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)

People with Long Covid and ME/CFS Exhibit Similarly Impaired Balance and Physical Capacity: A Case-Case-Control Study

Abstract:

Purpose: Postural sway and physical capacity had not previously been compared between people with long COVID and people with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Therefore, this study determined postural sway and physical capacity in people with long COVID (∼16 month illness duration; n=21) and ME/CFS (∼16 year illness duration; n=20), versus age-matched healthy controls (n=20).

Methods: Postural sway was during a 30 s static stand test. Physical capacity was determined using the timed up and go test and five times sit to stand test. Throughout, participants wore isoinertial measurement units.

Results: Postural sway was worse (i.e. greater) in people with long COVID and ME/CFS than controls, but not different between long COVID and ME/CFS. Performance of the timed up and go test and five times sit to stand test were worse in long COVID and ME/CFS than controls, but not different between long COVID and ME/CFS. 87% and 13% of long COVID and ME/CFS participants exceeded the threshold for muscle weakness in the five times sit to stand test and timed up and go test, respectively.

Conclusions: These data suggest that both people with long COVID and people with ME/CFS have similarly impaired balance and physical capacity. Therefore, there is an urgent need for interventions to target postural sway and physical capacity in people with ME/CFS, and given the current pandemic, people with long COVID.

Source: Lawrence D. Hayes, PhD, Nilihan E.M. Sanal-Hayes, PhD, Marie Mclaughlin, PhD, Ethan C.J. Berry, BSc (Hons), Nicholas F. Sculthorpe, PhD. People with Long Covid and ME/CFS Exhibit Similarly Impaired Balance and Physical Capacity: A Case-Case-Control Study. The American Journal of Medicine. Published: July 23, 2023 DOI: https://doi.org/10.1016/j.amjmed.2023.06.028 https://www.amjmed.com/article/S0002-9343(23)00465-5/fulltext#%20

Hypothesis: Matrix metalloproteinase inhibition with low-dose doxycycline in Long COVID and ME/CFS

Abstract:

Nonselective matrix metalloproteinase (MMP) inhibition with FDA approved subantimicrobial dose doxycycline formulations could improve systemic symptoms in at least a subset of patients with Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) as compared to those who receive placebo.

Source: Sanders, E.C. (2023). Hypothesis: Matrix metalloproteinase inhibition with low-dose doxycycline in Long COVID and ME/CFS. Patient-Generated Hypotheses Journal for Long COVID & Associated Conditions, Vol. 1, 21-29 https://patientresearchcovid19.com/hypothesis-matrix-metalloproteinase-inhibition-with-low-dose-doxycycline-in-long-covid-and-me-cfs-pghj-issue1-may2023/ (Full text)

Hypothesis: Symptomatic myodesopsia/vitreous floaters may constitute a risk factor for Long COVID and ME/CFS

Abstract:

The ophthalmological condition known as myodesopsia or vitreous floaters results from aggregates of proteins or cellular debris in the vitreous body casting shadows onto the retina that are perceived as objects moving through the visual field. While this is commonly viewed as a benign condition associated with aging, a growing body of research suggests that for some patients it can severely impact visual function and quality of life. Myodesopsia is often caused by posterior vitreous detachment, but can also result from other conditions such as asteroid hyalosis, uveitis, or myopic vitreopathy.

There are strong reasons to suspect that its presence may be indicative of a susceptibility to collagen degradation in response to inflammatory triggers, which may represent a risk factor for the development of Long COVID, ME/CFS, or related chronic illnesses. Evidence for such susceptibility includes the presence of collagen-degrading enzymes in the vitreous, associations with other connective tissue disorders, and links between myodesopsia and infections with various pathogens.

Source: Mazewski, M. (2023). Hypothesis: Symptomatic myodesopsia/vitreous floaters may constitute a risk factor for Long COVID and ME/CFS. Patient-Generated Hypotheses Journal for Long COVID & Associated Conditions, Vol. 1, 13-20 https://patientresearchcovid19.com/hypothesis-symptomatic-myodesopsia-vitreous-floaters-may-constitute-a-risk-factor-for-long-covid-and-me-cfs-pghj-issue1-may2023/ (Full text)

Hypothesis: Astrocyte dysregulation of sympathetic nervous system causes metabolic dysfunction in subset of Long COVID and ME/CFS patients

Abstract:

An overactive sympathetic nervous system (SNS) may cause one subtype of Long COVID. People who are genetically at risk for noradrenergic nerve problems may develop an overactive SNS after an infection. Alternatively, genetic or virus-induced dysregulation of astrocytes could lead to overactivation of the SNS. An overactive SNS could disrupt regulation of immune cells, energy metabolism, sleep homeostasis, respiratory rate, gastrointestinal function, and systemic and cerebral blood pressure, causing fatigue and cognitive dysfunction.

Hypothesis: Long COVID refers to symptoms that continue for more than four weeks after onset of acute COVID-19 illness. This umbrella term includes a wide variety of symptoms and presentations. Long COVID patients may have different types of biological dysfunction, meaning that there may be distinct subtypes of Long COVID. One possible subtype is sympathetic nervous system (SNS) over-activation. This subtype may exist in both Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)1.

Underlying mechanisms of the SNS overactivation subtype: Theoretically, patients with this subtype already have a genetic dysregulation of neuronal norepinephrine (NE) release/clearance or noradrenergic receptor sensitivity2. This latent genetic dysfunction of NE signaling may not cause significant problems unless there is a trigger that causes excess NE release.

As NE affects immune cell signaling, this could result in an over-activation or prolonged activation of the immune system in response to infection with SARS-CoV-2, the virus that causes COVID-193 . This subtype could explain why ME/CFS is often triggered by a virus or brain injury, as these occurrences can trigger noradrenergic signaling3.

Possible mechanisms for the SNS overactivation subtype include viral reservoirs, antibody reaction, and dysregulation of noradrenergic receptor expression. In Long COVID patients, viral antigens and reservoirs that remain in the body long after the initial infection may keep the overactive immune system in an inflammatory state4,5. A healthy person may not react to these SARS-CoV-2 reservoirs, as their functional immune cells should develop immune tolerance. Another possibility is that the immune system is reacting to SARS-CoV-2 antibodies.

Finally, it is possible that excess extracellular NE could keep the SNS and noradrenergic systems in the brain stuck in an overactive state. A prolonged period of increased levels of extracellular NE could lead to dysregulation of noradrenergic receptor expression. The excess extracellular NE may be due to a prolonged release of excess NE during the initial infection, or a failure of the negative feedback mechanisms that should reduce NE release.

Symptoms of an overactive SNS: An overactive SNS explains many of the symptoms found in Long COVID patients, such as IBS/gastrointestinal symptoms6, heart palpitations7, and sleep disturbance8. Additionally, in orthostatic intolerance, which is common in Long COVID and ME/CFS, the release of NE causes pronounced tachycardia. This rapid heart rate may cause palpitations, breathlessness, and chest pain.

Dysfunctional energy metabolism causes fatigue and cognitive dysfunction: An important piece of the puzzle is to explain how a dysregulated SNS could lead to chronic fatigue and brain fog (cognitive dysfunction). The most likely explanation is a dysregulation of metabolic function. There are many ways excess NE could affect metabolism, including enhancing aerobic glycolysis and depleting glycogen stores.

Source: Carnac, T. (2023). Hypothesis: Astrocyte dysregulation of sympathetic nervous system causes metabolic dysfunction in subset of Long COVID and ME/CFS patients. Patient-Generated Hypotheses Journal for Long COVID & Associated Conditions, Vol. 1, 36-43 https://patientresearchcovid19.com/hypothesis-astrocyte-dysregulation-of-sympathetic-nervous-system-causes-metabolic-dysfunction-in-subset-of-long-covid-and-me-cfs-patients-pghj-issue1-may2023/ (Full text)

Utility of Serum Ferritin for Predicting Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in Patients with Long COVID

Abstract:

Objective: The most common symptom of post-acute coronavirus disease 2019 (COVID-19) is fatigue, and it potentially leads to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS); however, a specific prognosticator is lacking. We aimed to elucidate the clinical characteristics of patients who developed ME/CFS after COVID-19.
Methods: In this retrospective observational study, patients who visited Okayama University Hospital for long COVID between February 2021 and March 2022 were investigated.
Results: Of the 234 patients, 139 (59.4%) had fatigue symptoms. Fifty patients with fatigue symptoms (21.4%) met the criteria for ME/CFS (ME/CFS group), while the other 89 patients did not (non-ME/CFS group); 95 patients had no fatigue complaints (no-fatigue group). Although the patients’ backgrounds were not significantly different between the three groups, the ME/CFS group presented the highest scores on the self-rating symptom scales, including the Fatigue Assessment Scale (FAS), EuroQol, and the Self-Rating Depression Scale (SDS). Furthermore, serum ferritin levels, which were correlated with FAS and SDS scores, were significantly higher in the ME/CFS group (193.0 μg/mL, interquartile range (IQR): 58.8–353.8) than in the non-ME/CFS group (98.2 μg/mL, 40.4–251.5) and no-fatigue group (86.7 μg/mL, 37.5–209.0), and a high serum ferritin level was prominent in female patients. Endocrine workup further showed that the ME/CFS group had higher thyrotropin levels but lower growth hormone levels in serum and that insulin-like growth factor-I levels were inversely correlated with ferritin levels (R = −0.328, p < 0.05).
Conclusions: Serum ferritin level is a possible predictor of the development of ME/CFS related to long COVID, especially in female patients.
Source: Yamamoto Y, Otsuka Y, Tokumasu K, Sunada N, Nakano Y, Honda H, Sakurada Y, Hasegawa T, Hagiya H, Otsuka F. Utility of Serum Ferritin for Predicting Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in Patients with Long COVID. Journal of Clinical Medicine. 2023; 12(14):4737. https://doi.org/10.3390/jcm12144737 https://www.mdpi.com/2077-0383/12/14/4737 (Full text)

Fatigue presentation, severity, and related outcomes in a prospective cohort following post-COVID-19 hospitalization in British Columbia, Canada

Abstract:

Introduction: Increasing evidence on long-term health outcomes following SARS CoV-2 infection shows post-viral symptoms can persist for months. These symptoms are often consistent with those of Myalgic Encephalomyelitis or Chronic Fatigue Syndrome (ME/CFS). The aim of the present study was to examine the prevalence and outcome predictors of post-viral fatigue and related symptoms 3- and 6-months following symptom onset.

Methods: A prospective cohort of patients hospitalized with Coronavirus disease (COVID-19) (n = 88) were recruited from a Post-COVID-19 Respiratory Clinic (PCRC) in Vancouver, Canada to examine predictors of long-term fatigue and substantial fatigue. Multivariable mixed effects analyses examined the relationship between patient predictors, including pre-existing comorbidities, patient reported outcome measures, and fatigue and substantial fatigue at follow-up.

Results: The number of patients experiencing fatigue or substantial fatigue at 3 months post-infection were 58 (67%) and 14 (16%) respectively. At 6 months these numbers declined to 47 (60%) patients experiencing fatigue and 6 (6%) experiencing substantial fatigue. Adjusted analysis, for sex, age, and time, revealed the number of pre-existing comorbidities to be associated with fatigue (OR 2.21; 95% CI 1.09-4.49; 0.028) and substantial fatigue (OR 1.73; 95% CI 1.06-2.95; 0.033) at 3 months follow-up. Except for shortness of breath, self-care, and follow-up time, all follow-up variables were found to be associated with fatigue and substantial fatigue at 3 months.

Conclusion: Fatigue and substantial fatigue are common after COVID-19 infection but often diminish over time. A significant number of patients continue to exhibit long-term fatigue at 6 months follow-up. Further research is needed to clarify the causality of viral infections in the development and severity of fatigue as a symptom and in meeting post-viral fatigue syndrome or ME/CFS diagnostic criteria.

Source: Magel T, Meagher E, Boulter T, Albert A, Tsai M, Muñoz C, Carlsten C, Johnston J, Wong AW, Shah A, Ryerson C, Mckay RJ, Nacul L. Fatigue presentation, severity, and related outcomes in a prospective cohort following post-COVID-19 hospitalization in British Columbia, Canada. Front Med (Lausanne). 2023 Jun 29;10:1179783. doi: 10.3389/fmed.2023.1179783. PMID: 37457578; PMCID: PMC10344448. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10344448/ (Full text)

Fatigue in Post-Acute Sequelae of Coronavirus Disease 2019

Abstract:

Fatigue from post-acute sequelae of coronavirus disease 2019 is a complex constellation of symptoms that could be driven by a wide spectrum of underlying etiologies. Despite this, there seems to be hope for treatment plans that focus on addressing possible etiologies and creating a path to improving quality of life and a paced return to activity.

Source: Abbott Z, Summers W, Niehaus W. Fatigue in Post-Acute Sequelae of Coronavirus Disease 2019. Phys Med Rehabil Clin N Am. 2023 Aug;34(3):607-621. doi: 10.1016/j.pmr.2023.04.006. Epub 2023 Apr 24. PMID: 37419535; PMCID: PMC10123359. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10123359/ (Full text)

System and methods to determine ME/CFS & Long Covid disease severity using wearable sensor & survey data

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease with high probability of misdiagnosis and significant unmet medical needs that affects as many as 2.5 million people in the U.S. and causes enormous burden for patients, their caregivers, the healthcare system and society. Between 84 to 91 percent of ME/CFS patients are not yet diagnosed [6, 19], and at least one-quarter of ME/CFS patients are house- or bedbound at some point in their lives [12, 13]. The impact of ME/CFS to the U.S. economy, is about $17 to $24 billion in medical bills and lost income from lost household and labor force productivity per year [7, 13].

Current widely used diagnosis methods of ME/CFS and other diseases with similar clinical symptoms like Long COVID [6, 21] are highly dependent on patients’ self reporting [4, 5] and standardized survey, which are not optimal for medical diagnosis. In a joint study with The Bateman Horne Center (BHC)1, we designed and developed a system prototype that was able to stably collect terabytes of inertial measurement unit (IMU) time-series data, and analyzed multiple candidate parameters derived from them that could be used as reliable biomarkers for ME/CFS and other diseases with similar clinical symptoms.

Utilizing our system prototype, MetaProcessor, we conducted grouped t-tests on data collected from the EndoPAT study group (55 recruited, 51 participated, 30 ME/CFS, 15 Long COVID, 6 healthy control) to evaluate the predictive power of Upright Position Time (UpTime), Hours of Upright Activity (HUA), and Steps/Day. Through statistical analysis, we were able to assert the following for ME/CFS versus healthy control:

1. UpTime yielded a low p-value of 0.00004, indicating a significant difference between the groups and demonstrating its potential as a reliable measure for differentiating ME/CFS from healthy control populations.

2. HUA had a p-value of less than 0.00004, suggesting it could also serve as a useful measure for distinguishing ME/CFS from healthy control groups.

3. Steps/Day, x-axis and y-axis, had p-values of 0.01059 and 0.08665, respectively, indicating that step count may be relevant for differentiating ME/CFS individuals from healthy controls, but step count alone may not be sufficient to reliably distinguish between these groups.

In a linear regression analysis, we found a moderately positive correlation between UpTime and HUA with r 2 = 0.68. Overall, we can confidently conclude that UpTime is a superior overall predictor due to its objective nature and the lowest p-values observed across all groups.

Source: System and methods to determine ME/CFS & Long Covid disease severity using wearable sensor & survey data. Sun, Y. Thesis, Bachelor of Science, The University of Utah. https://ccs.neu.edu/~ysun/publications/system-and-methods-to-determine-mecfs-and-longcovid-disease-severity-using-wearable-sensor-and-survey-data.pdf (Full text)

An understanding of the immune dysfunction in susceptible people who develop the post-viral fatigue syndromes Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Long COVID

Abstract:

Viral infection in most people results in a transient immune/inflammatory response resulting in elimination of the virus and recovery where the immune system returns to that of the pre-infectious state. In susceptible people by contrast there is a transition from an acute immune response to a chronic state that can lead to an ongoing lifelong complex post-viral illness, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. This susceptibility is proposed to be genetic or be primed by prior health history. Complex abnormalities occur in immune cell functions, immune cell metabolism and energy production, and in cytokine immune modulator regulation. The immune system of the brain/central nervous system becomes activated leading to dysfunction in regulation of body physiology and the onset of many neurological symptoms.

A dysfunctional immune system is core to the development of the post-viral condition as shown with diverse strategies of immune profiling.  Many studies have shown changes in numbers and activity of immune cells of different phenotypes and their metabolism. Immune regulating cytokines show complex altered patterns and vary with the stage of the disease, and there are elements of associated autoimmunity.  These complex changes are accompanied by an altered molecular homeostasis with immune cell transcripts and proteins no longer produced in a tightly regulated manner, reflected in the instability of the epigenetic code that controls gene expression.

Potential key elements of the altered immune function in this disease needing further exploration are changes to the gut-brain-immune axis as a result of changes in the microbiome of the gut, and viral reactivation from latent elements of the triggering virus or from a prior viral infection. Long COVID, an Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-like illness, is the post-viral condition that has arisen in large numbers solely from the pandemic virus Severe Acute Respiratory Syndrome Coronovirus-2.

With over 760 million cases worldwide, an estimated ~100 million cases of Long COVID have occurred within a short period. This now provides an unprecedented opportunity to understand the progression of these post-viral diseases, and to progress from a research phase mainly documenting the immune changes to considering potential immunotherapies that might improve the overall symptom profile of affected patients, and provide them with a better quality of life.

Source: WALKER, Max O.M. et al. An understanding of the immune dysfunction in susceptible people who develop the post-viral fatigue syndromes Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Long COVID. Medical Research Archives, [S.l.], v. 11, n. 7.1, july 2023. ISSN 2375-1924. Available at: <https://esmed.org/MRA/mra/article/view/4083>. Date accessed: 15 july 2023. doi: https://doi.org/10.18103/mra.v11i7.1.4083. https://esmed.org/MRA/mra/article/view/4083/99193547075 (Full text as PDF file)