Chronic inflammation, neuroglia dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome

Highlights:

  • Plasmalogens (Pls) are lipids containing a vinyl-ether bond in their glycerol backbone
  • Pls have antioxidant properties and are important for curved membrane assemblies
  • Post-COVID-19 symptoms are highly prevalent and share several features with ME/CFS
  • Pls depletion is a shared biological hallmark of ME/CFS and acute COVID-19 syndrome
  • Pls replacement is a promising tool against neuroinflammation in these two conditions

Abstract:

After five waves of COVID-19 outbreaks, it has been recognized that a significant portion of the affected individuals developed long-term debilitating symptoms marked by chronic fatigue, cognitive difficulties (“brain fog”), post-exertional malaise, and autonomic dysfunction. The onset, progression, and clinical presentation of this condition, generically named post-COVID-19 syndrome, overlap significantly with another enigmatic condition, referred to as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Several pathobiological mechanisms have been proposed for ME/CFS, including redox imbalance, systemic and central nervous system inflammation, and mitochondrial dysfunction. Chronic inflammation and glial pathological reactivity are common hallmarks of several neurodegenerative and neuropsychiatric disorders and have been consistently associated with reduced central and peripheral levels of plasmalogens, one of the major phospholipid components of cell membranes with several homeostatic functions.

Of great interest, recent evidence revealed a significant reduction of plasmalogens contents, biosynthesis, and metabolism in ME/CFS and acute COVID-19, with a strong association to symptom severity and other relevant clinical outcomes. These bioactive lipids have increasingly attracted attention due to their reduced levels representing a common pathophysiological manifestation between several disorders associated with aging and chronic inflammation. However, alterations in plasmalogen levels or their lipidic metabolism have not yet been examined in individuals suffering from post-COVID-19 symptoms.

Here, we proposed a pathobiological model for post-COVID-19 and ME/CFS based on their common inflammation and dysfunctional glial reactivity, and highlighted the emerging implications of plasmalogen deficiency in the underlying mechanisms. Along with the promising outcomes of plasmalogen replacement therapy (PRT) for various neurodegenerative/neuropsychiatric disorders, we sought to propose PRT as a simple, effective, and safe strategy for the potential relief of the debilitating symptoms associated with ME/CFS and post-COVID-19 syndrome.

Source: Chaves AM, Braniff O, Angelova A, Deng Y, Tremblay MÈ. Chronic inflammation, neuroglia dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome. Brain Res Bull. 2023 Jul 7:110702. doi: 10.1016/j.brainresbull.2023.110702. Epub ahead of print. PMID: 37423295. https://www.sciencedirect.com/science/article/pii/S0361923023001272?via%3Dihub (Full text)

The impact of acute SARS-CoV-2 on testicular function including insulin-like factor 3 [INSL3] in men with mild COVID-19: A longitudinal study

Abstract:

Background: SARS-CoV-2 may affect the male reproductive system as it uses angiotensin-converting enzyme [ACE]2, which is expressed in testicular tissue, as an entry point into the cell. Few studies have evaluated the long-term effects of mild COVID-19 on testicular function, and INSL3 levels have not previously been assessed during acute SARS-CoV-2 infection.

Objectives: To assess the impact of acute SARS-CoV-2 infection on testicular function including INSL3 and the presence of SARS-CoV-2 RNA in semen in non-hospitalised men with mild COVID-19.

Materials and methods: This longitudinal study included 36 non-hospitalised SARS-CoV-2-positive men (median age 29 years). Inclusion was within seven days following a positive SARS-CoV-2 RT-PCR test. Reproductive hormone levels, semen parameters, and the presence of SARS-CoV-2 RNA in oropharyngeal and semen samples were assessed during acute SARS-CoV-2 infection (baseline) and at three- and six-month follow-up. Wilcoxon matched-pair signed-rank (two samples) test was used to assess time-related alterations in reproductive hormone levels and semen parameters.

Results: Lower plasma testosterone [T] (total and calculated free [c-fT]) and higher LH concentrations were observed during acute SARS-CoV-2 infection (baseline) compared to three- and six-month follow-up. Consequently, ratios of c-fT/LH were lower at baseline compared to three- and six-month follow-up (P < 0.001 and P = 0.003, respectively). Concomitantly, lower INSL3 concentrations were observed at baseline compared to three-month follow-up (P = 0.01). The total number of motile spermatozoa was also lower at baseline compared to six-month follow-up (P = 0.02). The alterations were detected irrespective of whether the men had experienced SARS-CoV-2-related fever episodes or not. No SARS-CoV-2 RNA was detected in semen at any time point.

Discussion and conclusion: This study showed a reduction in testicular function, which was for the first time confirmed by INSL3, in men mildly affected by SARS-CoV-2 infection. The risk of transmission of SARS-CoV-2 RNA via semen seems to be low. Febrile episodes may impact testicular function, but a direct effect of SARS-CoV-2 cannot be excluded. This article is protected by copyright. All rights reserved.

Source: Lauritsen MP, Kristensen TL, Bo Hansen C, Schneider UV, Talbot AL, Skytte AB, Petersen JH, Johannsen TH, Zedeler A, Albrethsen J, Juul A, Priskorn L, Jørgensen N, Westh H, Freiesleben NC, Nielsen HS. The impact of acute SARS-CoV-2 on testicular function including insulin-like factor 3 [INSL3] in men with mild COVID-19: A longitudinal study. Andrology. 2023 Jul 8. doi: 10.1111/andr.13494. Epub ahead of print. PMID: 37421657. https://pubmed.ncbi.nlm.nih.gov/37421657/

Increase in gut permeability and oxidized ldl is associated with post-acute sequelae of SARS-CoV-2

Abstract:

Background: Post-acute sequelae of SARS-CoV-2 (PASC) is marked by persistent or newly developing symptoms beyond 4 weeks of infection. Investigating gut integrity, oxidized lipids and inflammatory markers is important for understanding PASC pathogenesis.

Methods: A cross-sectional study including COVID+ with PASC, COVID+ without PASC, and COVID-negative (COVID-) participants. We measured plasma markers by enzyme-linked immunosorbent assay to assess intestinal permeability (ZONULIN), microbial translocation (lipopolysaccharide-binding protein or LBP), systemic inflammation (high-sensitivity C-reactive protein or hs-CRP), and oxidized low-density lipoprotein (Ox-LDL).

Results: 415 participants were enrolled in this study; 37.83% (n=157) had prior COVID diagnosis and among COVID+, 54% (n=85) had PASC. The median zonulin among COVID- was 3.37 (IQR: 2.13, 4.91) mg/mL, 3.43 (IQR: 1.65, 5.25) mg/mL among COVID+ no PASC, and highest [4.76 (IQR: 3.2, 7.35) mg/mL] among COVID+ PASC+ (p<.0001). The median ox-LDL among COVID- was 47.02 (IQR: 35.52, 62.77) U/L, 57.24 (IQR: 40.7, 75.37) U/L among COVID+ No PASC, and the highest [76.75 (IQR: 59.95, 103.28) U/L] among COVID+ PASC+ (p<.0001). COVID+ PASC+ was positively associated with zonulin (p=0.0002) and ox-LDL (p<.0001), and COVID- was negatively associated with ox-LDL (p=0.01), compared to COVID+ No PASC. Every unit increase in zonulin was associated with 44% higher predicted odds of having PASC [aOR: 1.44 (95%CI: 1.1, 1.9)] and every one-unit increase in ox-LDL was associated with more than four-fold increased odds of having PASC [aOR: 2.44 (95%CI: 1.67, 3.55)].

Conclusions: PASC is associated with increased gut permeability and oxidized lipids. Further studies are needed to clarify whether these relationships are causal which could lead to targeted therapeutics.

Source: Mouchati C, Durieux JC, Zisis SN, Labbato D, Rodgers MA, Ailstock K, Reinert BL, Funderburg NT, McComsey GA. Increase in gut permeability and oxidized ldl is associated with post-acute sequelae of SARS-CoV-2. Front Immunol. 2023 May 12;14:1182544. doi: 10.3389/fimmu.2023.1182544. PMID: 37251403; PMCID: PMC10217362. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10217362/ (Full text)

 

Divergent Adaptive Immune Responses Define Two Types Of Long Covid

The role of adaptive immune responses in long COVID remains poorly understood, with contrasting hypotheses suggesting either an insufficient antiviral response or an excessive immune response associated with inflammatory damage. To address this issue, we set to characterize humoral and CD4+ T cell responses in long COVID patients prior to SARS-CoV-2 vaccination.

Long COVID patients who were seropositive (LC+, n=28) or seronegative (LC-, n=23) by spike ELISA assay were recruited based on (i) an initial SARS-CoV-2 infection documented by PCR or the conjunction of three major signs of COVID-19 and (ii) the persistence or resurgence of at least 3 symptoms for over 3 months. They were compared to COVID patients with resolved symptoms (RE, n=29) and uninfected control individuals (HD, n=29).

The spectrum of persistent symptoms proved similar in both long COVID groups, with a trend for a higher number of symptoms in the seronegative group (median=6 vs 4.5; P=0.01). The use a highly sensitive S-flow assay enabled the detection of low levels of SARS-CoV-2 spike-specific IgG in 22.7% of ELISA-seronegative long COVID (LC-) patients. In contrast, spike-specific IgG levels were uniformly high in the LC+ and RE groups.

Multiplexed antibody analyses to 30 different viral antigens showed that LC-patients had defective antibody responses to all SARS-CoV-2 proteins tested but had in most cases preserved responses to other viruses. A sensitive primary T cell line assay revealed low but detectable SARS-CoV-2-specific CD4 responses in 39.1% of LC-patients, while response frequencies were high in the LC+ and RE groups. Correlation analyses showed overall strong associations between humoral and cellular responses, with exceptions in the LC-group.

These findings provide evidence for two major types of antiviral immune responses in long COVID. Seropositive patients showed coordinated cellular and humoral responses at least as high as those of recovered patients. In contrast, ELISA-seronegative long COVID patients showed overall low antiviral responses, with detectable specific CD4+ T cells and/or antibodies in close to half of patients (52.2%). These divergent findings in patients sharing a comparable spectrum of persistent symptoms raise the possibility of multiple etiologies in long COVID.

Source: Jérôme Kervevan, Isabelle Staropoli, Dorsaf Slama, Raphaël Jeger-Madiot, Françoise Donnadieu, Delphine Planas, Marie-Pierre Pietri, Wiem Loghmari-Bouchneb, Motolete A. Tanah, Rémy Robinot, Faroudy Boufassa, Michael White, Dominique SALMON and Lisa A. Chakrabarti. Front. Immunol. Sec. Viral Immunology. Volume 14 – 2023 | doi: 10.3389/fimmu.2023.1221961 https://www.frontiersin.org/articles/10.3389/fimmu.2023.1221961/abstract

Physiological underpinnings of long COVID: what have we learned?

In a review, Batta et al 2 , addressed the cardiovascular symptoms in COVID-19 patients with a focus on vascular dysfunction, arrhythmias, myocardial ischemia, and discussed the most updated recommendations for the treatment of COVID-19. We previously reported the presence of almost all the receptors of SARS-CoV-2 on cardiomyocytes which makes the heart a favorable target for this virus 3 . Batta et al 2 indicated that the vascular endothelial dysfunction is involved in the pathogenesis of SARS-CoV-2 and hence the activation of pro-inflammatory cytokines leading to increased vascular permeability and thrombosis in many organs.

Tachycardia was the most common cardiac presentation associated with SARS-CoV-2 infection, along with arrhythmias and conduction blocks, myocardial ischemia and injury, and hypertension. Interestingly, the authors reported that the elevated ACE-2 expression on endothelial cells of COVID -19 patients’ lungs indicates an elevated pro-hypertensive angiotensin II level leading to vasoconstriction and aldosterone-driven hypervolemia. Thus, the use of renin-angiotensin-aldosterone inhibitors in hypertension treatment of patients infected with SARS-CoV-2 was cautioned to avoid exacerbated cardiovascular clinical outcome.

An article from Gonzalez-Gonzalez et al. 4 reviewed the application of Virchow’s Triad in detail for the risk of developing stroke and related intravascular thrombotic diseases in the context of COVID-19 infection. The authors discussed each part of Virchow’s triad in detail, such as hypercoagulable state, vascular damage, and intravascular stasis of blood. They looked into literature on the effects of COVID-19 infection for the formation of intravascular and intracardiac clots (leading to stroke), formation of cardiac sequelae and autopsy studies reporting elevated markers in ventricular myocardium. The authors reviewed the risk factor for stroke development, differences between ischemic vs haemorrhagic stroke and frequent complications of COVID-19 patients such as pulmonary embolism. The authors also discussed the current treatment plans and recommended some differential treatment approaches for COVID-19 infection patients concerning known mechanisms of Virchow’s triad. Finally, the authors discussed the outcomes and long-term consequences of COVID-19 infection and the cardiovascular effects of COVID-19 vaccines.

The work from A. Mujalli and co-workers 5 investigated genetic pathways in patients with severe COVID-19 and comorbidities, by means of genome-wide transcriptomic datasets publicly available within the first year of the pandemic. Differential gene expression (DGE), gene ontology (GO), pathway enrichment, functional similarity, phenotypic analysis and drug target identification studies were conducted using a cohort of 120 COVID-19 patients, 281 patients with chronic comorbidities (153 CVD, 64 atherosclerosis, 33 diabetes, and 31 obesity), and 252 patients with different infectious diseases (145 respiratory syncytial virus, 95 influenza, and 12 MERS). In total, 29 genes were identified to contributing to the clinical severity of COVID-19 infection in patients with comorbidities. Remarkably, identified genes were found to be involved in immune cell homeostasis during innate immunity, mostly in monocyte and macrophage function. In addition, results from drug target identification studies show a mismatch between the currently used drugs in COVID-19 therapy and predicted drugs against identified genes.

Furtheremore, in this issue of the Journal, Chan et al 6 examined the association of COVID-19 with heart rate (HR) and blood pressure (BP) variability during exercise in a cohort of 18 patients with prior COVID-19 infection (equally split between symptomatic and asymptomatic), and a cohort of 9 controls who were never infected with COVID-19. Using a rigorous experimental design, the investigators measured HR and BP at regular intervals before, during, and after submaximal exercise, and quantified HR and BP variability on time and frequency domains. Baseline HR and BP were not significantly different between groups (symptomatic vs. asymptomatic vs. controls), nor were they different after completing a bout of submaximal exercise at a comparable workload. However, HR and BP variability was blunted only in individuals with prior symptomatic COVID-19 infection, but not in controls or those with a prior asymptomatic infection, suggesting an underlying degree of autonomic nervous system dysfunction in affected individuals.

The authors are to be lauded for their elegant and clinically relevant work, despite the obvious limitation of small sample size, since it provides much needed insight into COVID-19-induced abnormalities in cardiac physiology. The current findings provide a potential explanation for exercise intolerance, a frequently reported long-term symptom among survivors of COVID-19, since blunting of HR and BP variability are markers of impaired parasympathetic nervous system and poor cardiovascular health.In conclusion, the COVID-19 pandemic affected millions around the globe before it started abating with the advent of the emergent vaccines that were approved for use on emergency basis.

The WHO declared the end of the pandemic after three years of its surge. While millions succumbed to this deadly respiratory infection, survivors from this illness, particularity those who were severely sick, are reporting cardiac and nervous abnormalities. We hope that this series provides a new perspectives on the manifestations of COVID-19 in the heart, the brain, and the vasculature with the hope to guide therapeutic interventions for patients suffering from long term sequelae of SARS-CoV-2 infection.

Source: Moni Nader1, Georges E. Haddad, Jacobo Elies, Sriharsha Kantamneni and Firas Albadarin. Physiological underpinnings of long COVID: what have we learned? Front. Physiol. Sec. Clinical and Translational Physiology. Volume 14 – 2023 | doi: 10.3389/fphys.2023.122455 https://www.frontiersin.org/articles/10.3389/fphys.2023.1224550/full (Full text)

A systematic review and meta-analysis of urinary biomarkers in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a multifactorial illness that affects many body systems including the immune, nervous, endocrine, cardiovascular, and urinary systems. There is currently no universal diagnostic marker or targeted treatment for ME/CFS. Urine is a non-invasive sample that provides biomarkers that may have the potential to be used in a diagnostic capacity for ME/CFS. While there are several studies investigating urine-based biomarkers for ME/CFS, there are no published systematic reviews to summarise existing evidence of these markers. The aim of this systematic review was to compile and appraise literature on urinary-based biomarkers in ME/CFS patients compared with healthy controls.

Methods: Three databases: Embase, PubMed, and Scopus were searched for articles pertaining to urinary biomarkers for ME/CFS compared with healthy controls published between December 1994 to December 2022. The final articles included in this review were determined through application of specific inclusion and exclusion criteria. Quality and bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Case Control Studies. A meta-analysis according to Cochrane guidelines was conducted on select studies, in particular, those that investigate urinary free cortisol levels in ME/CFS patients compared to healthy controls using the program STATA 17.

Results: Twenty-one studies were included in this review. All of the studies investigated urinary-based markers in ME/CFS patients compared with healthy controls. The reported changes in urinary outputs include urinary free cortisol (38.10%), carnitine (28.6%), iodine (4.76%), and the metabolome (42.86%). In most cases, there was minimal overlap in the main outcomes measured across the studies, however, differences in urinary free cortisol between ME/CFS patients and healthy controls were commonly reported. Seven studies investigating urinary free cortisol were included in the meta-analysis. While there were significant differences found in urinary free cortisol levels in ME/CFS patients, there was also substantial heterogeneity across the included studies that makes drawing conclusions difficult.

Conclusions: There is limited evidence suggesting a consistent and specific potential urinary-based biomarker for ME/CFS. Further investigations using more standardised methodologies and more stringent case criteria may be able to identify pathophysiological differences with diagnostic potential in ME/CFS patients compared with healthy controls.

Source: Taccori A, Maksoud R, Eaton-Fitch N, Patel M, Marshall-Gradisnik S. A systematic review and meta-analysis of urinary biomarkers in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). J Transl Med. 2023 Jul 5;21(1):440. doi: 10.1186/s12967-023-04295-0. PMID: 37408028; PMCID: PMC10320942. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10320942/ (Full text)

MTHFR and LC, CFS, POTS, MCAS, SIBO, EDS: Methylating the Alphabet

Abstract:

Long Covid (LC), Chronic Fatigue Syndrome (CFS), Postural Orthostatic Tachycardia Syndrome (POTS), Mast Cell Activation Syndrome (MCAS), Small Intestine Bacterial Overgrowth (SIBO), and Ehlers-Danlos Syndrome (EDS) are all loosely connected, some poorly defined, some with overlapping symptoms.

The female preponderance, the prominence of fatigue and chronic inflammation, and methylenetetrahydrofolate reductase (MTHFR) abnormalities may connect them all. Indeed differential methylation may lie at the root. Two – EDS and MTHFR – are genetic. But epigenetic factors may ultimately determine their phenotypic expression.

Oxidative stress, overloaded mitochondria, an antioxidant and nutrient shortfall, and suboptimal gut microbiome appear to be the primary determinants. A deep dive into the folate and methionine cycles is undertaken in an attempt to connect these syndromes.

The active forms of vitamin D and vitamins B2,3,6,9,12 are shown to be biochemically integral to optimal methylation and control of the epigenome. Their status largely determines the symptoms of abnormal MTHFR in all its phenotypes. The wider implications for aging, cancer, cardiovascular disease, neurodegenerative disease, and autoimmune disease are briefly explored.

Source: Chambers P. MTHFR and LC, CFS, POTS, MCAS, SIBO, EDS: Methylating the Alphabet. Preprint from 30 Jun 2023. https://www.qeios.com/read/ZPYS4F (Full text)

The Role of Hypothalamic Phospholipid Liposomes in the Supportive Therapy of Some Manifestations of Long Covid: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Brain Fog

Abstract:

Long Covid is a heterogeneous clinical condition in which Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and brain fog stand out among the different clinical symptoms and syndromes. The cerebral metabolic alterations and neuroendocrine disorders seem to constitute an important part of Long Covid.

Given the substantial lack of drugs and effective therapeutic strategies, hypothalamic phospholipid liposomes which have been on the market for several years as adjuvant therapy of cerebral metabolic alterations resulting from neuroendocrine disorders, can be taken into consideration in an overall therapeutic strategy that aims to control the Long Covid associated symptoms and syndromes. Their pharmacological mechanisms and clinical effects strongly support their usefulness in Long Covid. Our initial clinical experience corroborates this rationale. Further research is imperative in order to obtain robust clinical evidence.

Source: Menichetti, F. The Role of Hypothalamic Phospholipid Liposomes in the Supportive Therapy of Some Manifestations of Long Covid: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Brain Fog. Preprints.org 2023, 2023070005. https://doi.org/10.20944/preprints202307.0005.v1 https://www.preprints.org/manuscript/202307.0005/v1 (Full text available as PDF file)

Comparing Frequency and Severity Ratings for ME/CFS versus Controls

Abstract:

Most questionnaires for somatic symptoms focus on occurrence, frequency, or severity, and in doing so, they might not be able to comprehensively assess the burden that symptoms present to patients. For example, a symptom might occur at a high frequency but only a minimal severity, so that it is less likely to be a burden on a patient; whereas a symptom that has both a high frequency and severity is more likely to be negatively impacting a patient.
Study 1 examined frequency and severity scores for classic Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) symptoms among patients with ME/CFS versus a control group. Findings in Study 1 indicate there were more frequency/severity discrepancies for individuals with ME/CFS versus the control group. Study 1 concluded that collecting data on both measures of symptom burden provides unique indicators that can better assess the burden of the symptoms on patients.
In a separate data set, Study 2 reported reliability data on slight differences in the time period and the way the severity was assessed. Study 2 findings indicated high levels of reliability for these changes in the time period and the way questions were asked. These studies provide important psychometric properties that could lead to more reliable and valid assessments of patients with post-viral illnesses.
Source: Jason LA, Benner S, Hansel N. Comparing Frequency and Severity Ratings for ME/CFS versus Controls. Psych. 2023; 5(3):662-669. https://doi.org/10.3390/psych5030042 https://www.mdpi.com/2624-8611/5/3/42 (Full text)

Cognitive functioning in postural orthostatic tachycardia syndrome among different body positions: a prospective pilot study (POTSKog study)

Abstract:

Purpose: Approximately 96% of patients with postural orthostatic tachycardia syndrome (PoTS) report cognitive complaints. We investigated whether cognitive function is impaired during sitting and active standing in 30 patients with PoTS compared with 30 healthy controls (HCs) and whether it will improve with the counter manoeuvre of leg crossing.

Methods: In this prospective pilot study, patients with PoTS were compared to HCs matched for age, sex, and educational level. Baseline data included norepinephrine plasma levels, autonomic testing and baseline cognitive function in a seated position [the Montreal Cognitive Assessment, the Leistungsprüfsystem (LPS) subtests 1 and 2, and the Test of Attentional Performance (TAP)]. Cognitive functioning was examined in a randomized order in supine, upright and upright legs crossed position. The primary outcomes were the cognitive test scores between HCs and patients with PoTS at baseline testing, and among the different body positions.

Results: Patients with PoTS had impaired attention (TAP median reaction time) in the seated position and impaired executive functioning (Stroop) while standing compared with HC. Stroop was influenced by position (supine versus upright versus upright legs crossed) only in the PoTS group. Leg crossing did not result in an improvement in executive function. In patients with PoTS, there was a negative correlation of Stroop with norepinephrine plasma levels while standing.

Conclusion: Compared with HCs, PoTS participants showed impaired cognitive attention and executive function in the upright position that did not improve in the legs crossed position. Data provide further evidence for orthostatic cognitive deterioration in patients with PoTS.

Trial Registration Information: The study was registered at ClinicalTrials.gov (NCT03681080).

Source: Maier, A., Schopen, L., Thiel, J.C. et al. Cognitive functioning in postural orthostatic tachycardia syndrome among different body positions: a prospective pilot study (POTSKog study). Clin Auton Res (2023). https://doi.org/10.1007/s10286-023-00950-0 https://link.springer.com/article/10.1007/s10286-023-00950-0 (Full text)