Tag: long covid neurology

Neuropathology and Neurological Manifestations in ME/CFS and Long COVID with focus on Post-Exertional Symptom Exacerbation: a Literature Review

Summary:

Many of the people that get infected with the Coronavirus develop long-lasting complaints and are diagnosed with Long COVID after the acute infection is gone. These complains can last several months or years and include fatigue, cognitive impairment, sleeping problems and post-exertional symptom exacerbation (PESE). Research shows that COVID-19 patients with an acute infection have abnormalities in their brain, which could potentially lead to long-lasting neurological problems and symptoms. However, although many researchers are trying to uncover the underlying mechanisms, Long COVID is still very new.
The underlying mechanisms causing and maintaining the disease are therefore unclear. A large group of Long COVID patients resembles patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) in terms of symptoms and, in many cases, the viral trigger of the disease. A core symptom of ME/CFS is PESE, which is uncommon in other fatiguing illnesses, but frequently seen in Long COVID patients. PESE involves an abnormal worsening of symptoms and cognitive and physical functions after any type of normal activity. Because of the large symptom overlap and lack of knowledge regarding PESE, underlying brain-mechanisms associated with Long COVID and ME/CFS in general as well as after physical exertion were investigated.
The findings of this review indicate that ME/CFS is associated with several abnormalities in the brain which are also proposed to be present in Long COVID patients. Such abnormalities include inflammation of the brain, shrinkage of the brain and less blood flow to the brain. After physical exertion, these abnormalities might be exacerbated in ME/CFS patients. This results in a brain that needs to work harder than the healthy brain to complete a task. It is demonstrated by increased brain activity in several brain regions after physical exertion and general symptom exacerbation. Since the two diseases seem to have a large overlap in symptoms and underlying brain-mechanisms, this finding might apply to patients with long COVID as well. Importantly, Long COVID seems to consist of different subgroups of which a large part fulfills the criteria for ME/CFS.
Treatment and therapy for ME/CFS patients is therefore likely transferable to this subgroup of Long COVID patients, with explicit attention towards the PESE phenomenon. More research is needed to uncover the underlying mechanisms as well as correct treatment approach of these diseases. Future research should take subgroups of Long COVID into account.
Source: Rodenburg, Sanne. Neuropathology and Neurological Manifestations in ME/CFS and Long COVID with focus on Post-Exertional Symptom Exacerbation: a Literature Review. Master Thesis, Utrecht University. March 14, 2023. https://studenttheses.uu.nl/bitstream/handle/20.500.12932/43647/Rodenburg_7433050_Neuropathology%20and%20neurological%20manifestations%20in%20MECFS%20and%20Long%20COVID%20with%20focus%20on%20PESE.pdf (Full text)

Pathogenesis Underlying Neurological Manifestations of Long COVID Syndrome and Potential Therapeutics

Abstract:

The development of long-term symptoms of coronavirus disease 2019 (COVID-19) more than four weeks after primary infection, termed “long COVID” or post-acute sequela of COVID-19 (PASC), can implicate persistent neurological complications in up to one third of patients and present as fatigue, “brain fog”, headaches, cognitive impairment, dysautonomia, neuropsychiatric symptoms, anosmia, hypogeusia, and peripheral neuropathy. Pathogenic mechanisms of these symptoms of long COVID remain largely unclear; however, several hypotheses implicate both nervous system and systemic pathogenic mechanisms such as SARS-CoV2 viral persistence and neuroinvasion, abnormal immunological response, autoimmunity, coagulopathies, and endotheliopathy.
Outside of the CNS, SARS-CoV-2 can invade the support and stem cells of the olfactory epithelium leading to persistent alterations to olfactory function. SARS-CoV-2 infection may induce abnormalities in innate and adaptive immunity including monocyte expansion, T-cell exhaustion, and prolonged cytokine release, which may cause neuroinflammatory responses and microglia activation, white matter abnormalities, and microvascular changes. Additionally, microvascular clot formation can occlude capillaries and endotheliopathy, due to SARS-CoV-2 protease activity and complement activation, can contribute to hypoxic neuronal injury and blood–brain barrier dysfunction, respectively.
Current therapeutics target pathological mechanisms by employing antivirals, decreasing inflammation, and promoting olfactory epithelium regeneration. Thus, from laboratory evidence and clinical trials in the literature, we sought to synthesize the pathophysiological pathways underlying neurological symptoms of long COVID and potential therapeutics.
Source: Leng A, Shah M, Ahmad SA, Premraj L, Wildi K, Li Bassi G, Pardo CA, Choi A, Cho S-M. Pathogenesis Underlying Neurological Manifestations of Long COVID Syndrome and Potential Therapeutics. Cells. 2023; 12(5):816. https://doi.org/10.3390/cells12050816 (Full text)

Effect of Repetitive Transcranial Magnetic Stimulation on Long Coronavirus Disease 2019 with Fatigue and Cognitive Dysfunction

Abstract:

Objectives: There is no established treatment for chronic fatigue and various cognitive dysfunctions (brain fog) caused by long coronavirus disease 2019 (COVID-19). We aimed to clarify the effectiveness of repetitive transcranial magnetic stimulation (rTMS) for treating these symptoms.

Methods: High-frequency rTMS was applied to occipital and frontal lobes in 12 patients with chronic fatigue and cognitive dysfunction 3 months after severe acute respiratory syndrome coronavirus 2 infection. Before and after ten sessions of rTMS, Brief Fatigue Inventory (BFI), Apathy Scale (AS), and Wechsler Adult Intelligence Scale-fourth edition (WAIS4) were determined and N-isopropyl-p-[123I]iodoamphetamine single photon emission computed tomography (SPECT) was performed.

Results: Twelve subjects completed ten sessions of rTMS without adverse events. The mean age of the subjects was 44.3 ± 10.7 years, and the mean duration of illness was 202.4 ± 114.5 days. BFI, which was 5.7 ± 2.3 before the intervention, decreased significantly to 1.9 ± 1.8 after the intervention. The AS was significantly decreased after the intervention from 19.2 ± 8.7 to 10.3 ± 7.2. All WAIS4 sub-items were significantly improved after rTMS intervention, and the full-scale intelligence quotient increased from 94.6 ± 10.9 to 104.4 ± 13.0. Hypoperfusion in the bilateral occipital and frontal lobes observed on SPECT improved in extent and severity after ten sessions of rTMS.

Conclusions: Although we are still in the early stages of exploring the effects of rTMS, the procedure has the potential for use as a new non-invasive treatment for the symptoms of long COVID.

Source: Sasaki N, Yamatoku M, Tsuchida T, Sato H, Yamaguchi K. Effect of Repetitive Transcranial Magnetic Stimulation on Long Coronavirus Disease 2019 with Fatigue and Cognitive Dysfunction. Prog Rehabil Med. 2023 Feb 28;8:20230004. doi: 10.2490/prm.20230004. PMID: 36861061; PMCID: PMC9968785. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9968785/ (Full text)

Investigating brain cortical activity in patients with post-COVID-19 brain fog

Abstract:

Brain fog is a kind of mental problem, similar to chronic fatigue syndrome, and appears about 3 months after the infection with COVID-19 and lasts up to 9 months. The maximum magnitude of the third wave of COVID-19 in Poland was in April 2021.

The research referred here aimed at carrying out the investigation comprising the electrophysiological analysis of the patients who suffered from COVID-19 and had symptoms of brain fog (sub-cohort A), suffered from COVID-19 and did not have symptoms of brain fog (sub-cohort B), and the control group that had no COVID-19 and no symptoms (sub-cohort C). The aim of this article was to examine whether there are differences in the brain cortical activity of these three sub-cohorts and, if possible differentiate and classify them using the machine-learning tools. The dense array electroencephalographic amplifier with 256 electrodes was used for recordings.

The event-related potentials were chosen as we expected to find the differences in the patients’ responses to three different mental tasks arranged in the experiments commonly known in experimental psychology: face recognition, digit span, and task switching. These potentials were plotted for all three patients’ sub-cohorts and all three experiments. The cross-correlation method was used to find differences, and, in fact, such differences manifested themselves in the shape of event-related potentials on the cognitive electrodes.

The discussion of such differences will be presented; however, an explanation of such differences would require the recruitment of a much larger cohort. In the classification problem, the avalanche analysis for feature extractions from the resting state signal and linear discriminant analysis for classification were used. The differences between sub-cohorts in such signals were expected to be found. Machine-learning tools were used, as finding the differences with eyes seemed impossible. Indeed, the A&B vs. C, B&C vs. A, A vs. B, A vs. C, and B vs. C classification tasks were performed, and the efficiency of around 60-70% was achieved.

In future, probably there will be pandemics again due to the imbalance in the natural environment, resulting in the decreasing number of species, temperature increase, and climate change-generated migrations. The research can help to predict brain fog after the COVID-19 recovery and prepare the patients for better convalescence. Shortening the time of brain fog recovery will be beneficial not only for the patients but also for social conditions.

Source: Wojcik GM, Shriki O, Kwasniewicz L, Kawiak A, Ben-Horin Y, Furman S, Wróbel K, Bartosik B, Panas E. Investigating brain cortical activity in patients with post-COVID-19 brain fog. Front Neurosci. 2023 Feb 9;17:1019778. doi: 10.3389/fnins.2023.1019778. PMID: 36845422; PMCID: PMC9947499. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9947499/ (Full text)

Identification of the pathogenic relationship between Long COVID and Alzheimer’s disease by bioinformatics methods

Abstract:

Background: The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused an unprecedented global health crisis. Although many Corona Virus Disease 2019 (COVID-19) patients have recovered, the long-term consequences of SARS-CoV-2 infection are unclear. Several independent epidemiological surveys and clinical studies have found that SARS-CoV-2 infection and Long COVID are closely related to Alzheimer’s disease (AD). This could lead to long-term medical challenges and social burdens following this health crisis. However, the mechanism between Long COVID and AD is unknown.

Methods: Genes associated with Long COVID were collected from the database. Two sets of AD-related clinical sample datasets were collected in the Gene Expression Omnibus (GEO) database by limiting screening conditions. After identifying the differentially expressed genes (DEGs) of AD, the significant overlapping genes of AD and Long COVID were obtained by taking the intersection. Then, four kinds of analyses were performed, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis, protein-protein interaction (PPI) analysis, identification of hub genes, hub gene verification and transcription factors (TFs) prediction.

Results: A total of 197 common genes were selected for subsequent analysis. GO and KEGG enrichment analysis showed that these genes were mainly enriched in multiple neurodegenerative disease related pathways. In addition, 20 important hub genes were identified using cytoHubba. At the same time, these hub genes were verified in another data set, where 19 hub gene expressions were significantly different in the two diseases and 6 hub genes were significantly different in AD patients of different genders. Finally, we collected 9 TFs that may regulate the expression of these hub genes in the Transcriptional Regulatory Relationships Unraveled by Sentence-based Text mining (TRUSST) database and verified them in the current data set.

Conclusion: This work reveals the common pathways and hub genes of AD and Long COVID, providing new ideas for
the pathogenic relationship between these two diseases and further mechanism research.

Source:

Structural brain changes in patients with post-COVID fatigue: a prospective observational study

Summary:

Background: Post-COVID syndrome is a severe long-term complication of COVID-19. Although fatigue and cognitive complaints are the most prominent symptoms, it is unclear whether they have structural correlates in the brain. We therefore explored the clinical characteristics of post-COVID fatigue, describe associated structural imaging changes, and determine what influences fatigue severity.

Methods: We prospectively recruited 50 patients from neurological post-COVID outpatient clinics (age 18–69 years, 39f/8m) and matched non-COVID healthy controls between April 15 and December 31, 2021. Assessments included diffusion and volumetric MR imaging, neuropsychiatric, and cognitive testing. At 7.5 months (median, IQR 6.5–9.2) after the acute SARS-CoV-2 infection, moderate or severe fatigue was identified in 47/50 patients with post-COVID syndrome who were included in the analyses. As a clinical control group, we included 47 matched multiple sclerosis patients with fatigue.

Findings: Our diffusion imaging analyses revealed aberrant fractional anisotropy of the thalamus. Diffusion markers correlated with fatigue severity, such as physical fatigue, fatigue-related impairment in everyday life (Bell score) and daytime sleepiness. Moreover, we observed shape deformations and decreased volumes of the left thalamus, putamen, and pallidum. These overlapped with the more extensive subcortical changes in MS and were associated with impaired short-term memory. While fatigue severity was not related to COVID-19 disease courses (6/47 hospitalised, 2/47 with ICU treatment), post-acute sleep quality and depressiveness emerged as associated factors and were accompanied by increased levels of anxiety and daytime sleepiness.

Interpretation: Characteristic structural imaging changes of the thalamus and basal ganglia underlie the persistent fatigue experienced by patients with post-COVID syndrome. Evidence for pathological changes to these subcortical motor and cognitive hubs provides a key to the understanding of post-COVID fatigue and related neuropsychiatric complications.

Source: Josephine Heine, et al. Structural brain changes in patients with post-COVID fatigue: a prospective observational study. The Lancet, VOLUME 58, 101874, APRIL 2023.  Published: February 27, 2023 DOI: https://doi.org/10.1016/j.eclinm.2023.101874 (Full text)

Brainstem volume changes in myalgic encephalomyelitis/chronic fatigue syndrome and long COVID patients

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID patients have overlapping neurological, autonomic, pain, and post-exertional symptoms. We compared volumes of brainstem regions for 10 ME/CFS (CCC or ICC criteria), 8 long COVID (WHO Delphi consensus), and 10 healthy control (HC) subjects on 3D, T1-weighted MRI images acquired using sub-millimeter isotropic resolution using an ultra-high field strength of 7 Tesla.

Group comparisons with HC detected significantly larger volumes in ME/CFS for pons (p = 0.004) and whole brainstem (p = 0.01), and in long COVID for pons (p = 0.003), superior cerebellar peduncle (p = 0.009), and whole brainstem (p = 0.005). No significant differences were found between ME/CFS and long COVID volumes. In ME/CFS, we detected positive correlations between the pons and whole brainstem volumes with “pain” and negative correlations between the midbrain and whole brainstem volumes with “breathing difficulty.”

In long COVID patients a strong negative relationship was detected between midbrain volume and “breathing difficulty.” Our study demonstrated an abnormal brainstem volume in both ME/CFS and long COVID consistent with the overlapping symptoms.

Source: Thapaliya K, Marshall-Gradisnik S, Barth M, Eaton-Fitch N, Barnden L. Brainstem volume changes in myalgic encephalomyelitis/chronic fatigue syndrome and long COVID patients. Frontiers in Neuroscience, 2023 March 2; 17:1125208. https://www.frontiersin.org/articles/10.3389/fnins.2023.1125208/full (Full text)

The Very Long COVID: Persistence of Symptoms after 12–18 Months from the Onset of Infection and Hospitalization

Abstract:

According to the World Health Organization’s definition, long COVID is the persistence or development of new symptoms 3 months after the initial infection. Various conditions have been explored in studies with up to one-year follow-up but very few looked further. This prospective cohort study addresses the presence of a wide spectrum of symptoms in 121 patients hospitalized during the acute phase of COVID-19 infection, and the association between factors related to the acute phase of the disease and the presence of residual symptoms after one year or longer from hospitalization.
The main results are as follows: (i) post-COVID symptoms persist in up to 60% of the patient population at a mean follow-up of 17 months; (ii) the most frequent symptoms are fatigue and dyspnea, but neuropsychological disturbances persist in about 30% of the patients (iii) when corrected for the duration of follow-up with a freedom-from-event analysis; only complete (2 doses) vaccination at the time of hospital admission remained independently associated with persistence of the major physical symptoms, while vaccination and previous neuropsychological symptoms remained independently associated with persistence of major neuropsychological symptoms.
Source: Ranucci M, Baryshnikova E, Anguissola M, Pugliese S, Ranucci L, Falco M, Menicanti L. The Very Long COVID: Persistence of Symptoms after 12–18 Months from the Onset of Infection and Hospitalization. Journal of Clinical Medicine. 2023; 12(5):1915. https://doi.org/10.3390/jcm12051915 https://www.mdpi.com/2077-0383/12/5/1915 (Full text)

The role of serum brain injury biomarkers in individuals with a mild-to-moderate COVID infection and Long-COVID – results from the prospective population-based COVI-GAPP study

Abstract:

Background During and after mild (no hospitalization) or moderate (hospitalization without ICU) SARS-CoV-2 infections, a wide range of symptoms, including neurological disorders have been reported. It is, however, unknown if these neurological symptoms are associated with brain injury and whether brain injury and related symptoms also emerge in patients suffering from Long-COVID. Neuronal biomarkers such as serum neurofilament light chain and glial fibrillary acidic protein can be used to elucidate neuro-axonal and astroglial injuries. We therefore investigated whether these biomarkers are associated with the COVID-19 infection status (mild-to-moderate), the associated symptoms and Long-COVID.

Methods From 146 individuals of the general population with a post-acute, mild-to-moderate SARS-CoV-2 infection, serum neurofilament light chain (sNfL; marker of intra-axonal neuronal injury) and serum glial fibrillary acidic protein (sGFAP; marker of astrocytic activation/injury) were measured. Samples were taken before, during and after (five and ten months) a SARS-CoV-2 infection. Individual symptoms and Long-COVID status were assessed using questionnaires.

Results Neurological symptoms were described for individuals after a mild and moderate COVID-19 infection, however, serum markers of brain injury (sNfL/sGFAP) did not change after an infection (sNfL: P = 0.74; sGFAP: P = 0.24) and were not associated with headache (P = 0.51), fatigue (P = 0.93), anosmia (P = 0.77) and ageusia (P = 0.47). In participants with Long-COVID, sGFAP (P = 0.038), but not sNfL (P = 0.58) significantly increased but was not associated with neurological symptoms.

Conclusion Neurological symptoms in individuals after a mild-to-moderate SARS-CoV-2 infection with and without Long-COVID were not associated with brain injury, although there was some astroglial injury observed in Long-COVID patients.

Source: Julia Telser, Kirsten Grossmann, Ornella C Weideli, Dorothea Hillmann, Stefanie Aeschbacher, Niklas Wohlwend, Laura Velez, Jens Kuhle, Aleksandra Maleska, Pascal Benkert, Corina Risch, David Conen, Martin Risch, Lorenz Risch. The role of serum brain injury biomarkers in individuals with a mild-to-moderate COVID infection and Long-COVID – results from the prospective population-based COVI-GAPP study. medRxiv 2023.02.15.23285972; doi: https://doi.org/10.1101/2023.02.15.23285972 https://www.medrxiv.org/content/10.1101/2023.02.15.23285972v1.full-text (Full text)

Racial, ethnic, and sex disparities in the incidence and cognitive symptomology of long COVID-19

Abstract:

Background: The pandemic has highlighted and exacerbated health inequities in both acute coronavirus disease 2019 (COVID-19) and its longer-term sequelae. Given the heterogeneity in definitions of long COVID and the lack of centralized registries of patients with the disease, little is known about the differential prevalence among racial, ethnic, and sex subgroups. This study examines long COVID among Black, White, Asian, and Hispanic Americans and evaluates differences in the associated cognitive symptomology.

Method: Data from four releases of the Census Bureau’s Household Pulse Survey detailing COVID-19 incidence and the duration and type of symptoms among a nationally representative sample of adults from June 1, 2022, through October 17, 2022, were combined. Binary logistic regression assessed the relative likelihood of long COVID among those who had been diagnosed COVID between racial, ethnic, and sex subgroups. Among those reporting long COVID, differences in the prevalence of difficulty understanding and difficulty remembering were assessed. Empirical models accounted for household, regional, vaccination, and insurance differences between respondents. Two-stage selection models were applied to test the robustness of the results.

Results: Among respondents who tested positive for COVID-19, Blacks (OR=1.097, CI=1.034-1.163), females (OR=1.849, CI=1.794-1.907), and Hispanics (OR=1.349, CI=1.286-1.414) were more likely to experience long COVID (symptoms lasting for 3 months or longer) compared to Whites, males, and non-Hispanics respectively. However, those with private health insurance (OR=0.634, CI=0.611-0.658) and who received the COVID vaccine (OR=0.901, CI=0.864-0.94) were less likely to have endured COVID symptoms than their counterparts. Symptoms of long COVID varied significantly between population subgroups. Compared to Whites, Blacks were more likely to have trouble remembering (OR=1.878, CI=1.765-1.808) while Hispanics were more likely to report difficult understanding (OR=1.827, CI=1.413, 2.362). Females, compared to males, were less likely to experience trouble understanding (OR=0.664, CI=0.537, 0.821), but more likely to report trouble remembering (OR=1.34, CI=1.237, 1.451).

Conclusions: Long COVID is more prevalent among Blacks, Hispanics, and females, but each group appears to experience long COVID differently. Therefore, additional research is needed to determine the best method to treat and manage this poorly understood condition.

Source: Jacobs MM, Evans E, Ellis C. Racial, ethnic, and sex disparities in the incidence and cognitive symptomology of long COVID-19. J Natl Med Assoc. 2023 Feb 13:S0027-9684(23)00025-1. doi: 10.1016/j.jnma.2023.01.016. Epub ahead of print. PMID: 36792456; PMCID: PMC9923441. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9923441/ (Full text)