Frequent neurocognitive deficits after recovery from mild COVID-19

Fatigue Symptoms Associated With COVID-19 in Convalescent or Recovered COVID-19 Patients; a Systematic Review and Meta-Analysis

BACKGROUND

The prevalence and prognosis of post-acute stage SARS-CoV-2 infection fatigue symptoms remain largely unknown.

AIMS

We performed a systematic review to evaluate the prevalence of fatigue in post-recovery from SARS-CoV-2 infection.

METHOD

Medline, Embase, PsycINFO, CINAHL, Web of Science, Scopus, trial registries, Cochrane Central Register of Controlled Trials, and Google Scholar were searched for studies on fatigue in samples that recovered from polymerase chain reaction (PCR) diagnosed COVID-19. English, French, and Spanish studies were included. Meta-analyses were conducted separately for each recruitment setting.

RESULTS

We identified 41 studies with 9,362 patients that recovered from COVID-19. Post-COVID-19 patients self-report of fatigue was higher compared to healthy controls (risk ratio (RR) = 3.688, 95%CI [2.502, 5.436], p < .001). Over 50% of patients discharged from inpatient care reported symptoms of fatigue during the first (event rate [ER] = 0.517, 95%CI [0.278, 0.749]) and second month following recovery (ER = 0.527, 95%CI [0.337, 0.709]). Ten percent of the community patients reported fatigue in the first-month post-recovery. Patient setting moderated the association between COVID-19 recovery and fatigue symptoms (R2 = 0.11, p < .001). Female patients recovering from COVID-19 had a greater self-report of fatigue (odds ratio [OR] = 1.782, 95%CI [1.531, 2.870]). Patients recruited through social media had fatigue above 90% across multiple time points. Fatigue was highest in studies from Europe.

CONCLUSION

Fatigue is a symptom associated with functional challenges which could have economic and social impacts. Developing long-term planning for fatigue management amongst patients beyond the acute stages of SARS-CoV-2 infection is essential to optimizing patient care and public health outcomes. Further studies should examine the impact of sociodemographic, pandemic-related restrictions and pre-existing conditions on fatigue.

Fatigue and cognitive impairment in Post-COVID-19 Syndrome: A systematic review and meta-analysis

IMPORTANCE

COVID-19 is associated with clinically significant symptoms despite resolution of the acute infection (i.e., post-COVID-19 syndrome). Fatigue and cognitive impairment are amongst the most common and debilitating symptoms of post-COVID-19 syndrome.

OBJECTIVE

To quantify the proportion of individuals experiencing fatigue and cognitive impairment 12 or more weeks following COVID-19 diagnosis, and to characterize the inflammatory correlates and functional consequences of post-COVID-19 syndrome.

DATA SOURCES

Systematic searches were conducted without language restrictions from database inception to June 8, 2021 on PubMed/MEDLINE, The Cochrane Library, PsycInfo, Embase, Web of Science, Google/Google Scholar, and select reference lists.

STUDY SELECTION

Primary research articles which evaluated individuals at least 12 weeks after confirmed COVID-19 diagnosis and specifically reported on fatigue, cognitive impairment, inflammatory parameters, and/or functional outcomes were selected.

DATA EXTRACTION & SYNTHESIS

Two reviewers independently extracted published summary data and assessed methodological quality and risk of bias. A meta-analysis of proportions was conducted to pool Freeman-Tukey double arcsine transformed proportions using the random-effects restricted maximum-likelihood model.

MAIN OUTCOMES & MEASURES

The co-primary outcomes were the proportions of individuals reporting fatigue and cognitive impairment, respectively, 12 or more weeks following COVID-19 infection. The secondary outcomes were inflammatory correlates and functional consequences associated with post-COVID-19 syndrome.

RESULTS

The literature search yielded 10,979 studies, and 81 studies were selected for inclusion. The fatigue meta-analysis comprised 68 studies, the cognitive impairment meta-analysis comprised 43 studies, and 48 studies were included in the narrative synthesis. Meta-analysis revealed that the proportion of individuals experiencing fatigue 12 or more weeks following COVID-19 diagnosis was 0.32 (95% CI, 0.27, 0.37; p < 0.001; n = 25,268; I2 = 99.1%). The proportion of individuals exhibiting cognitive impairment was 0.22 (95% CI, 0.17, 0.28; p < 0.001; n = 13,232; I2 = 98.0). Moreover, narrative synthesis revealed elevations in proinflammatory markers and considerable functional impairment in a subset of individuals.

CONCLUSIONS & RELEVANCE

A significant proportion of individuals experience persistent fatigue and/or cognitive impairment following resolution of acute COVID-19. The frequency and debilitating nature of the foregoing symptoms provides the impetus to characterize the underlying neurobiological substrates and how to best treat these phenomena.

STUDY REGISTRATION

PROSPERO (CRD42021256965).

Cognitive Dysfunction, Psychiatric Distress, and Functional Decline After COVID-19

BACKGROUND

There is a limited understanding of the cognitive and psychiatric sequelae of COVID-19 during the post-acute phase, particularly among racially and ethnically diverse patients.

OBJECTIVE

We sought to prospectively characterize cognition, mental health symptoms, and functioning approximately four months after an initial diagnosis of COVID-19 in a racially and ethnically diverse group of patients.

METHODS

Approximately four months after COVID-19 diagnosis, patients in the Johns Hopkins Post-Acute COVID-19 Team Pulmonary Clinic underwent a clinical telephone-based assessment of cognition, depression, anxiety, trauma, and function.

RESULTS

Most Johns Hopkins Post-Acute COVID-19 Team patients assessed were women (59%) and members of racial/ethnic minority groups (65%). Of 82 patients, 67% demonstrated ≥1 abnormally low cognitive score. Patients requiring intensive care unit (ICU) stays displayed greater breadth and severity of impairment than those requiring less intensive treatment. Processing speed (35%), verbal fluency (26%-32%), learning (27%), and memory (27%) were most commonly impaired. Among all patients, 35% had moderate symptoms of depression (23%), anxiety (15%), or functional decline (15%); 25% of ICU patients reported trauma-related distress. Neuropsychiatric symptoms and functional decline did not differ by post-ICU versus non-ICU status and were unrelated to global cognitive composite scores.

CONCLUSIONS

At approximately 4 months after acute illness, cognitive dysfunction, emotional distress, and functional decline were common among a diverse clinical sample of COVID-19 survivors varying in acute illness severity. Patients requiring ICU stays demonstrated greater breadth and severity of cognitive impairment than those requiring less intensive treatment. Findings help extend our understanding of the nature, severity, and potential duration of neuropsychiatric morbidity after COVID-19 and point to the need for longitudinal assessment of cognitive and mental health outcomes among COVID-19 survivors of different demographic backgrounds and illness characteristics.

Cognitive Impairment in Non-critical, Mild-to-Moderate COVID-19 Survivors

IMPORTANCE

Previous studies of post-acute COVID-19 syndrome have focused on critical cases with severe disease. However, most cases are mild to moderate in disease severity.

OBJECTIVE

We aimed to examine cognitive outcomes in cases of non-critical, mild-to-moderate COVID-19. Design, Setting, and Participants: In this cross-sectional study, we enrolled 72 adults aged 22 to 65 years in Central Texas who had non-critical, mild-to-moderate COVID-19 infection between 13 January 2021 and 20 April 2021.

MAIN OUTCOMES AND MEASURES

We remotely administered cognitive-behavioral testing to determine the frequency of cognitive impairment and examine demographic, clinical, and psychosocial contributors to impairment.

RESULTS

The frequency of objective cognitive impairment was 40%. The largest number of participants (24%) showed impairment on a measure of executive functioning. Attention and processing speed was more impaired in males (OR = 1.5, 95%CI = 0.23-2.9). Males endorsed lower adherence to social distancing guidelines (U = 590, p = 0.01), which was in turn associated with cognitive impairment across participants (r = -0.30, p = 0.01). Younger age was correlated with impairment (r = -0.26, p = 0.03) but was also associated with racial/ethnic minority status (r = -0.31, p = 0.01) and increased psychological symptoms (p < 0.04). Greater number of COVID-19 symptoms was correlated with lower subjective cognitive function (r = -0.38, p = 0.001) as well as psychosocial function (r > 0.24, p < 0.05). Moderate COVID-19 severity was associated with attention/processing speed impairment (r = 0.27, p = 0.03), increased pain (r = 0.31, p = 0.01), and higher number of COVID-19 symptoms (r = 0.32, p = 0.01).

CONCLUSION AND RELEVANCE

Mild or moderate COVID-19 infection may be associated with cognitive impairments, especially in the domain of executive functioning. A subgroup of younger individuals may be more vulnerable to cognitive and psychosocial effects of COVID-19.

HIGHLIGHTS

Question: How frequent is cognitive impairment among non-critical, mild-to-moderate COVID-19 survivors?

FINDINGS

In this cross-sectional study of 72 adults, 40% demonstrated cognitive impairment, particularly in executive function.

MEANING

Neurologic sequelae, such as cognitive impairment, may be common following COVID-19 infection.

Molecular imaging findings on acute and long-term effects of COVID-19 on the brain: A systematic review

Molecular imaging techniques such as PET and SPECT have been used to shed light on how coronavirus disease 2019 (COVID-19) affects the human brain. We provide a systematic review that summarizes the current literature according to 5 predominant topics. First, a few case reports have suggested reversible cortical and subcortical metabolic alterations in rare cases with concomitant para- or postinfectious encephalitis. Second, imaging findings in single patients with the first manifestations of parkinsonism in the context of COVID-19 resemble those in neurodegenerative parkinsonism (loss of nigrostriatal integrity), but scarceness of data and a lack of follow-up preclude further etiologic conclusions (e.g., unmasking/hastening of neurodegeneration vs. infectious or parainfectious parkinsonism). Third, several case reports and a few systematic studies have addressed focal symptoms and lesions, most notably hyposmia. The results have been variable, although some studies found regional hypometabolism of regions related to olfaction (e.g., orbitofrontal and mesiotemporal). Fourth, a case series and systematic studies in inpatients with COVID-19–related encephalopathy (acute to subacute stage) consistently found a frontoparietal-dominant neocortical dysfunction (on imaging and clinically) that proved to be grossly reversible in most cases until 6 mo. Fifth, studies on post–COVID-19 syndrome have provided controversial results. In patients with a high level of self-reported complaints (e.g., fatigue, memory impairment, hyposmia, and dyspnea), some authors found extensive areas of limbic and subcortical hypometabolism, whereas others found no metabolic alterations on PET and only minor cognitive impairments (if any) on neuropsychologic assessment. Furthermore, we provide a critical appraisal of studies with regard to frequent methodologic issues and current pathophysiologic concepts. Finally, we devised possible applications of PET and SPECT in the clinical work-up of diagnostic questions related to COVID-19.

COVID-19 and the Peripheral Nervous System. A 2-year review from the pandemic to the vaccine era

Increasing literature has linked COVID‐19 to peripheral nervous system (PNS) diseases. In addition, as we move from the pandemic to the vaccination era, literature interest is shifting towards the potential association between COVID‐19 vaccines and PNS manifestations. We reviewed published literature on COVID‐19, COVID‐19 vaccines and PNS manifestations between 1 January 2020 and 1 December 2021. For Guillain‐Barré syndrome (GBS), isolated cranial neuropathy (ICN) and myositis associated with COVID‐19, the demographic, clinical, laboratory, electrophysiological and imaging features were included in a narrative synthesis. We identified 169 studies on COVID‐19‐associated complications, including 63 papers (92 patients) on GBS, 29 papers (37 patients) on ICN and 11 papers (18 patients) on myositis. Additional clinical phenotypes included chronic inflammatory demyelinating polyneuropathy, vasculitic neuropathies, neuralgic amyotrophy, critical care‐related complications, and myasthenia gravis. PNS complications secondary to COVID‐19 vaccines have been reported during randomized clinical trials, in real‐world case reports, and during large‐scale surveillance programs. These mainly include cases of GBS, Bell's palsy, and cases of neuralgic amyotrophy. Based on our extensive review of the literature, any conclusion about a pathophysiological correlation between COVID‐19 and PNS disorders remains premature, and solely supported by their temporal association, while epidemiological and pathological data are insufficient. The occurrence of PNS complications after COVID‐19 vaccines seems limited to a possible higher risk of facial nerve palsy and GBS, to a degree that widespread access to the ongoing vaccination campaign should not be discouraged, while awaiting for more definitive data from large‐scale surveillance studies.

Case Report: Neurodegenerative Diseases After Severe Acute Respiratory Syndrome Coronavirus 2 Infection, a Report of Three Cases: Creutzfeldt–Jakob Disease, Rapidly Progressive Alzheimer's Disease, and Frontotemporal Dementia

The relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and neurodegenerative diseases is yet to be fully clarified. Rapid worsening and even new-onset cases of those disorders have been reported in association with coronavirus disease 2019 (COVID-19). We describe three cases of neurodegenerative diseases in patients with SARS-CoV-2: a case of Creutzfeldt–Jakob disease during the COVID-19 acute phase, to our knowledge, is the second one described in the literature; a rapidly progressive Alzheimer's Disease; and a patient with frontotemporal dementia, and a quick decline of both cognitive and behavioral domains. This report suggests an association between SARS-CoV-2 infection and a higher probability of developing or accelerating neurodegenerative chronic neurologic conditions. We reinforce the need for a close cognitive follow-up in the aftermath of Sars-Cov2 infection.

Chronic fatigue syndrome and cognitive deficit are associated with acute-phase neuropsychiatric manifestations of COVID-19: A 9-month follow-up study

The preva lence of long-COVID symptoms is rising but it is not still possible to predict which patients will present them, and which types of symptoms they will present. We followed up 95 patients with confirmed COVID-19 for 9 months to identify and characterize long-COVID symptoms. Easy fatigability was the most common symptom (51.04%), followed by anxiety (38.54%), dyspnea (38.54%), and new-onset headache (38.54%). There was no association between COVID-19 severity in the acute phase and the number of long-COVID symptoms (F(1,93) = 0.75, p = 0.45), and cognitive function (MoCA) scores (F(1,90) = 0.073, p = 0.787) at follow-up. Being female (F(1,92) =  − 2.27, p = 0.02), having a higher number of symptoms (F(1,93) = 2.76, p = 0.0068), and experiencing constitutional neuropsychiatric symptoms (F(1,93) = 2.529, p = 0.01) in the acute phase were associated with having chronic fatigue syndrome at follow-up. Moreover, constitutional neuropsychiatric symptoms in the acute phase were associated with a lower MoCA score (F(1,93) = 10.84, p = 0.001) at follow-up. Specific clinical presentations such as constitutional neuropsychiatric symptoms in the acute phase might be predictors of debilitating long-COVID symptoms such as chronic fatigue syndrome and cognitive deficits.

Significant cognitive impairment likely associated with COVID-19 infection with relatively nonsevere symptoms

COVID-19 infection may involve the nervous system and has been associated with a number of neuropsychiatric complications, including impairment of cognition and dementia. Such complications are more likely to occur in (but are not limited to) patients with severe COVID-19 infections and those with concomitant risk factors. In this case report, the authors describe a normally functioning 51-year-old woman who developed cognitive impairment of a degree that rendered her unable to care for herself most likely related to a relatively nonsevere infection with COVID-19 about 2 months earlier. A detailed report of her deficits of different areas of cognitive functioning is provided. This report aims to make clinicians more aware of the potential for cognitive impairment in patients who have suffered from COVID-19, including those with infections that were not severe.

Rapid vigilance and episodic memory decrements in COVID-19 survivors

Recent studies indicate that COVID-19 infection can lead to serious neurological consequences in a small percentage of individuals. However, in the months following acute illness, many more suffer from fatigue, low motivation, disturbed mood, poor sleep and cognitive symptoms, colloquially referred to as 'brain fog'. But what about individuals who had asymptomatic to moderate COVID-19 and reported no concerns after recovering from COVID-19? Here, we examined a wide range of cognitive functions critical for daily life (including sustained attention, memory, motor control, planning, semantic reasoning, mental rotation and spatial-visual attention) in people who had previously suffered from COVID-19 but were not significantly different from a control group on self-reported fatigue, forgetfulness, sleep abnormality, motivation, depression, anxiety and personality profile. Reassuringly, COVID-19 survivors performed well in most abilities tested, including working memory, executive function, planning and mental rotation. However, they displayed significantly worse episodic memory (up to 6 months post-infection) and greater decline in vigilance with time on task (for up to 9 months). Overall, the results show that specific chronic cognitive changes following COVID-19 are evident on objective testing even amongst those who do not report a greater symptom burden. Importantly, in the sample tested here, these were not significantly different from normal after 6-9 months, demonstrating evidence of recovery over time.

Risk factors and abnormal cerebrospinal fluid associate with cognitive symptoms after mild COVID-19

Cognitive post-acute sequelae of SARS-CoV-2 (PASC) can occur after mild COVID-19. Detailed clinical characterizations may inform pathogenesis. We evaluated 22 adults reporting cognitive PASC and 10 not reporting cognitive symptoms after mild SARS-CoV-2 infection through structured interviews, neuropsychological testing, and optional cerebrospinal fluid (CSF) evaluations (53%). Delayed onset of cognitive PASC occurred in 43% and associated with younger age. Cognitive PASC participants had a higher number of pre-existing cognitive risk factors (2.5 vs. 0; p = 0.03) and higher proportion with abnormal CSF findings (77% vs. 0%; p = 0.01) versus controls. Cognitive risk factors and immunologic mechanisms may contribute to cognitive PASC pathogenesis.

Cognitive impairment in health care workers recovering from COVID-19 infection: a cross-sectional comparative study

Background

The COVID-19 outbreak has infected people all over the world where many clinics are being constructed to diagnose and treat lingering symptoms or long COVID. Neurological and long-term cognitive consequences are very worrisome. Many of COVID-19’s neurological symptoms are likely the result of the body’s extensive immunological response to infection rather than the virus attacking the brain or nervous system directly. At the same time, the extent and type of COVID-19’s cognitive consequences are unknown. The goal of this study was to assess the cognitive functions of healthcare workers 2 weeks to 3 months after COVID-19 infection. Ninety-two healthcare workers participated in the study; 32 were post-COVID-19 cases, and 60 were healthy people (the comparison group). The cognitive functions of the participants were assessed using the Addenbrooke’s Cognitive Examination (ACE-III) test, which evaluated attention, memory, language, and visuospatial skills, as well as the Arabic version of the Patient Health Questionnaire Anxiety GAD-7 and Depression Assessments PHQ-9.

Results

The study revealed that there was a highly significant direct correlation between post-infection with COVID-19 and scores of both anxiety and depression and an inverse correlation in the case of attention and memory. On the other hand, there is no statistical effect of post-COVID-19 on verbal fluency, language scores, and visio-spatial abilities. Using multiple linear regression, there was a powerful significant decrease effect of post-COVID-19 on memory scores controlling both anxiety and depression degrees (Beta = − 0.745, P < 0.001). Also, there was a strong negative correlation post-COVID-19 on attention scores controlling both anxiety and depression degrees (Beta = − 0.745, P < 0.001).

Conclusions

The study showed a strong negative effect of post-COVID-19 on the attention and memory of patients. Furthermore, both anxiety and depression scores increased significantly among the post-COVID-19 patients.

OUP accepted manuscript

Lack of awareness of cognitive impairment (i.e. anosognosia) could be a key factor for distinguishing between neuropsychological post-COVID-19 condition phenotypes. In this context, the 2-fold aim of the present study was to (i) establish the prevalence of anosognosia for memory impairment, according to the severity of the infection in the acute phase and (ii) determine whether anosognosic patients with post-COVID syndrome have a different cognitive and psychiatric profile from nosognosic patients, with associated differences in brain functional connectivity. A battery of neuropsychological, psychiatric, olfactory, dyspnoea, fatigue and quality-of-life tests was administered 227.07 ± 42.69 days post-SARS-CoV-2 infection to 102 patients (mean age: 56.35 years, 65 men, no history of neurological, psychiatric, neuro-oncological or neurodevelopmental disorder prior to infection) who had experienced either a mild (not hospitalized; n = 45), moderate (conventional hospitalization; n = 34) or severe (hospitalization with intensive care unit stay and mechanical ventilation; n = 23) presentation in the acute phase. Patients were first divided into two groups according to the presence or absence of anosognosia for memory deficits (26 anosognosic patients and 76 nosognosic patients). Of these, 49 patients underwent an MRI. Structural images were visually analysed, and statistical intergroup analyses were then performed on behavioural and functional connectivity measures. Only 15.6% of patients who presented mild disease displayed anosognosia for memory dysfunction, compared with 32.4% of patients with moderate presentation and 34.8% of patients with severe disease. Compared with nosognosic patients, those with anosognosia for memory dysfunction performed significantly more poorly on objective cognitive and olfactory measures. By contrast, they gave significantly more positive subjective assessments of their quality of life, psychiatric status and fatigue. Interestingly, the proportion of patients exhibiting a lack of consciousness of olfactory deficits was significantly higher in the anosognosic group. Functional connectivity analyses revealed a significant decrease in connectivity, in the anosognosic group as compared with the nosognosic group, within and between the following networks: the left default mode, the bilateral somatosensory motor, the right executive control, the right salient ventral attention and the bilateral dorsal attention networks, as well as the right Lobules IV and V of the cerebellum. Lack of awareness of cognitive disorders and, to a broader extent, impairment of the self-monitoring brain system, may be a key factor for distinguishing between the clinical phenotypes of post-COVID syndrome with neuropsychological deficits.

The blood-brain barrier is dysregulated in COVID-19 and serves as a CNS entry route for SARS-CoV-2

Neurological complications are common in COVID-19. Although SARS-CoV-2 has been detected in patients’ brain tissues, its entry routes and resulting consequences are not well understood. Here, we show a pronounced upregulation of interferon signaling pathways of the neurovascular unit in fatal COVID-19. By investigating the susceptibility of human induced pluripotent stem cell (hiPSC)-derived brain capillary endothelial-like cells (BCECs) to SARS-CoV-2 infection, we found that BCECs were infected and recapitulated transcriptional changes detected in vivo. While BCECs were not compromised in their paracellular tightness, we found SARS-CoV-2 in the basolateral compartment in transwell assays after apical infection, suggesting active replication and transcellular transport of virus across the blood-brain barrier (BBB) in vitro. Moreover, entry of SARS-CoV-2 into BCECs could be reduced by anti-spike-, anti-angiotensin-converting enzyme 2 (ACE2)-, and anti-neuropilin-1 (NRP1)-specific antibodies or the transmembrane protease serine subtype 2 (TMPRSS2) inhibitor nafamostat. Together, our data provide strong support for SARS-CoV-2 brain entry across the BBB resulting in increased interferon signaling.

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IFNγ signaling is upregulated in COVID-19 human neurovascular unit

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SARS-CoV-2-infected hiPS-BCECs display similar upregulation of IFNγ signaling

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SARS-CoV-2 replicates in hiPS-BCECs and is released while barrier remains intact

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SARS-CoV-2 infection of hiPS-BCECs is decreased by antibodies and protease inhibitors

The Use of Electroconvulsive Therapy in Neuropsychiatric Complications of Coronavirus Disease 2019: A Systematic Literature Review and Case Report

BACKGROUND

There is a significant prevalence of new onset neuropsychiatric symptoms (NPS), some severe and persistent, in patients with coronavirus disease 2019 (COVID-19).

OBJECTIVE

This study reports on the use of electroconvulsive therapy (ECT) to treat NPS associated with COVID-19.

METHODS

A review of the literature pertaining to the use of ECT in patients with COVID-19 and NPS was performed through PubMed, PsycINFO, and MEDLINE. Search terms included "Electroconvulsive Therapy" and "ECT," combined with "COVID-19" and "Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2)." In addition, we present a case in which ECT was used to achieve complete remission in a patient who developed new onset, treatment-resistant depression, psychosis, and catatonia, associated with COVID-19.

RESULTS

A total of 67 articles were reviewed with 3 selected for inclusion. These articles detailed 3 case reports of patients with new onset NPS (mania, psychosis and suicidality, and catatonia) that developed in the context of active COVID-19 and were treated successfully with ECT.

CONCLUSIONS

ECT, a broad-spectrum treatment that has been found to be effective in various NPS (independent of etiology), is shown in our case report and others, to be safe and effective for NPS associated with COVID-19. Although we identified only 3 other cases in the literature, we believe that the probable antiinflammatory mechanism of ECT, its safety and tolerability, and the faster time to symptom remission support the need for more research and increased clinician awareness about this life-saving procedure.

Acute and chronic neurological disorders in COVID-19: potential mechanisms of disease

Coronavirus disease 2019 (COVID-19) is a global pandemic caused by SARS-CoV-2 infection and is associated with both acute and chronic disorders affecting the nervous system. Acute neurological disorders affecting patients with COVID-19 range widely from anosmia, stroke, encephalopathy/encephalitis, and seizures to Guillain-Barré syndrome. Chronic neurological sequelae are less well defined although exercise intolerance, dysautonomia, pain, as well as neurocognitive and psychiatric dysfunctions are commonly reported. Molecular analyses of CSF and neuropathological studies highlight both vascular and immunologic perturbations. Low levels of viral RNA have been detected in the brains of few acutely ill individuals. Potential pathogenic mechanisms in the acute phase include coagulopathies with associated cerebral hypoxic-ischaemic injury, blood-brain barrier abnormalities with endotheliopathy and possibly viral neuroinvasion accompanied by neuro-immune responses. Established diagnostic tools are limited by a lack of clearly defined COVID-19 specific neurological syndromes. Future interventions will require delineation of specific neurological syndromes, diagnostic algorithm development and uncovering the underlying disease mechanisms that will guide effective therapies.

A genetic link between risk for Alzheimer's disease and severe COVID-19 outcomes via the OAS1 gene

Recently, we reported oligoadenylate synthetase 1 (OAS1) contributed to the risk of Alzheimer's disease, by its enrichment in transcriptional networks expressed by microglia. However, the function of OAS1 within microglia was not known. Using genotyping from 1313 individuals with sporadic Alzheimer's disease and 1234 control individuals, we confirm the OAS1 variant, rs1131454, is associated with increased risk for Alzheimer's disease. The same OAS1 locus has been recently associated with severe coronavirus disease 2019 (COVID-19) outcomes, linking risk for both diseases. The single nucleotide polymorphisms rs1131454(A) and rs4766676(T) are associated with Alzheimer's disease, and rs10735079(A) and rs6489867(T) are associated with severe COVID-19, where the risk alleles are linked with decreased OAS1 expression. Analysing single-cell RNA-sequencing data of myeloid cells from Alzheimer's disease and COVID-19 patients, we identify co-expression networks containing interferon (IFN)-responsive genes, including OAS1, which are significantly upregulated with age and both diseases. In human induced pluripotent stem cell-derived microglia with lowered OAS1 expression, we show exaggerated production of TNF-α with IFN-γ stimulation, indicating OAS1 is required to limit the pro-inflammatory response of myeloid cells. Collectively, our data support a link between genetic risk for Alzheimer's disease and susceptibility to critical illness with COVID-19 centred on OAS1, a finding with potential implications for future treatments of Alzheimer's disease and COVID-19, and development of biomarkers to track disease progression.

Relationship between COVID-19 and movement disorders: A narrative review

BACKGROUND AND PURPOSE

The scientific literature on COVID-19 is increasingly growing.

METHODS

In this paper, we review the literature on movement disorders in the context of the COVID-19 pandemic.

RESULTS

First, there are a variety of transient movement disorders that may manifest in the acute phase of COVID-19, most often myoclonus, with more than 50 patients described in the literature. New onset parkinsonism, chorea, and tic-like behaviours have also been reported. Movement disorders as a side effect after COVID-19 vaccination are rare, occurring with a frequency of 0.00002-0.0002 depending on the product used, mostly manifesting with tremor. Current evidence for potential long-term manifestations, for example, long COVID parkinsonism, is separately discussed. Second, the pandemic has also had an impact on patients with pre-existing movement disorder syndromes, with negative effects on clinical status and overall well-being, and reduced access to medication and health care. In many parts, the pandemic has led to reorganization of the medical system, including the development of new digital solutions. The movement disorder-related evidence for this is reviewed and discussed.

CONCLUSIONS

The pandemic and the associated preventive measures have had a negative impact on the clinical status, access to health care, and overall well-being of patients with pre-existing movement disorders.

Ischaemic background of brain fog in long-haul COVID-19 - a nuclear magnetic resonance spectroscopy-based metabonomic analysis. Preliminary results

PURPOSE

Long-haul COVID-19 is a condition of unknown background occurring in COVID-19 survivors regardless of the severity of the SARS-CoV-2 infection itself. The aim of the study was to evaluate brain changes in patients suffering from variable symptoms of brain fog after COVID-19.

MATERIAL AND METHODS

Eleven patients hospitalized due to symptoms of severe brain fog, i.e. insomnia, sudden impairment of cognitive function, headache, and depression, and 14 healthy volunteers underwent brain imaging including MR spectroscopy.

RESULTS

Routine MR imaging revealed no specific macroscopic changes in keeping with brain fog. Considering that the clinical manifestation of brain fog is transient, the evaluation of the metabolic status of the brain remained the method of choice. The concentration of the major cerebral metabolites, i.e. NAA, Cho, and Cr, remained stable. However, changes in Glx and Lac concentration were observed in MR spectroscopy.

CONCLUSIONS

Following results along with clinical course of the brain for imply probable ischaemic background of symptoms.

[Postcovid syndrome - a new reality]

The second year of the COVID-19 (Coronavirus Disease 2019) pandemic has seen the need to identify and assess the long-term consequences of a SARS-CoV-2 (Severe acute respiratory syndrome coronavirus-2) infection on an individual's, including adequate cognitive functioning. This review is attempting to highlight the current understanding of the various direct and indirect mechanisms of nervous system damage, describing the causality of similar symptoms following SARS-CoV-2 infection. This understanding is essential to establish the long-term consequences from the disease (including the potential for increased risk of dementia in some cases) and to identify means of preventing or ameliorating the brain damage. There is urgent need for research to better understand the pathogenesis of neurological disturbances in COVID-19, some of which have probably been covert and the prevalence of which may be considerably underestimated. Neuropsychiatric monitoring follow-up of COVID-19 patients will be important in determining the extent and prevalence of long-term neurological and psychiatric consequences of COVID-19. Early intervention for emerging these problems will be critical for improving quality of life for many COVID-19 survivors.

[Neurological Manifestations of COVID-19]

After first reports of a new predominantely respiratory illness detected in Wuhan City, Hubei Province of China in Dezember 2019, the novel coronavirus SARS-CoV-2 rapidly spreads all over China and the world. Growing evidence suggests that neurological signs, symptoms and complications occur during the course of the COVID-19 disease. This article highlights neurological aspects of COVID-19 and also discusses the impact of the COVID-19 pandemic on patients with Parkinson's disease.

Follow-up of renal transplant recipients after acute COVID-19-A prospective cohort single-center study

INTRODUCTION

Although most patients recover within several weeks after acute COVID-19, some of them develop long-lasting clinical symptoms. Renal transplant recipients have an increased mortality risk from COVID-19. We aimed to describe complications occurring after COVID-19 in this group of patients.

METHODS

A prospective single-center cohort study was conducted at University Hospital Centre Zagreb. Patients with two negative reverse transcriptase-polymerase chain reaction (RT-PCR) tests for SARS-CoV-2 after COVID-19 were eligible for further follow-up at our outpatient clinic. They underwent detailed clinical and laboratory assessments. The primary outcome was the development of complications after COVID-19.

RESULTS

Only 11.53% of renal transplant recipients who survived acute COVID-19 were symptomless and free from new-onset laboratory abnormalities during the median follow-up of 64 days (range: 50-76 days). Three patients died from sepsis after discharge from the hospital. In 47 patients (45.2%), clinical complications were present, while 74 patients (71.2%) had one or more laboratory abnormalities. The most common clinical complications included shortness of breath (19.2%), tiredness (11.5%), peripheral neuropathy (7.7%), self-reported cognitive impairments (5.7%), and dry cough (7.7%). Most common laboratory abnormalities included shortened activated partial thromboplastin time (50%), elevated D-dimers (36.5%), elevated fibrinogen (30.16%), and hypogammaglobulinemia (24%). Positive RT-PCR for cytomegalovirus (8.7%), Epstein-Barr virus (26%), or BK virus (16.3%). Multivariate analysis identified the history of diabetes mellitus and eGFR CKD-EPI as predictors for the development of post-COVID clinical complications. Six months after acute COVID-19, elevated D-dimers persisted with normalization of other laboratory parameters. Twenty-nine patients were hospitalized, mostly with several concomitant problems. However, initially reported clinical problems gradually improved in the majority of patients.

CONCLUSION

Post-COVID-19 clinical and laboratory complications are frequent in the renal transplant population, in some of them associated with significant morbidity. All patients recovered from acute COVID-19 should undergo long-term monitoring for evaluation and treatment of complications.

Epidemiology, pathophysiology, and classification of the neurological symptoms of post-COVID-19 syndrome

Introduction

Post-COVID-19 syndrome is a series of chronic signs and symptoms that may appear after SARS-CoV-2 infection, including fatigue, dyspnoea, chest pain, palpitations, anxiety, depression, and joint and muscle pain. The purpose of this study was to review the controversies on post-COVID-19 syndrome, the frequency of neurological symptoms, and the potential pathophysiological mechanisms.

Methods

We present a narrative review of studies published in PubMed since the beginning of the pandemic (January 2020-July 2021).

Results

Patients with history of COVID-19 have been found to present persistent neurological symptoms, including cognitive complaints, memory and concentration problems, headache, anosmia, ageusia, vertigo, and insomnia. Post-COVID-19 syndrome is a heterogeneous disease that lacks a universally accepted definition, which may explain the great variability in the estimated prevalence (2.3%-85%) and symptom duration. The criteria differentiating post-COVID-19 syndrome from chronic fatigue syndrome or critical illness syndrome are ambiguous. Risk factors include older age, female sex, certain comorbidities, and greater number of symptoms in the acute phase. The pathophysiology of the syndrome is largely unknown, although it is probably multifactorial, including immunological mechanisms, neural network dysfunction, neurotransmitter alterations, persistent viral damage, and functional impairment.

Conclusions

Post-COVID-19 syndrome may present after mild or even asymptomatic SARS-CoV-2 infection, causing limitations in activities of daily living and in quality of life. Further research will clarify the origin and most appropriate management of these neurological alterations.

Cognitive symptoms after COVID-19

Introduction

SARS-CoV-2 infection frequently causes neurological symptoms. Cognitive alterations are among the most frequent symptoms, and may persist beyond the acute phase of infection.

Methods

We conducted a narrative review of the literature.

Results

Hospitalised patients, and especially critically ill patients, are at greater risk of developing cognitive symptoms. Post-COVID-19 cognitive symptoms, unlike those associated with other viral illnesses, have been observed in patients with mild infection, and present some atypical features. Cognitive symptoms may last longer in COVID-19 than in other infectious processes, and more frequently affect young people. Post-COVID-19 cognitive symptoms share common features with those described in chronic fatigue syndrome, including a similar profile with affective symptoms. Brief screening tests for cognitive impairment present suboptimal diagnostic performance, and standardised criteria are needed to ensure correct diagnosis.Post-COVID-19 cognitive impairment can have a significant impact on the patient's quality of life and functional independence, regardless of other post-COVID-19 symptoms. Currently, no specific treatments have been approved for post-COVID-19 cognitive impairment, although cognitive stimulation may be useful in some patients.

Conclusions

Post-COVID-19 cognitive symptoms are common and are often associated with other systemic symptoms. Neuropsychological evaluation may be useful for diagnosis and to quantify their severity and long-term prognosis. Detailed, and individualised assessment of cognitive impairment may enable the design of treatment plans.

"Brain Fog" by COVID-19 or Alzheimer's Disease? A Case Report

Cognitive symptoms after COVID-19 have been increasingly recognized several months after the acute infection and have been designated as “brain fog.” We report a patient with cognitive symptoms that started immediately after COVID-19, in which cerebrospinal fluid biomarkers were highly suggestive of Alzheimer’s disease. Our case highlights the need to examine patients with cognitive symptoms following COVID-19 comprehensively. A detailed assessment combining clinical, cognitive, and biomarker studies may help disentangle the underlying mechanisms associated with cognitive dysfunction in each case. The investigation of neurodegenerative processes in an early stage, especially in older patients, is probably warranted.

More Than 100 Persistent Symptoms of SARS-CoV-2 (Long COVID): A Scoping Review

Background: Persistent coronavirus disease 2019 (COVID-19) symptoms are increasingly well-reported in cohort studies and case series. Given the spread of the pandemic, number of individuals suffering from persistent symptoms, termed ‘long COVID', are significant. However, type and prevalence of symptoms are not well reported using systematic literature reviews.

Objectives: In this scoping review of the literature, we aggregated type and prevalence of symptoms in people with long COVID.

Eligibility Criteria: Original investigations concerning the name and prevalence of symptoms were considered in participants ≥4-weeks post-infection.

Sources of Evidence: Four electronic databases [Medline, Web of Science, Scopus, and the Cochrane Central Register of Controlled Trials (CENTRAL)] were searched.

Methods: A scoping review was conducted using the Arksey and O'Malley framework. Review selection and characterisation was performed by three independent reviewers using pretested forms.

Results: Authors reviewed 2,711 titles and abstracts for inclusion with 152 selected for full-text review. 102 articles were subsequently removed as this did not meet inclusion criteria. Thus, fifty studies were analysed, 34 of which were described as cohort studies or prospective cohort studies, 14 were described as cross-sectional studies, one was described as a case control study, and one was described as a retrospective observational study. In total, >100 symptoms were identified and there was considerable heterogeneity in symptom prevalence and setting of study. Ten studies reported cardiovascular symptoms, four examined pulmonary symptoms, 25 reported respiratory symptoms, 24 reported pain-related symptoms, 21 reported fatigue, 16 reported general infection symptoms, 10 reported symptoms of psychological disorders, nine reported cognitive impairment, 31 reported a sensory impairment, seven reported a dermatological complaint, 11 reported a functional impairment, and 18 reported a symptom which did not fit into any of the above categories.

Conclusion: Most studies report symptoms analogous to those apparent in acute COVID-19 infection (i.e., sensory impairment and respiratory symptoms). Yet, our data suggest a larger spectrum of symptoms, evidenced by >100 reported symptoms. Symptom prevalence varied significantly and was not explained by data collection approaches, study design or other methodological approaches, and may be related to unknown cohort-specific factors.

COVID-19 Infection: A Neuropsychiatric Perspective

As a potentially life-threatening disease with no definitive treatment and without fully implemented population-wide vaccination, COVID-19 has created unprecedented turmoil in socioeconomic life worldwide. In addition to physical signs from the respiratory and many other systems, the SARS-CoV-2 virus produces a broad range of neurological and neuropsychiatric problems, including olfactory and gustatory impairments, encephalopathy and delirium, stroke and neuromuscular complications, stress reactions, and psychoses. Moreover, the psychosocial impact of the pandemic and its indirect effects on neuropsychiatric health in noninfected individuals in the general public and among health care workers are similarly far-ranging. In addition to acute neuropsychiatric manifestations, COVID-19 may also produce late neuropsychiatric sequelae as a function of the psychoneuroimmunological cascade that it provokes. The present article presents a state-of-the-science review of these issues through an integrative review and synthesis of case series, large-cohort studies, and relevant meta-analyses. Heuristics for evaluation and further study of the neuropsychiatric manifestations of SARS-CoV-2 infection are offered.

COVID-19 and Aphasia

PURPOSE OF REVIEW

Aphasia is an acquired neurological language disorder after brain damages. Persons with aphasia (PWA) are more susceptible to behavioral and emotional implications due to inherent communication and/or cognitive difficulties. Currently, little is known regarding the impact of COVID-19 on PWA.

RECENT FINDINGS

There are now growing reports with evidence of neurological and dysexecutive syndromes subsequent to interference of brain functions in acute patients with COVID-19, leading to variable aphasia-like symptoms. COVID-19 affected chronic PWA more in terms of disrupted communication and daily routines, worsened psychosocial well-being, and difficulties getting aphasia services that adequately addressed their needs. Acute versus chronic PWA were disproportionately affected by COVID-19. Recognizing, examining, and managing COVID-19-related neurological and behavioral problems in PWA is not straightforward. As we passed the 1-year mark and approaching the 2-year mark of the onset of COVID-19, more research is necessary to prioritize strategies for improving current evidence-based care and rehabilitation of aphasia.

Neuropsychological profiles and cerebral glucose metabolism in neurocognitive Long COVID-syndrome

During the Corona Virus Disease 2019 (COVID-19) pandemic, Long COVID-syndrome, which impairs patients through cognitive deficits, fatigue, and exhaustion, has become increasingly relevant. Its underlying pathophysiology, however, is unknown. In this study, we assessed cognitive profiles and regional cerebral glucose metabolism as a biomarker of neuronal function in outpatients suffering from long-term neurocognitive symptoms after COVID-19. Methods: Outpatients seeking neurological counseling with neurocognitive symptoms persisting for more than three months after polymerase chain reaction (PCR)-confirmed COVID-19 were included prospectively between June 16, 2020, and January 29, 2021. Patients (n = 31, 54±2.0 years) in the long-term phase after COVID-19 (202±58 days after positive PCR) were assessed with a neuropsychological test battery. Cerebral ¹⁸F-FDG PET imaging was performed in 14/31 patients. Results: Patients self-reported impaired attention, memory, and multitasking abilities (31/31), word-finding difficulties (27/31), and fatigue (24/31). Twelve of 31 patients could not return to the previous level of independence/employment. For all cognitive domains, average group results of the neuropsychological test-battery showed no impairment, but deficits (z-score<-1.5) were present on single-patient level mainly in the domain of visual memory (in 7/31; other domains ≤2/31). Mean MoCA performance (27/30 points) was above the cutoff-value for detection of cognitive impairment (< 26 points), although 9/31 patients performed slightly below this level (23-25 points). In the subgroup of patients who underwent ¹⁸F-FDG PET, we found no significant changes of regional cerebral glucose metabolism. Conclusion: Long COVID patients self-report uniform symptoms hampering their ability to work in a relevant fraction. However, cognitive testing showed minor impairments only on single-patient level approximately six months after the infection, whereas functional imaging revealed no distinct pathological changes. This clearly deviates from previous findings in subacute COVID-19 patients, suggesting that underlying neuronal causes are different and possibly related to the high prevalence of fatigue.

The impact of Post-COVID-Syndrome on functioning - results from a community survey in patients after mild and moderate SARS-CoV-2-infections in Germany

Background

In COVID-19 survivors a relatively high number of long-term symptoms have been observed. Besides impact on quality of life, these symptoms (now called Post-COVID-Syndrome) may have an impact on functioning and may also hinder to participation in social life in affected people. However, little is known about developing such syndrome a for patients with mild and moderate COVID-19 who did not need hospitalization or intensive care.

Methods

A cross-sectional study in 1027 patients with mild or moderate COVID-19 was performed in two communities in Bavaria, Germany. The Rehabilitation-Needs-Survey (RehabNeS) including the Short Form 36 Health Survey (SF-36) on health-related quality of life, was used. Descriptive statistics were calculated.

Results

In all, 97.5% of patients reported one symptom in the infection stage, such as fatigue, respiratory problems, limitations of the senses of taste and smell, fear and anxiety and other symptoms. In this time period, 84.1% of the participants experienced activity limitations and participation restrictions such as carrying out daily routines, handling stress, getting household tasks done, caring for/supporting others, and relaxing and leisure concerns.

In all, 61.9% of participants reported persisting symptoms more than 3 months after infection. These were fatigue, sleep disturbances, respiratory problems, pain, fear and anxiety, and restrictions in movement; 49% of the participants reported activity limitations and participation restrictions. Predominately, these were handling stress, carrying out daily routines, looking after one’s health, relaxing and leisure activities and doing house work.

The impacts on quality of life and vocational performance were rather low.

Conclusion

The results show that long-term symptoms after mild and moderate COVID-19 are common and lead to limitations of activities and participation. However, it seems that in most cases they are not severe and do not lead to frequent or serious issues with quality of life or work ability.

Long COVID or post-COVID-19 syndrome: putative pathophysiology, risk factors, and treatments

Long COVID or post-COVID-19 syndrome first gained widespread recognition among social support groups and later in scientific and medical communities. This illness is poorly understood as it affects COVID-19 survivors at all levels of disease severity, even younger adults, children, and those not hospitalized. While the precise definition of long COVID may be lacking, the most common symptoms reported in many studies are fatigue and dyspnoea that last for months after acute COVID-19. Other persistent symptoms may include cognitive and mental impairments, chest and joint pains, palpitations, myalgia, smell and taste dysfunctions, cough, headache, and gastrointestinal and cardiac issues. Presently, there is limited literature discussing the possible pathophysiology, risk factors, and treatments in long COVID, which the current review aims to address. In brief, long COVID may be driven by long-term tissue damage (e.g. lung, brain, and heart) and pathological inflammation (e.g. from viral persistence, immune dysregulation, and autoimmunity). The associated risk factors may include female sex, more than five early symptoms, early dyspnoea, prior psychiatric disorders, and specific biomarkers (e.g. D-dimer, CRP, and lymphocyte count), although more research is required to substantiate such risk factors. While preliminary evidence suggests that personalized rehabilitation training may help certain long COVID cases, therapeutic drugs repurposed from other similar conditions, such as myalgic encephalomyelitis or chronic fatigue syndrome, postural orthostatic tachycardia syndrome, and mast cell activation syndrome, also hold potential. In sum, this review hopes to provide the current understanding of what is known about long COVID.

Olfactory Bulb and Amygdala Gene Expression Changes in Subjects Dying with COVID-19

In this study we conducted RNA sequencing on two brain regions (olfactory bulb and amygdala) from subjects who died from COVID-19 or who died of other causes. We found several-fold more transcriptional changes in the olfactory bulb than in the amygdala, consistent with our own work and that of others indicating that the olfactory bulb may be the initial and most common brain region infected. To some extent our results converge with pseudotime analysis towards common processes shared between the brain regions, possibly induced by the systemic immune reaction following SARS-CoV-2 infection. Changes in amygdala emphasized upregulation of interferon-related neuroinflammation genes, as well as downregulation of synaptic and other neuronal genes, and may represent the substrate of reported acute and subacute COVID-19 neurological effects. Additionally, and only in olfactory bulb, we observed an increase in angiogenesis and platelet activation genes, possibly associated with microvascular damages induced by neuroinflammation. Through coexpression analysis we identified two key genes (CAMK2B for the synaptic neuronal network and COL1A2 for the angiogenesis/platelet network) that might be interesting potential targets to reverse the effects induced by SARS-CoV-2 infection. Finally, in olfactory bulb we detected an upregulation of olfactory and taste genes, possibly as a compensatory response to functional deafferentation caused by viral entry into primary olfactory sensory neurons. In conclusion, we were able to identify transcriptional profiles and key genes involved in neuroinflammation, neuronal reaction and olfaction induced by direct CNS infection and/or the systemic immune response to SARS-CoV-2 infection.

Post-COVID syndrome. A case series and comprehensive review

The existence of a variety of symptoms with a duration beyond the acute phase of COVID-19, is referred to as post-COVID syndrome (PCS). We aimed to report a series of patients with PCS attending a Post-COVID Unit and offer a comprehensive review on the topic. Adult patients with previously confirmed SARS-CoV-2 infection and PCS were systematically assessed through a semi-structured and validated survey. Total IgG, IgA and IgM serum antibodies to SARS-CoV-2 were evaluated by an electrochemiluminescence immunoassay. A systematic review of the literature and meta-analysis were conducted, following PRISMA guidelines. Univariate and multivariate methods were used to analyze data. Out of a total of 100 consecutive patients, 53 were women, the median of age was 49 years (IQR: 37.8–55.3), the median of post-COVID time after the first symptoms was 219 days (IQR: 143–258), and 65 patients were hospitalized during acute COVID-19. Musculoskeletal, digestive (i.e., diarrhea) and neurological symptoms including depression (by Zung scale) were the most frequent observed in PCS patients. A previous hospitalization was not associated with PCS manifestation. Arthralgia and diarrhea persisted in more than 40% of PCS patients. The median of anti-SARS-CoV-2 antibodies was 866.2 U/mL (IQR: 238.2–1681). Despite this variability, 98 patients were seropositive. Based on autonomic symptoms (by COMPASS 31) two clusters were obtained with different clinical characteristics. Levels of anti-SARS-CoV-2 antibodies were not different between clusters. A total of 40 articles (11,196 patients) were included in the meta-analysis. Fatigue/muscle weakness, dyspnea, pain and discomfort, anxiety/depression and impaired concentration were presented in more than 20% of patients reported. In conclusion, PCS is mainly characterized by musculoskeletal, pulmonary, digestive and neurological involvement including depression. PCS is independent of severity of acute illness and humoral response. Long-term antibody responses to SARS-CoV-2 infection and a high inter-individual variability were confirmed. Future studies should evaluate the mechanisms by which SARS-CoV-2 may cause PCS and the best therapeutic options.

Multi-Organ Histopathological Changes in a Mouse Hepatitis Virus Model of COVID-19

Infection with SARS-CoV-2, the virus responsible for the global COVID-19 pandemic, causes a respiratory illness that can severely impact other organ systems and is possibly precipitated by cytokine storm, septic shock, thrombosis, and oxidative stress. SARS-CoV-2 infected individuals may be asymptomatic or may experience mild, moderate, or severe symptoms with or without pneumonia. The mechanisms by which SARS-CoV-2 infects humans are largely unknown. Mouse hepatitis virus 1 (MHV-1)-induced infection was used as a highly relevant surrogate animal model for this study. We further characterized this animal model and compared it with SARS-CoV-2 infection in humans. MHV-1 inoculated mice displayed death as well as weight loss, as reported earlier. We showed that MHV-1-infected mice at days 7-8 exhibit severe lung inflammation, peribronchiolar interstitial infiltration, bronchiolar epithelial cell necrosis and intra-alveolar necrotic debris, alveolar exudation (surrounding alveolar walls have capillaries that are dilated and filled with red blood cells), mononuclear cell infiltration, hyaline membrane formation, the presence of hemosiderin-laden macrophages, and interstitial edema. When compared to uninfected mice, the infected mice showed severe liver vascular congestion, luminal thrombosis of portal and sinusoidal vessels, hepatocyte degeneration, cell necrosis, and hemorrhagic changes. Proximal and distal tubular necrosis, hemorrhage in interstitial tissue, and the vacuolation of renal tubules were observed. The heart showed severe interstitial edema, vascular congestion, and dilation, as well as red blood cell extravasation into the interstitium. Upon examination of the MHV-1 infected mice brain, we observed congested blood vessels, perivascular cavitation, cortical pericellular halos, vacuolation of neuropils, darkly stained nuclei, pyknotic nuclei, and associated vacuolation of the neuropil in the cortex, as well as acute eosinophilic necrosis and necrotic neurons with fragmented nuclei and vacuolation in the hippocampus. Our findings suggest that the widespread thrombotic events observed in the surrogate animal model for SARS-CoV-2 mimic the reported findings in SARS-CoV-2 infected humans, representing a highly relevant and safe animal model for the study of the pathophysiologic mechanisms of SARS-CoV-2 for potential therapeutic interventions.

SARS-CoV-2 and the Brain: What Do We Know about the Causality of 'Cognitive COVID?

The second year of the COVID-19 (coronavirus disease) pandemic has seen the need to identify and assess the long-term consequences of a SARS-CoV-2 infection on an individual's overall wellbeing, including adequate cognitive functioning. 'Cognitive COVID' is an informal term coined to interchangeably refer to acute changes in cognition during COVID-19 and/or cognitive sequelae with various deficits following the infection. These may manifest as altered levels of consciousness, encephalopathy-like symptoms, delirium, and loss of various memory domains. Dysexecutive syndrome is a peculiar manifestation of 'Cognitive COVID' as well. In the previous major outbreaks of viruses like SARS-CoV, MERS-CoV and Influenza. There have been attempts to understand the underlying mechanisms describing the causality of similar symptoms following SARS-CoV-2 infection. This review, therefore, is attempting to highlight the current understanding of the various direct and indirect mechanisms, focusing on the role of neurotropism of SARS-CoV-2, the general pro-inflammatory state, and the pandemic-associated psychosocial stressors in the causality of 'Cognitive COVID.' Neurotropism is associated with various mechanisms including retrograde neuronal transmission via olfactory pathway, a general hematogenous spread, and the virus using immune cells as vectors. The high amounts of inflammation caused by COVID-19, compounded with potential intubation, are associated with a deleterious effect on the cognition as well. Finally, the pandemic's unique psychosocial impact has raised alarm due to its possible effect on cognition. Furthermore, with surfacing reports of post-COVID-vaccination cognitive impairments after vaccines containing mRNA encoding for spike glycoprotein of SARS-CoV-2, we hypothesize their causality and ways to mitigate the risk. The potential impact on the quality of life of an individual and the fact that even a minor proportion of COVID-19 cases developing cognitive impairment could be a significant burden on already overwhelmed healthcare systems across the world make it vital to gather further evidence regarding the prevalence, presentation, correlations, and causality of these events and reevaluate our approach to accommodate early identification, management, and rehabilitation of patients exhibiting cognitive symptoms.

Mental health, substance use, and suicidal ideation during a prolonged COVID-19-related lockdown in a region with low SARS-CoV-2 prevalence

The coronavirus disease 2019 (COVID-19) pandemic has been associated with mental health consequences due to direct (i.e., SARS-CoV-2 infection, potentially due to neuronal or astrocytic infection, microvascular, or inflammatory mechanisms) and indirect (i.e., social and economic impacts of COVID-19 prevention measures) effects. Investigation of mental health in a region with one of the longest lockdowns and lowest COVID-19 prevalence globally (Victoria, Australia) allowed for evaluation of mental health in the absence of substantial direct pandemic mental health consequences. Surveys were administered during 15-24 September 2020 to Victorian residents aged ≥18 years for The COVID-19 Outbreak Public Evaluation (COPE) Initiative. Responses were compared cross-sectionally with April-2020 data, and longitudinally among respondents who completed both surveys. Multivariable Poisson regressions were used to estimate prevalence ratios for adverse mental health symptoms, substance use, and suicidal ideation adjusted for demographics, sleep, and behaviours (e.g., screen-time, outdoor-time). In September-2020, among 1157 Victorians, one-third reported anxiety or depressive disorder symptoms, one-fifth reported suicidal ideation, and one-tenth reported having seriously considered suicide in the prior 30 days. Young adults, unpaid caregivers, people with disabilities, and people with diagnosed psychiatric or sleep conditions showed increased prevalence of adverse mental health symptoms. Prevalence estimates of symptoms of burnout, anxiety, and depressive disorder were unchanged between April-2020 and September-2020. Persistently common experiences of adverse mental health symptoms despite low SARS-CoV-2 prevalence during prolonged lockdown highlight the urgent need for mental health support services.

Cognitive Impairment After COVID-19-A Review on Objective Test Data

Objective: The aim was to conduct a review on the literature on objective cognitive impairment in patients after COVID-19. Methods: We performed a literature review and searched Ovid Medline in February 2021 based on a PECO scheme. Results: Twelve articles met all inclusion criteria. Total patient sample was <1,000. All studies on global cognitive function found impairment, ranging from 15 to 80% of the sampled patients. Seven studies on attention and executive functions reported impairment, with varying results depending on sub-domain and different tests. Three out of four studies reported memory difficulties, with two studies reporting short-term memory deficits. Although results indicate possible language impairment, only one study used domain-specific language tasks. Two out of four studies on visuospatial function did not report any impairment. Conclusion: Patients with recent SARS-CoV-2 infection appear to experience global cognitive impairment, impairment in memory, attention and executive function, and in particular verbal fluency. Based on the current results, we recommend clinicians to evaluate the need for cognitive assessment of patients with a recent COVID-19 infection, regardless of the severity of the disease, treatment methods and length of ICU stay. We need studies with larger sample and control group.

Brain Stress Mapping in COVID-19 Survivors Using MR Spectroscopy: New Avenue of Mental Health Status Monitoring$

Coronavirus (COVID-19) has emerged as a human catastrophe worldwide, and it has impacted human life more detrimentally than the combined effect of World Wars I and II. Various research studies reported that the disease is not confined to the respiratory system but also leads to neurological and neuropsychiatric disorders suggesting that the virus is potent to affect the central nervous system (CNS). Moreover, the damage to CNS may continue to rise even after the COVID-19 infection subsides which may further induce a long-term impact on the brain, resulting in cognitive impairment. Neuroimaging techniques is the ideal platform to detect and quantify pathological manifestations in the brain of COVID-19 survivors. In this context, a scheme based on structural, spectroscopic, and behavioral studies could be executed to monitor the gradual changes in the brain non-invasively due to COVID-19 which may further help in quantifying the impact of COVID-19 on the mental health of the survivors. Extensive research is required in this direction for identifying the mechanism and implications of COVID-19 in the brain. Cohort studies are urgently required for monitoring the effects of this pandemic on individuals of various subtypes longitudinally.

A systematic review of neuropsychological and psychiatric sequalae of COVID-19: implications for treatment

PURPOSE OF REVIEW

COVID-19 impacts multiple organ systems and is associated with high rates of morbidity and mortality. Pathogenesis of viral infection, co-morbidities, medical treatments, and psychosocial factors may contribute to COVID-19 related neuropsychological and psychiatric sequelae. This systematic review aims to synthesize available literature on psychiatric and cognitive characteristics of community-dwelling survivors of COVID-19 infection.

RECENT FINDINGS

Thirty-three studies met inclusion/exclusion criteria for review. Emerging findings link COVID-19 to cognitive deficits, particularly attention, executive function, and memory. Psychiatric symptoms occur at high rates in COVID-19 survivors, including anxiety, depression, fatigue, sleep disruption, and to a lesser extent posttraumatic stress. Symptoms appear to endure, and severity of acute illness is not directly predictive of severity of cognitive or mental health issues. The course of cognitive and psychiatric sequelae is limited by lack of longitudinal data at this time. Although heterogeneity of study design and sociocultural differences limit definitive conclusions, emerging risk factors for psychiatric symptoms include female sex, perceived stigma related to COVID-19, infection of a family member, social isolation, and prior psychiatry history.

SUMMARY

The extant literature elucidates treatment targets for cognitive and psychosocial interventions. Research using longitudinal, prospective study designs is needed to characterize cognitive and psychiatric functioning of COVID-19 survivors over the course of illness and across illness severity. Emphasis on delineating the unique contributions of premorbid functioning, viral infection, co-morbidities, treatments, and psychosocial factors to cognitive and psychiatric sequelae of COVID-19 is warranted.

Outside-in induction of the IFITM3 trafficking system by infections, including SARS-CoV-2, in the pathobiology of Alzheimer's disease

BACKGROUND

IFITM3 is a viral restriction protein that enables sequestration of viral particles and subsequent trafficking to lysosomes. Recently, IFITM3 upregulation was found to induce gamma - secretase activity and the production of amyloid beta. The purpose of this study was to determine whether dysregulation of IFITM3-dependent pathways was present in neurons and peripheral immune cells donated by AD patients. As a secondary aim, we sought to determine whether these perturbations could be induced by viruses, including SARS-CoV-2.

METHODS

Gene set enrichment analyses (GSEA) previously performed on publicly available transcriptomic data from tissues donated by AD patients were screened for enriched pathways containing IFITM3. Subsequently, signature containing IFITM3, derived from entorhinal cortex (EC) neurons containing neurofibrillary tangles (NFT) was screened for overlap with curated, publicly available, viral infection-induced gene signatures (including SARS-CoV-2).

RESULTS

GSEA determined that IFITM3 gene networks are significantly enriched both in CNS sites (entorhinal and hippocampal cortices) and in peripheral blood mononuclear cells (PBMCs) donated by AD patients. Overlap screening revealed that IFITM3 signatures are induced by several viruses, including SARS-CoV, MERS-CoV, SARS-CoV-2 and HIV-1 (adjusted p-value <0.001; Enrichr Database).

DISCUSSION

A data-driven analysis of AD tissues revealed IFITM3 gene signatures both in the CNS and in peripheral immune cells. GSEA revealed that an IFITM3 derived gene signature extracted from EC/NFT neurons overlapped with those extracted from publicly available viral infection datasets, including SARS-CoV-2. Our results are in line with currently emerging evidence on IFITM3's role in AD, and SARS-CoV-2's potential contribution in the setting of an expanded antimicrobial protection hypothesis.

Post-covid syndrome: a review of pathophysiology, neuropsychiatric manifestations and treatment perspectives

In the context of the COVID-19 pandemic, healthcare is faced with several new problems, one of which is a post-covid syndrome. Symptoms in many COVID-19 survivors can persist for a long time, significantly affecting the quality of life and work performance. All of the above makes post-covid syndrome a socially significant disease, requires dynamic follow-up of such patients, and rehabilitation programs development. We are currently at the stage of accumulating knowledge about the SARS-CoV-2 pathophysiology and morphogenesis and its long-term consequences. This article discusses neuropsychiatric aspects of the post-covid syndrome: pathogenetic hypotheses, clinical features, and potentially promising treatment strategies.

Health-related quality of life issues, including symptoms, in patients with active COVID-19 or post COVID-19; a systematic literature review

Purpose

This systematic review was performed to identify all relevant health-related quality of life (HRQoL) issues associated with COVID-19.

Methods

A systematic literature search was undertaken in April 2020. In four teams of three reviewers each, all abstracts were independently reviewed for inclusion by two reviewers. Using a pre-defined checklist of 93 criteria for each publication, data extraction was performed independently by two reviewers and subsequently compared and discussed. If necessary, a third reviewer resolved any discrepancies. The search was updated in February 2021 to retrieve new publications on HRQoL issues including issues related to the long-term consequences of COVID-19.

Results

The search in April 2020 identified 3342 potentially relevant publications, and 339 publications were selected for full-text review and data extraction. We identified 75 distinct symptoms and other HRQoL issues categorized into 12 thematic areas; from general symptoms such as fever, myalgia, and fatigue, to neurological and psychological issues. The updated search revealed three extra issues experienced during active disease and long-term problems with fatigue, psychological issues and impaired cognitive function.

Conclusion

This first comprehensive systematic review provides a detailed overview of the wide range of HRQoL issues experienced by patients with COVID-19 throughout the course of the disease. It demonstrates the devastating impact of the disease and provides critically important information for clinicians, to enable them to better recognize the disease and to provide knowledge important for treatment and follow-up. The results provided the foundation for the international development of a COVID-19 specific patient-reported HRQoL questionnaire.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11136-021-02908-z.

Incomplete Systemic Recovery and Metabolic Phenoreversion in Post-Acute-Phase Nonhospitalized COVID-19 Patients: Implications for Assessment of Post-Acute COVID-19 Syndrome

We present a multivariate metabotyping approach to assess the functional recovery of nonhospitalized COVID-19 patients and the possible biochemical sequelae of "Post-Acute COVID-19 Syndrome", colloquially known as long-COVID. Blood samples were taken from patients ca. 3 months after acute COVID-19 infection with further assessment of symptoms at 6 months. Some 57% of the patients had one or more persistent symptoms including respiratory-related symptoms like cough, dyspnea, and rhinorrhea or other nonrespiratory symptoms including chronic fatigue, anosmia, myalgia, or joint pain. Plasma samples were quantitatively analyzed for lipoproteins, glycoproteins, amino acids, biogenic amines, and tryptophan pathway intermediates using Nuclear Magnetic Resonance (NMR) spectroscopy and mass spectrometry. Metabolic data for the follow-up patients (n = 27) were compared with controls (n = 41) and hospitalized severe acute respiratory syndrome SARS-CoV-2 positive patients (n = 18, with multiple time-points). Univariate and multivariate statistics revealed variable patterns of functional recovery with many patients exhibiting residual COVID-19 biomarker signatures. Several parameters were persistently perturbed, e.g., elevated taurine (p = 3.6 × 10-3 versus controls) and reduced glutamine/glutamate ratio (p = 6.95 × 10-8 versus controls), indicative of possible liver and muscle damage and a high energy demand linked to more generalized tissue repair or immune function. Some parameters showed near-complete normalization, e.g., the plasma apolipoprotein B100/A1 ratio was similar to that of healthy controls but significantly lower (p = 4.2 × 10-3) than post-acute COVID-19 patients, reflecting partial reversion of the metabolic phenotype (phenoreversion) toward the healthy metabolic state. Plasma neopterin was normalized in all follow-up patients, indicative of a reduction in the adaptive immune activity that has been previously detected in active SARS-CoV-2 infection. Other systemic inflammatory biomarkers such as GlycA and the kynurenine/tryptophan ratio remained elevated in some, but not all, patients. Correlation analysis, principal component analysis (PCA), and orthogonal-partial least-squares discriminant analysis (O-PLS-DA) showed that the follow-up patients were, as a group, metabolically distinct from controls and partially comapped with the acute-phase patients. Significant systematic metabolic differences between asymptomatic and symptomatic follow-up patients were also observed for multiple metabolites. The overall metabolic variance of the symptomatic patients was significantly greater than that of nonsymptomatic patients for multiple parameters (χ2p = 0.014). Thus, asymptomatic follow-up patients including those with post-acute COVID-19 Syndrome displayed a spectrum of multiple persistent biochemical pathophysiology, suggesting that the metabolic phenotyping approach may be deployed for multisystem functional assessment of individual post-acute COVID-19 patients.

Impact of COVID-19 on chronic migraine treated with erenumab: a case report

Background

Headache is a frequent symptom of the novel coronavirus 19 disease (COVID-19). To date, there are limited information on how COVID-19 affects migraine and its treatment.

Case description

A 47-year-old patient, suffering from chronic migraine and medication-overuse headache, in September 2020 started erenumab at 70 mg once monthly. Two months later, monthly migraine days decreased from 20 to 5. On the third month, the patient developed mild COVID-19 symptoms, experiencing extreme fatigue, hyposmia, and attention deficit, resulting positive for SARS-Cov-2 RNA. A significant increase in migraine attacks frequency was reported. Brain MRI and EEG were normal. Erenumab was increased to 140 mg/month, and attacks decreased to 3 monthly migraine days and remained stable. All the headaches experienced by our patient during the infection fulfilled the criteria of the migraine attacks, without tensive-like features.

Conclusion

We report the first case showing the effects of SARS-CoV-2 infection in a patient with chronic migraine and medication-overuse headache treated with erenumab. Our case description suggests that inflammatory processes induced by SARS-CoV-2 infection may increase the frequency of migraine attacks, probably through an activation of the trigeminovascular system. Whether treatment with CGRP receptor antagonist may influence COVID is still debated. Additional studies regarding anti-CGRP monoclonal antibodies in COVID-19 patients are warranted.