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Two-year impact of COVID-19: Longitudinal MRI brain changes and neuropsychiatric trajectories

AIM

Up to 10% of SARS-CoV-2 infected individuals suffer from post-COVID-19 condition, marked by fatigue and cognitive dysfunction as major symptoms. Longitudinal studies on neuropsychological and clinical trajectories and related brain changes are scarce. Here, we aimed to examine their evolution up to 2 years post-infection.

METHODS

In a multi-center, longitudinal study of 79 post-COVID patients (mean age 46, 48 female) with persistent symptoms and 21 age- and sex-matched never-infected, healthy controls (mean age 42, eight female), we analyzed neuropsychological performance, self-reported outcomes and associated neuroimaging alterations of resting-state functional and structural magnetic resonance imaging data 23 months post-infection.

RESULTS

In post-COVID patients 23 months after SARS-CoV-2 infection we observed (1) that fatigue severity had reduced but still remained present in most patients, (2) widespread brain changes involving the brainstem, the pre- and postcentral gyrus and the limbic olfactory network, (3) a weakening of self-reported fatigue and its cerebral associations. Notably, findings of brain aberrations were more pronounced in hospitalized patients.

CONCLUSION

Our findings indicate that complex brain adaptations take place up to 2 years following SARS-CoV-2 infection. Some regions manifest enduring abnormalities while others undergo restitution. The attenuation of radio-clinical associations suggests a compensatory function for these regions, pointing to non-brain intrinsic factors to sustain persistent fatigue.

[Chronic pain syndrome in musculoskeletal diseases-how different are fibromyalgia and long COVID?-Part 2]

Acute and chronic pain play an important part in the care of patients with musculoskeletal diseases. For rheumatologists this represents a frequent challenge. For the management of chronic pain conditions in rheumatology those that cannot be explained by objective tissue damage are particularly important-which makes patients' subjective assessment of pain a central building block of the diagnosis. For the diagnosis of fibromyalgia (FM) standardized questionnaires such as the Widespread Pain Index (WPI) and the Symptom Severity Score (SSS) are used. In connection with the recent global SARS-CoV‑2 pandemic protracted courses and health problems have been described, which have been termed long COVID syndrome and have some similarities but, as is shown in the following, also demonstrate some differences from FM. There has recently been an interesting scientific controversy that culminated in a pros and cons session at the EULAR congress 2024, following several publications. The arguments and citations exchanged have served as the basis for the overview produced here, which is intended to offer rheumatologists confronted with such clinical pictures assistance with the assessment of these diseases, even if the results of the studies presented are definitely controversial.

[Psychocorporal approach to functional somatic disorders]

Functional somatic disorders (FSD) are common conditions that result in a significant deterioration of the quality of life. Their origin is multifactorial and poorly understood, and their management is often inadequately defined. Medications typically show limited effectiveness, while mind-body approaches play a central role, guided by three key principles: establishing an empathetic, respectful, and sincere doctor-patient relationship; promoting regular and gradual physical activity; and implementing cognitive behavioral therapy (CBT). Special attention must be devoted to establishing a trustworthy relationship between the physician and the patient. Recognizing the reality and severity of symptoms and providing a positive diagnosis as well as an explanatory model to account for them rationally are fundamental aspects of patient management. Cognitive and behavioral maintenance factors should be investigated and constitute therapeutic targets. Cognitive factors include focused attention on body functioning and catastrophizing. Patients frequently display avoidance behaviors, particularly in relation to physical exertion, and it is crucial to motivate them to reintroduce gradual physical activity customized to their abilities. This approach has demonstrated efficacy in improving fatigue, pain, and the physical and mental quality of life for patients with FSD. Among psychotherapeutic approaches, the benefit of CBT is well-established. The combination of gradual physical activity and CBT appears to be complementary. Other mind-body approaches such as mindfulness meditation might help although their level of evidence is weaker. Given the prevalence of FSD in the general population, it seems necessary for all physicians to be trained in managing this condition.

Neurocognitive Impairment in Post-COVID-19 Condition in Adults: Narrative Review of the Current Literature

The severe acute respiratory syndrome coronavirus 2 virus has, up to the time of this article, resulted in >770 million cases of COVID-19 illness worldwide, and approximately 7 million deaths, including >1.1 million in the United States. Although defined as a respiratory virus, early in the pandemic, it became apparent that considerable numbers of people recovering from COVID-19 illness experienced persistence or new onset of multi-system health problems, including neurologic and cognitive and behavioral health concerns. Persistent multi-system health problems are defined as Post-COVID-19 Condition (PCC), Post-Acute Sequelae of COVID-19, or Long COVID. A significant number of those with PCC report cognitive problems. This paper reviews the current state of scientific knowledge on persisting cognitive symptoms in adults following COVID-19 illness. A brief history is provided of the emergence of concerns about persisting cognitive problems following COVID-19 illness and the definition of PCC. Methodologic factors that complicate clear understanding of PCC are reviewed. The review then examines research on patterns of cognitive impairment that have been found, factors that may contribute to increased risk, behavioral health variables, and interventions being used to ameliorate persisting symptoms. Finally, recommendations are made about ways neuropsychologists can improve the quality of existing research.

Cognitive-behavioral therapy for patients with post-COVID-19 condition (CBT-PCC): a feasibility trial

BACKGROUND

The post-COVID-19 condition describes the persistence or onset of somatic symptoms (e.g. fatigue) after acute COVID-19. Based on an existing cognitive-behavioral treatment protocol, we developed a specialized group intervention for individuals with post-COVID-19 condition. The present study examines the feasibility, acceptance, and effectiveness of the program for inpatients in a neurological rehabilitation setting.

METHODS

The treatment program comprises eight sessions and includes psychoeducational and experience-based interventions on common psychophysiological mechanisms of persistent somatic symptoms. A feasibility trial was conducted using a one-group design in a naturalistic setting. N = 64 inpatients with a history of mild COVID-19 that fulfilled WHO criteria for post-COVID-19 condition were enrolled. After each session, evaluation forms were completed and psychometric questionnaires on somatic and psychopathological symptom burden were collected pre- and post-intervention.

RESULTS

The treatment program was well received by participants and therapists. Each session was rated as comprehensible and overall satisfaction with the sessions was high. Pre-post effect sizes (of standard rehabilitation incl. new treatment program; intention-to-treat) showed significantly reduced subjective fatigue (p < 0.05, dav = 0.33) and improved disease coping (ps < 0.05, dav = 0.33-0.49).

CONCLUSIONS

Our results support the feasibility and acceptance of the newly developed cognitive-behavioral group intervention for individuals with post-COVID-19 condition. Yet, findings have to be interpreted cautiously due to the lack of a control group and follow-up measurement, the small sample size, and a relatively high drop-out rate.

Impact of pre-existing mental health diagnoses on development of post-COVID and related symptoms: a claims data-based cohort study

This study aimed to examine the association of prior mental health diagnoses with the onset of Post-COVID-19 condition (PCC). We conducted a retrospective comparative cohort study and secondary analysis of routinely collected claims data from participants in statutory health insurance in Bavaria, Germany, from January 2015 to June 2022. Study participants were 619,560 patients with confirmed COVID-19, 42,969 with other respiratory tract infection (ORI), and 438,023 controls. Using diagnoses coded according to the German modification of the ICD-10, the associations between prior mental health diagnoses and a PCC diagnosis (primary outcome) or associated symptoms (secondary outcomes) were estimated using multiple Cox proportional hazards regression models. Mental disorders (hazard ratio [HR] 1.36, 95% confidence interval [CI] 1.30-1.42), anxiety (HR 1.14, 95% CI 1.07-1.20), depression (HR 1.25, 95% CI 1.19-1.30) and somatoform disorders (HR 1.30, 95% CI 1.24-1.36) were associated with higher risks for PCC. Mental disorders were associated with the same or even greater risk for a diagnosis of malaise and fatigue in the control cohort (HR 1.71, 95% CI 1.52-1.93) and ORI cohort (HR 1.43, 95% CI 1.20-1.72), than in the COVID-19 cohort (HR 1.43, 95% CI 1.35-1.51). In summary, prior mental comorbidity was associated with an increased risk of PCC and its associated symptoms in all cohorts, not specifically in COVID-19 patients.

Patients with persistent symptoms after COVID-19 attending a multidisciplinary evaluation: Characteristics, medical conclusions, and satisfaction

OBJECTIVE

Among patients attending a multidisciplinary day-hospital program for persistent symptoms after COVID-19, we aimed i) to describe their characteristics ii) to present the medical conclusions (diagnoses and recommendations) and iii) to assess the patients' satisfaction and its correlates.

METHODS

For this retrospective chart review study, frequent symptoms were systematically assessed. Standardized questionnaires explored fatigue (Pichot scale), physical activity (Ricci & Gagnon scale), health-related quality of life (Short-Form Health Survey), anxiety and depressive symptoms (Hospital Anxiety and Depression scale) and associated psychological burden (Somatic-Symptom-Disorder B criteria Scale). Medical record conclusions were collected and a satisfaction survey was performed at 3-months follow-up.

RESULTS

Among 286 consecutive patients (median age: 44 years; 70% women), the most frequent symptoms were fatigue (86%), breathlessness (65%), joint/muscular pain (61%) and cognitive dysfunction (58%), with a median duration of 429 days (Inter-quartile range (IqR): 216-624). Questionnaires revealed low levels of physical activity and quality of life, and high levels of fatigue, anxiety, depression, and psychological burden, with 32% and 23% meeting the diagnostic criteria for a depressive or anxiety disorder, respectively. Positive arguments for a functional somatic disorder were found in 76% of patients, including 96% with no abnormal clinical or test findings that may explain the symptoms. Physical activity rehabilitation was recommended for 91% of patients. Patients' median satisfaction was 8/10 (IqR: 6-9).

CONCLUSION

Most patients attending this program presented with long-lasting symptoms and severe quality of life impairment, received a diagnosis of functional somatic disorder, and reported high levels of satisfaction regarding the program.

The long-term health outcomes, pathophysiological mechanisms and multidisciplinary management of long COVID

There have been hundreds of millions of cases of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the growing population of recovered patients, it is crucial to understand the long-term consequences of the disease and management strategies. Although COVID-19 was initially considered an acute respiratory illness, recent evidence suggests that manifestations including but not limited to those of the cardiovascular, respiratory, neuropsychiatric, gastrointestinal, reproductive, and musculoskeletal systems may persist long after the acute phase. These persistent manifestations, also referred to as long COVID, could impact all patients with COVID-19 across the full spectrum of illness severity. Herein, we comprehensively review the current literature on long COVID, highlighting its epidemiological understanding, the impact of vaccinations, organ-specific sequelae, pathophysiological mechanisms, and multidisciplinary management strategies. In addition, the impact of psychological and psychosomatic factors is also underscored. Despite these crucial findings on long COVID, the current diagnostic and therapeutic strategies based on previous experience and pilot studies remain inadequate, and well-designed clinical trials should be prioritized to validate existing hypotheses. Thus, we propose the primary challenges concerning biological knowledge gaps and efficient remedies as well as discuss the corresponding recommendations.

Depression and anxiety before and at the beginning of the COVID-19 pandemic and incident persistent symptoms: a prospective population-based cohort study

Many patients affected by COVID-19 suffer from debilitating persistent symptoms whose risk factors remained poorly understood. This prospective study examined the association of depression and anxiety symptoms measured before and at the beginning of the COVID-19 pandemic with the incidence of persistent symptoms. Among 25,114 participants [mean (SD) age, 48.72 years (12.82); 51.1% women] from the SAPRIS and SAPRIS-Sérologie surveys nested in the French CONSTANCES population-based cohort, depression and anxiety symptoms were measured with the Center for Epidemiologic Studies-Depression scale and the 12-item General Health Questionnaire before the pandemic, and with the 9-item Patient Health Questionnaire and the 7-Item Generalized Anxiety Disorder scale at the beginning of the pandemic (i.e., between April 6, 2020 and May 4, 2020). Incident persistent symptoms were self-reported between December 2020 and January 2021. The following variables were also considered: gender, age, educational level, household income, smoking status, BMI, hypertension, diabetes, self-rated health, and SARS-CoV-2 infection according to serology/PCR test results. After a follow-up of seven to ten months, 2329 participants (9.3%) had been infected with SARS-CoV-2 and 4262 (17.0%) reported at least one incident persistent symptom that emerged from March 2020, regardless of SARS-CoV-2 infection. In multi-adjusted logistic regression models, participants in the highest (versus the lowest) quartile of depressive or anxiety symptom levels before or at the beginning of the pandemic were more likely to have at least one incident persistent symptom (versus none) at follow-up [OR (95%CI) ranging from 2.10 (1.89-2.32) to 3.01 (2.68-3.37)], with dose-response relationships (p for linear trend <0.001). Overall, these associations were significantly stronger in non-infected versus infected participants, except for depressive symptoms at the beginning of the pandemic. Depressive symptoms at the beginning of the pandemic were the strongest predictor of incident persistent symptoms in both infected and non-infected participants [OR (95%CI): 2.88 (2.01-4.14) and 3.03 (2.69-3.42), respectively]. In exploratory analyses, similar associations were found for each symptom taken separately in different models. Depression and anxiety symptoms should be tested as a potential target for preventive interventions against persistent symptoms after an infection with SARS-CoV-2.

Reported neurological symptoms after severe acute respiratory syndrome coronavirus type 2 infection: A systematic diagnostic approach

BACKGROUND AND PURPOSE

Following increasing demands of patients with suspected neurological symptoms after infection with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), the Department of Neurology at the Medical University of Vienna established a new outpatient clinic to systematically assess, diagnose, and document neurological complaints potentially associated with a prior SARS-CoV-2 infection.

METHODS

The data presented here include prospectively collected 156 outpatients from May 2021 to April 2022. Patients underwent semistandardized interviewing about symptoms with reported onset after SARS-CoV-2 infection, neurological examination, and comprehensive diagnostic workup.

RESULTS

Reported new onset symptoms after infection included fatigue (77.6%), subjective cognitive impairment (72.4%), headache (47.7%), loss of smell and/or taste (43.2%), and sleep disturbances (42.2%). Most patients had a mild coronavirus disease (COVID-19) disease course (84%) and reported comorbidities (71%), of which the most frequent were psychiatric disorders (34%). Frequency of symptoms was not associated with age, sex, or severity of COVID-19 course. A comprehensive diagnostic workup revealed no neurological abnormalities in the clinical examination, or electrophysiological or imaging assessments in the majority of patients (n = 143, 91.7%). Neuropsychological assessment of a subgroup of patients (n = 28, 17.9%) showed that cognitive impairments in executive functions and attention, anxiety, depression, and somatization symptoms were highly common.

CONCLUSIONS

In this systematic registry, we identified fatigue, cognitive impairment, and headache as the most frequently reported persisting complaints after SARS-CoV-2 infection. Structural neurological findings were rare. We also suspect a link between the growing burden of the COVID-19 pandemic on personal lives and the increase in reported neurological and psychiatric complaints.

Long COVID as a functional somatic symptom disorder caused by abnormally precise prior expectations during Bayesian perceptual processing: A new hypothesis and implications for pandemic response

This review proposes a model of Long-COVID where the constellation of symptoms are in fact genuinely experienced persistent physical symptoms that are usually functional in nature and therefore potentially reversible, that is, Long-COVID is a somatic symptom disorder. First, we describe what is currently known about Long-COVID in children and adults. Second, we examine reported "Long-Pandemic" effects that create a risk for similar somatic symptoms to develop in non-COVID-19 patients. Third, we describe what was known about somatization and somatic symptom disorder before the COVID-19 pandemic, and suggest that by analogy, Long-COVID may best be conceptualized as one of these disorders, with similar symptoms and predisposing, precipitating, and perpetuating factors. Fourth, we review the phenomenon of mass sociogenic (functional) illness, and the concept of nocebo effects, and suggest that by analogy, Long-COVID is compatible with these descriptions. Fifth, we describe the current theoretical model of the mechanism underlying functional disorders, the Bayesian predictive coding model for perception. This model accounts for moderators that can make symptom inferences functionally inaccurate and therefore can explain how to understand common predisposing, precipitating, and perpetuating factors. Finally, we discuss the implications of this framework for improved public health messaging during a pandemic, with recommendations for the management of Long-COVID symptoms in healthcare systems. We argue that the current public health approach has induced fear of Long-COVID in the population, including from constant messaging about disabling symptoms of Long-COVID and theorizing irreversible tissue damage as the cause of Long-COVID. This has created a self-fulfilling prophecy by inducing the very predisposing, precipitating, and perpetuating factors for the syndrome. Finally, we introduce the term "Pandemic-Response Syndrome" to describe what previously was labeled Long-COVID. This alternative perspective aims to stimulate research and serve as a lesson learned to avoid a repeat performance in the future.

Pathophysiology, diagnosis, and management of neuroinflammation in covid-19

Although neurological complications of SARS-CoV-2 infection are relatively rare, their potential long term morbidity and mortality have a significant impact, given the large numbers of infected patients. Covid-19 is now in the differential diagnosis of a number of common neurological syndromes including encephalopathy, encephalitis, acute demyelinating encephalomyelitis, stroke, and Guillain-Barré syndrome. Physicians should be aware of the pathophysiology underlying these presentations to diagnose and treat patients rapidly and appropriately. Although good evidence has been found for neurovirulence, the neuroinvasive and neurotropic potential of SARS-CoV-2 is limited. The pathophysiology of most complications is immune mediated and vascular, or both. A significant proportion of patients have developed long covid, which can include neuropsychiatric presentations. The mechanisms of long covid remain unclear. The longer term consequences of infection with covid-19 on the brain, particularly in terms of neurodegeneration, will only become apparent with time and long term follow-up.

Routine Brain MRI Findings on the Long-Term Effects of COVID-19: A Scoping Review

RATIONALE AND OBJECTIVES

Post-COVID condition (PCC) is associated with long-term neuropsychiatric symptoms. Magnetic resonance imaging (MRI) in PCC examines the brain metabolism, connectivity, and morphometry. Such techniques are not easily available in routine practice. We conducted a scoping review to determine what is known about the routine MRI findings in PCC patients.

MATERIALS AND METHODS

The PubMed database was searched up to 11 April 2023. We included cohort, cross-sectional, and before-after studies in English. Articles with only advanced MRI sequences (DTI, fMRI, VBM, PWI, ASL), preprints, and case reports were excluded. The National Heart, Lung, and Blood Institute and PRISMA Extension tools were used for quality assurance.

RESULTS

A total of 7 citations out of 167 were included. The total sample size was 451 patients (average age 51 ± 8 years; 67% female). Five studies followed a single recovering cohort, while two studies compared findings between two severity groups. The MRI findings were perivascular spaces (47%), microbleeds (27%) and white matter lesions (10%). All the studies agreed that PCC manifestations are not associated with specific MRI findings.

CONCLUSION

The results of the included studies are heterogeneous due to the low agreement on the types of MRI abnormalities in PCC. Our findings indicate that the routine brain MRI protocol has little value for long COVID diagnostics.

[Role of psychological factors in post-COVID-19 condition]

Even after a mild episode of coronavirus disease 2019 (COVID-19), many patients suffer from persistent symptoms that can impair their quality of life for months. The potential role of psychological mechanisms in this post-COVID-19 condition, often referred to as long COVID, has been discussed early in the pandemic. Evidence supporting this hypothesis is now accumulating. First, a history of anxiety or depression is now an established risk factor for post-COVID-19 condition with a dose-response relationship and effect size similar to those of other known risk factors. This association extends to other forms of psychological distress, including perceived stress and loneliness. Second, specific beliefs about COVID-19 have been associated with the risk of subsequent similar symptoms, occurring weeks to several months later. Other studies, which have yet to be replicated, suggest an influence of the context of the initial infection (first versus second wave of the pandemic, before the emergence of significant variants and vaccination) and the trust in various sources of information about COVID-19 on the risk of subsequent symptoms. Bayesian models of perception can account for these results particularly well within a theoretical framework similar to that advanced for functional somatic disorders, integrating increased symptom expectations with decreased perception of the body internal state (interoception) and intolerance of uncertainty in the context of symptoms initially triggered by an infectious episode. These psychological mechanisms should obviously not be considered as exclusive. However, since they are modifiable, they could be targeted in clinical trials, within an integrative and multidisciplinary approach.

[Neurological forms of long COVID in adults: Critical approach]

Now recognized by health authorities, long COVID is identified as a frequent condition complicating the evolution of SARS-CoV-2 infection. Its polymorphic and sometimes disconcerting clinical expression raises questions about its mechanism. Patterns of clinical expression suggest extensive involvement of the nervous system through an almost ubiquitous cognitive complaint. This article reviews the neurological symptoms and forms of these patients, and the neuropsychological explorations aimed at objectifying a cognitive deficit. The studies published until now confronted with the clinical mode of expression, did not make it possible to define a deficit neuropsychological profile at the level of the groups, and evoked more a functional impairment than a lesion. However, each series mentions a small number of patients in whom a cognitive deficit is objectified. The uncertainties about the causes of the prolonged forms of COVID, the heterogeneity of the published studies, and the virtual absence of temporal evolution data should make one cautious about the interpretation of these data but should in no way delay or prevent taking into account care of these patients.

Persistent somatic symptoms are key to individual illness perception at one year after COVID-19 in a cross-sectional analysis of a prospective cohort study

OBJECTIVE

Subjective illness perception (IP) can differ from physician's clinical assessment results. Herein, we explored patient's IP during coronavirus disease 2019 (COVID-19) recovery.

METHODS

Participants of the prospective observation CovILD study (ClinicalTrials.gov: NCT04416100) with persistent somatic symptoms or cardiopulmonary findings one year after COVID-19 were analyzed (n = 74). Explanatory variables included demographic and comorbidity, COVID-19 course and one-year follow-up data of persistent somatic symptoms, physical performance, lung function testing, chest computed tomography and trans-thoracic echocardiography. Factors affecting IP (Brief Illness Perception Questionnaire) one year after COVID-19 were identified by regularized modeling and unsupervised clustering.

RESULTS

In modeling, 33% of overall IP variance (R2) was attributed to fatigue intensity, reduced physical performance and persistent somatic symptom count. Overall IP was largely independent of lung and heart findings revealed by imaging and function testing. In clustering, persistent somatic symptom count (Kruskal-Wallis test: η2 = 0.31, p < .001), fatigue (η2 = 0.34, p < .001), diminished physical performance (χ2 test, Cramer V effect size statistic: V = 0.51, p < .001), dyspnea (V = 0.37, p = .006), hair loss (V = 0.57, p < .001) and sleep problems (V = 0.36, p = .008) were strongly associated with the concern, emotional representation, complaints, disease timeline and consequences IP dimensions.

CONCLUSION

Persistent somatic symptoms rather than abnormalities in cardiopulmonary testing influence IP one year after COVID-19. Modifying IP represents a promising innovative approach to treatment of post-COVID-19 condition. Besides COVID-19 severity, individual IP should guide rehabilitation and psychological therapy decisions.

Association between somatic symptom disorder and symptoms with daily life impairment after SARS-CoV-2 infection - results from a population-based cross-sectional study

BACKGROUND

Post-COVID syndrome (PCS) is defined by symptom persistence accompanied by daily life impairment (DLI). The association of somatic symptom disorder (SSD) and symptoms with DLI after SARS-CoV-2 infection in the general population is unclear to date. The main objective of the study was to investigate the association of possible SSD, depression, anxiety, and participant-reported symptoms with DLI in a local population sample.

METHODS

Anonymised cross-sectional study. A symptom questionnaire, including the scales Patient Health Questionnaire PHQ-15 (somatisation module), SSD-12 (psychological distress in SSD), PHQ-2 (depression), GAD-2 (anxiety), and FAS (fatigue assessment scale) was sent in 02/2022 to all adult residents of the district Bad Tölz-Wolfratshausen, Germany, who were registered for SARS-CoV-2-infection between 03/2020 and 11/2021 (8925 delivered). Associations between DLI, symptoms and scales were estimated using binary logistic regression models and network analysis.

RESULTS

2828 questionnaires (31.7%) were complete. 1486 (52.5%) reported persistent symptoms, and 509 (18.0%) perceived DLI. DLI was strongest associated with self-reported fatigue (OR 7.86; 95%CI 5.63-10.97), dyspnea (3.93; 2.73-5.67), impaired concentration (3.05; 2.17-4.30), SSD-12 (4.36; 2.57-7.41), and PHQ-2 (2.48; 1.57-3.92). Self-reported fatigue showed the strongest correlation (rp = 0.248) and closest proximity to DLI in network analysis.

CONCLUSION

PCS appears as a complex clinical picture in which SSD might play an important role when DLI is present. The pychological burden might partly be explained by the persistent symptoms, which are difficult to treat up to now. Screening for SSD could help in differential diagnostic decision-making to ensure that patients receive appropriate psychosocial interventions for disease coping.

Functional cognitive disorders: clinical presentations and treatment approaches

Functional cognitive disorders (FCDs) are a common cause of subjective and mild cognitive impairment. Isolated FCDs commonly present to the cognitive clinic, but examination of the nature of the symptoms suggests that they can also be understood as a transdiagnostic feature of many other conditions. This article examines methods of formulating the cognitive difficulties in order to identify treatment targets in people with FCDs.

How viral infections cause neuronal dysfunction: a focus on the role of microglia and astrocytes

In recent decades, a number of infectious viruses have emerged from wildlife or reemerged that pose a serious threat to global health and economies worldwide. Although many of these viruses have a specific target tissue, neurotropic viruses have evolved mechanisms to exploit weaknesses in immune defenses that eventually allow them to reach and infect cells of the central nervous system (CNS). Once in the CNS, these viruses can cause severe neuronal damage, sometimes with long-lasting, life-threatening consequences. Remarkably, the ability to enter the CNS and cause neuronal infection does not appear to determine whether a viral strain causes neurological complications. The cellular mechanisms underlying the neurological consequences of viral infection are not fully understood, but they involve neuroimmune interactions that have so far focused mainly on microglia. As the major immune cells in the brain, reactive microglia play a central role in neuroinflammation by responding directly or indirectly to viruses. Chronic reactivity of microglia leads to functions that are distinct from their beneficial roles under physiological conditions and may result in neuronal damage that contributes to the pathogenesis of various neurological diseases. However, there is increasing evidence that reactive astrocytes also play an important role in the response to viruses. In this review article, we summarize the recent contributions of microglia and astrocytes to the neurological impairments caused by viral infections. By expanding knowledge in this area, therapeutic approaches targeting immunological pathways may reduce the incidence of neurological and neurodegenerative disorders and increase the therapeutic window for neural protection.

Prediction of Long COVID Based on Severity of Initial COVID-19 Infection: Differences in predictive feature sets between hospitalized versus non-hospitalized index infections

Long COVID is recognized as a significant consequence of SARS-COV2 infection. While the pathogenesis of Long COVID is still a subject of extensive investigation, there is considerable potential benefit in being able to predict which patients will develop Long COVID. We hypothesize that there would be distinct differences in the prediction of Long COVID based on the severity of the index infection, and use whether the index infection required hospitalization or not as a proxy for developing predictive models. We divide a large population of COVID patients drawn from the United States National Institutes of Health (NIH) National COVID Cohort Collaborative (N3C) Data Enclave Repository into two cohorts based on the severity of their initial COVID-19 illness and correspondingly trained two machine learning models: the Long COVID after Severe Disease Model (LCaSDM) and the Long COVID after Mild Disease Model (LCaMDM). The resulting models performed well on internal validation/testing, with a F1 score of 0.94 for the LCaSDM and 0.82 for the LCaMDM. There were distinct differences in the top 10 features used by each model, possibly reflecting the differences in type and amount of pathophysiological data between the hospitalized and non-hospitalized patients and/or reflecting different pathophysiological trajectories in the development of Long COVID. Of particular interest was the importance of Plant Hardiness Zone in the feature set for the LCaMDM, which may point to a role of climate and/or sunlight in the progression to Long COVID. Future work will involve a more detailed investigation of the potential role of climate and sunlight, as well as refinement of the predictive models as Long COVID becomes increasingly parsed into distinct clinical phenotypes.

Fatigue and perceived fatigability, not objective fatigability, are prevalent in people with post-COVID-19

Persistent symptoms after acute COVID-19 infection, termed post-COVID-19 fatigue, occur in 44-70% of patients. Characterizing fatigue in this population is vital to determine the etiology of post-COVID-19 fatigue symptoms and to assess the effectiveness of potential interventions. The purpose of this study was to assess differences in perceived and objective fatigability between people with post-COVID-19 symptoms (N = 29, 20 females) and people who had COVID-19 but are not experiencing persistent symptoms (N = 20, 12 females). Perceived fatigability, fatigue, pain, and quality of life were assessed with the Fatigue Severity Scale (FSS), Fatigue Assessment Scale (FAS), Visual Analog Scale for Pain (VAS), and the EQ-5D-5L, respectively. Objective fatigability was evaluated with torque and work fatigue indices (FI-T and FI-W), calculated via an isokinetic fatigue task. The results revealed that, the subjects with post-COVID-19 symptoms had significantly higher FAS (p < 0.01), FSS (p < 0.01), VAS (p < 0.01), and EQ-5D-5L VAS (p < 0.01) scores compared to subjects without post-COVID-19 symptoms, indicating greater fatigue and perceived fatigability, increased pain, and worse quality of life. However, there were no differences between the two groups for the FI-Ts (all p ≥ 0.07) or FI-W (all p ≥ 0.08), indicating no differences in objective fatigability. This study found that people with post-COVID-19 symptoms have increased fatigue and perceived fatigability, but not objective fatigability, compared to subjects without post-COVID-19 symptoms.

Efficacy of traditional Chinese exercises in patients with post-COVID-19 chronic fatigue syndrome: A protocol for systematic review and meta-analysis

BACKGROUND

Some patients develop long-term symptoms after Corona virus disease 2019 (COVID-19), and chronic fatigue syndrome (CFS) is one of the main symptoms. CFS is characterized by fatigue lasting for more than 6 months accompanied by sleep disorders, anxiety, and depression, which causes a certain degree of harm to both physiological and psychological aspects of the individual. Traditional Chinese exercises (TCEs) are an ancient Chinese therapy and has recently been reported to be effective for CFS. Therefore, we will conduct a systematic review and meta-analysis aiming to accurately evaluate the efficacy of TCEs on post-COVID-19 CFS and provide an alternative treatment for post-COVID-19 CFS.

METHODS

Seven databases (PubMed, Ovid Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), and Wanfang) will be searched from establishment to August 2022, and we will only include randomized controlled trials of TCEs for post-COVID-19 CFS. Two reviews will independently include the research according to the inclusion and exclusion criteria. Review Manager 5.2 software will be used to analyze the accepted literature, and the relative risk ratio (RR) and 95% confidence interval (CI) will be used as effect indicators for the outcome indicator dichotomous variables. For continuous variables, weighted mean difference (MD) and 95% CI will be used as effect indicators. The heterogeneity test will be assessed using the I2 statistic and Q statistic. The PEDro scale was used to evaluate the methodological quality of the included studies. Subgroup analysis was performed according to different TCEs, age, gender, and duration of CFS.

RESULTS

This systematic review and meta-analysis will evaluate the efficacy of TCEs in post-COVID-19 CFS.

CONCLUSION

The results of this study will provide reliable evidence for the effects of TCEs for post-COVID-19 CFS on patients' fatigue, anxiety, depression, sleep, and quality of life.

Excess of Post-Acute Sequelae of COVID-19 After the First Wave of the Pandemic

INTRODUCTION

To compare the time distribution of initial COVID-19 among patients with self-reported post-acute sequelae of COVID-19 (PASC).

METHODS

We compared the distribution of the date of the reported initial COVID-19 among patients with self-reported PASC and the COVID-19 cases in France between the first wave (January 1-May 11, 2020) and the later period (May 12, 2020-June 30, 2021) using the chi-squared test. COVID-19 cases in France were assessed using previous modeling of COVID-19 burden in France for the first time period, and positive RT-PCR testing for the second time period.

RESULTS

The study included 567 individuals with PASC (median age 44, [IQR 37-50]; 83.4% women). A total of 293 (51.7%) patients reported an initial COVID-19 infection during the first period while 272 (48%) reported it during the later period (missing data, n = 2; 0.3%). Patients with PASC were 82% more likely to report initial COVID-19 during the first pandemic wave than afterward (OR 1.82, 95% CI [1.55-2.15]; p < 0.0001).

CONCLUSIONS

The incidence of self-reported PASC wave was significantly higher when initial COVID-19 happened during the first pandemic wave than afterward, suggesting the importance of non-viral factors in PASC development.