Tag: long covid symptoms

Brainstem Reduction and Deformation in the 4th Ventricle Cerebellar Peduncles in Long COVID Patients: Insights into Neuroinflammatory Sequelae and “Broken Bridge Syndrome”

Abstract:

Post-COVID Syndrome (PCS), also known as Long COVID, is characterized by persistent and often debilitating neurological sequelae, including fatigue, cognitive dysfunction, motor deficits, and autonomic dysregulation (Dani et al., 2021). This study investigates structural and functional alterations in the brainstem and cerebellar peduncles of individuals with PCS using diffusion tensor imaging (DTI) and volumetric analysis. Forty-four PCS patients (15 bedridden) and 14 healthy controls underwent neuroimaging. Volumetric analysis focused on 22 brainstem regions, including the superior cerebellar peduncle (SCP), middle cerebellar peduncle (MCP), periaqueductal gray (PAG), and midbrain reticular formation (mRt).

Significant volume reductions were observed in the SCP (p < .001, Hedges’ g = 3.31) and MCP (p < .001, Hedges’ g = 1.77), alongside decreased fractional anisotropy (FA) in the MCP, indicative of impaired white matter integrity. FA_Avg fractional anisotropy average tested by FreeSurfer Tracula, is an index of white matter integrity, reflecting axonal fiber density, axonal diameter and myelination. These neuroimaging findings correlated with clinical manifestations of motor incoordination, proprioceptive deficits, and autonomic instability. Furthermore, volume loss in the dorsal raphe (DR) and midbrain reticular formation suggests disruption of pain modulation and sleep-wake cycles, consistent with patient-reported symptoms.

Post-mortem studies provide supporting evidence for brainstem involvement in COVID-19. Radtke et al. (2024) reported activation of intracellular signaling pathways and release of immune mediators in brainstem regions of deceased COVID-19 patients, suggesting an attempt to inhibit viral spread. While viral genetic material was detectable, infected neurons were not observed. Matschke et al. (2020) found that microglial activation and cytotoxic T lymphocyte infiltration were predominantly localized to the brainstem and cerebellum, with limited involvement of the frontal lobe. This aligns with clinical observations implicating the brainstem in PCS pathophysiology. Cell-specific expression analysis of genes contributing to viral entry (ACE2, TMPRSS2, TPCN2, TMPRSS4, NRP1, CTSL) in the cerebral cortex showed their presence in neurons, glial cells, and endothelial cells, indicating the potential for SARS-CoV-2 infection of these cell types. Associations with autoimmune diseases with specific autoantibodies, including beta-2 and M-2 against G-protein coupled alpha-1, beta-1, beta-2 adrenoceptors against angiotensin II type 1 receptor or M1,2,3-mAChR, among others, voltage-gated calcium channels (VGCC) are known (Blitshteyn et al. 2015 and Wallukat and Schminke et al. 2014).

These findings support the “Broken Bridge Syndrome” hypothesis, positing that structural disconnections between the brainstem and cerebellum contribute to PCS symptomatology. Furthermore, we propose that chronic activation of the Extended Autonomic System (EAS), encompassing the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system, may perpetuate these symptoms (Goldstein, 2020). Perturbations in this system may relate to the elevation of toxic autoantibodies AABs (Beta-2 and M-2), specific epitopes of the COVID virus’s SPIKE protein and Cytokine storm of IL-1, IL-6, and IL-8 in their increased numbers (1,000->10,000)

Further research is warranted to elucidate the underlying neuroinflammatory mechanisms, EAS dysregulation, and potential therapeutic interventions for PCS

Source: Ziaja Peter Christof, Young Yvette Susanne, Stark Sadre-Chirazi Michael, Lindner Thomas, Zurék Grzegorz, Sedlacik Jan. Brainstem Reduction and Deformation in the 4th Ventricle Cerebellar Peduncles in Long COVID Patients: Insights into Neuroinflammatory Sequelae and “Broken Bridge Syndrome” medRxiv 2025.04.08.25325108; doi: https://doi.org/10.1101/2025.04.08.25325108 https://www.medrxiv.org/content/10.1101/2025.04.08.25325108v1.full-text (Full text)

Identifying commonalities and differences between EHR representations of PASC and ME/CFS in the RECOVER EHR cohort

Abstract:

Background: Shared symptoms and biological abnormalities between post-acute sequelae of SARS-CoV-2 infection (PASC) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) could suggest common pathophysiological bases and would support coordinated treatment efforts. Empirical studies comparing these syndromes are needed to better understand their commonalities and differences.

Methods: We analyzed electronic health record data from 6.5 million adult patients from the National COVID Cohort Collaborative. PASC and ME/CFS diagnostic groups were defined based on recorded diagnoses, and other recorded conditions within the two groups were used to train separate machine learning-driven computable phenotypes (CPs). The most predictive conditions for each CP were examined and compared, and the overlap of patients labeled by each CP was examined. Condition records from the diagnostic groups were also used to statistically derive condition clusters. Rates of subphenotypes based on these clusters were compared between PASC and ME/CFS groups.

Results: Approximately half of patients labeled by one CP are also labeled by the other. Dyspnea, fatigue, and cognitive impairment are the most-predictive conditions shared by both CPs, whereas other most-predictive conditions are specific to one CP. Recorded conditions separate into cardiopulmonary, neurological, and comorbidity clusters, with the cardiopulmonary cluster showing partial specificity for the PASC groups.

Conclusions: Data-driven approaches indicate substantial overlap in the condition records associated with PASC and ME/CFS diagnoses. Nevertheless, cardiopulmonary conditions are somewhat more commonly associated with PASC diagnosis, whereas other conditions, such as pain and sleep disturbances, are more associated with ME/CFS diagnosis. These findings suggest that symptom management approaches to these illnesses could overlap.

Source: Powers JP, McIntee TJ, Bhatia A, Madlock-Brown CR, Seltzer J, Sekar A, Jain N, Hornig M, Seibert E, Leese PJ, Haendel M, Moffitt R, Pfaff ER; N3C Consortium and RECOVER-EHR. Identifying commonalities and differences between EHR representations of PASC and ME/CFS in the RECOVER EHR cohort. Commun Med (Lond). 2025 Apr 11;5(1):109. doi: 10.1038/s43856-025-00827-5. PMID: 40210986. https://www.nature.com/articles/s43856-025-00827-5 (Full text)

Health outcomes one year after Omicron infection among 12,789 adults: a community-based cross-sectional study

Summary:

Background: Characterizing the paradigm and impact of long COVID is crucial for addressing this worldwide health challenge. This study aimed to investigate the prevalence of long COVID one year after primary Omicron infection and characterize differences in long-term health consequence between participants with persistent long COVID and those who fully recovered.

Methods: This a community-based cross-sectional study conducted from December 2023 to March 2024 at the China-Japan Friendship Hospital and 16 administrative districts in Beijing. 12,789 participants infected with Omicron between December 2022 and January 2023 were recruited through stratified multistage random sampling and included in the final analysis. Of them, 376 participants with persistent long COVID and 229 without long COVID were matched for further physical examinations. The primary outcome was the prevalence of long COVID one year after infection. Secondary outcomes included muscle strength, exercise capacity, health-related quality of life (HRQoL), mental health, work status, laboratory tests, and examinations.

Findings: Among 12,789 participants (media [IQR] age, 48.4 [37.3 to 61.4] years; 7817 females [61.1%]), 995 of them (7.8%) experienced long COVID within one year, with 651 (5.1%) having persistent symptoms. Fatigue (598/995 [60.1%]) and post-exertional malaise (367/995 [36.9%]) were the most common symptoms. Brain fog had the lowest resolution proportion as 4.2% within one year. The odds of long COVID increased with reinfections (odds ratios for one reinfection 2.592 [95% CI: 2.188 to 3.061]; two or more: 6.171 [3.227 to 11.557]; all p < 0.001). Participants with persistent long COVID had markedly lower muscle strength (upper-limb: 26.9 ± 12.4 vs. 29.1 ± 14.5 Kg; lower-limb: 40.0 [27.0 to 62.0] vs. 43.0 [28.0 to 59.0] s), worse exercise capacity and poorer HRQoL, and meaningful difference in laboratory tests results compared to those without long COVID. They also exhibited significantly higher proportions of abnormal lung function (FEV1 %pred<80%: 13.0% vs. 2.0%; DLco %pred<80%: 32.7% vs. 19.9%) and lung imaging abnormalities (23.5% vs. 13.6%).

Interpretation: The considerable health burden of long COVID and the progression of neurological symptoms following Omicron infection warrant close monitoring. Utilizing professional questionnaires and developing reliable diagnostic tools are necessary for improving diagnosis and treatment of long COVID.

Funding: This work was supported by Beijing Research Center for Respiratory Infectious Diseases (BJRID2024-012), Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (2022-I2M-CoV19-005/CIFMS 2021-I2M-1-048), the National Natural Science Foundation of China (82241056/82200114/82200009), the New Cornerstone Science Foundation.

Source: Zhang, Hui et al.Health outcomes one year after Omicron infection among 12,789 adults: a community-based cross-sectional study. The Lancet Regional Health – Western Pacific, Volume 0, Issue 0, 101507  https://www.thelancet.com/journals/lanwpc/article/PIIS2666-6065(25)00044-6/fulltext (Full text)

Novel Oronasal Drainage for Long COVID: Proposed Mechanisms-Case Report

Abstract:

Long COVID, potentially emerging post COVID-19 infection, involves extreme health challenges. Based on current literature in the field, we propose a novel approach to Long COVID treatment based on epipharyngeal abrasive therapy targeting ostia of the oral and nasal mucosa, having been identified for the first time. The presented case report documents the application of innovative oronasal drainage (OND), a novel treatment integrating physiological, biochemical, and fluid mechanical components simultaneously.

OND led to remarkable improvements and even remissions of various symptoms, along with enhanced hand blood circulation. While the case suggests potential efficacy in Long COVID therapy, acknowledging inherent limitations is essential and its impact needs further validation through clinical trials.

Source: Lorenz C, Frankenberger R. Novel Oronasal Drainage for Long COVID: Proposed Mechanisms-Case Report. Viruses. 2025 Jan 31;17(2):210. doi: 10.3390/v17020210. PMID: 40006965. https://www.mdpi.com/1999-4915/17/2/210 (Full text)

Post-COVID-19 Small Fiber Neuropathy as a New Emerging Quality of Life-Threatening Disease: A Systematic Review

Abstract:

Post-acute sequelae of COVID-19 (PASC) syndrome is considered an emergent and diffuse multidisciplinary problem. Compelling evidence suggests that COVID-19 increases symptoms of pre-existent small fiber neuropathy (SFN) and might trigger de novo onset of SFN. In this systematic review, for the first time, we provide a comprehensive overview of the clinical and diagnostic features of PASC-SFN, including the accompanying disorders, disease evolution, and possible treatments, described in the recent literature.
Following infection, many patients reported a wide range of symptoms and complications, not self-limiting and independent from previous infection severity. SFN begins more frequently with distal limb burning pain and numbness, which accompany other dysautonomia, cognitive, visual, and osteoarticular disorders involving multiple organ systems. In an initial diagnostic suspicion, some tests might be useful as complementary examinations, such as nerve quantitative sensory testing, electromyography, and optic nerve tomography. Otherwise, definite diagnosis is reached with skin biopsy as the gold standard, along with corneal in vivo microscopy when ocular discomfort is present.
Being a long-term condition, multiple and dissimilar symptomatic and disease-modifying drugs were employed for the treatment of this condition with the achievement of partial results, including steroids, pregabalin, gabapentin, duloxetine, vitamins, homotaurine and phosphatidylserine, alpha lipoic acid, immunosuppressants, and intravenous immunoglobulin therapy. PASC-SFN is a complex emerging disease and extremely challenging for physicians. At present, the only feasible management of PASC-SFN is represented by a multidisciplinary tailored approach, with future definitive protocols for diagnosis and treatment deemed essential.
Source: Bandinelli F, Di Carlo M, Colantuono VA, Nozzoli F, Salaffi F, Chiocchetti B, Nucci E, Mastricci A, Gherardi E, Manetti M. Post-COVID-19 Small Fiber Neuropathy as a New Emerging Quality of Life-Threatening Disease: A Systematic Review. Microorganisms. 2025; 13(2):328. https://doi.org/10.3390/microorganisms13020328 https://www.mdpi.com/2076-2607/13/2/328 (Full text)

Exploring DNA methylation, telomere length, mitochondrial DNA, and immune function in patients with Long-COVID

Abstract:

Background: Long-COVID is defined as the persistency or development of new symptoms 3 months after the initial SARS-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation. Common persistent symptoms are fatigue, sleep disturbances, post-exertional malaise (PEM), pain, and cognitive problems. Long-COVID is estimated to be present in about 65 million people. We aimed to explore clinical and biological factors that might contribute to Long-COVID.

Methods: Prospective longitudinal cohort study including patients infected with SARS-CoV-2 between March 2020 and March 2022. Patients were assessed between 4 and 12 months after infection at the COVID follow-up clinic at UZ Leuven. We performed a comprehensive clinical assessment (including questionnaires and the 6-min walking test) and biological measures (global DNA methylation, telomere length, mitochondrial DNA copy number, inflammatory cytokines, and serological markers such as C-reactive protein, D-dimer, troponin T).

Results: Of the 358 participants, 328 were hospitalised, of which 130 had severe symptoms requiring intensive care admission; 30 patients were ambulatory referrals. Based on their clinical presentation, we could identify 6 main clusters. One-hundred and twenty-seven patients (35.4%) belonged to at least one cluster. The bigger cluster included PEM, fatigue, sleep disturbances, and pain (n = 57). Troponin T and telomere shortening were the two main markers predicting Long-COVID and PEM-fatigue symptoms.

Conclusions: Long-COVID is not just one entity. Different clinical presentations can be identified. Cardiac involvement (as measured by troponin T levels) and telomere shortening might be a relevant risk factor for developing PEM-fatigue symptoms and deserve further exploring.

Source: Polli A, Godderis L, Martens DS, Patil MS, Hendrix J, Wyns A, Van Campenhout J, Richter E, Fanning L, Vandekerckhove O, Claeys E, Janssens W, Lorent N. Exploring DNA methylation, telomere length, mitochondrial DNA, and immune function in patients with Long-COVID. BMC Med. 2025 Feb 4;23(1):60. doi: 10.1186/s12916-025-03881-x. PMID: 39901177; PMCID: PMC11792217. https://pmc.ncbi.nlm.nih.gov/articles/PMC11792217/ (Full text)

Digital health app data reveals an effect of ovarian hormones on long COVID and myalgic encephalomyelitis symptoms

Abstract:

Background. Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) disproportionately affect females, suggesting modulation by sex hormones. We sought to investigate whether symptom severity is influenced by changes in sex hormones over the menstrual cycle, or by hormonal contraception.

Methods: We carried out a retrospective analysis of menstrual and symptom data, prospectively collected via the Visible app from individuals with long COVID, ME/CFS, or both, who had regular menstrual cycles, between 7 September 2022 and 6 March 2024. Mixed-effects models were used to examine associations between symptom severity, menstrual cycle phase and contraception type.

Findings: 948 users were included; 100% of users were female and 92.6% identified as women. The most tracked symptoms were fatigue (99.5% of users), brain fog (88.3%), headaches (85.1%) and muscle aches (78.6%). All menstrual cycle phases showed a modest, but significant, improvement compare to the menstrual phase, most markedly in the early luteal (IRR 0.963%, 95% CI: 0.958 – 0.968), but also the follicular (IRR = 0.985, 95% CI: 0.981 – 0.990) and late luteal phase (IRR = 0.980, 95% CI: 0.974-0.985). Crashes (sudden and severe worsening of symptoms following exertion) were significantly more frequent during menstruation than in other phases. Users of combined hormonal contraception (n=70) had a statistically significant reduction in overall symptom score (OR = 0.827, 95% CI: 0.690 – 0.992) and crash incidence (OR = 0.548, 95% CI: 0.350 – 0.856) compared to those not using hormonal contraception (=786).

Interpretation: Menstruation is associated with worsened symptoms in long COVID and ME/CFS. Users of combined hormonal contraception report a lower symptom burden than non-users, suggesting a modulatory role of ovarian hormones. These findings could empower menstruating people living with long COVID and ME/CFS to anticipate cyclical changes in symptoms and plan their activities accordingly, and could also inform their use of contraception.

Source: Abigail Goodship, Rory Preston, Joseph T Hicks, Harry Leeming, Christian Morgenstern, Victoria Male. Digital health app data reveals an effect of ovarian hormones on long COVID and myalgic encephalomyelitis symptoms. medRxiv 2025.01.24.25321092; doi: https://doi.org/10.1101/2025.01.24.25321092 https://www.medrxiv.org/content/10.1101/2025.01.24.25321092v1 (Full text available as PDF file)

Hippocampal subfield volume alterations and associations with severity measures in long COVID and ME/CFS: A 7T MRI study

Abstract:

Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients share similar symptoms including post-exertional malaise, neurocognitive impairment, and memory loss. The neurocognitive impairment in both conditions might be linked to alterations in the hippocampal subfields. Therefore, this study compared alterations in hippocampal subfields of 17 long COVID, 29 ME/CFS patients, and 15 healthy controls (HC).

Structural MRI data was acquired with sub-millimeter isotropic resolution on a 7 Telsa MRI scanner and hippocampal subfield volumes were then estimated for each participant using FreeSurfer software. Our study found significantly larger volumes in the left hippocampal subfields of both long COVID and ME/CFS patients compared to HC.

These included the left subiculum head (long COVID; p = 0.01, ME/CFS; p = 0.002,), presubiculum head (long COVID; p = 0.004, ME/CFS; p = 0.005), molecular layer hippocampus head (long COVID; p = 0.014, ME/CFS; p = 0.011), and whole hippocampal head (long COVID; p = 0.01, ME/CFS; p = 0.01). Notably, hippocampal subfield volumes were similar between long COVID and ME/CFS patients.

Additionally, we found significant associations between hippocampal subfield volumes and severity measures of ‘Pain’, ‘Duration of illness’, ‘Severity of fatigue’, ‘Impaired concentration’, ‘Unrefreshing sleep’, and ‘Physical function’ in both conditions. These findings suggest that hippocampal alterations may contribute to the neurocognitive impairment experienced by long COVID and ME/CFS patients. Furthermore, our study highlights similarities between these two conditions.

Source: Thapaliya K, Marshall-Gradisnik S, Eaton-Fitch N, Barth M, Inderyas M, Barnden L. Hippocampal subfield volume alterations and associations with severity measures in long COVID and ME/CFS: A 7T MRI study. PLoS One. 2025 Jan 13;20(1):e0316625. doi: 10.1371/journal.pone.0316625. PMID: 39804864; PMCID: PMC11729965. https://pmc.ncbi.nlm.nih.gov/articles/PMC11729965/ (Full text)

More than “Brain Fog”: Cognitive Dysfunction and the Role of Occupational Therapy in Long COVID

Abstract:

Long COVID is a disabling condition which affects occupational performance and quality of life. It interferes with activities of daily living, work, and many meaningful life roles. Cognitive dysfunction is a frequently reported symptom, yet it is commonly overlooked. It is important that cognitive activity is considered when working with people with long COVID, particularly when identifying triggers of post exertional symptom exacerbation. There are many potential mechanisms that could be driving cognitive dysfunction in long COVID including neuroinflammation, viral persistence, vascular damage, and orthostatic intolerance. It is important to consider these to help guide intervention.

The purpose of this clinical perspective is to highlight the debilitating impact of cognitive dysfunction in those with long COVID and share the key role of occupational therapists in this area. Cognitive dysfunction may be missed on standardized assessments as they may not be sensitive enough due to the episodic nature of symptoms. Occupational therapists can play a key role in this area as they are experts in assessing occupational performance and in providing safe cognitive assessment and rehabilitation.

Source: Skiffington, Helen OT, BSc Hons1,2; Breen, Ciara MSc, HCM3,4,5. More than “Brain Fog”: Cognitive Dysfunction and the Role of Occupational Therapy in Long COVID. Cardiopulmonary Physical Therapy Journal 36(1):p 39-49, January 2025. | DOI: 10.1097/CPT.0000000000000274 https://journals.lww.com/cptj/fulltext/2025/01000/more_than__brain_fog___cognitive_dysfunction_and.7.aspx (Full text)

Phase-dependent trends in the prevalence of myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) related to long COVID: A criteria-based retrospective study in Japan

Abstract:

Background: The characteristics of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) related to COVID-19 have remained uncertain. To elucidate the clinical trend of ME/CFS induced by long COVID, we examined data for patients who visited our outpatient clinic established in a university hospital during the period from Feb 2021 to July 2023.

Methods: Long COVID patients were classified into two groups, an ME/CFS group and a non-ME/CFS group, based on three diagnostic criteria.

Results: The prevalence of ME/CFS in the long COVID patients was 8.4% (62 of 739 cases; female: 51.6%) and factors related to ME/CFS were severe illness, smoking and alcohol drinking habits, and fewer vaccinations. The frequency of ME/CFS decreased from 23.9% in the Preceding period to 13.7% in the Delta-dominant period and to 3.3% in the Omicron-dominant period. Fatigue and headache were commonly frequent complaints in the ME/CFS group, and the frequency of poor concentration in the ME/CFS group was higher in the Omicron period. Serum ferritin levels were significantly higher in female patients in the ME/CFS group infected in the Preceding period. In the ME/CFS group, the proportion of patients complaining of brain fog significantly increased from 22.2% in the Preceding period to 47.9% in the Delta period and to 81.3% in the Omicron period. The percentage of patients who had received vaccination was lower in the ME/CFS group than the non-ME/CFS group over the study period, whereas there were no differences in the vaccination rate between the groups in each period.

Conclusion: The proportion of long COVID patients who developed ME/CFS strictly diagnosed by three criteria was lower among patients infected in the Omicron phase than among patients infected in the other phases, while the proportion of patients with brain fog inversely increased. Attention should be paid to the variant-dependent trends of ME/CFS triggered by long COVID (300 words).

Source: Morita S, Tokumasu K, Otsuka Y, Honda H, Nakano Y, Sunada N, Sakurada Y, Matsuda Y, Soejima Y, Ueda K, Otsuka F. Phase-dependent trends in the prevalence of myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) related to long COVID: A criteria-based retrospective study in Japan. PLoS One. 2024 Dec 9;19(12):e0315385. doi: 10.1371/journal.pone.0315385. PMID: 39652555; PMCID: PMC11627433. https://pmc.ncbi.nlm.nih.gov/articles/PMC11627433/ (Full text)