Tag: long covid neurology

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

Abstract:

Although neurological complications of SARS-CoV-2 infection are relatively rare, their potential long term morbidity and mortality have a significant impact, given the large numbers of infected patients. Covid-19 is now in the differential diagnosis of a number of common neurological syndromes including encephalopathy, encephalitis, acute demyelinating encephalomyelitis, stroke, and Guillain-Barré syndrome.

Physicians should be aware of the pathophysiology underlying these presentations to diagnose and treat patients rapidly and appropriately. Although good evidence has been found for neurovirulence, the neuroinvasive and neurotropic potential of SARS-CoV-2 is limited. The pathophysiology of most complications is immune mediated and vascular, or both. A significant proportion of patients have developed long covid, which can include neuropsychiatric presentations. The mechanisms of long covid remain unclear. The longer term consequences of infection with covid-19 on the brain, particularly in terms of neurodegeneration, will only become apparent with time and long term follow-up.

Source: Brown R L, Benjamin L, Lunn M P, Bharucha T, Zandi M S, Hoskote C et al. Pathophysiology, diagnosis, and management of neuroinflammation in covid-19 BMJ 2023; 382 :e073923 doi:10.1136/bmj-2022-073923 https://www.bmj.com/content/382/bmj-2022-073923.abstract (Full text available as PDF file)

Evaluation of Post–COVID-19 Cognitive Dysfunction: Recommendations for Researchers

Opinion:

SARS-CoV-2 infection is associated with increased rates of postillness cognitive dysfunction, colloquially referred to as “brain fog,”1 that may portend significant consequences for patient functioning and quality of life. Post–COVID-19 cognitive dysfunction is 1 of approximately 200 symptoms of post–COVID-19 condition (PCC), defined by the World Health Organization as developing within 3 months of an initial SARS-CoV-2 infection, lasting at least 2 months, and cannot be explained by an alternative diagnosis. A pooled analysis of 54 studies and 1.2 million individuals found that 3.2% of patients’ self-reported cognitive problems 3 months after symptomatic infection,1 while other studies have shown objective evidence of cognitive dysfunction in approximately 24% of patients nearly 1 year later.2 Accumulating evidence also supports the hypothesis that COVID-19 may increase risk for later neurodegeneration3 and exacerbate preexisting cognitive dysfunction.4 As one of the most common symptoms of PCC and one for which affected individuals may seek accommodations and disability benefits in accordance with the Americans With Disabilities Act, it is imperative that we use more rigorous studies of cognitive outcomes. Accordingly, the following recommendations have been generated by members of the NeuroCOVID International Neuropsychology Taskforce based on initial guidelines.5

Source: Jaqueline H. Becker, PhD; Tracy D. Vannorsdall, PhD; Sara L. Weisenbach, PhD. JAMA Psychiatry. Published online August 16, 2023. doi:10.1001/jamapsychiatry.2023.2820 https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2808155

Differential effects of SARS-CoV-2 variants on central nervous system cells and blood–brain barrier functions

Abstract:

Background: Although mainly causing a respiratory syndrome, numerous neurological symptoms have been identified following of SARS-CoV-2 infection. However, how the virus affects the brain and how the mutations carried by the different variants modulate those neurological symptoms remain unclear.

Methods: We used primary human pericytes, foetal astrocytes, endothelial cells and a microglial cell line to investigate the effect of several SARS-CoV-2 variants of concern or interest on their functional activities. Cells and a 3D blood-brain barrier model were infected with the wild-type form of SARS-CoV-2, Alpha, Beta, Delta, Eta, or Omicron (BA.1) variants at various MOI. Cells and supernatant were used to evaluate cell susceptibility to the virus using a microscopic assay as well as effects of infection on (i) cell metabolic activity using a colorimetric MTS assay; (ii) viral cytopathogenicity using the xCELLigence system; (iii) extracellular glutamate concentration by fluorometric assay; and (iv) modulation of blood-brain barrier permeability.

Results: We demonstrate that productive infection of brain cells is SARS-CoV-2 variant dependent and that all the variants induce stress to CNS cells. The wild-type virus was cytopathic to all cell types except astrocytes, whilst Alpha and Beta variants were only cytopathic for pericytes, and the Omicron variant cytopathic for endothelial cells and pericytes. Lastly wild-type virus increases blood-brain barrier permeability and all variants, except Beta, modulate extracellular glutamate concentration, which can lead to excitotoxicity or altered neurotransmission.

Conclusions: These results suggest that SARS-CoV-2 is neurotropic, with deleterious consequences for the blood-brain barrier integrity and central nervous system cells, which could underlie neurological disorders following SARS-CoV-2 infection.

Source: Proust A, Queval CJ, Harvey R, Adams L, Bennett M, Wilkinson RJ. Differential effects of SARS-CoV-2 variants on central nervous system cells and blood-brain barrier functions. J Neuroinflammation. 2023 Aug 3;20(1):184. doi: 10.1186/s12974-023-02861-3. PMID: 37537664; PMCID: PMC10398935. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398935/ (Full text)

SARS-CoV-2 Spike Protein Accumulation in the Skull-Meninges-Brain Axis: Potential Implications for Long-Term Neurological Complications in post-COVID-19

Abstract:

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), has been associated mainly with a range of neurological symptoms, including brain fog and brain tissue loss, raising concerns about the virus’s acute and potential chronic impact on the central nervous system. In this study, we utilized mouse models and human post-mortem tissues to investigate the presence and distribution of the SARS-CoV-2 spike protein in the skull-meninges-brain axis.

Our results revealed the accumulation of the spike protein in the skull marrow, brain meninges, and brain parenchyma. The injection of the spike protein alone caused cell death in the brain, highlighting a direct effect on brain tissue. Furthermore, we observed the presence of spike protein in the skull of deceased long after their COVID-19 infection, suggesting that the spike’s persistence may contribute to long-term neurological symptoms. The spike protein was associated with neutrophil-related pathways and dysregulation of the proteins involved in the PI3K-AKT as well as complement and coagulation pathway.

Overall, our findings suggest that SARS-CoV-2 spike protein trafficking from CNS borders into the brain parenchyma and identified differentially regulated pathways may present insights into mechanisms underlying immediate and long-term consequences of SARS-CoV-2 and present diagnostic and therapeutic opportunities.

Source: Zhouyi Rong, Hongcheng Mai, Saketh Kapoor, Victor G. Puelles, Jan Czogalla, Julia Schädler, Jessica Vering, Claire Delbridge, Hanno Steinke, Hannah Frenzel, Katja Schmidt, Özüm Sehnaz Caliskan, Jochen Martin Wettengel, Fatma Cherif, Mayar Ali, Zeynep Ilgin Kolabas, Selin Ulukaya, Izabela Horvath, Shan Zhao, Natalie Krahmer, Sabina Tahirovic, Ali Önder Yildirim, Tobias B. Huber, Benjamin Ondruschka, Ingo Bechmann, Gregor Ebert, Ulrike Protzer, Harsharan Singh Bhatia, Farida Hellal, Ali Ertürk. SARS-CoV-2 Spike Protein Accumulation in the Skull-Meninges-Brain Axis: Potential Implications for Long-Term Neurological Complications in post-COVID-19. bioRxiv 2023.04.04.535604; doi: https://doi.org/10.1101/2023.04.04.535604 https://www.biorxiv.org/content/10.1101/2023.04.04.535604v1.full (Full text)

Pediatric de novo movement disorders and ataxia in the context of SARS-CoV-2

Abstract:

Objective: In the fourth year of the COVID-19 pandemic, mortality rates decreased, but the risk of neuropsychiatric disorders remained the same, with a prevalence of 3.8% of pediatric cases, including movement disorders (MD) and ataxia.

Methods: In this study, we report on a 10-year-old girl with hemichorea after SARS-CoV-2 infection and immunostained murine brain with patient CSF to identify intrathecal antibodies. Additionally, we conducted a scoping review of children with MD and ataxia after SARS-CoV-2 infection.

Results: We detected antibodies in the patient’s CSF binding unknown antigens in murine basal ganglia. The child received immunosuppression and recovered completely. In a scoping review, we identified further 32 children with de novo MD or ataxia after COVID-19. While in a minority of cases, MD or ataxia were a symptom of known clinical entities (e.g. ADEM, Sydenham’s chorea), in most children, the etiology was suspected to be of autoimmune origin without further assigned diagnosis. (i) Children either presented with ataxia (79%), but different from the well-known postinfectious acute cerebellar ataxia (older age, less favorable outcome, or (ii) had hypo-/hyperkinetic MD (21%), which were choreatic in most cases. Besides 14% of spontaneous recovery, immunosuppression was necessary in 79%. Approximately one third of children only partially recovered.

Conclusions: Infection with SARS-CoV-2 can trigger de novo MD in children. Most patients showed COVID-19-associated-ataxia and fewer-chorea. Our data suggest that patients benefit from immunosuppression, especially steroids. Despite treatment, one third of patients recovered only partially, which makes up an increasing cohort with neurological sequelae.

Source: Wilpert NM, de Almeida Marcelino AL, Knierim E, Incoronato P, Sanchez-Sendin E, Staudacher O, Drenckhahn A, Bittigau P, Kreye J, Prüss H, Schuelke M, Kühn AA, Kaindl AM, Nikolaus M. Pediatric de novo movement disorders and ataxia in the context of SARS-CoV-2. J Neurol. 2023 Jul 29. doi: 10.1007/s00415-023-11853-5. Epub ahead of print. PMID: 37515734. https://link.springer.com/article/10.1007/s00415-023-11853-5 (Full text)

Genetic Risk Factors for Severe and Fatigue Dominant Long COVID and Commonalities with ME/CFS Identified by Combinatorial Analysis

Abstract:

Background Long COVID is a debilitating chronic condition that has affected over 100 million people globally. It is characterized by a diverse array of symptoms, including fatigue, cognitive dysfunction and respiratory problems. Studies have so far largely failed to identify genetic associations, the mechanisms behind the disease, or any common pathophysiology with other conditions such as ME/CFS that present with similar symptoms.

Methods We used a combinatorial analysis approach to identify combinations of genetic variants significantly associated with the development of long COVID and to examine the biological mechanisms underpinning its various symptoms. We compared two subpopulations of long COVID patients from Sano Genetics’ Long COVID GOLD study cohort, focusing on patients with severe or fatigue dominant phenotypes. We evaluated the genetic signatures previously identified in an ME/CFS population against this long COVID population to understand similarities with other fatigue disorders that may be triggered by a prior viral infection. Finally, we also compared the output of this long COVID analysis against known genetic associations in other chronic diseases, including a range of metabolic and neurological disorders, to understand the overlap of pathophysiological mechanisms.

Results Combinatorial analysis identified 73 genes that were highly associated with at least one of the long COVID populations included in this analysis. Of these, 9 genes have prior associations with acute COVID-19, and 14 were differentially expressed in a transcriptomic analysis of long COVID patients. A pathway enrichment analysis revealed that the biological pathways most significantly associated with the 73 long COVID genes were mainly aligned with neurological and cardiometabolic diseases.

Expanded genotype analysis suggests that specific SNX9 genotypes are a significant contributor to the risk of or protection against severe long COVID infection, but that the gene-disease relationship is context dependent and mediated by interactions with KLF15 and RYR3.

Comparison of the genes uniquely associated with the Severe and Fatigue Dominant long COVID patients revealed significant differences between the pathways enriched in each subgroup. The genes unique to Severe long COVID patients were associated with immune pathways such as myeloid differentiation and macrophage foam cells. Genes unique to the Fatigue Dominant subgroup were enriched in metabolic pathways such as MAPK/JNK signaling. We also identified overlap in the genes associated with Fatigue Dominant long COVID and ME/CFS, including several involved in circadian rhythm regulation and insulin regulation. Overall, 39 SNPs associated in this study with long COVID can be linked to 9 genes identified in a recent combinatorial analysis of ME/CFS patient from UK Biobank.

Among the 73 genes associated with long COVID, 42 are potentially tractable for novel drug discovery approaches, with 13 of these already targeted by drugs in clinical development pipelines. From this analysis for example, we identified TLR4 antagonists as repurposing candidates with potential to protect against long term cognitive impairment pathology caused by SARS-CoV-2. We are currently evaluating the repurposing potential of these drug targets for use in treating long COVID and/or ME/CFS.

Conclusion This study demonstrates the power of combinatorial analytics for stratifying heterogeneous populations in complex diseases that do not have simple monogenic etiologies. These results build upon the genetic findings from combinatorial analyses of severe acute COVID-19 patients and an ME/CFS population and we expect that access to additional independent, larger patient datasets will further improve the disease insights and validate potential treatment options in long COVID.

Source: Krystyna Taylor, Matthew Pearson, Sayoni Das, Jason Sardell, Karolina Chocian, Steve Gardners. Genetic Risk Factors for Severe and Fatigue Dominant Long COVID and Commonalities with ME/CFS Identified by Combinatorial Analysis. medRxiv 2023.07.13.23292611; doi: https://doi.org/10.1101/2023.07.13.23292611 https://www.medrxiv.org/content/10.1101/2023.07.13.23292611v1.full-text (Full text)

Vagus nerve inflammation contributes to dysautonomia in COVID-19

Abstract:

Dysautonomia has substantially impacted acute COVID-19 severity as well as symptom burden after recovery from COVID-19 (long COVID), yet the underlying causes remain unknown. Here, we hypothesized that vagus nerves are affected in COVID-19 which might contribute to autonomic dysfunction.

We performed a histopathological characterization of postmortem vagus nerves from COVID-19 patients and controls, and detected SARS-CoV-2 RNA together with inflammatory cell infiltration composed primarily of monocytes. Furthermore, we performed RNA sequencing which revealed a strong inflammatory response of neurons, endothelial cells, and Schwann cells which correlated with SARS-CoV-2 RNA load. Lastly, we screened a clinical cohort of 323 patients to detect a clinical phenotype of vagus nerve affection and found a decreased respiratory rate in non-survivors of critical COVID-19.

Our data suggest that SARS-CoV-2 induces vagus nerve inflammation followed by autonomic dysfunction which contributes to critical disease courses and might contribute to dysautonomia observed in long COVID.

Source:Woo MS, Shafiq M, Fitzek A, Dottermusch M, Altmeppen H, Mohammadi B, Mayer C, Bal LC, Raich L, Matschke J, Krasemann S, Pfefferle S, Brehm TT, Lütgehetmann M, Schädler J, Addo MM, Schulze Zur Wiesch J, Ondruschka B, Friese MA, Glatzel M. Vagus nerve inflammation contributes to dysautonomia in COVID-19. Acta Neuropathol. 2023 Jul 15. doi: 10.1007/s00401-023-02612-x. Epub ahead of print. PMID: 37452829. https://link.springer.com/article/10.1007/s00401-023-02612-x (Full text)

Neuropsychological measures of post-COVID-19 cognitive status

Abstract:

Background: COVID-19 may result in persistent symptoms in the post-acute phase, including cognitive and neurological ones. The aim of this study is to investigate the cognitive and neurological features of patients with a confirmed diagnosis of COVID-19 evaluated in the post-acute phase through a direct neuropsychological evaluation.

Methods: Individuals recovering from COVID-19 were assessed in an out-patient practice with a complete neurological evaluation and neuropsychological tests (Mini-Mental State Examination; Rey Auditory Verbal Test, Multiple Feature Target Cancellation Test, Trial Making Test, Digit Span Forward and Backward, and Frontal Assessment Battery). Pre- and post-COVID-19 global and mental health status was assessed along with the history of the acute phase of infection. Post-COVID-19 cognitive status was modeled by combining persistent self-reported COVID-related cognitive symptoms and pathologic neuropsychological tests.

Results: A total of 406 individuals (average age 54.5 ± 15.1 years, 45.1% women) were assessed on average at 97.8 ± 48.0 days since symptom onset. Persistent self-reported neurological symptoms were found in the areas of sleep (32%), attention (31%), and memory (22%). The MMSE mean score was 28.6. In total, 84 subjects (20.7%) achieved pathologic neuropsychological test results. A high prevalence of failed tests was found in digit span backward (18.7%), trail making (26.6%), and frontal assessment battery (10.9%). Cognitive status was associated with a number of factors including cardiovascular disease history, persistent fatigue, female sex, age, anxiety, and mental health stress.

Conclusion: COVID-19 is capable of eliciting persistent measurable neurocognitive alterations particularly relevant in the areas of attention and working memory. These neurocognitive disorders have been associated with some potentially treatable factors and others that may stratify risk at an early stage.

Source: Lauria A, Carfì A, Benvenuto F, Bramato G, Ciciarello F, Rocchi S, Rota E, Salerno A, Stella L, Tritto M, Di Paola A, Pais C, Tosato M, Janiri D, Sani G, Lo Monaco R, Pagano FC, Fantoni M, Bernabei R, Landi F, Bizzarro A; Gemelli Against COVID-19 Post-acute Care Group. Neuropsychological measures of post-COVID-19 cognitive status. Front Psychol. 2023 Jul 10;14:1136667. doi: 10.3389/fpsyg.2023.1136667. PMID: 37492442; PMCID: PMC10363721. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10363721/ (Full text)

Mitigating neurological, cognitive, and psychiatric sequelae of COVID-19-related critical illness

Abstract:

Despite advances in the treatment and mitigation of critical illness caused by infection with SARS-CoV-2, millions of survivors have a devastating, post-acute infection syndrome known as long COVID. A large proportion of patients with long COVID have nervous system dysfunction, which is also seen in the distinct but overlapping condition of post-intensive care syndrome (PICS), putting survivors of COVID-19-related critical illness at high risk of long-lasting morbidity affecting multiple organ systems and, as a result, engendering measurable deficits in quality of life and productivity.

In this Series paper, we discuss neurological, cognitive, and psychiatric sequelae in patients who have survived critical illness due to COVID-19. We review current knowledge of the epidemiology and pathophysiology of persistent neuropsychological impairments, and outline potential preventive strategies based on safe, evidence-based approaches to the management of pain, agitation, delirium, anticoagulation, and ventilator weaning during critical illness. We highlight priorities for current and future research, including possible therapeutic approaches, and offer considerations for health services to address the escalating health burden of long COVID.

Source: Pandharipande P, Williams Roberson S, Harrison FE, Wilson JE, Bastarache JA, Ely EW. Mitigating neurological, cognitive, and psychiatric sequelae of COVID-19-related critical illness. Lancet Respir Med. 2023 Jul 17:S2213-2600(23)00238-2. doi: 10.1016/S2213-2600(23)00238-2. Epub ahead of print. PMID: 37475124. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(23)00238-2/fulltext (Full text)

Post-COVID cognitive dysfunction: current status and research recommendations for high risk population

Abstract:

Post-COVID cognitive dysfunction (PCCD) is a condition in which patients with a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, usually three months from the onset, exhibit subsequent cognitive impairment in various cognitive domains, and cannot be explained by an alternative diagnosis.

While our knowledge of the risk factors and management strategy of PCCD is still incomplete, it is necessary to integrate current epidemiology, diagnosis and treatment evidence, and form consensus criteria to better understand this disease to improve disease management. Identifying the risk factors and vulnerable population of PCCD and providing reliable strategies for effective prevention and management is urgently needed.

In this paper, we reviewed epidemiology, diagnostic markers, risk factors and available treatments on the disease, formed research recommendation framework for vulnerable population, under the background of post-COVID period.

Source: Quan M, Wang X, Gong M, Wang Q, Li Y, Jia J. Post-COVID cognitive dysfunction: current status and research recommendations for high risk population. Lancet Reg Health West Pac. 2023 Jul 5;38:100836. doi: 10.1016/j.lanwpc.2023.100836. PMID: 37457901; PMCID: PMC10344681. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10344681/ (Full text)