SARS-CoV-2 is associated with changes in brain structure in UK Biobank

Persistent alterations in gray matter in COVID-19 patients experiencing sleep disturbances: a 3-month longitudinal study

JOURNAL/nrgr/04.03/01300535-202510000-00030/figure1/v/2024-11-26T163120Z/r/image-tiff Sleep disturbances are among the most prevalent neuropsychiatric symptoms in individuals who have recovered from severe acute respiratory syndrome coronavirus 2 infections. Previous studies have demonstrated abnormal brain structures in patients with sleep disturbances who have recovered from coronavirus disease 2019 (COVID-19). However, neuroimaging studies on sleep disturbances caused by COVID-19 are scarce, and existing studies have primarily focused on the long-term effects of the virus, with minimal acute phase data. As a result, little is known about the pathophysiology of sleep disturbances in the acute phase of COVID-19. To address this issue, we designed a longitudinal study to investigate whether alterations in brain structure occur during the acute phase of infection, and verified the results using 3-month follow-up data. A total of 26 COVID-19 patients with sleep disturbances (aged 51.5 ± 13.57 years, 8 women and 18 men), 27 COVID-19 patients without sleep disturbances (aged 47.33 ± 15.98 years, 9 women and 18 men), and 31 age- and gender-matched healthy controls (aged 49.19 ± 17.51 years, 9 women and 22 men) were included in this study. Eleven COVID-19 patients with sleep disturbances were included in a longitudinal analysis. We found that COVID-19 patients with sleep disturbances exhibited brain structural changes in almost all brain lobes. The cortical thicknesses of the left pars opercularis and left precuneus were significantly negatively correlated with Pittsburgh Sleep Quality Index scores. Additionally, we observed changes in the volume of the hippocampus and its subfield regions in COVID-19 patients compared with the healthy controls. The 3-month follow-up data revealed indices of altered cerebral structure (cortical thickness, cortical grey matter volume, and cortical surface area) in the frontal-parietal cortex compared with the baseline in COVID-19 patients with sleep disturbances. Our findings indicate that the sleep disturbances patients had altered morphology in the cortical and hippocampal structures during the acute phase of infection and persistent changes in cortical regions at 3 months post-infection. These data improve our understanding of the pathophysiology of sleep disturbances caused by COVID-19.

Untreated if unrecognized: A cognitive profile of sustained subjective executive dysfunctions in COVID-19

& STATEMENT OF IMPACTSARS-COV-2 infection can result in acute and long-lasting cognitive complaints, causing ongoing impairments in daily life which poses a challenge to society. Consequently, the evaluation and characterization of cognitive complaints, specifically in the domain of executive functions (EFs) affecting daily life, is imperative in formulating an effective neuropsychological response.In total 442 participants aged 18-65+ years from the Netherlands, Germany, Mexico, and Spain were included in an online questionnaire. Among others, the questionnaire consisted of demographics, the Behavior Rating Inventory of Executive Functioning for Adults (BRIEF-A), measures of subjective disease progression severity and experienced subjective impairment in daily activities. To assess whether daily life activities are affected by EF impairments, the main BRIEF-A composite score (GEC) was analyzed. To determine whether disease-related COVID-19 factors predict EFs complaints in daily life, a stepwise regression analysis was performed with i) experienced disease severity, ii) time since disease, and iii) health risk factor as predictors.The study revealed noteworthy differences in the occurrence of EFs problems in daily life between both groups, as indicated by the GEC, which exhibited a medium effect size even 6 months post-COVID-19 diagnosis even in mild disease progression. The scores of the BRIEF-A subscales follow a domain-specific profile, and includes clinically relevant impairments in: Working memory, Plan/Organize, Task Monitor, Shift, which are affected by the experienced severity of the disease. This cognitive profile has important implications for targeted cognitive training in rehabilitation and has the potential for an applicability to other viruses as well.

Cognitive impairment and associated neurobehavioral dysfunction in post-COVID syndrome

There is a high prevalence of neuropsychiatric sequelae in post-COVID syndrome, most commonly chronic fatigue, the mechanisms of which remain poorly understood. As altered function of the reward system has been suggested as a causal factor, we aimed to distinguish whether reward processing or task-unspecific cognitive operations are impaired in post-COVID syndrome. Our cohort study included 24 patients diagnosed with post-COVID syndrome and 24 demographically matched healthy controls. Questionnaire assessment of neuropsychiatric symptoms and socio-demographic variables, the Monetary Incentive Delay Task during an fMRI scan, and pupillary measurements were performed. In addition to clinical neuropsychiatric symptoms, participants in the post-COVID group demonstrated significantly slower task performance compared to healthy controls, although the function of behavioral reward circuits appeared unimpaired. However, the influence of rewarding cues on post-COVID patients increased significantly over time during task performance, correlating with temporally delayed activation of the left frontal gyrus and increased activity in task-unspecific brain regions in post-COVID patients. Furthermore, slower reaction times on the task were associated with a lower pupil diameter and a higher pupillary unrest index. This study proposes that post-COVID syndrome is a process that may not affect reward processing, but leads to neural hypoarousal and temporally altered brain activity in frontal and task-unspecific brain regions.

A mini-review: Application of the radiopharmaceutical [18F]DPA-714 in neuroinflammation research in post-SARS-CoV-2 patients

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has been linked to significant neurological complications, including neuroinflammation. This mini review explores the application of the radiopharmaceutical [18F]DPA-714 in neuroinflammation studies in post-SARS-CoV-2 patients using Positron Emission Tomography - Computed Tomography (PET-CT) imaging technology. [18F]DPA-714, a specific ligand for the translocator protein (TSPO), enables precise visualization and quantification of microglial activation, a key marker of neuroinflammation. Recent studies demonstrate that post-COVID-19 patients exhibit increased uptake of [18F]DPA-714 in various brain regions, correlating with persistent symptoms such as fatigue, cognitive dysfunction, and mood alterations. The application of [18F]DPA-714 in longitudinal studies can monitor the progression of neuroinflammation and evaluate the efficacy of therapeutic interventions, allowing personalized treatment adjustments. Additionally, exploring new TSPO ligands can complement data obtained with [18F]DPA-714, offering a more comprehensive view of neuroinflammatory processes. This article discusses the technical challenges in synthesizing and applying [18F]DPA-714, including the need for standardized imaging protocols and variability in binding due to genetic polymorphisms in TSPO. As a conclusion that [18F]DPA-714 is a valuable tool for research and treatment of neuroinflammation in post-SARS-CoV-2 patients, with significant implications for the development of personalized therapies and clinical monitoring.

Optimization of a panel of behavioral tests for use in containment using a golden Syrian hamster model

Golden Syrian hamsters are an often-overlooked model in behavioral testing. While previously utilized for research examining circadian rhythms and mammalian reproduction, they are less common than murine models in both infectious disease and behavioral studies. However, coronavirus disease-19 (COVID-19) quickly pushed hamster modeling to the forefront due to its myriad of advantages over mice in recapitulating human pathology and transmission. At least 10 % of COVID-19 survivors suffer from post-acute sequelae of COVID-19 (PASC), a collection of some 200 sequelae with neurologic sequelae (neuro-PASC) presenting with potentially debilitating symptomology. This presents a clear need for a small animal model that recapitulates human disease with the ability to assess any potential long term neurological changes. We adapted and optimized a panel of behavioral tests from previously accepted murine models utilizing the golden Syrian hamster model for use within biocontainment facilities. Our panel includes grip strength, Porsolt forced swim, and novel object recognition testing to measure muscle fatigue or weakness, depression, and memory loss or cognitive impairment, respectively. Apart from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), this panel of tests is applicable to other pathogens that cause neurologic sequelae, such as Nipah or eastern equine encephalitis viruses, or any other model systems that require the use of hamsters. In this manuscript, we detail the methods for each of these three behavioral tests, how to interpret and analyze the resulting data, and emphasize additional factors for consideration. We also provide baseline data for both male and female golden Syrian hamsters.

Persistent neurocognitive deficits in long COVID: Evidence of structural changes and network abnormalities following mild infection

This study aimed to investigate the neurocognitive deficits, structural brain alterations, and network abnormalities in individuals who had a mild SARS-CoV-2 infection, with and without brain fog, as a symptom of long COVID. A cross-sectional study was conducted involving 75 participants, categorized into three groups: 24 healthy controls (HCs), 26 COVID-19 survivors without brain fog (woFOG), and 25 with brain fog (wFOG). Neuropsychological assessments included the Free and Cued Selective Reminding Test (FCSRT) and Addenbrooke's Cognitive Examination-Revised (ACE-R). Structural and functional brain alterations were examined using voxel-based morphometry (VBM) and resting-state functional MRI (rs-fMRI). The wFOG group exhibited significant cognitive impairments, particularly in delayed free recall, attention, memory, and visuospatial skills, compared to both the woFOG and HC groups. Structural MRI analyses revealed reduced gray matter concentrations (GMC) in the left inferior temporal gyrus, left fusiform gyrus, and right orbital gyri in both COVID-19 groups relative to HCs. Additionally, the wFOG group exhibited further GMC reductions in the bilateral caudate nuclei, right putamen/pallidum, and amygdala compared to the woFOG group. rs-fMRI analyses demonstrated altered connectivity patterns in COVID-19 survivors, characterized by increased connectivity in the default mode network and visual networks, alongside decreased connectivity in the dorsal attention network. These findings indicate that even mild COVID-19 can result in persistent neurocognitive deficits, structural brain alterations, and functional network abnormalities, both in individuals with and without brain fog. The observed changes highlight the importance of long-term monitoring and targeted interventions to address potential cognitive and neurological consequences of long COVID.

Updates on the neurological manifestations of SARS-CoV-2 infection

PURPOSE OF REVIEW

Since its emergence in 2020, the COVID-19 pandemic has created a global surge of survivors experiencing neurologic effects from SARS-CoV-2 infection. This review aims to provide an updated synthesis of the acute and chronic neurological manifestations of COVID-19, and to outline the current therapeutic strategies for these conditions.

RECENT FINDINGS

Epidemiological studies have shown that COVID-19 patients with neurological symptoms during acute infection tend to have poorer hospital and functional outcomes. While the risk of adverse neurologic symptoms including cognitive dysfunction, headache, autonomic dysfunction, and chronic fatigue are thought to be greatest following infection with the original SARS-CoV-2 strain and its alpha variant, they remain prevalent after infection with subsequent less virulent strains as well. Some recent work has also found a link between SARS-CoV-2 and structural brain changes. However, ongoing trials show promising results for pharmacologic and nonpharmacologic treatments targeting the postacute neurological sequelae of COVID-19.

SUMMARY

Lingering neurological manifestations after COVID-19 still pose considerable individual, healthcare system, and socioeconomic repercussions. Both preventive and multimodal treatment approaches are necessary to address these conditions. Further research is required to assess the lasting impacts of SARS-CoV-2 on the nervous system, particularly its potential contribution to the development of neurodegenerative diseases.

Variables associated with cognitive alterations in a cohort of COVID-19 survivors at a third-level hospital in Mexico

BACKGROUND

Cognitive impairments are one of the most common, insidious, and disabling symptoms of post-COVID-19 syndrome (PC-19), which have been correlated with damage to different brain structures.

OBJECTIVE

To describe cognitive impairments in PC-19, identify associated variables, and compare the impact of mechanical ventilation on cognitive and neuroimaging outcomes.

METHODS

A cohort of COVID-19 survivors was evaluated with neuropsychological tests (NPT) and cranial magnetic resonance imaging (MRI) 12 weeks after hospital discharge. Patients were classified into two groups based on whether they required invasive mechanical ventilation (IMV) or non-invasive mechanical ventilation (NIMV).

RESULTS

60 patients completed the study, 41 received IMV and 19 NIMV, with an average age of 57.11 years. 66% scored below 26 points on the MoCA test and 83.3% reported everyday memory failures (EMF). 85% showed impairments in at least one NPT. When comparing results between groups, significant differences were observed in the total MoCA test score (p = 0.045) and EMF (p = 0.032). Significant relationships were observed between the Boston Naming Test (-0.287; p = 0.035), the Rey Figure Recall Test (-0.324; p = 0.017) with parietal atrophy, as well as phonological verbal fluency with frontal atrophy (-0.276; p = 0.042). The HVLT (learning trial) test was related to hippocampal hyperintensity (-0.266; p = 0.050) and cingulate hyperintensity (0.311; p = 0.021). The TMT-B test was related to white matter hyperintensity (0.345; p = 0.010). The presence of poor functional prognosis was correlated with anxiety (p < 0.001), depression (p < 0.001), elevated D-dimer levels (p = 0.002) and the increase in days of intubation (p = 0.005).

CONCLUSION

Our study suggests that COVID-19 survivors who had moderate-to-severe infection experience subjective complaints and cognitive impairments in executive function, attention, and memory, regardless of whether invasive mechanical ventilation was used during treatment. We found white matter lesions and cerebral atrophy in frontal and parietal regions that were associated with cognitive deficits. Our findings highlight the clinical need for longitudinal programmes capable of evaluating the real impact of SARS-CoV-2 infection on the central nervous system, particularly in the cognitive and emotional domains.

Intravenous SARS-CoV-2 Spike protein induces neuroinflammation and alpha-synuclein accumulation in brain regions relevant to Parkinson's disease

BACKGROUND

Coronavirus disease 2019 (COVID-19) frequently presents with neurological symptoms in human patients and leads to long-lasting brain pathology in a hamster model. There is no overt SARS-CoV-2 virus replication in central neurons. Whether viral proteins are sufficient to cause this pathology requires further investigations. The SARS-CoV-2 Spike-protein S1-subunit (S1-protein) has recently gained interest for causing neuroinflammation and accelerating aggregation of alpha-synuclein (aSyn) in vitro. Here, we show the impact of S1-protein in a broad spectrum of brain regions after injection via three different application routes in C57/BL6 mice.

METHODS

S1-protein was administered either intranasally, intravenously or intracerebrally. We quantified aSyn immunoreactivity and phosphorylated aSyn (pS129), microglia and astrocyte reactivity, ACE2/Neuropilin-1 receptor expression, and parvalbumin-positive interneurons in limbic system, basal ganglia, and cortical regions 14 days post-application. Plasma cytokine profiles were assessed 6 days post-injection.

RESULTS

While intracerebral injection resulted in decreased aSyn immunoreactivity with increased pS129 in males, intravenous injection led to increased levels of aSyn immunoreactivity and microglia cell density, predominantly in brain regions associated with Parkinson's disease pathology. Intranasal application of S1-protein induced microgliosis in some brain regions but resulted in sex-dependent alterations of aSyn levels, with increases in females and decreases in males. All routes showed sex-dependent alterations in astrocytic reactivity, receptor expression, and parvalbumin-positive interneurons.

CONCLUSION

Our results demonstrate that S1-protein itself leads to neuroinflammation, altered aSyn homeostasis, and disruption of inhibitory circuits in a route- and sex-dependent manner. These findings indicate the possibility of S1-protein being a crucial agent for both neuroinflammatory processes and altered protein regulation mechanisms. S1-protein trapped in tissue reservoirs could therefore explain symptoms occurring or persisting beyond viral clearance (Post COVID-19 condition).

Post-COVID microvascular dysfunction in hospitalized COVID-19 survivors is associated with acute disease severity and persistent cognitive complaints

OBJECTIVE

Coronavirus disease 2019 (COVID-19) is known to have adverse effects on the brain's vasculature in some patients. After recovery of the infection, vascular abnormalities may persist, but it remains unclear which pathological pathways play a role in post-COVID vascular and cognitive dysfunction and may contribute to post-COVID cognitive complaints.

METHODS

In this observational cohort study, 108 previously hospitalized COVID-19 survivors (general ward: n = 53; intensive care unit (ICU): n = 55) were compared. Cerebral microvascular properties in the cortical gray matter (cGM), normal-appearing white matter (NAWM), and white matter hyperintensities (WMH) were assessed using multi-b-value diffusion MRI around 9 months post-infection and related to acute systemic blood markers and post-COVID cognitive performance and complaints.

RESULTS

A lower microvascular perfusion volume fraction (fmv) and blood flow-related measure (fmv·Dmv) were found in ICU compared to general ward patients in the cGM (p = .032; p = .021), NAWM (p = .008; p = .006), and WMH (p = .014; p = .035). No associations were found between diffusion/perfusion metrics and cognitive performance, but a lower fmv in the NAWM was found in those with more cognitive complaints (p = .047). In ICU survivors, higher median blood lactate levels during ICU admission were associated with lower fmv (p = .031) and fmv·Dmv (p = .044) in the NAWM.

INTERPRETATION

Significantly more widespread post-COVID cerebral microvascular dysfunction was found in COVID-19 ICU compared to general ward survivors. Post-COVID microvascular dysfunction in the NAWM may be due to more severe cerebral tissue hypoxia at time of the infection and is associated with persisting subjective cognitive complaints, even in absence of objective cognitive problems.

Persistent neuropsychological deficits in recovered COVID-19 patients: Correlations with disease biomarkers

OBJECTIVE

Cognitive impairment, including deficits in attention, memory, executive function, and processing speed, is common in post-COVID-19 conditions, though language performance remains less studied. The present study examined the long-term effects of COVID-19 condition on cognition and language - communication, and its associations with disease severity, Body Mass Index (BMI), inflammatory markers, and quality of life.

METHOD

Nighty eight Greek participants under 65 years of age were recruited for this study. Forty-seven participants were allocated in the COVID-19 group and 51 served as cognitively healthy controls. The COVID-19 group was categorized by disease severity and long COVID status. Assessments occurred 12 weeks post-infection, with 12 patients reevaluated after another 12 weeks. Neurocognitive tests included ABCD-II, verbal fluency, CCT, SDMT, and Euro QoL EQ-5D. Blood samples were analyzed for inflammatory markers.

RESULTS

Covid-19 survivors experienced significant cognitive deficits compared to healthy controls, particularly in processing speed, memory, and verbal fluency. Long COVID patients showed notably lower scores in processing speed and QoL, compared to those without Long COVID. However, no significant differences were observed between groups on episodic memory and executive functions tasks. Cognitive deficits were associated with biomarkers such as d-dimers and C-Reactive protein, with elevated d-dimers linked to poorer performance on generative drawing and cognitive flexibility. Higher education served as a protective factor, and was associated with higher scores in tasks such as story retelling, confrontation naming, generative drawing and reading comprehension. Older age and higher Body Mass Index were associated with poorer cognitive performance, especially on processing speed. Sex appears to influence language comprehension outcomes, with males exhibiting enhanced performance on the reading comprehension-sentence task. Disease severity negatively affected performance on the Symbol Digit Modalities Test and generative naming, indicating that greater severity was linked to poorer outcomes in these domains. Follow-up evaluations of recovered COVID-19 patients revealed significant improvements in processing speed and recall, suggesting partial recovery in these areas, although some deficits persisted over time.

CONCLUSION

The study supports findings that the prolonged effects of COVID-19 markedly impaired neurocognitive functions in recovering patients, especially those with severe or long COVID syndrome. Moreover, while several cognitive domains may improve over time, many other domains remain impaired and vulnerable.

A Randomized Controlled Trial of Anodal transcranial Direct Current Stimulation (A-tDCS) and Olfactory Training in persistent COVID-19 anosmia

BACKGROUND

Persistent anosmia due to COVID-19 affects approximately 20 million individuals worldwide, with a serious detrimental effect on their quality of life. Effective treatments remain lacking, with olfactory training (OT) being supported by some evidence of benefit. We implemented a double-blind, randomized, controlled trial (RCT) combining OT with Anodal transcranial Direct Current Stimulation (A-tDCS) with the aim to confirm the encouraging results of a preliminary study by our group. We also evaluated the long-term effectiveness of this intervention at both one- and six-months post-treatment assessments.

METHODS

This RCT involved 52 patients with persistent hypo/anosmia due to COVID-19. Participants were randomly assigned to undergo OT coupled with either A-tDCS targeting the Prefrontal Cortex (PFC) (experimental group, n=35), or sham stimulation (placebo group, n=17) for two weeks (10 sessions). The end point was the change in smell function from the baseline, as assessed by subjective and objective scores (VAS and Sniffin' Sticks test or SST).

RESULTS

The experimental group demonstrated a significant amelioration of both smell measures. Specifically, the mean VAS-smell increased from 2.56 to 4.70 (p < 0.001) and the mean SST from 6.97 to 9.69 (p < 0.001). Seventy-seven percent of patients in the experimental group significantly improved, with 63% achieving a complete recovery. No olfactory amelioration was observed in the placebo group. The significant smell improvement was sustained at both follow-up assessments.

CONCLUSION

This RCT demonstrates that combining A-tDCS with concurrent OT is able to restore the olfactory function in individuals suffering from persistent COVID-19 anosmia, with a durable effect. This safe and inexpensive treatment can therefore represent a suitable and widespread option for millions of individuals. These positive results also support the hypothesis that the brain olfactory networks are involved in the pathophysiology of COVID-19 anosmia.

Need for awareness and surveillance of long-term post-COVID neurodegenerative disorders. A position paper from the neuroCOVID-19 task force of the European Academy of Neurology

BACKGROUND

Neuropathological and clinical studies suggest that infection with SARS-CoV-2 may increase the long-term risk of neurodegeneration.

METHODS

We provide a narrative overview of pathological and clinical observations justifying the implementation of a surveillance program to monitor changes in the incidence of neurodegenerative disorders in the years after COVID-19.

RESULTS

Autopsy studies revealed diverse changes in the brain, including loss of vascular integrity, microthromboses, gliosis, demyelination, and neuronal- and glial injury and cell death, in both unvaccinated and vaccinated individuals irrespective of the severity of COVID-19. Recent data suggest that microglia play an important role in sustained COVID-19-related inflammation, which contributes to the etiology initiating a neurodegenerative cascade, to the worsening of pre-existing neurodegenerative disease or to the acceleration of neurodegenerative processes. Histopathological data have been supported by neuroimaging, and epidemiological studies also suggested a higher risk for neurodegenerative diseases after COVID-19.

CONCLUSIONS

Due to the high prevalence of COVID-19 during the pandemic, healthcare systems should be aware of, and be prepared for a potential increase in the incidence of neurodegenerative diseases in the upcoming years. Strategies may include follow-up of well-described cohorts, analyses of outcomes in COVID-19-registries, nationwide surveillance programs using record-linkage of ICD-10 diagnoses, and comparing the incidence of neurodegenerative disorders in the post-pandemic periods to values of the pre-pandemic years. Awareness and active surveillance are particularly needed, because diverse clinical manifestations due to earlier SARS-CoV-2 infections may no longer be quoted as post-COVID-19 symptoms, and hence, increasing incidence of neurodegenerative pathologies at the community level may remain unnoticed.

No brain MRI abnormalities after mild-to-moderate COVID-19: an observational study

PURPOSE

To assess COVID-19-related morphological brain changes in individuals who recovered from mild-to-moderate COVID-19.

METHOD

This prospective cohort study enrolled 112 consecutive individuals who recovered from mild-to-moderate COVID-19 and underwent an MRI of the brain between September 2020 and March 2022. MR exams were consistently obtained on a clinical 3T MR scanner in all study participants and 50 age-matched matched controls. The following clinical neuroradiological MR imaging findings were analyzed: post- and acute ischemic lesions, cortical signal alterations, microbleeds, perfusion abnormalities, cytotoxic lesions of the corpus callosum, and vascular abnormalities. Additionally, we manually quantified white matter lesion loads and the number of perivascular spaces and performed an automated brain volumetric analysis.

RESULTS

In 112 consecutive individuals the mean age was 45 years, female: male = 70:42, mean days at MRI after SARS CoV-2 infection: 228 (sd: 140), and hospitalized: non-hospitalized ratio = 30:82. Using general linear regression models, adjusting for age and gender, the frequency of white matter hyperintensities was not significantly different between subjects who recovered from COVID-19 and matched controls: 9.8 (sd: 17.3) vs. 7.6 (sd: 12.7), p = 0.590. Similarly, the number of enlarged perivascular spaces was not significantly different between the two groups: 62.7 (sd: 43.5) vs. 61.3 (sd: 47.2), p = 0.902. A subgroup analysis between those who were hospitalized in the course of the disease, in which no one required intensive care, and those who remained outpatients, also did not reveal any differences in MRI measures. We did not find evidence for perfusion-/diffusion abnormalities, (micro-)hemorrhages, or cortical abnormalities.

CONCLUSIONS

In the present cohort, there was currently no evidence of COVID-19-related morphological brain changes in individuals who recovered from mild-to-moderate COVID-19.

SARS-CoV-2-induced sensory perturbations: A narrative review of clinical phenotypes, molecular pathologies, and possible interventions

Background

The acute and post-acute sequelae of SARS-CoV-2 infection have been of great clinical interest since the inception of the COVID-19 pandemic. Despite a high prevalence of individuals with persistent symptoms, a wholistic view of the effects of SARS-CoV-2 on special sensory systems is lacking. Considering the significant impact of normal sensory function on quality of life, the goal of this review is to highlight unresolved issues related to SARS-CoV-2-associated insults to the sensory nervous system.

Major findings

In this narrative review, we discuss the epidemiology of SARS-CoV-2-induced sensory perturbations, underlying pathological mechanisms, and possible therapeutic strategies across the olfactory, gustatory, somatosensory, visual, and auditory systems. Examined literature included studies with human biospecimens, human-derived cell lines, and naturally susceptible animal models, which highlighted evidence of persistent functional disruption in all sensory systems. SARS-CoV-2 infection was associated with persistent inflammation in the olfactory epithelium/bulb, somatosensory ganglia, and gustatory systems, long-term transcriptional perturbations in the sensory central nervous system and peripheral nervous system, and detectable degeneration/apoptosis in the gustatory and visual systems. Few studies have proposed evidence-based therapeutic strategies for attenuating specific sensory abnormalities after SARS-CoV-2 infection.

Conclusion

While the olfactory system, and to some extent the visual and somatosensory systems, have been more thoroughly investigated from symptomatology, behavioral and molecular perspectives, there is still an unmet need for the development of therapeutics to treat COVID-induced impairment of these systems. Further, additional attention must be placed on COVID-associated impairment of the gustatory, visual, and auditory systems, which lack detailed mechanistic investigations into their pathogenesis.

Maternal COVID-19 infection associated with offspring neurodevelopmental disorders

Maternal COVID-19 infection increases the incidence of neurodevelopmental disorders (NDDs) in offspring, although the underlying mechanisms have not been elucidated. This study demonstrated that COVID-19 infection during pregnancy disrupted the balance of maternal and fetal immune environments, driving alterations in astrocytes, endothelial cells, and excitatory neurons. A risk score was established using 47 unique genes in the single-cell transcriptome of gestational mothers. The high risk score in CD4 proliferating T cell level served as an indicator for increased risk of offspring NDDs. Summary-based Mendelian randomization and phenome-wide association study analyses were conducted to identify the causal association of the transcriptional changes with the increased risk of offspring NDDs. Additionally, 10 drugs were identified as potential therapeutic candidates. Our findings support a model where the maternal COVID-19 infection changed the levels of CD4 proliferating T cells, leading to the alterations of astrocytes, endothelial cells, and excitatory neurons in offspring, contributing to the increased risk of NDDs in these individuals.

Santos LS, Oliveira MA, Ferreira Felix I, de Sousa PR, Cardoso LG, Muiños PJ, Maia RM, Catto MB, Wittlich EA, Rodrigues-Ribeiro L, Botelho VL, Nunes MCP, Ribeiro ALP, Barbosa e Silva LC, Aras R, Furie KL, Oliveira Filho J. Cognitive impairment in Chagas disease patients in Brazil, 2007-2021: A cross-sectional study

INTRODUCTION

Chagas Disease (CD) is frequently associated with heart failure (HF). Cognitive impairment is reported, but whether it results from CD or is a nonspecific symptom of HF is unknown. We aimed to compare cognitive function of HF patients with or without CD.

METHODS

Multicenter cross-sectional study of HF patients. Investigators blinded to the etiology of HF evaluated global cognition and domains of memory, executive and visuospatial function. Logistic regression tested the association between CD and cognitive impairment (Z-score < -1.5) in each domain adjusted for age, sex, educational level and left ventricular ejection fraction.

RESULTS

We recruited 518 patients, 250 (48.3%) with CD. Cognitive impairment was more common in CD vs. non-CD patients (27.1% vs 13.1%, p < 0.001), mostly in memory (10.4% vs 5.0%, p = 0.022) and visuospatial function (45.2% vs 29.6%, p < 0.001). In the multivariable analysis, CD remained associated with global cognitive impairment (odds ratio 1.90; 95% CI 1.13-3.21, p = 0.016) and visuospatial function impairment (OR 1.56; 95% CI 1.02-2.39, p = 0.039).

DISCUSSION

Chagas disease is associated with cognitive impairment independently of heart failure severity, suggesting other competing mechanisms.

Within person predictors of physical activity and fatigue in long Covid: Findings from an ecological momentary assessment study

OBJECTIVE

We aimed to examine the extent to which current perceived demand for energy and affect predict subsequent physical activity and fatigue in people with Long Covid using an intensive longitudinal method (ecological momentary assessment).

METHODS

Analysis of data from a study of 69 adults with self-reported Long Covid combining 3-hourly self-report data perceived energy, and fatigue, on a smartphone app with continuous physical activity recording. We tested three hypotheses derived from cognitive behavioural and neuroscientific models of fatigue. These related to expectation, current affect and recalled emotional demand. Analysis used linear mixed effects models with fatigue and physical activity as outcomes.

RESULTS

Expectation of energy need for the next 3 h was predictive of physical activity, fatigue and recalled demandingness of the period. (p-values 0.005 to <0.0001). Currently feeling positive was predictive of slightly more subsequent physical activity and less fatigue 3 h later (p = 0.01). Feeling negative was not predictive of physical activity or subsequent fatigue but was predictive of subsequent recall of the period being emotionally demanding. Feeling more anxious was predictive of greater fatigue 3 h later (p = 0.001) but not of reduced physical activity. Absolute effects were small: a one-point increase in anticipated demand (on a scale of 1-7) was associated with an extra 2.2 min of moderate or vigorous physical activity and a one standard deviation increase in anxiety was associated with a one-point increase in fatigue (0-100 scale).

CONCLUSION

In the day-to-day experience of Long Covid expectation and affect have little detectable effect on subsequent physical activity or fatigue.

Long COVID psychiatric sequelae, biochemical markers & tau protein: A 3-year follow-up study

BACKGROUND

A significant percentage of COVID-19 survivors experience long-term neuropsychiatric and physical issues. Baseline biochemical parameters may be linked to these psychiatric sequelae.

AIM

This study aimed to explore the association between baseline biochemical parameters and psychiatric outcomes in COVID-19 survivors three years post-infection.

METHODS

We enrolled 100 COVID-19 survivors (mild and severe) and conducted comprehensive biochemical, endocrine, and psychiatric evaluations using peripheral blood samples and psychological assessments (GAD-7, PHQ-9, MoCA, ISI) at 3 years of follow-up assessment. Tau protein levels were measured at follow-up. Baseline biochemical data were retrieved from medical records, and linear regression analysis was used to identify predictors of psychiatric symptoms.

RESULTS

HbA1c levels were significantly higher in severe cases at baseline (7.08±2.11 vs. 6.22±1.62) and follow-up (6.54±2.01 vs. 5.78±1.07). Severe cases also had elevated p-tau protein levels (99.34±120 vs. 59.7 ± 45.9). Low sodium and potassium at baseline were negatively correlated with anxiety and depression scores, predicting anxiety (8 %) and depressive symptoms (6 %) in mild cases. Low calcium predicted depressive (10 %) and anxiety symptoms (7.5 %) across all cases.

CONCLUSION

COVID-19 survivors with a history of severe infection displayed higher p-tau and HbA1c levels, indicating potential new-onset diabetes and neuronal damage. Electrolyte imbalances, particularly sodium, potassium, and calcium, during acute infection predicted long-term psychiatric symptoms, including depression, anxiety, and somatization.

Assessment of the therapeutic potential of salubrinal for ME/CFS and long-COVID

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic debilitating condition with no cure that shares commonality with long-COVID. This review examines current understanding of long-COVID symptoms, characteristics of the affected population, the connection with ME/CFS, and the potential for salubrinal, an agent known for its influence on cellular stress pathways, to mitigate these disorders It also describes the historical development and mechanism of action of salubrinal, to mitigate endoplasmic reticulum (ER)/cellular stress responses, that could potentially contribute to symptom improvement in both ME/CFS and long-COVID patients. Further research and clinical trials are warranted to advance our understanding of the potential role of salubrinal in improving the quality of life for individuals with long-COVID-related ME/CFS symptoms as well as ME/CFS patients.

Identifying Neurological Autoantibodies in COVID-19: mGluR2 as a Marker of Immune Dysregulation During the Omicron Outbreak in China

Aimed to comprehensively investigate the presence of neural autoantibodies in the cerebrospinal fluid (CSF) and plasma of COVID-19 patients experiencing neurological complications during the Omicron wave in China. Forty consecutive COVID-19 patients with severe neurological complications and 15 disease controls (DC) were enrolled. Neural autoantibodies were detected using both the indirect immunofluorescence assay (IFA) on mouse brain tissue and the Brain-neuronal-antigen microarray. Our results indicated a significantly higher prevalence of neural autoantibodies in the CSF (62.16% vs. 0.0%) and plasma (38.71% vs. 13.33%) of COVID-19 patients compared to DC. Additionally, we identified 12 upregulated intrathecal IgG autoantibodies with differential levels between COVID-19 patients and DC, as well as 51 upregulated IgG autoantibodies in plasma. A high prevalence of anti-mGluR2 antibodies (13.33%) in COVID-19 patients was confirmed by cell-based assays. Western blot analysis showed these antibodies cross-react with both the nucleocapsid (N) and spike (S) proteins of SARS-CoV-2. Notably, strong binding to both the S protein's RBD-Fc and mGluR2 was observed, an association that was substantiated by bioinformatics analysis evaluating the similarity between SARS-CoV-2 proteins and the targeted antigens on the microarray. This finding hints at a potential cross-reactivity between anti-mGluR2 antibodies and the S protein in COVID-19 patients.

Correlation Between COVID-19 Recovery, Executive Function Decline, and Emotional State

Objective

The aim of this study was to determine whether there is a relationship between the time since recovery from coronavirus disease 2019 (COVID-19) and alterations in executive functions. We also evaluate the emotional state of post-COVID-19 patients.

Patients and Methods

We assessed patients between 18 and 50 years old, who had a history of COVID-19 with mild, moderate, or severe illness. We used the Batería Neuropsicológica de Funciones Ejecutivas y Lóbulos Frontales-3 (BANFE-3), Mini-Mental State Examination (MMSE), and Mini-International Neuropsychiatric Interview (MINI), in addition to a semi-structured interview. Spearman's correlation coefficient was used, with a p value <0.05 indicating significance.

Results

We evaluated 67 patients with a mean age of 34.6±9.6 years, most of whom had ≥13 years of schooling (n=55, 82.1%). Among them, 52 (77.6%) reported persistent symptoms after resolution of the condition, with fatigue being the most frequent (n=20, 29.9%). Most participants had an adequate score on the MMSE (n=60, 89.6%). However, 19 (28.4%) showed alterations in the BANFE-3 total score, with mental flexibility as the most affected function (n=25, 37.3%). In participants from the first COVID-19 wave, a negative correlation was observed between the standardized orbitofrontal area scores and the time since recovery from the infection (r=-0.841, p=0.016), suggesting a pattern of deterioration over time, mainly in stimulus inhibition (r=0.880, p=0.021). Regarding emotional state, 45 subjects (67.2%) exhibited emotional alterations, with anxiety symptoms being the most frequent (n=33, 49.3%). Furthermore, individuals with depressive symptoms (n=32, 47.8%) were more likely to experience executive function impairment after COVID-19 (ExpB 0.302, 95% CI 0.098-0.933, p=0.038).

Conclusion

COVID-19 could lead to alterations in executive functions, probably resulting from progressive damage to orbitofrontal area functions, mainly in stimulus inhibition. However, the generalizability of these findings is limited, highlighting the need for further research with robust methodology. Furthermore, depression appears to be an indicator of cognitive impairment in individuals recovering from COVID-19. Therefore, cognitive rehabilitation and psychological support are essential for patients affected by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection.

Long COVID clinical evaluation, research and impact on society: a global expert consensus

BACKGROUND

Long COVID is a complex, heterogeneous syndrome affecting over four hundred million people globally. There are few recommendations, and no formal training exists for medical professionals to assist with clinical evaluation and management of patients with Long COVID. More research into the pathology, cellular, and molecular mechanisms of Long COVID, and treatments is needed. The goal of this work is to disseminate essential information about Long COVID and recommendations about definition, diagnosis, treatment, research and social issues to physicians, researchers, and policy makers to address this escalating global health crisis.

METHODS

A 3-round modified Delphi consensus methodology was distributed internationally to 179 healthcare professionals, researchers, and persons with lived experience of Long COVID in 28 countries. Statements were combined into specific areas: definition, diagnosis, treatment, research, and society.

RESULTS

The survey resulted in 187 comprehensive statements reaching consensus with the strongest areas being diagnosis and clinical assessment, and general research. We establish conditions for diagnosis of different subgroups within the Long COVID umbrella. Clear consensus was reached that the impacts of COVID-19 infection on children should be a research priority, and additionally on the need to determine the effects of Long COVID on societies and economies. The consensus on COVID and Long COVID is that it affects the nervous system and other organs and is not likely to be observed with initial symptoms. We note, biomarkers are critically needed to address these issues.

CONCLUSIONS

This work forms initial guidance to address the spectrum of Long COVID as a disease and reinforces the need for translational research and large-scale treatment trials for treatment protocols.

Impact of corticoid receptors on Alzheimer's disease: a neuroendocrine perspective

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that has been strongly associated with changes in corticoid receptor function and HPA axis dysregulation. This review gives an overview of the complex role of GC and MC receptors in AD, especially how chronic exposure to elevated cortisol contributes to hippocampal degeneration, oxidative stress, and cognitive decline. Specific emphasis lies with cortisol, brought to the attention of neurotoxicity, and relates it to Cushing syndrome with chronic hyper-cortisolism simulating cognitive and structural impairments seen in AD. The impact of HPA axis over-activity in AD pathology is presented, demonstrating its contribution to neuro-inflammation and possible utilization as a biomarker for disease progression. This review further includes pharmacological strategies that modulate corticoid receptors for the reduction of GC-induced neurotoxicity and includes selective GR antagonists and MR agonists. Lifestyle modifications, which modulate HPA activity, are the other non-pharmacological approach to managing AD. Finally, novel drugs and interventions targeting the regulation of GC, anti-inflammatory pathways, as well as attenuation of oxidative stress are emerging strategies. Such a strategy implies that it is possible that receptor activity balance can delay or arrest AD progression.

Longitudinal alterations in morphological brain networks and cognitive function in common-type COVID-19: a 3-month follow-up study

Purpose

To investigate the morphological network and cognitive function of patients with common-type coronavirus disease 2019 (COVID-19) during the acute phase, and examine dynamic changes at 3-month follow-up.

Methods

At baseline, high-resolution T1-weighted imaging was conducted in 35 patients with COVID-19 and 40 healthy controls; 22 patients were reassessed at 3 months. All patients underwent cognitive assessments. Individual morphological brain networks were constructed using grey matter volume similarity, and topological properties were analyzed using graph theory. We used an independent sample t-test at baseline and a paired sample t-test to compare the 3-month follow-up with the acute phase, with false discovery rate corrections (p < 0.05).

Results

In the acute phase, patients exhibited increased subcortical network (SCN) connectivity, and reduced connectivity between the frontoparietal network (FPN) and limbic network (LN), the SCN and dorsal/ventral attention network (DAN/VAN), and the LN and DAN. At follow-up, SCN connectivity remained elevated, with partial recovery in SCN-DAN/VAN and LN-DAN connectivity, and significant FPN-LN improvements. Enhanced global efficiency and reduced path length indicated improved network integration. Additionally, digit symbol substitution test and verbal fluency test scores improved over time.

Conclusion

COVID-19 induces short-term disruptions in cognition-related morphological subnetworks, with subcortical networks compensating for these changes. Significant recovery in FPN-LN connectivity and partial restoration of other networks highlight the plasticity of the brain and suggest that FPN-LN connectivity is a potential neuroimaging marker for cognitive recovery.

Brain organoids: building higher-order complexity and neural circuitry models

Brain organoids are 3D tissue models of the human brain that are derived from pluripotent stem cells (PSCs). They have enabled studies that were previously stymied by the inaccessibility of human brain tissue or the limitations of mouse models of some brain diseases. Despite their enormous potential, brain organoids have had significant limitations that prevented them from recapitulating the full complexity of the human brain and reduced their utility in disease studies. We describe recent progress in addressing these limitations, especially building complex organoids that recapitulate the interactions between multiple brain regions, and reconstructing in vitro the neural circuitry present in in vivo. These major advances in the human brain organoid technology will remarkably facilitate brain disease modeling and neuroscience research.

Functional connectivity of default mode network in non-hospitalized patients with post-COVID cognitive complaints

Introduction

Neurologic impairment is common in patients with acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. While patients with severe COVID have a higher prevalence of neurologic symptoms, as many as one in five patients with mild COVID may also be affected, exhibiting impaired memory as well as other cognitive dysfunctions.

Methods

To characterize the effect of COVID on the brain, the current study recruited a group of adults with post-COVID cognitive complaints but with mild, non-hospitalized cases. They were then evaluated through formal neuropsychological testing and underwent functional MRI of the brain. The participants in our study performed nearly as expected for cognitively intact individuals. Additionally, we characterized the functional connectivity of the default mode network (DMN), which is known for cognitive functions including memory as well as the attention functions involved in normal aging and degenerative diseases.

Results

Along with the retention of functional connectivity in the DMN, our results found the DMN to be associated with neurocognitive performance through region-of-interest and whole-brain analyses. The connectivity between key nodes of the DMN was positively correlated with cognitive scores (r = 0.51, p = 0.02), with higher performers exhibiting higher DMN connectivity.

Discussion

Our findings provide neuroimaging evidence of the functional connectivity of brain networks among individuals experiencing cognitive deficits beyond the recovery of mild COVID. These imaging outcomes indicate expected functional trends in the brain, furthering understanding and guidance of the DMN and neurocognitive deficits in patients recovering from COVID.

Driving under viral impairment: Linking acute SARS-CoV-2 infections to elevated car crash risks

This study explores the linkage between acute SARS-CoV-2 and car crashes across U.S. states, correlating with COVID-19 mitigation strategies, vaccination rates, and Long COVID prevalence. This investigation analyzed aggregate COVID-19 and car crash data spanning 2020-2023, with data collection occurring between March and May 2024. Analysis was done via a Poisson regression model, adjusted for population. Key variables included vaccination status, month-specific effects relating to initial pandemic shutdowns, and Long COVID rates. Results demonstrated a significant association between acute COVID-19 infections and an increase in car crashes, independent of Long COVID status to the tune of an OR of 1.25 [1.23-1.26]. This association was observed despite varying mitigation efforts and vaccination rates across states. The study found no protective effect of vaccination against car crashes, challenging prior assumptions about the benefits of vaccination. Notably, the risk associated with COVID-19 was found to be analogous to driving impairments seen with alcohol consumption at legal limits. Findings suggest significant implications for public health policies, especially in assessing the readiness of individuals recovering from COVID-19 to engage in high-risk activities such as pilots or nuclear plant employees. Further research is necessary to establish causation and explore the exact effects of COVID-19 within the CNS affecting cognition and behavior.

The implications of somatic symptom disorder on the impairment of daily life are greater in post-COVID syndrome than in asthma or COPD - results of a cross-sectional study in a rehabilitation clinic

The aim was to compare the relationship between somatic symptom disorder (SSD), anxiety, depression, clinical symptoms, and daily life impairment (DLI) in post-COVID syndrome (PCS), asthma and chronic obstructive pulmonary disease (COPD). In a cross-sectional study, 371 patients (161 PCS, 121 asthma, 89 COPD) of a pulmonary rehabilitation clinic received the questionnaires PHQ-15 (Patient Health Questionnaire-15) and SSD-12 (Somatic Symptom Disorder-12) to determine SSD, GAD-7 (Generalized Anxiety Disorder-7) to determine anxiety disorder, and PHQ-9 (Patient Health Questionnaire-9) to determine depression. Lung function was estimated using whole-body plethysmography. Predictors for DLI were assessed by regression models and ROC analyses. Association of SSD with DLI was stronger in PCS (odds ratio 13.8; 95% confidence interval 1.7-109.9) than in asthma (8.5; 2.4-30.1), and was not significant in COPD (1.9; 0.5-7.5). In asthma and COPD, strongest predictors were GAD-7 (15.0; 1.9-116.8) and PHQ-9 (8.9; 1.1-71.8), respectively. Diffusion capacity was predictive in COPD (0.947; 0.916-0.979) and asthma (0.967; 0.943-0.993), but not in PCS. To conclude, SSD appears to have greater impact on DLI in PCS than asthma or COPD patients. This should be recognized appropriately during rehabilitation. Furthermore, increased psychological comorbidity should also be considered and adequately treated in asthma and COPD if necessary.

Multimodal MRI analysis of COVID-19 effects on pediatric brain

The COVID-19 pandemic has raised significant concerns regarding its impact on the central nervous system, including the brain. While the effects on adult populations are well documented, less is known about its implications for pediatric populations. This study investigates alterations in cortical metrics and structural covariance networks (SCNs) based on the Local Gyrification Index (LGI) in children with mild COVID-19, alongside changes in non-invasive MRI proxies related to glymphatic function. We enrolled 19 children with COVID-19 and 22 age-comparable healthy controls. High-resolution T1-weighted and diffusion-weighted MRI images were acquired. Cortical metrics, including thickness, surface area, volume, and LGI, were compared using vertex-wise general linear models. SCNs were analyzed for differences in global and nodal metrics, and MRI proxies, including diffusion tensor imaging along the perivascular space and choroid plexus (CP) volume, were also assessed. Our results showed increased cortical area, volume, and LGI in the left superior parietal cortex, as well as increased cortical thickness in the left lateral occipital cortex among children with COVID-19. SCN analysis revealed altered network topology and larger CP volumes in the COVID group, suggesting virus-induced neuroinflammation. These findings provide evidence of potential brain alterations in children following mild COVID-19, emphasizing the need for further investigation into long-term neurodevelopmental outcomes.

Characterising mental wellbeing and associations with subcortical grey matter volume at short intervals in early adolescence

This temporally rich, longitudinal study of early adolescents (N = 88, 277 datasets, 12-13 years) investigated the relationship between bilateral subcortical grey matter volume (GMV) in the hippocampus, amygdala, accumbens-area, caudate, putamen and pallidum with self-reported mental wellbeing at four timepoints, across 12 months. Generalised Estimating Equations (GEE) revealed (1) higher 'total wellbeing' was associated with smaller left caudate and larger left accumbens-area; (2) higher eudaimonic wellbeing was associated with smaller left caudate and larger right caudate; and (3) higher hedonic wellbeing was associated with larger left accumbens-area. Further analyses and plots highlighted different associations between GMV and wellbeing for adolescents who consistently experienced 'moderate-to-flourishing' wellbeing (n = 63, 201 datasets), compared with those who experienced 'languishing' wellbeing at any timepoint (n = 25, 76 datasets). These findings demonstrate several associations between subcortical GMV and measures of wellbeing, at short intervals in early adolescence. Taken together, sub-types of wellbeing appear uniquely associated with specific subcortical regions; and there may be a distinct neurobiological and wellbeing profile for adolescents who experience poorer wellbeing over the course of their first year(s) of secondary school. This study implicates the bilateral caudate and left accumbens-area as important targets for future research into the mental wellbeing of adolescents.

COVID-19 Pandemic-Related Exposures and Cognitive Function in Middle-Aged Women

Importance

The COVID-19 pandemic has been associated with risk factors for cognitive decline, such as bereavement and SARS-CoV-2 infection.

Objective

To examine whether the COVID-19 pandemic and pandemic-related exposures are associated with cognitive function among middle-aged women.

Design, Setting, and Participants

This cohort study analyzed data from the Nurses' Health Study II, an ongoing study of registered nurses in the US. The present study focused on women aged 51 to 76 years who completed 2 to 8 objective cognitive assessments both prior to (October 1, 2014, to February 29, 2020) and during the COVID-19 pandemic (March 1, 2020, to September 30, 2022). Statistical analyses were performed from January 2023 to January 2025.

Exposure

COVID-19 pandemic.

Main Outcomes and Measures

Two standardized (ie, z-scored) composite cognitive scores (psychomotor speed and attention, learning and working memory) and a global score constituted the primary outcomes. Higher scores indicated better cognitive function. Cognitive function was assessed using the Cogstate Brief Battery, a computer-administered cognitive test battery. Participants completed cognitive assessments every 6 to 12 months.

Results

A total of 5191 women (mean [SD] age at first cognitive assessment, 63.0 [4.8] years) completed both prepandemic and during-pandemic measures, contributing 23 678 cognitive assessments. After adjustment for age at cognitive assessment, educational level for both participants and their parents, cognitive test practice effects, and comorbidities (eg, diabetes, hypertension), no difference in cognitive function was observed between assessments taken during vs before the pandemic (psychomotor speed and attention: β = -0.01 SD [95% CI, -0.05 to 0.02 SD]; learning and working memory: β = 0.00 SD [95% CI, -0.03 to 0.03 SD]; global score: β = 0.00 SD [95% CI, -0.03 to 0.02 SD]). Among 4456 participants who responded to the COVID-19 substudy (ie, surveys about pandemic-related events), those with a history of SARS-CoV-2 infection (164 [3.7%]) or post-COVID-19 conditions (PCC; 62 [1.4%]), at a median (IQR) 20.0 (18.5-22.1) months after initial infection, had reduced cognitive function compared with women without infection or PCC; however, these differences did not reach statistical significance, and the wide CIs suggested considerable uncertainty.

Conclusions and Relevance

This cohort study of middle-aged women found that the COVID-19 pandemic and pandemic-related events were not associated with cognitive decline up to 2.5 years after the onset of the pandemic. Future studies are needed to examine the long-term implications of SARS-CoV-2 infection and PCC for cognitive function.

[Association between obesity and Long-Covid: A narrative review]

To analyze the evidence in the scientific literature that relates Long-Covid and obesity, a narrative review of articles published in English and Spanish in Medline and Embase in the last 5years has been carried out. Infection with the SARS-CoV-2 virus causes a systemic inflammatory state increasing nutritional demand that favors sarcopenia in Long-Covid syndrome. It also causes endothelial dysfunction and a prothrombotic state that favors the formation of microthrombi and tissue hypoxia. A healthy and balanced diet is essential to treat obesity in addition to modifying the microbiota in Long-Covid and promoting physical and mental well-being. Obesity is an independent risk factor that increases the need for hospitalization, cardiovascular risk and mortality, as well as susceptibility to Long-Covid. Adipose tissue is a good reservoir of the virus, enhancing the comorbidities associated with obesity (high blood pressure, diabetes mellitus, dyslipidemia or fatty liver). There is insufficient evidence to recommend nutritional supplements to improve Long-Covid symptoms.

Autoimmunity in long COVID

Long COVID (also termed postacute sequelae of SARS-CoV-2, or PASC) affects up to 10% of people recovering from infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Diagnosis is hampered by diffuse symptomatology, lack of biomarkers, incomplete understanding of pathogenesis, and lack of validated treatments. In terms of pathogenesis, hypothesized causes include virus persistence, the legacy of endotheliitis and thrombosis, low-grade tissue-based inflammation and/or scarring, perturbation of the host virome/microbiome, or triggering of autoimmunity. Several studies show preexisting and/or de novo production of autoantibodies after infection with SARS-CoV-2, but the persistence of these antibodies and their role in causing long COVID is debated. Here, we review the mechanisms through which autoimmune responses can arise during and after viral infection, focusing on the evidence for B-cell dysregulation and autoantibody production in acute and long COVID.

Correlation between changes of sleep quality and brain functional connectivity patterns in COVID-19 patients: A three-month longitudinal cohort study

OBJECTIVE

This study aimed to explore variations of brain functional connectivity patterns among post-COVID-19 patients with different outcomes of sleep quality.

METHODS

Post-COVID-19 patients were prospectively enrolled and categorized into improvement or deterioration groups based on changes in sleep quality after a three-month follow-up. Functional MRI and blood samples were collected, while a battery of assessments was administered to evaluate sleep quality, mental status, and cognition. Baseline and follow-up data were compared to identify post-infection alterations. Brain functional networks and graph theory analysis were employed to derive network properties, with subsequent investigation into the correlation between these properties, sleep and psychological assessment scores, and blood test outcomes.

RESULTS

The graph theory analysis revealed a significantly increase in global efficiency (Eglob) and local efficiency (Eloc), and a decrease in λ, in the improvement group. A notable enhancement of frontoparietal network (FPN) were observed. The deterioration group exhibited a significant increase in Eloc and λ, along with a decrease in Eglob. Furthermore, the deterioration group demonstrated a lower level of Eglob at follow-up. With respect to network strength, all networks except FPN showed significantly higher values in the improvement group. Pittsburgh Sleep Quality Index and Self-Rating Anxiety Scale scores differed between two groups.

CONCLUSION

Changes in sleep quality following COVID-19 infection are associated with brain functional connectivity patterns. Decreased Eglob is related to worsened sleep quality. The normalized strength of FPN serves as a key indicator for improved sleep quality, while other networks also play roles in regulating sleep quality.

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.

Altered brain glucose metabolism in COVID-19 disease: an activation likelihood estimation meta-analysis of PET studies

COVID-19 disease, caused by the SARS-CoV-2 virus, has significantly altered modern society and lifestyles. We investigated its impact on brain glucose metabolism by meta-analyzing existing studies that utilized 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scans of the brain. We conducted a systematic search of MEDLINE and EMBASE databases from inception to August 2024 for English-language publications using the keywords "positron emission tomography", and "COVID-19". We included original research articles that reported changes in brain glucose metabolism following COVID-19 disease. ALE values from these studies were aggregated and tested against a null hypothesis that anticipated a random distribution of ALE values, which proved to be significantly higher than chance. We identified nine papers that met our inclusion criteria. Significant increases in brain glucose metabolism were noted in the left anterior cingulate gyrus, right thalamus, and brainstem. In children with COVID-19 disease, decreased glucose metabolism was observed in the right and left cerebellum, left amygdala/hippocampus, left anterior cingulate gyrus, and right amygdala. In adults with COVID-19 disease, decreased metabolism was seen in the right temporal lobe, brainstem (acute phase), left occipital lobe, left and right temporal lobe (chronic phase). In conclusion, COVID-19 disease impacts brain glucose metabolism, typically manifesting as areas of decreased metabolism in 18F-FDG PET scans, though increases are also observed. These changes in metabolism vary with the patient's age and the time elapsed between the diagnosis of COVID-19 disease and the PET scan.

Impact of Severe COVID-19 on Accelerating Dementia Onset: Clinical and Epidemiological Insights

Importance

Severe COVID-19 infection has been associated with neurological complications, but its role in accelerating cognitive decline remains unclear.

Objective

To determine whether individuals hospitalized for severe COVID-19 exhibit a higher incidence of new onset cognitive impairment compared to those hospitalized for other conditions.

Design

A retrospective study emulating a target trial using Mass General Brigham electronic health records (March 2020-August 2024). The causal effect of COVID-19 hospitalization was estimated via cumulative incidence functions accounting for the competing risk of death.

Setting

Multicenter hospital-based study across the Mass General Brigham healthcare system.

Participants

A total of 221613 hospitalized patients met the eligibility criteria, including 6454 (2.0%) admitted due to COVID-19 and 215159 (98.0%) for all other conditions. Patients were excluded if they had less than three months of follow-up (due to censoring, cognitive impairment, or death), were younger than 55 years at baseline, or had no prior visit to Mass General Brigham in the year before baseline.

Main Outcomes and Measures

The primary outcome was new-onset cognitive impairment, identified via ICD codes and dementia medication prescriptions. The primary analysis estimated the hazard ratio for cognitive impairment with COVID-19 hospitalization relative to other hospitalizations, along with the risk difference at 4.5 years estimated via cumulative incidence functions. Inverse propensity score weighting was used to balance covariates (age, sex, comorbidities, hospitalization period).

Results

Among eligible patients (mean [SD] age, 69.55 [9.42] years, 55% female), those hospitalized for COVID-19 were significantly older and had more comorbidities (p < 0.05). COVID-19 hospitalization was associated with a higher risk of developing cognitive impairment (Hazard Ratio: 1.14 [95% CI: 1.02-1.30], P = 0.018). At 4.5 years, the cumulative incidence of cognitive impairment was 12.5% [95% CI: 11.3-13.5] in the COVID-19 group, compared to 11.6% [95% CI: 11.1-12.1] in the non-COVID-19 group.

Conclusions and Relevance

Severe COVID-19 infection was associated with an elevated risk of developing clinically recognized cognitive impairment. Future studies are needed to validate findings in other health care settings. Early screening and intervention for cognitive decline may help optimize long-term outcomes for COVID-19 patients.

Elevated neuroinflammation, autoimmunity, and altered IgG glycosylation profile in the cerebral spinal fluid of severe COVID-19 patients

BACKGROUND AND OBJECTIVES

A spectrum of neurologic complications associated with COVID-19 are well documented. While neuroinflammation in the brain of COVID-19 patients likely contributes to these complications, the mechanisms of neuroinflammation and correlates of neurologic complications remain elusive, especially since the etiologic pathogen of COVID-19, SARS-CoV-2, minimally invades the CNS. This study aimed to evaluate markers of neuroinflammation, IgG glycosylation patterns indicative of pro- or anti-inflammatory state, and prevalence of brain auto-reactive antibodies in the CSF of COVID-19 patients and their relationship to brain neuropathology.

METHODS

We evaluated the CSF of 11 deceased unvaccinated COVID-19 donors and 13 matched non-COVID-19 controls. Markers of neuroinflammation, IgG glycosylation patterns, and brain auto-reactive antibodies were assessed, along with their correlation to brain neuropathology. Statistical analyses were performed to compare groups and assess relationships between variables, using non-parametric tests and bootstrap analysis.

RESULTS

COVID-19 CSF showed higher levels of neopterin and ANNA-1, markers of neuroinflammation and autoimmunity, respectively, and lower IFN response compared to non-COVID-19 donors. In brain regions of high microglial activation, IL4 and RANTES were significantly increased. SARS-CoV-2 was undetectable in the CSF and brain of COVID-19 donors, yet anti-SARS-CoV-2 CSF antibodies were detected. Fucosylated IgG were associated with Spike IgG, CSF protein, and soluble CD14, whereas afucosylated bisecting IgG were inversely correlated with Spike IgG. Sialic acid containing IgG were positively correlated with IL1β and TNFα. These associations were not found in non-COVID-19 donors. Inflammatory agalactosylated fucosylated IgG (G0F) were associated with infiltrating CD4 + T cells in the brains of COVID-19 donors. COVID-19 donor CSF displayed higher levels of auto-reactive antibodies to human brain antigens compared to non-COVID-19 donors and donors with positive autoantibodies showed higher levels of neopterin.

DISCUSSION

These data describe increased neuroinflammation and autoreactive antibody markers in the CSF of COVID-19 donors and suggest that IgG glycosylation and autoimmunity may contribute to COVID-19 pathology, highlighting potential mechanisms underlying the neurologic complications associated with COVID-19.

Brain Structural Abnormalities in Patients with Post-COVID-19 Headache

BACKGROUND/OBJECTIVES

Headache is one of the most common neurological symptoms associated with COVID-19, affecting approximately 25% of patients. While most headaches resolve within weeks, some persist for months, suggesting underlying structural brain changes. This study aimed to identify brain MRI abnormalities associated with chronic headaches in patients with a history of COVID-19 infection.

METHODS

This retrospective study included 30 patients with post-COVID-19 headaches and 30 control patients with no history of COVID-19. Demographic characteristics were analyzed using t-tests and chi-square tests. MRI findings were categorized into six types: cortical atrophy, white matter lesions, vascular lesions, lacunar lesions, vascular encephalopathy, and sinusitis. Differences in MRI findings between the two groups were evaluated using chi-square tests. Secondary outcomes included the analysis of symptoms accompanying headaches, diagnoses following MRI, and treatments applied.

RESULTS

White matter lesions were significantly more frequent in the post-COVID-19 group (50%) compared to controls (20%) (p = 0.015). Conversely, sinusitis was more prevalent in the control group (36.7%) than in the post-COVID-19 group (6.7%) (p = 0.005). Other MRI abnormalities showed no significant differences. Cognitive dysfunction (30%) and dizziness (33.3%) were the most common associated symptoms. The most frequent diagnoses after MRI in the post-COVID-19 group were headaches/migraines (23.3%), post-COVID-19 headache (20%), and vestibular syndrome (13.3%).

CONCLUSIONS

Persistent post-COVID-19 headaches may be linked to structural white matter changes observed in MRI. Further research, ideally including pre-infection imaging data, is needed to determine the causal relationship between these lesions and chronic headache symptoms.

TRIAL REGISTRATION

This study was registered in ClinicalTrials with the trial registration number NCT06825741 on 13 February 2025.

COVID-19 Pandemic Impacts on STRESS, PTSD, and Prefrontal Cortical Thickness in Pre-Pandemic Trauma Survivors

Background/Objectives: The COVID-19 pandemic increased psychiatric symptoms in patients with pre-pandemic mental health conditions. However, the effects of pandemic on the brain, stress, and mental illness remain largely conjectural. Our objective was to examine how the pandemic affected prefrontal cortical thicknesses (CTs), stress, and PTSD symptoms in people with pre-pandemic trauma histories. Methods: Fifty-one survivors from a pre-pandemic trauma study who had completed a pre-pandemic PTSD Checklist-5 (PCL) to assess PTSD symptoms and a sMRI scan to measure prefrontal CTs were re-recruited after the pandemic. They subsequently completed the COVID Stress Scale (CSS) to assess stress, the Clinician Administered PTSD Scale-5 (CAPS) to diagnose PTSD, and a second sMRI scan. COVID-19 infection was self-reported. Associations between stress and symptom assessments and post-pandemic CTs, differences in CTs in PTSD vs. non-PTSD groups, and changes in pre- to post-pandemic CTs were examined. Results: Pre-pandemic PCL scores were positively associated with CSS scores which, in turn, were higher in the PTSD group. Thicker IFG-opercularis CTs were associated with COVID-19 infection. Post-pandemic rMFG and IFG-orbitalis CTs were positively associated with CAPS scores. rACC CTs were negatively associated with CSS scores. Pre- to post-pandemic rMFG and frontal pole CTs thickened in the PTSD group but thinned in the non-PTSD group, whereas rACC CTs thinned in the PTSD group but thickened in the non-PTSD group. Conclusions: These findings provide novel evidence that the COVID-19 pandemic had diverse effects involving prefrontal cortex structure, stress, and PTSD symptoms in subjects with pre-pandemic trauma history and suggest that treatments are needed to counter these diverse effects.

Neurocognitive and emotional long-term effects of COVID-19 infections in children and adolescents: results from a clinical survey in Bavaria, Germany

BACKGROUND

While children and adolescents typically experience mild symptoms during the acute phase of the COVID-19 infection, some may develop severe post-infectious symptoms. In our study Post-COVID Kids Bavaria we integrated somatic and psychiatric aspects of the post-COVID syndrome to provide a holistic description of symptoms, provide early treatment, and detect possible risk factors associated with post-infectious neurocognitive and emotional impairments.

METHODS

We conducted an observational study involving 85 pediatric patients aged 12-17 years (M = 12.48, 61.2% female) who had confirmed COVID-19 infections and were experiencing persistent symptoms for at least 4 weeks. Our neuropsychological assessment comprised infection-specific patient interviews, psychopathological examinations, emotional well-being and behavioral difficulty questionnaires, and (computerized) tests assessing concentration, attention, and memory skills. Additionally, patients underwent neurologic, pneumologic, gastrointestinal, and cardiologic assessments.

RESULTS

Overall, the majority of patients reported experiencing elevated levels of fatigue (82.4%), loss of motivation (72.9%), concentration and attention deficits (71.8%), a worsened mood (53%), and a higher level of anxiety (31.8%). The most common diagnosis was the post-COVID adjustment disorder (ICD-10 F43.2, U09.9!; 38.8%) followed by the post-COVID attention deficit disorder (ICD-10 F98.80, U09.9!; 23.5%). Neuropsychiatric evaluation primarily identified deficits in sustained attention. There was a significant association between somatic and psychiatric post-COVID diagnoses. Patients with allergies exhibited a higher risk of developing a post-COVID adjustment disorder. For the post-COVID attention deficit disorder, age, sex, obesity, pre-existing psychiatric diagnosis, and the virus variant were relevant factors.

CONCLUSIONS

Our findings indicate a diverse array of neuropsychiatric symptoms associated with the post-COVID syndrome, emphasizing the interconnectedness between somatic and neuropsychiatric diagnoses. To optimize treatment, comprehensive strategies involving both somatic and psychiatric professionals are crucial for addressing the syndrome's complexity and managing symptoms effectively.

STUDY REGISTRATION

The study Post-COVID Kids Bavaria was registered with the German Clinical Trials Register (DRKS), funded by the Bavarian State Ministry of Health, Care and Prevention and approved by the Ethics Committee of the University of Regensburg on the 29th of November, 2021 (Reference: 21-2691-101).

Role of toll-like receptors in post-COVID-19 associated neurodegenerative disorders?

In the intricate realm of interactions between hosts and pathogens, Toll-like receptors (TLRs), which play a crucial role in the innate immune response, possess the ability to identify specific molecular signatures. This includes components originating from pathogens such as SARS-CoV-2, as well as the resulting damage-associated molecular patterns (DAMPs), the endogenous molecules released after cellular damage. A developing perspective suggests that TLRs play a central role in neuroinflammation, a fundamental factor in neurodegenerative conditions like Alzheimer's and Parkinson's disease (PD). This comprehensive review consolidates current research investigating the potential interplay between TLRs, their signaling mechanisms, and the processes of neurodegeneration following SARS-CoV-2 infection with an aim to elucidate the involvement of TLRs in the long-term neurological complications of COVID-19 and explore the potential of targeting TLRs as a means of implementing intervention strategies for the prevention or treatment of COVID-19-associated long-term brain outcomes.

Serotonergic psychedelics as potential therapeutics for post-COVID-19 syndrome (or Long COVID): A comprehensive review

RATIONALE

In our ongoing battle against the coronavirus 2019 (COVID-19) pandemic, a major challenge is the enduring symptoms that continue after acute infection. Also known as Long COVID, post-COVID-19 syndrome (PCS) often comes with debilitating symptoms like fatigue, disordered sleep, olfactory dysfunction, and cognitive issues ("brain fog"). Currently, there are no approved treatments for PCS. Recent research has uncovered that the severity of PCS is inversely linked to circulating serotonin levels, highlighting the potential of serotonin-modulating therapeutics for PCS. Therefore, we propose that serotonergic psychedelics, acting mainly via the 5-HT2A serotonin receptor, hold promise for treating PCS.

OBJECTIVES

Our review aims to elucidate potential mechanisms by which serotonergic psychedelics may alleviate the symptoms of PCS.

RESULTS

Potential mechanisms through which serotonergic psychedelics may alleviate PCS symptoms are discussed, with emphasis on their effects on inflammation, neuroplasticity, and gastrointestinal function. Additionally, this review explores the potential of serotonergic psychedelics in mitigating endothelial dysfunction, a pivotal aspect of PCS pathophysiology implicated in organ dysfunction. This review also examines the potential role of serotonergic psychedelics in alleviating specific PCS symptoms, which include olfactory dysfunction, cognitive impairment, sleep disturbances, and mental health challenges.

CONCLUSIONS

Emerging evidence suggests that serotonergic psychedelics may alleviate PCS symptoms. However, further high-quality research is needed to thoroughly assess their safety and efficacy in treating patients with PCS.

COVID-19 related complications

The COVID-19 pandemic has significantly impacted global healthcare systems, revealed vulnerabilities and prompted a re-evaluation of medical practices. Acute complications from the virus, including cardiovascular and neurological issues, have underscored the necessity for timely medical interventions. Advances in diagnostic methods and personalized therapies have been pivotal in mitigating severe outcomes. Additionally, Long COVID has emerged as a complex challenge, affecting various body systems and leading to respiratory, cardiovascular, neurological, psychological, and musculoskeletal problems. This broad spectrum of complications highlights the importance of multidisciplinary management approaches that prioritize therapy, rehabilitation, and patient-centered care. Vulnerable populations such as paediatric patients, pregnant women, and immunocompromised individuals face unique risks and complications, necessitating continuous monitoring and tailored management strategies to reduce morbidity and mortality associated with COVID-19.

Neurobiology of COVID-19-Associated Psychosis/Schizophrenia: Implication of Epidermal Growth Factor Receptor Signaling

COVID-19 exhibits not only respiratory symptoms but also neurological/psychiatric symptoms rarely including delirium/psychosis. Pathological studies on COVID-19 provide evidence that the cytokine storm, in particular (epidermal growth factor) EGF receptor (EGFR, ErbB1, Her1) activation, plays a central role in the progression of viral replication and lung fibrosis. Of note, SARS-CoV-2 virus (specifically, S1 spike domain) mimics EGF and directly transactivates EGFR, preceding the inflammatory process. In agreement, the anticancer drugs targeting EGFR such as Nimotuzumab and tyrosine kinase inhibitors are markedly effective on COVID-19. However, these data might raise a provisional caution regarding implication of psychiatric disorder such as schizophrenia. The author's group has been investigating the etiologic and neuropathologic associations of EGFR signaling with schizophrenia. There are significant molecular associations between schizophrenia and EGFR ligand levels in blood as well as in the brain. In addition, perinatal challenges of EGFR ligands and intraventricular administration of EGF to rodents and monkeys both resulted in severe behavioral and/or electroencephalographic endophenotypes relevant to this disorder. These animal models also display postpubertal abnormality in soliloquy-like self-vocalization as well as in intercortical functional connectivity. Here, we discuss neuropsychiatric implication of coronavirus infection and its interaction with the EGFR system, by searching related literatures in PubMed database as of the end of 2023.

Cognitive Sequelae of COVID-19: Mechanistic Insights and Therapeutic Approaches

BACKGROUND

The COVID-19 pandemic has left an indelible mark on the world, with mounting evidence suggesting that it not only posed acute challenges to global healthcare systems but has also unveiled a complex array of long-term consequences, particularly cognitive impairment (CI). As the persistence of post-COVID-19 neurological syndrome could evolve into the next public health crisis, it is imperative to gain a better understanding of the intricate pathophysiology of CI in COVID-19 patients and viable treatment strategies.

METHODS

This comprehensive review explores the pathophysiology and management of cognitive impairment across the phases of COVID-19, from acute infection to Long-COVID, by synthesizing findings from clinical, preclinical, and mechanistic studies to identify key contributors to CI, as well as current therapeutic approaches.

RESULTS

Key mechanisms contributing to CI include persistent neuroinflammation, cerebrovascular complications, direct neuronal injury, activation of the kynurenine pathway, and psychological distress. Both pharmacological interventions, such as anti-inflammatory therapies and agents targeting neuroinflammatory pathways, and non-pharmacological strategies, including cognitive rehabilitation, show promise in addressing these challenges. Although much of the current evidence is derived from preclinical and animal studies, these findings provide foundational insights into potential treatment approaches.

CONCLUSION

By synthesizing current knowledge, this review highlights the importance of addressing COVID-19-related cognitive impairment and offers actionable insights for mitigation and recovery as the global community continues to grapple with the pandemic's long-term impact.

Risk factors for fatigue severity in the post-COVID-19 condition: A prospective controlled cohort study of nonhospitalised adolescents and young adults

Long COVID is a global health concern, leading to persistent symptoms and disability long after the acute SARS-CoV-2 infection in most age groups. The condition can manifest even following mild COVID-19, and in young people, it may have serious adverse consequences for educational attainment and transition to adulthood. Fatigue is the most prevalent symptom, but the underlying mechanisms remain poorly understood. In this prospective study of 404 SARS-CoV-2-positive and 105 SARS-CoV-2 negative, non-hospitalised youth (ages 12-25, female 62%), we investigated which factors in the early convalescent stage (<28 days since test) were associated with the severity of persistent fatigue at 6 months after infection. Participants completed questionnaires regarding clinical symptoms, social factors and psychological traits, and were subject to clinical and functional testing and biomarker analyses. Variables with significant (p < 0.2) associations to the outcome in simple linear regression were chosen for multivariable modelling, together with potential confounders. In the final multivariable model, SARS-CoV-2-positivity was a minor risk factor for fatigue severity at six months. Baseline severity of symptoms was the main risk factor and correlated with psychosocial factors such as loneliness and neuroticism, rather than biomarkers. Our results suggest that factors not related to infection are major risk factors for persistent fatigue in this age group.