Tag: letter

Bias in Exercise Trials for ME/CFS: the Importance of Objective Outcomes and Long-term Follow-up

Sharpe and colleagues recommend that patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) be offered cognitive behavior therapy (CBT) and graded exercise therapy (GET)1, advice that contrasts with recent NICE guidance on ME/CFS.2 The authors argue that “there are many randomized trials indicating the safety and efficacy of these treatments.”1

All of these trials, however, were nonblinded and relied on subjective symptom questionnaires as their main outcomes, a combination that creates a high risk of response bias. Treatment manuals used in these trials included explicit encouragements to raise patients’ expectations of GET and CBT. One patient booklet, for example, informed patients: “You will experience a snowballing effect as increasing fitness leads to increasing confidence in your ability. You will have conquered CFS by your own effort and you will be back in control of your body again.”3 These encouragements were not provided to participants in the control group and might have influenced how patients rated their health. In contrast to what Sharpe and colleagues claim, measuring the expectations of patients before the trial begins, does not address how therapists might have influenced symptom reporting during the trial.

There are further arguments that suggest these trials might have measured response bias rather than improvements in health. There were, for example, no clinically significant differences on objective outcome measures that are less prone to response bias such as employment figures, activity levels, or fitness tests.3 In addition, at long-term follow-up, the control group seemed to perform just as well as participants who received GET or CBT. This could not be explained by additional treatment received after the trial ended.4 These findings are difficult to interpret if patients did indeed rehabilitate successfully following GET or CBT. It is unfortunate that the authors, who were primary researchers in many of these trials, do not address these concerns.

Lastly, Sharpe and colleagues argue that “harm reported from patient community surveys reflects poorly implemented therapy.”1 Patient surveys, however, indicate that ME/CFS patients report harm of GET even if prescribed by a specialist or physiotherapist.5 The authors have previously been challenged for misrepresenting the findings of these surveys.5 Post-exertional malaise or a marked worsening of symptoms when patients exceed their energy limit, is a characteristic feature of ME/CFS.2 There are therefore reasonable safety concerns about treatments such as GET and CBT that try to push patients to exceed their limits.

Read the full article HERE.

Source: Tack, M. Bias in Exercise Trials for ME/CFS: the Importance of Objective Outcomes and Long-term Follow-up. J GEN INTERN MED 37, 3193 (2022). https://doi.org/10.1007/s11606-022-07704-0  (Full text)

Microvascular Injury in the Brains of Patients with Covid-19

To the Editor:

We conducted postmortem high-resolution magnetic resonance imaging (magnetic resonance microscopy) of the brains of patients with coronavirus disease 2019 (Covid-19) (median age, 50 years) and histopathological examination that focused on microvascular changes in the olfactory bulb and brain stem. (See the Materials and Methods section in the Supplementary Appendix, available with the full text of this letter at NEJM.org.) Images were obtained from the brains of 13 patients with the use of an 11.7-Tesla scanner at a resolution of 25 μm for the olfactory bulb and at a resolution of 100 μm for the brain. Abnormalities were seen in the brains of 10 patients.

We examined the brains of patients that showed abnormalities by means of multiplex fluorescence imaging (in 5 patients) and by means of chromogenic immunostaining (in 10 patients). We performed conventional histopathological examination of the brains of 18 patients. Fourteen patients had chronic illnesses, including diabetes and hypertension, and 11 had been found dead or had died suddenly and unexpectedly. Of the 16 patients with available medical histories, 1 had delirium, 5 had mild respiratory symptoms, 4 had acute respiratory distress syndrome, 2 had pulmonary embolism, and the symptoms were not known in 3.

Read the rest of this letter HERE.

Source: Lee MH, Perl DP, Nair G, Li W, Maric D, Murray H, Dodd SJ, Koretsky AP, Watts JA, Cheung V, Masliah E, Horkayne-Szakaly I, Jones R, Stram MN, Moncur J, Hefti M, Folkerth RD, Nath A. Microvascular Injury in the Brains of Patients with Covid-19. N Engl J Med. 2021 Feb 4;384(5):481-483. doi: 10.1056/NEJMc2033369. Epub 2020 Dec 30. PMID: 33378608; PMCID: PMC7787217. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7787217/ (Full text)

Post-acute COVID-19 syndrome presented as a cerebral and systemic vasculitis: a case report

To the Editor,

Post-acute Coronavirus Disease of 2019 (COVID-19) syndrome is defined as the appearance of symptoms or an organ dysfunction, which occurs at least 4 weeks after the first COVID-19 manifestations and cannot be explained by any alternative diagnosis []. Neurological complications are also well recognized, and include acute cerebrovascular events, encephalopathy, meningoencephalitis, Guillain–Barre syndrome, demyelination, dementia, parkinsonism, and others []. On the other hand, cerebral vasculitis is one of the causes which can lead to brain damage related to COVID-19 infection []. We present a 69-year-old male with systemic vasculitis and central nervous system (CNS) involvement as a manifestation of post-acute COVID-19 syndrome.

Read the rest of this article HERE.

Source: Ivanovic, Jovana et al. “Post-acute COVID-19 syndrome presented as a cerebral and systemic vasculitis: a case report.” Acta neurologica Belgica, 1–3. 13 Mar. 2022, doi:10.1007/s13760-022-01923-2 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8918071/ (Full text)

Immunological dysfunction persists for 8 months following initial mild-to-moderate SARS-CoV-2 infection

Abstract:

A proportion of patients surviving acute coronavirus disease 2019 (COVID-19) infection develop post-acute COVID syndrome (long COVID (LC)) lasting longer than 12 weeks. Here, we studied individuals with LC compared to age- and gender-matched recovered individuals without LC, unexposed donors and individuals infected with other coronaviruses. Patients with LC had highly activated innate immune cells, lacked naive T and B cells and showed elevated expression of type I IFN (IFN-β) and type III IFN (IFN-λ1) that remained persistently high at 8 months after infection.

Using a log-linear classification model, we defined an optimal set of analytes that had the strongest association with LC among the 28 analytes measured. Combinations of the inflammatory mediators IFN-β, PTX3, IFN-γ, IFN-λ2/3 and IL-6 associated with LC with 78.5–81.6% accuracy. This work defines immunological parameters associated with LC and suggests future opportunities for prevention and treatment.

Source: Phetsouphanh, C., Darley, D.R., Wilson, D.B. et al. Immunological dysfunction persists for 8 months following initial mild-to-moderate SARS-CoV-2 infection. Nat Immunol (2022). https://doi.org/10.1038/s41590-021-01113-x  (Full article)

Letter: Could endothelial dysfunction and vascular damage contribute to pain, inflammation and post-exertional malaise in individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)?

To the Editor,

In their hypothesis paper, Wirth, Scheibenbogen, and Paul describe how endothelial dysfunction could produce a wide range of neurological symptoms in people with ME/CFS [1]. As they and others work to refine their understanding of ME/CFS and the related Long COVID syndrome, I would encourage consideration of the possibility that endothelial dysfunction and vascular damage could also explain other symptoms, including widespread pain and inflammation and post-exertional malaise.

For the past four years, my wife and I have been caregivers for our teenage daughter, who has ME/CFS, hypermobile Ehlers-Danlos syndrome, craniocervical instability, Chiari malformation and several other comorbid conditions. Through observation and trial and error, I have developed a number of hypotheses on these matters that I offer here in the hope they might prompt formal research into how to effectively treat these conditions [2].

Widespread pain and inflammation

Discussion of endothelial dysfunction and vascular damage in ME/CFS and Long COVID generally focuses on how leakages from dysfunctional blood vessels lead to reduced blood flow, which has many consequences, including reduced oxygenation of muscles and reduced cerebral brain flow. As researchers study this phenomenon, I would encourage consideration of the additional possibility that the leaking fluid causes independent damage. Lipedema researchers have found that leakages from microangiopathic blood vessels cause an excess of interstitial fluid that stimulates the formation of subcutaneous adipose tissue [3], which generates hypoxic conditions and becomes fibrotic, contributing to pain and inflammation [4].

I hypothesize that a similar process happens when fluid leaks from faulty blood vessels in ME/CFS, possibly exacerbated by endothelial dysfunction in lymphatic vessels that inhibit the fluid’s removal, causing widespread pain and inflammation. This mechanism appears most pronounced among people with hypermobility or other connective tissue disorders, a common trait among people with both ME/CFS and lipedema.

My daughter experiences pain from fibrotic adipose tissue as well as what appears to be nerve compression from accumulated interstitial / lymphatic fluid. Manual lymphatic drainage, the squeezing of affected tissue, and the manual break-up of fibrotic adipose tissue have helped to ameliorate these symptoms.

In my daughter, I have also observed impaired drainage of fluid from the glymphatic system, both at the cribriform plate and down her spine. Could this be related to damaged lymphatic vessels or blockages from fibrotic adipose tissue?

Post-exertional malaise

Like many people with moderate or severe ME/CFS, my daughter struggles to recover from even small amounts of physical exertion. In addition to mitigating her pain, manual lymphatic drainage and the squeezing of affected tissue greatly accelerates this recovery process. We have observed a direct dose–response relationship: the more exercise, the more fluid is present in her tissues, and the more manual draining / squeezing is necessary for her to recover.

Based on this experience, I hypothesize that excess interstitial fluid resulting from dysfunctional blood and lymphatic vessels contributes to the experience of post-exertional malaise, with fluid literally drowning affected tissue, leading to hypoxic conditions and inflammation. Possible explanations for the increased interstitial fluid are increases in blood pressure during physical exertion, hypermobile joints going out of place, prompting localized increases in interstitial fluid, and increases in cortisol that generate an increase in fluid and blood volume. Increases in fluid leakage due to elevated cortisol levels may also explain why some people with ME/CFS feel worse when stressed or anxious. The role of cortisol (or another mediator with fluid retaining properties) may explain why cognitive exertion can also generate post-exertional malaise. When present, elevated estrogen levels may exacerbate leakage by increasing fluid volume.

I am not sure why there is typically a delay between physical exertion and the experience of the most acute symptoms of post-exertional malaise. One possibility is that it takes time for the tissue inundated with fluid to feel the full effects of the hypoxic conditions. Another possibility is that a biphasic reaction triggered during physical exertion leads to the release of a mediator that causes heightened endothelial dysfunction and fluid release.

Further research is needed into the causes of endothelial dysfunction and damage (in addition to initial infection and inflammatory overreaction, consider major “crashes,” mast cell activations, surgeries and microclots as additional contributors) and appropriate treatment.

References

1. Wirth KJ, Scheibenbogen C, Paul F. An attempt to explain the neurological symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. J Transl Med. 2021;19:471. https://doi.org/10.1186/s12967-021-03143-3.

Article PubMed PubMed Central Google Scholar

2. For background, see Lubell, J. To speed progress in treating chronic conditions, engage patients and caregivers as research partners. 2021 Sept.20 In: BMJ Opinion. https://blogs.bmj.com/bmj/2021/09/20/to-speed-progress-in-treating-chronic-conditions-engage-patients-and-caregivers-as-research-partners/

3. Allen M, Schwartz M, Herbst KL. Interstitial Fluid in Lipedema and Control Skin. Womens Health Rep (New Rochelle). 2020;1(1):480–7. https://doi.org/10.1089/whr.2020.0086.PMID:33786515;PMCID:PMC7784769.

Article Google Scholar

4. Herbst KL. Subcutaneous Adipose Tissue Diseases: Dercum Disease, Lipedema, Familial Multiple Lipomatosis, and Madelung Disease. [Updated 2019 Dec 14]. In: Feingold KR, Anawalt B, Boyce A, et al., editors. South Dartmouth (MA).

Source: Lubell J. Letter: Could endothelial dysfunction and vascular damage contribute to pain, inflammation and post-exertional malaise in individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)? J Transl Med. 2022 Jan 24;20(1):40. doi: 10.1186/s12967-022-03244-7. PMID: 35073915. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03244-7

Impaired systemic oxygen extraction long after mild COVID-19: potential perioperative implications

Editor:

The extraordinary number of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections world-wide has made it inevitable that patients who have recovered from COVID-19 will present for anaesthesia and surgery. Recent data indicate that in the United States alone, roughly one-third of the population had been infected by the end of 20201. With this in mind, we read with interest the recent correspondence by Silvapulle and colleagues2 underscoring the wide range of symptoms that often follow recovery from COVID-19 and the complexity of considering residual physiologic abnormalities when assessing perioperative risk. They note that patients suffering from “long COVID” have been reported to exhibit demonstrable abnormalities in several biomarkers as well as cardiac, neurologic, haematologic, renal, hepatic, and endocrine impairment. Based on current evidence, the authors suggest that patients previously experiencing mild COVID-19 but without clear evidence of these sequelae can be regarded as having minimal additional perioperative risk. In this context, the relatively young person who suffered mild COVID-19 a year earlier, complains of exertional fatigue but admits to being sedentary and unfit, and has no objective evidence of cardiopulmonary disease or other organ dysfunction will likely raise little concern.

While the morbidity and mortality associated with severe COVID-19 has appropriately received considerable attention, most SARS-CoV-2 infections result in relatively mild, self-limited symptoms not requiring hospitalization. Nonetheless, some of these patients subsequently experience persistent fatigue and reduced exercise capacity that is not attributable to cardiopulmonary impairment diagnosed by conventional means3. Several mechanisms have been proposed including anaemia, deconditioning, and red blood cell abnormalities4. However, many of the studies describing these mechanisms were conducted in patients following hospitalization and/or within a few months of recovery.

A central focus of perioperative management has always been maintenance of systemic oxygen delivery (DO2) and tissue perfusion. Toward this end, research has defined how the fundamental relationships between DO2, tissue oxygen consumption (VO2), and oxygen extraction (EO2) shift from the intraoperative setting where VO2 tends to be reduced, to the postoperative period when VO2 increases5. Although a range of postoperative complications has been linked to suboptimal tissue DO26,  7, the incidence of these complications appears relatively low in relation to the documented incidence of perioperative hypoxaemia8,  9, particularly when considered in light of potential coincidence with other common factors such as anaemia, hypovolaemia, and transient hypotension. A contributing factor may be that, as with most physiological systems, evolutionary pressure has yielded compensatory mechanisms for reduced DO2 to many organs. Under most circumstances, when DO2 is low, VO2 is maintained by augmented EO2 to prevent tissue hypoxia10. This compensatory EO2 reserve persists until limits that vary among tissue beds are reached and VO2 becomes DO2-dependent. Ultimately, in the perioperative setting where alterations in regional VO2/DO2 balance occur with regularity it is probable that this EO2 reserve is working continuously ‘behind the scenes’ for organ protection.

But what if this seemingly occult protective mechanism is impaired? Clinical experience imparts heightened suspicion of tissue vulnerability in patients with defined end-organ impairment or risk factors for reduced functional reserve such as aging, smoking, diabetes mellitus, or hypertension. But how does this affect that relatively young person who admits to being sedentary and unfit but has no objective evidence of cardiopulmonary disease, and whose only other notable medical history is mild COVID-19 a year earlier? A recent report proposed the existence of a specific “long COVID phenotype” with exertional intolerance and dyspnoea despite normal pulmonary function11, raising the question of whether there is more to this patient than meets the eye.

Read the rest of this article HERE.

Source: Paul M. Heerdt, Ben Shelley, Inderjit Singh. Impaired systemic oxygen extraction long after mild COVID-19: potential perioperative implications. Published: December 27, 2021. DOI:https://doi.org/10.1016/j.bja.2021.12.036

ME/CFS: Exercise goals should be set by patients and not driven by treatment plan, says NICE

Letter:

Rapid Response:

Patient reports of harm from GET cannot be ignored

Dear Editor

Professor Trudie Chalder from King’s College Hospital states that:

“The NICE guidelines for CFS/ME are at odds with the research evidence. Researchers from different institutions in different countries have found graded exercise therapy and cognitive behaviour therapy to be effective for some patients with CFS.

Evidence has shown they reduce fatigue and improve functioning without harm, if delivered by trained therapists in specialist clinics. Being a clinician and researcher in this field, I can’t help but think clinicians will be confused by this message from a respected organisation.”

Having carefully reviewed all the very extensive evidence on efficacy and safety for graded exercise therapy (GET) from relevant clinical trials, medical experts and from people with ME/CFS, the NICE guideline committee concluded that in addition to there being no sound evidence for efficacy for GET there was also consistent patient evidence of harm, sometimes serious and persisting, occurring.

Read the rest of this letter HERE. 

Source: Charles Shepherd. BMJ 2021; 375 doi: https://doi.org/10.1136/bmj.n2643 (Published 29 October 2021) BMJ 2021;375:n2643

Measuring improvement and deterioration in myalgic encephalomyelitis/chronic fatigue syndrome: the pitfalls of the Chalder Fatigue Questionnaire

Adamson et al. considered a 2-point decrease in Chalder Fatigue Questionnaire score to indicate improvement in fatigue and a 2-point increase in Chalder Fatigue Questionnaire score to indicate deterioration in fatigue.1 While intuitively appealing, data exist that suggest a more complex relationship between changes in Chalder Fatigue Questionnaire scores and clinical change.

Collin and Crawley studied treatment outcomes at 11 specialist myalgic encephalomyelitis/chronic fatigue syndrome clinics in England.2 The authors tabulated mean change in Chalder Fatigue Questionnaire score at one year against Clinical Global Impression scores (see additional file 1, table S3). A 2-point decrease in Chalder Fatigue Questionnaire score was reported patients who deemed their health as follows: ‘no change’, ‘a little worse’, ‘much worse’ and ‘very much worse’. The mean changes in Chalder Fatigue Questionnaire score in those categories were similar, with overlapping 95% confidence intervals within the range [4.77, 2.29]. This suggests that a 2-point decrease in Chalder Fatigue Questionnaire score indicates deterioration or no change in the health of a person with myalgic encephalomyelitis/chronic fatigue syndrome, not improvement.

Read the rest of this letter here: https://sci-hub.se/10.1177/0141076820977843

Source: Kirke KD. Measuring improvement and deterioration in myalgic encephalomyelitis/chronic fatigue syndrome: the pitfalls of the Chalder Fatigue Questionnaire. J R Soc Med. 2020 Dec 15:141076820977843. doi: 10.1177/0141076820977843. Epub ahead of print. PMID: 33319615.

Retinal nerve fiber layer thinning in chronic fatigue syndrome as a possible ocular biomarker of underlying glymphatic system dysfunction

In a recent article published in Medical Hypotheses, my colleague and I speculated that glymphatic dysfunction, causing toxic build up within the central nervous system, may be responsible for at least some cases of chronic fatigue syndrome (CFS) [1]. We further postulated that cerebrospinal fluid diversion such as lumboperitoneal shunting may be beneficial to this subgroup of patients by restoring glymphatic transport and waste removal from the brain. In this context, it would be helpful to have a predictive biomarker that can identify CFS patients who are good candidates for this specific treatment. For reasons discussed below, I believe that retinal nerve fiber layer (RNFL) thinning may be a sign of underlying glymphatic system dysfunction in neurodegenerative diseases that result from protein toxicity.

Read the rest of this article here.

Is chronic fatigue syndrome truly associated with haplogroups or mtDNA single nucleotide polymorphisms?

Letter to the Editor:

With interest we read the article by Billing-Ross et al. [1] about 193 patients with chronic fatigue syndrome (CFS) diagnosed according to the Fukuda or Canadian Consensus criteria and undergoing sequencing of the mtDNA, the DePaul Symptom questionnaire and the Medical Outcome Survey Short Form-36. The study showed that CFS is associated with mtDNA haplogroups J, U and H, that 8 mtDNA single nucleotide polymorphisms (SNPs) were associated with 16 symptom categories, and that three haplogroups were associated with six symptom categories [1]. We have the following comments and concerns.

The main limitation of this study is that only the mtDNA was investigated for sequence variants. Since it is well-known that mitochondrial disorders (MIDs) may be also caused by mutations in nDNA-located genes, particularly in children [2], disease-causing mutations or SNPs facilitating the development of CFS may have been missed. Furthermore, MIDs may not only be due to respiratory chain dysfunction but also due to disruption of other mitochondrial pathways, such as the beta-oxidation, the hem synthesis, the calcium handling, the coenzyme-Q metabolism, or the urea cycle. There is also consensus that investigations of mtDNA mutations or SNPs in mtDNA from lymphocytes may not be constructive since some mutations may not be present or heteroplasmy rates may be lower than in more severely affected tissues [3].

You can read the rest of this letter here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4912808/

 

Source: Finsterer J, Zarrouk-Mahjoub S. Is chronic fatigue syndrome truly associated with haplogroups or mtDNA single nucleotide polymorphisms? J Transl Med. 2016 Jun 18;14(1):182. doi: 10.1186/s12967-016-0939-0. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4912808/ (Full article)