of the pathogenic mechanisms underlying central nervous system-related symptoms associated with SARS-CoV-2 infection.

Clinical practice guidelines and expert consensus statements on rehabilitation for patients with COVID-19: a systematic review

OBJECTIVES

To appraise the quality of clinical practice guidelines (CPGs) and expert consensus statements on rehabilitation for patients with COVID-19, summarise recommendations of rehabilitation assessments and interventions and evaluate the heterogeneity of the recommendations.

DESIGN

Systematic review.

DATA SOURCES

PubMed and Embase databases and five online guideline repositories: The National Guideline Clearinghouse, Guidelines International Network, Scottish Intercollegiate Guidelines Network, National Institute for Health and Clinical Excellence and WHO were searched from their inception to August 2024. In addition, we reviewed reference lists of eligible citations and searched the grey literature on the relevant websites.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included CPGs and expert consensus statements which provided information about rehabilitation of patients with COVID-19. To be eligible, the CPGs and expert consensus statements were issued in English by a nationally or internationally recognised government authority, medical/academic society or organisation. If there were multiple versions of the guidelines, we included the latest one. The translations, interpretations and abstracts of guidelines were excluded.

DATA EXTRACTION AND SYNTHESIS

All recommendations on rehabilitation assessments and interventions for COVID-19 were extracted and summarised. Two reviewers independently evaluated the methodological quality with the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument, and two other reviewers assessed the reporting quality using the Reporting Items for Practice Guidelines in Healthcare (RIGHT) statement of included CPGs and expert consensus statements. We used the Measurement Scale of Rate of Agreement to evaluate the heterogeneity of the recommendations in different CPGs and expert consensus statements.

RESULTS

A total of 31 CPGs and expert consensus statements were included. 14 guidelines provided recommendations for rehabilitation assessments. At the early, development, critical and recovery stages of COVID-19, the most frequently recommended were exercise therapy (25.8%, 35.5%, 25.8% and 58.1%, respectively). According to AGREE II, 17 included guidelines were assessed as low methodological quality (35%-56%), 10 guidelines were rated as moderate quality (46%- 62%) and four had high quality (69%-79%). Among 31 eligible guidelines, the reporting rate of 22 items in the RIGHT checklist ranged from 10% to 100%. The included guidelines were consistent with the reference guidelines (80%-100%). Only one guideline existed minor (60%-80%) disagreements in respiratory muscle training relative to the reference guideline.

CONCLUSIONS

Rehabilitation assessments and interventions should be implemented consistently throughout the entire process of COVID-19. The recommendations should be tailored to each stage of COVID-19. The methodological and reporting qualities of several guidelines remain suboptimal. Therefore, developers should adhere strictly to the AGREE II standard and RIGHT checklist to formulate and publish CPGs and expert consensus statements with high quality.

PROSPERO REGISTRATION NUMBER

CRD42020190761.

Neuropsychology practice guidance for the neuropsychiatric aspects of Long COVID

Objective: The coronavirus disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has had a profound global impact on individual health and well-being in adults and children. While most fully recover from COVID-19, a relatively large subgroup continues to experience persistent physical, cognitive, and emotional/behavioral symptoms beyond the initial infection period. The World Health Organization has termed this phenomenon "Post-COVID-19 Condition" (PCC), better known as "Long COVID." Due to the cognitive and psychosocial symptoms, neuropsychologists often assess and recommend treatment for individuals with Long COVID. However, guidance for neuropsychologists' involvement in clinical care, policy-making, and research has not yet been developed. The authors of this manuscript convened to address this critical gap and develop guidance for clinical neuropsychologists working with patients presenting with Long COVID. Method: Authors include pediatric and adult neuropsychologists with expertise in Long COVID and behavioral health. All authors have been engaged in clinical and research efforts examining the impact of COVID-19. Authors summarized the literature-to-date pertinent to the neuropsychiatric sequelae of Long COVID and developed guidance for neuropsychologists working with individuals with Long COVID. Conclusions: Research findings regarding neuropsychiatric symptoms associated with Long COVID are mixed and limited by methodological differences. As they practice and conduct research, neuropsychologists should remain mindful of the evolving and tenuous nature of the literature.