Tag: long covid neurology

Natural and Semi-Synthetic Flavonoid Anti-SARS-CoV-2 Agents for the Treatment of Long COVID-19 Disease and Neurodegenerative Disorders of Cognitive Decline

Abstract:

The aim of this review is to highlight the beneficial attributes of flavonoids, a diverse family of widely-distributed polyphenolic phytochemicals that have beneficial cell and tissue protective properties. Phytochemicals are widely distributed in plants, herbs and shrubs used in traditional complimentary medical formulations for centuries. The bioactive components that convey beneficial medicinal effects in these complex herbal preparations are now being identified using network pharmacology and molecular docking procedures that identify their molecular targets. Flavonoids have anti-oxidant, anti-inflammatory, antiviral, antibacterial and anti-cancer properties that have inspired the development of potent multifunctional derivatised flavonoids of improved efficacy.

The antiviral properties of flavonoids and the emergence of the severe acute respiratory syndrome (SARS-CoV-2) pandemic has resulted in a resurgence of interest in phytochemicals in the search for efficacious compounds that can prevent viral infection or replication, with many promising plant compounds identified. Promising semi-synthetic flavonoid derivatives have also been developed that inhibit multiple pathological neurodegenerative processes; these offer considerable promise in the treatment of diseases of cognitive decline. Clinical trials are currently being undertaken to evaluate the efficacy of dietary supplements rich in flavonoids for the treatment of virally-mediated diseases. Such trials are expected to identify flavonoids with cell and tissue protective properties that can be harnessed in biomedical applications that may serve as supportive adjunctive procedures to conventional anti-viral drug therapies against diseases such as COVID-19.

Source: Melrose J, Smith MM. Natural and Semi-Synthetic Flavonoid Anti-SARS-CoV-2 Agents for the Treatment of Long COVID-19 Disease and Neurodegenerative Disorders of Cognitive Decline. Front Biosci (Elite Ed). 2022 Oct 9;14(4):27. doi: 10.31083/j.fbe1404027. PMID: 36575843.  https://www.imrpress.com/journal/FBE/14/4/10.31083/j.fbe1404027/htm (Full text)

Dynamic white matter changes in recovered COVID-19 patients: a two-year follow-up study

Abstract:

Background and purpose: Long COVID with regard to the neurological system deserves more attention, as a surge of treated patients are being discharged from the hospital. As the dynamic changes in white matter after two years remain unknown, this characteristic was the focus of this study.

Methods: We investigated 17 recovered COVID-19 patients at two years after discharge. Diffusion tensor imaging, neurite orientation dispersion and density imaging were performed to identify white matter integrity and changes from one to two years after discharge. Data for 13 revisited healthy controls were collected as a reference. Subscales of the Wechsler Intelligence scale were used to assess cognitive function. Repeated-measures ANOVA was used to detect longitudinal changes in 17 recovered COVID-19 patients and 13 healthy controls after one-year follow-up. Correlations between diffusion metrics, cognitive function, and other clinical characteristics (i.e., inflammatory factors) were also analyzed.

Results: Longitudinal analysis showed the recovery trends of large-scale brain regions, with small-scale brain region deterioration from one year to two years after SARS-CoV-2 infection. However, persistent white matter abnormalities were noted at two years after discharge. Longitudinal changes of cognitive function showed no group difference. But cross-sectional cognitive difference between recovered COVID-19 patients and revisited HCs was detected. Inflammation levels in the acute stage correlated positively with white matter abnormalities and negatively with cognitive function. Moreover, the more abnormal the white matter was at two years, the greater was the cognitive deficit present.

Conclusion: Recovered COVID-19 patients showed longitudinal recovery trends of white matter. But also had persistent white matter abnormalities at two years after discharge. Inflammation levels in the acute stage may be considered predictors of cognition and white matter integrity, and the white matter microstructure acts as a biomarker of cognitive function in recovered COVID-19 patients. These findings provide an objective basis for early clinical intervention.

Source: Huang S, Zhou X, Zhao W, Du Y, Yang D, Huang Y, Chen Y, Zhang H, Yang G, Liu J, Luo H. Dynamic white matter changes in recovered COVID-19 patients: a two-year follow-up study. Theranostics. 2023 Jan 1;13(2):724-735. doi: 10.7150/thno.79902. PMID: 36632218; PMCID: PMC9830428. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9830428/ (Full text)

Autonomic Nerve Involvement in Post-Acute Sequelae of SARS-CoV-2 Syndrome (PASC)

Abstract:

The novel SARS-CoV-2 virus and resulting COVID-19 global pandemic emerged in 2019 and continues into 2022. While mortality from COVID-19 is slowly declining, a subset of patients have developed chronic, debilitating symptoms following complete recovery from acute infection with COVID-19. Termed as post-acute sequelae of SARS-CoV-2 syndrome (PASC), the underlying pathophysiology of PASC is still not well understood.

Given the similarity between the clinical phenotypes of PASC and postural orthostatic tachycardia syndrome (POTS), it has been postulated that dysautonomia may play a role in the pathophysiology of PASC. However, there have been only a few studies that have examined autonomic function in PASC.

In this retrospective study, we performed an analysis of autonomic nerve function testing in PASC patients and compared the results with those of POTS patients and healthy controls. Our results suggest that a significant number of PASC patients have abnormal autonomic function tests, and their clinical features are indistinguishable from POTS.

Source: Chung TH, Azar A. Autonomic Nerve Involvement in Post-Acute Sequelae of SARS-CoV-2 Syndrome (PASC). J Clin Med. 2022 Dec 22;12(1):73. doi: 10.3390/jcm12010073. PMID: 36614874; PMCID: PMC9821608. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9821608/ (Full text)

Investigating the possible mechanisms of autonomic dysfunction post-COVID-19

Abstract:

Patients with long COVID suffer from many neurological manifestations that persist for 3 months following infection by SARS-CoV-2. Autonomic dysfunction (AD) or dysautonomia is one complication of long COVID that causes patients to experience fatigue, dizziness, syncope, dyspnea, orthostatic intolerance, nausea, vomiting, and heart palpitations. The pathophysiology behind AD onset post-COVID is largely unknown. As such, this review aims to highlight the potential mechanisms by which AD occurs in patients with long COVID.

The first proposed mechanism includes the direct invasion of the hypothalamus or the medulla by SARS-CoV-2. Entry to these autonomic centers may occur through the neuronal or hematogenous routes. However, evidence so far indicates that neurological manifestations such as AD are caused indirectly.

Another mechanism is autoimmunity whereby autoantibodies against different receptors and glycoproteins expressed on cellular membranes are produced. Additionally, persistent inflammation and hypoxia can work separately or together to promote sympathetic overactivation in a bidirectional interaction. Renin-angiotensin system imbalance can also drive AD in long COVID through the downregulation of relevant receptors and formation of autoantibodies. Understanding the pathophysiology of AD post-COVID-19 may help provide early diagnosis and better therapy for patients.

Source: Jammoul M, Naddour J, Madi A, Reslan MA, Hatoum F, Zeineddine J, Abou-Kheir W, Lawand N. Investigating the possible mechanisms of autonomic dysfunction post-COVID-19. Auton Neurosci. 2022 Dec 24;245:103071. doi: 10.1016/j.autneu.2022.103071. Epub ahead of print. PMID: 36580747; PMCID: PMC9789535. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9789535/ (Full text)

Deep Dive into the Long Haul: Analysis of Symptom Clusters and Risk Factors for Post-Acute Sequelae of COVID-19 to Inform Clinical Care

Abstract:

Long COVID is a chronic condition characterized by symptoms such as fatigue, dyspnea, and cognitive impairment that persist or relapse months after an acute infection with the SARS-CoV-2 virus. Many distinct symptoms have been attributed to Long COVID; however, little is known about the potential clustering of these symptoms and risk factors that may predispose patients to certain clusters. In this study, an electronic survey was sent to patients in the UC San Diego Health (UCSDH) system who tested positive for COVID-19, querying if patients were experiencing symptoms consistent with Long COVID.

Based on survey results, along with patient demographics reported in the electronic health record (EHR), linear and logistic regression models were used to examine putative risk factors, and exploratory factor analysis was performed to determine symptom clusters. Among 999 survey respondents, increased odds of Long COVID (n = 421; 42%) and greater Long COVID symptom burden were associated with female sex (OR = 1.73, 99% CI: 1.16-2.58; β = 0.48, 0.22-0.75), COVID-19 hospitalization (OR = 4.51, 2.50-8.43; β = 0.48, 0.17-0.78), and poorer pre-COVID self-rated health (OR = 0.75, 0.57-0.97; β = -0.19, -0.32–0.07).

Over one-fifth of Long COVID patients screened positive for depression and/or anxiety, the latter of which was associated with younger age (OR = 0.96, 0.94-0.99). Factor analysis of 16 self-reported symptoms suggested five symptom clusters-gastrointestinal (GI), musculoskeletal (MSK), neurocognitive (NC), airway (AW), and cardiopulmonary (CP), with older age (β = 0.21, 0.11-0.30) and mixed race (β = 0.27, 0.04-0.51) being associated with greater MSK symptom burden. Greater NC symptom burden was associated with increased odds of depression (OR = 5.86, 2.71-13.8) and anxiety (OR = 2.83, 1.36-6.14).

These results can inform clinicians in identifying patients at increased risk for Long COVID-related medical issues, particularly neurocognitive symptoms and symptom clusters, as well as informing health systems to manage operational expectations on a population-health level.

Source: Goldhaber NH, Kohn JN, Ogan WS, Sitapati A, Longhurst CA, Wang A, Lee S, Hong S, Horton LE. Deep Dive into the Long Haul: Analysis of Symptom Clusters and Risk Factors for Post-Acute Sequelae of COVID-19 to Inform Clinical Care. Int J Environ Res Public Health. 2022 Dec 15;19(24):16841. doi: 10.3390/ijerph192416841. PMID: 36554723; PMCID: PMC9778884. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9778884/ (Full text)

Cognitive Impairment after Post-Acute COVID-19 Infection: A Systematic Review of the Literature

Abstract:

The present study aims to provide a critical overview of the literature on the relationships between post-acute COVID-19 infection and cognitive impairment, highlighting the limitations and confounding factors. A systematic search of articles published from 1 January 2020 to 1 July 2022 was performed in PubMed/Medline. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only studies using validated instruments for the assessment of cognitive impairment were included. Out of 5515 screened records, 72 studies met the inclusion criteria.

The available evidence revealed the presence of impairment in executive functions, speed of processing, attention and memory in subjects recovered from COVID-19. However, several limitations of the literature reviewed should be highlighted: most studies were performed on small samples, not stratified by severity of disease and age, used as a cross-sectional or a short-term longitudinal design and provided a limited assessment of the different cognitive domains. Few studies investigated the neurobiological correlates of cognitive deficits in individuals recovered from COVID-19. Further studies with an adequate methodological design are needed for an in-depth characterization of cognitive impairment in individuals recovered from COVID-19.

Source: Perrottelli A, Sansone N, Giordano GM, Caporusso E, Giuliani L, Melillo A, Pezzella P, Bucci P, Mucci A, Galderisi S. Cognitive Impairment after Post-Acute COVID-19 Infection: A Systematic Review of the Literature. J Pers Med. 2022 Dec 15;12(12):2070. doi: 10.3390/jpm12122070. PMID: 36556290; PMCID: PMC9781311. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9781311/ (Full text)

T cell responses to SARS-CoV-2 in people with and without neurologic symptoms of long COVID

Abstract:

Many people experiencing long COVID syndrome, or post-acute sequelae of SARS-CoV-2 infection (PASC), suffer from debilitating neurologic symptoms (Neuro-PASC). However, whether virus-specific adaptive immunity is affected in Neuro-PASC patients remains poorly understood. We report that Neuro-PASC patients exhibit distinct immunological signatures composed of elevated humoral and cellular responses toward SARS-CoV-2 Nucleocapsid protein at an average of 6 months post-infection compared to healthy COVID convalescents. Neuro-PASC patients also had enhanced virus-specific production of IL-6 from and diminished activation of CD8+ T cells.

Furthermore, the severity of cognitive deficits or quality of life disturbances in Neuro-PASC patients were associated with a reduced diversity of effector molecule expression in T cells but elevated IFN-γ production to the C-terminal domain of Nucleocapsid protein. Proteomics analysis showed enhanced plasma immunoregulatory proteins and reduced pro-inflammatory and antiviral response proteins in Neuro-PASC patients compared with healthy COVID convalescents, which were also correlated with worse neurocognitive dysfunction. These data provide new insight into the pathogenesis of long COVID syndrome and a framework for the rational design of predictive biomarkers and therapeutic interventions.

One Sentence Summary Adaptive immunity is altered in patients with neurologic manifestations of long COVID.

Source: Lavanya Visvabharathy, Barbara A. Hanson, Zachary S. Orban, Patrick H. Lim, Nicole M. Palacio, Millenia Jimenez, Jeffrey R. Clark, Edith L. Graham, Eric M. Liotta, George Tachas, Pablo Penaloza-MacMaster, Igor J. Koralnik. T cell responses to SARS-CoV-2 in people with and without neurologic symptoms of long COVID. medRxiv 2021.08.08.21261763; doi: https://doi.org/10.1101/2021.08.08.21261763 https://www.medrxiv.org/content/10.1101/2021.08.08.21261763v4.full-text (Full text)

Long COVID: The latest manifestations, mechanisms, and potential therapeutic interventions

Abstract:

COVID-19 caused by SARS-CoV-2 infection affects humans not only during the acute phase of the infection, but also several weeks to 2 years after the recovery. SARS-CoV-2 infects a variety of cells in the human body, including lung cells, intestinal cells, vascular endothelial cells, olfactory epithelial cells, etc. The damages caused by the infections of these cells and enduring immune response are the basis of long COVID. Notably, the changes in gene expression caused by viral infection can also indirectly contribute to long COVID.

We summarized the occurrences of both common and uncommon long COVID, including damages to lung and respiratory system, olfactory and taste deficiency, damages to myocardial, renal, muscle, and enduring inflammation. Moreover, we provided potential treatments for long COVID symptoms manifested in different organs and systems, which were based on the pathogenesis and the associations between symptoms in different organs.

Importantly, we compared the differences in symptoms and frequency of long COVID caused by breakthrough infection after vaccination and infection with different variants of concern, in order to provide a comprehensive understanding of the characteristics of long COVID and propose improvement for tackling COVID-19.

Source: He ST, Wu K, Cheng Z, He M, Hu R, Fan N, Shen L, Li Q, Fan H, Tong Y. Long COVID: The latest manifestations, mechanisms, and potential therapeutic interventions. MedComm (2020). 2022 Dec 8;3(4):e196. doi: 10.1002/mco2.196. PMID: 36514781; PMCID: PMC9732402. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9732402/ (Full text)

Brain fog as a Long-term Sequela of COVID-19

Abstract:

Increasing data indicate that people infected with COVID-19 are at high risk for developing long-term neurological complications, such as “brain fog” or cognitive impairment. However, little is known about the long-term outcomes of COVID-19 survivors. This also applies to the prevalence, risk factors, and pathobiological findings associated with these consequences. Although cognitive complications are anticipated in patients who require a long-lasting hospital stay or intubation, milder cases of COVID-19 with no record of hospitalization have also been shown to experience assessable cognitive challenges. Cognitive impairment can have a devastating impact on daily functioning. Understanding the long-term effect of COVID-19 on cognitive function is vital for applying specific schemes to those who wish to return to their jobs productively.

Source: Nouraeinejad A. Brain fog as a Long-term Sequela of COVID-19. SN Compr Clin Med. 2023;5(1):9. doi: 10.1007/s42399-022-01352-5. Epub 2022 Nov 24. PMID: 36466122; PMCID: PMC9685075. https://link.springer.com/article/10.1007/s42399-022-01352-5 (Full text)

Psychological consequences of long COVID: comparing trajectories of depressive and anxiety symptoms before and after contracting SARS-CoV-2 between matched long- and short-COVID groups

Abstract:

Background: There is a growing global awareness of the psychological consequences of long COVID, supported by emerging empirical evidence. However, the emergence and long-term trajectories of psychological symptoms following the infection are still unclear.

Aims: To examine when psychological symptoms first emerge following infection with SARS-CoV-2 and the long-term trajectories of psychological symptoms comparing long- and short-COVID groups.

Method: We analysed longitudinal data from the UCL COVID-19 Social Study (March 2020 to November 2021). We included data from adults living in England who reported contracting SARS-CoV-2 by November 2021 (n = 3115). Of these, 15.9% reported having had long COVID (n = 495). They were matched to participants who had short COVID using propensity score matching on a variety of demographic, socioeconomic and health covariates (n = 962 individuals with 13 325 observations) and data were further analysed using growth curve modelling.

Results: Depressive and anxiety symptoms increased immediately following the onset of infection in both long- and short-COVID groups. But the long-COVID group had substantially greater initial increases in depressive symptoms and heightened levels over 22 months follow-up. Initial increases in anxiety were not significantly different between groups, but only the short-COVID group experienced an improvement in anxiety over follow-up, leading to widening differences between groups.

Conclusions: The findings support work on the psychobiological pathways involved in the development of psychological symptoms relating to long COVID. The results highlight the need for monitoring of mental health and provision of adequate support to be interwoven with diagnosis and treatment of the physical consequences of long COVID.

Source: Fancourt D, Steptoe A, Bu F. Psychological consequences of long COVID: comparing trajectories of depressive and anxiety symptoms before and after contracting SARS-CoV-2 between matched long- and short-COVID groups. Br J Psychiatry. 2022 Dec 2:1-8. doi: 10.1192/bjp.2022.155. Epub ahead of print. PMID: 36458509. https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/psychological-consequences-of-long-covid-comparing-trajectories-of-depressive-and-anxiety-symptoms-before-and-after-contracting-sarscov2-between-matched-long-and-shortcovid-groups/923140B3F95F1158C0CDC188002531AE (Full text)