Tag: chronic pain

Neutrophils infiltrate sensory ganglia and mediate chronic widespread pain in fibromyalgia

Abstract:

Fibromyalgia is a debilitating widespread chronic pain syndrome that occurs in 2 to 4% of the population. The prevailing view that fibromyalgia results from central nervous system dysfunction has recently been challenged with data showing changes in peripheral nervous system activity.

Using a mouse model of chronic widespread pain through hyperalgesic priming of muscle, we show that neutrophils invade sensory ganglia and confer mechanical hypersensitivity on recipient mice, while adoptive transfer of immunoglobulin, serum, lymphocytes, or monocytes has no effect on pain behavior.

Neutrophil depletion abolishes the establishment of chronic widespread pain in mice. Neutrophils from patients with fibromyalgia also confer pain on mice. A link between neutrophil-derived mediators and peripheral nerve sensitization is already established. Our observations suggest approaches for targeting fibromyalgia pain via mechanisms that cause altered neutrophil activity and interactions with sensory neurons.

Source: Caxaria S, Bharde S, Fuller AM, Evans R, Thomas B, Celik P, Dell’Accio F, Yona S, Gilroy D, Voisin MB, Wood JN, Sikandar S. Neutrophils infiltrate sensory ganglia and mediate chronic widespread pain in fibromyalgia. Proc Natl Acad Sci U S A. 2023 Apr 25;120(17):e2211631120. doi: 10.1073/pnas.2211631120. Epub 2023 Apr 18. PMID: 37071676. https://www.pnas.org/doi/10.1073/pnas.2211631120 (Full text)

Efficacy of Low-Dose Naltrexone and Predictors of Treatment Success or Discontinuation in Fibromyalgia and Other Chronic Pain Conditions: A Fourteen-Year, Enterprise-Wide Retrospective Analysis

Abstract:

Current pharmacologic treatments may provide limited analgesia in fibromyalgia and other chronic pain disorders. Low-dose naltrexone (LDN) has emerged as a potential analgesic option that has been minimally explored.

This study aims to describe current real-world prescribing practices of LDN, to investigate if patients have a perceived benefit of LDN in treating pain symptoms and to identify predictors associated with a perceived benefit or discontinuation of LDN.

We evaluated all outpatient prescriptions for LDN prescribed for any pain indication in the Mayo Clinic Enterprise from 1 January 2009 to 10 September 2022. A total of 115 patients were included in the final analysis.

The patients were 86% female, had a mean age of 48 ± 16 years, and 61% of prescriptions were for fibromyalgia-related pain. The final daily dose of oral LDN ranged from 0.8 to 9.0 mg, while the most common dose was 4.5 mg once daily.

Of patients who reported follow-up data, 65% reported benefit in their pain symptoms while taking LDN. Adverse effects were reported in 11 (11%) patients and 36% discontinued taking LDN by the most recent follow-up.

Concomitant analgesic medications were used by 60% of patients and were not associated with perceived benefit nor discontinuation of LDN, including concomitant opioids.

LDN is a relatively safe pharmacologic option that may benefit patients with chronic pain conditions and warrants further investigation in a prospective, controlled, and well-powered randomized clinical trial.

Source: Driver CN, D’Souza RS. Efficacy of Low-Dose Naltrexone and Predictors of Treatment Success or Discontinuation in Fibromyalgia and Other Chronic Pain Conditions: A Fourteen-Year, Enterprise-Wide Retrospective Analysis. Biomedicines. 2023; 11(4):1087. https://doi.org/10.3390/biomedicines11041087 https://www.mdpi.com/2227-9059/11/4/1087 (Full text)

Pain Management in the Post-COVID Era-An Update: A Narrative Review

Abstract:

An extensive computer search (from January 2020 to January 2023) was conducted including literature from the PubMed, Scopus, MEDLINE, Web of Science, and EMBASE databases. According to preset criteria, a total of 58 articles were included in this review article. Generally, any patient who becomes infected with COVID-19 can develop post-COVID-19 conditions. The course of COVID-19 is divided into three main stages: acute COVID-19 (up to 4 weeks), post-acute COVID-19 (from 4 to 12 weeks), and post-COVID (from 12 weeks to 6 months). If a more protracted course of COVID (over 6 months) is demonstrated, the term “long-COVID” is used.

Although the acute stage of COVID-19 infection most commonly manifests with acute respiratory symptoms, one very common symptom of the disease is pain, while the most common symptoms of post-COVID syndrome are shortness of breath, dry cough, fatigue, loss of olfactory and gustatory function, tightness and chest pain, sleep and mood disturbances, body aches, muscle and joint pain, sore throat, fever, and persistent headaches.

All observations demonstrated a high incidence of chronic pain syndromes of various localization in the post- and long-COVID period. Post-COVID chronic pain might include a newly developed chronic pain as a part of post-viral syndrome; worsening of preexisting chronic pain due to the associated changes in the medical services, or a de novo chronic pain in healthy individuals who are not infected with COVID.

Chronic pain during and post-COVID-19 pandemic is an important health issue due to the significant impacts of pain on the patients, health care systems, and society as well. Therefore, it is important that patients with chronic pain receive effective treatment according to their specific needs. Accordingly, the main goal of this review article is to provide a broad description about the post-COVID pain and to explore the impact of long COVID-19 on chronic pain patients, and also to give brief reports about the prevalence, risk factors, possible mechanisms, different presentations, and the management tools through a systematic approach.

Source: El-Tallawy SN, Perglozzi JV, Ahmed RS, Kaki AM, Nagiub MS, LeQuang JK, Hadarah MM. Pain Management in the Post-COVID Era-An Update: A Narrative Review. Pain Ther. 2023 Apr;12(2):423-448. doi: 10.1007/s40122-023-00486-1. Epub 2023 Feb 28. PMID: 36853484; PMCID: PMC9971680. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9971680/ (Full text)

Is Central Sensitisation the Missing Link of Persisting Symptoms after COVID-19 Infection?

Abstract:

Patients recovered from a COVID-19 infection often report vague symptoms of fatigue or dyspnoea, comparable to the manifestations in patients with central sensitisation. The hypothesis was that central sensitisation could be the underlying common aetiology in both patient populations. This study explored the presence of symptoms of central sensitisation, and the association with functional status and health-related quality of life, in patients post COVID-19 infection.

Patients who were previously infected with COVID-19 filled out the Central Sensitisation Inventory (CSI), the Post-COVID-19 Functional Status (PCFS) Scale and the EuroQol with five dimensions, through an online survey. Eventually, 567 persons completed the survey. In total, 29.73% of the persons had a score of <40/100 on the CSI and 70.26% had a score of ≥40/100. Regarding functional status, 7.34% had no functional limitations, 9.13% had negligible functional limitations, 37.30% reported slight functional limitations, 42.86% indicated moderate functional limitations and 3.37% reported severe functional limitations.

Based on a one-way ANOVA test, there was a significant effect of PCFS Scale group level on the total CSI score (F(4,486) = 46.17, p < 0.001). This survey indicated the presence of symptoms of central sensitisation in more than 70% of patients post COVID-19 infection, suggesting towards the need for patient education and multimodal rehabilitation, to target nociplastic pain.

Source: Goudman L, De Smedt A, Noppen M, Moens M. Is Central Sensitisation the Missing Link of Persisting Symptoms after COVID-19 Infection? J Clin Med. 2021 Nov 28;10(23):5594. doi: 10.3390/jcm10235594. PMID: 34884296; PMCID: PMC8658135. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8658135/ (Full text)

Myalgic Encephalitis/Chronic Fatigue Syndrome: Diagnostic and Therapeutic Approach and Biological Research

Abstract:

Myalgic encephalitis/chronic fatigue syndrome, an intractable disease characterized by profound fatigue, sleep disturbance, cognitive impairment, and orthostatic intolerance, among other features, often occurs after infectious episodes. Patients experience various types of chronic pain; however, post-exertional malaise is the most significant feature, which requires pacing. In this article, I summarize the current diagnostic and therapeutic approaches and describe recent biological research in this domain.

Source: Sato W. [Myalgic Encephalitis/Chronic Fatigue Syndrome: Diagnostic and Therapeutic Approach and Biological Research]. Brain Nerve. 2023 Mar;75(3):217-225. Japanese. doi: 10.11477/mf.1416202311. PMID: 36890757. https://pubmed.ncbi.nlm.nih.gov/36890757/ [Article in Japanese]

Could the fibromyalgia syndrome be triggered or enhanced by COVID-19?

Abstract:

Fibromyalgia (FM) is a complex disease with an uncertain aetiology and intricate pathophysiology. Although its genesis is not fully explained, potential environmental factors, such as viral infections might trigger FM or worsen patients’ clinical outcomes.

The SARS-CoV-2 virus may affect central and peripheral nervous systems, leading to musculoskeletal, neurological, and psychological disturbances. These symptoms might persist at least 12 months beyond the recovery, often referred to as post-COVID syndrome, which resembles FM syndrome. In this sense, we argued the potential consequences of COVID-19 exclusively on FM syndrome.

First, we have described post-COVID syndrome and its painful symptoms. Afterwards, we argued whether FM syndrome could be triggered or enhanced by COVID-19 infection or by numerous and persistent stressors imposed daily by the pandemic setting (isolation, uncertainty, depression, mental stress, generalized anxiety, and fear of the virus). In addition, we have demonstrated similarities between pathophysiological mechanisms and cardinal symptoms of FM and COVID-19, speculating that SARS-CoV-2 might represent a critical mediator of FM or an exacerbator of its symptoms once both syndromes share similar mechanisms and complaints.

Therefore, pharmacologic and non-pharmacological approaches commonly used to treat FM could serve as strategic therapies to attenuate painful and neurological manifestations of post-COVID syndrome. Although it is still theoretical, clinicians and researchers should be alert of patients who develop symptoms similar to FM or those who had their FM symptoms increased post-COVID to manage them better.

Source: Fialho MFP, Brum ES, Oliveira SM. Could the fibromyalgia syndrome be triggered or enhanced by COVID-19? Inflammopharmacology. 2023 Feb 27:1–19. doi: 10.1007/s10787-023-01160-w. Epub ahead of print. PMID: 36849853; PMCID: PMC9970139. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9970139/ (Full text)

Decolonization of staphylococcus aureus and therapeutic test to assist the diagnosis in me/cfs, long covid, post-vaccine covid syndrome and other diseases with fatigue and/or chronic pain

Abstract:

Nasal Decolonization is performed with an antiseptic such as Povidone-iodine. For the Therapeutic Test an Antibiotic such as Flucloxacillin plus Probiotics or other supplements with an effect against S.aureus is indicated.

There is a Subgroup of patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long COVID Syndrome or PACS who present a persistent bacterial infection that affects the upper respiratory tract, and especially at the level of the nostrils.

We estimate that this Subgroup of patients presenting this persistent infection as a causal or contributing factor would be around a third of all cases.

The most frequent causative agent of these persistent and/or recurrent infections is the Staphylococcus aureus bacterium. According to the studies carried out, this bacterium is present in the nasal passages of between 16 and 36% of the general population, who are asymptomatic carriers of Staphylococcus aureus, and are often unaware of it.

In health professionals who carry out care work, the percentage of carriers can exceed 50%. In a recent study carried out in health workers and medical students, 65% of nasal carriers of S. aureus were reported, and of these, 74% were multidrug-resistant (MDR) bacteria and 69% were biofilm-forming bacteria [1].

Source: Gustavo Aguirre Chang and Aurora Natividad Trujillo Figueredo. Decolonization of staphylococcus aureus and therapeutic test to assist the diagnosis in me/cfs, long covid, post-vaccine covid syndrome and other diseases with fatigue and/or chronic pain. ResearchGate [Preprint] 2/17/23. https://www.researchgate.net/publication/368646387_DECOLONIZATION_OF_STAPHYLOCOCCUS_AUREUS_AND_THERAPEUTIC_TEST_TO_ASSIST_THE_DIAGNOSIS_IN_MECFS_LONG_COVID_POST-VACCINE_COVID_SYNDROME_AND_OTHER_DISEASES_WITH_FATIGUE_ANDOR_CHRONIC_PAIN (Full text)

Role of the MicroRNAs in the Pathogenic Mechanism of Painful Symptoms in Long COVID: Systematic Review

Abstract:

The ongoing pandemic of COVID-19 has caused more than 6.7 million tragic deaths, plus, a large percentage of people who survived it present a myriad of chronic symptoms that last for at least 6 months; this has been named as long COVID. Some of the most prevalent are painful symptoms like headache, joint pain, migraine, neuropathic-like pain, fatigue and myalgia. MicroRNAs are small non-coding RNAs that regulate genes, and their involvement in several pathologies has been extensively shown. A deregulation of miRNAs has been observed in patients with COVID-19.
The objective of the present systematic review was to show the prevalence of chronic pain-like symptoms of patients with long COVID and based on the expression of miRNAs in patients with COVID-19, and to present a proposal on how they may be involved in the pathogenic mechanisms of chronic pain-like symptoms.
A systematic review was carried out in online databases for original articles published between March 2020 to April 2022; the systematic review followed the PRISMA guidelines, and it was registered in PROSPERO with registration number CRD42022318992. A total of 22 articles were included for the evaluation of miRNAs and 20 regarding long COVID; the overall prevalence of pain-like symptoms was around 10 to 87%, plus, the miRNAs that were commonly up and downregulated were miR-21-5p, miR-29a,b,c-3p miR-92a,b-3p, miR-92b-5p, miR-126-3p, miR-150-5p, miR-155-5p, miR-200a, c-3p, miR-320a,b,c,d,e-3p, and miR-451a.
The molecular pathways that we hypothesized to be modulated by these miRNAs are the IL-6/STAT3 proinflammatory axis and the compromise of the blood–nerve barrier; these two mechanisms could be associated with the prevalence of fatigue and chronic pain in the long COVID population, plus they could be novel pharmacological targets in order to reduce and prevent these symptoms.
Source: Reyes-Long S, Cortés-Altamirano JL, Bandala C, Avendaño-Ortiz K, Bonilla-Jaime H, Bueno-Nava A, Ávila-Luna A, Sánchez-Aparicio P, Clavijo-Cornejo D, Dotor-LLerena AL, Cabrera-Ruiz E, Alfaro-Rodríguez A. Role of the MicroRNAs in the Pathogenic Mechanism of Painful Symptoms in Long COVID: Systematic Review. International Journal of Molecular Sciences. 2023; 24(4):3574. https://doi.org/10.3390/ijms24043574 https://www.mdpi.com/1422-0067/24/4/3574 (Full text)

Blunted short-term autonomic cardiovascular reactivity to orthostatic and clinostatic challenges in fibromyalgia as an indicator of the severity of chronic pain

Abstract:

Fibromyalgia is a long-term pain disorder that has been related to autonomic dysfunctions and reduced cardiovascular reactivity. We aimed to assess the dynamic short-term cardiovascular responses to postural changes in fibromyalgia. Thirty-eight women with fibromyalgia and thirty-six healthy women underwent the “Chronic Pain Autonomic Stress Test”.

Electrocardiogram, blood pressure and impedance cardiography were continuously recorded during active standing and lying down. Second-by-second values were derived over the first 30 s of each posture. Lower reactivity during the beginning of each position was observed in fibromyalgia sufferers compared to healthy women, with smaller responses seen during stand up in heart rate, blood pressure, cardiac output, total peripheral resistance, and pre-ejection period, and smaller changes during lying down in heart rate, cardiac output and total peripheral resistance. The magnitude of the autonomic adjustments to postural changes was inversely associated with the severity of clinical pain.

These findings indicate an early impaired autonomic cardiovascular response to orthostatic and clinostatic challenges in fibromyalgia, suggesting less autonomic flexibility and adaptability to situational demands and challenges. Short-term second-by-second cardiovascular measures may be useful in the clinical assessment of fibromyalgia.

Source: Contreras-Merino AM, Davydov DM, Galvez-Sánchez CM, Reyes Del Paso GA. Blunted short-term autonomic cardiovascular reactivity to orthostatic and clinostatic challenges in fibromyalgia as an indicator of the severity of chronic pain. Int J Psychophysiol. 2022 May;175:61-70. doi: 10.1016/j.ijpsycho.2022.03.001. Epub 2022 Mar 11. PMID: 35283267. https://www.sciencedirect.com/science/article/pii/S0167876022000599?via%3Dihub (Full text)

The autoimmune aetiology of unexplained chronic pain

Abstract:

Chronic pain is the leading cause of life years lived with disability worldwide. The aetiology of most chronic pain conditions has remained poorly understood and there is a dearth of effective therapies. The WHO ICD-11 has categorised unexplained chronic pain states as ‘chronic primary pains’ (CPP), which are further defined by their association with significant distress and/or dysfunction. The new mechanistic term, ‘nociplasticic pain’ has been developed to illustrate their presumed generation by a structurally intact, but abnormally functioning nociceptive system.

Recently, researchers have unravelled the surprising, ubiquitous presence of pain-sensitising autoantibodies in four investigated CPP indicating autoimmune causation. In persistent complex regional pain syndrome, fibromyalgia syndrome, chronic post-traumatic limb pain, and non-inflammatory joint pain associated with rheumatoid arthritis, passive transfer experiments have shown that either IgG or IgM antibodies from patient-donors cause symptoms upon injection to rodents that closely resemble those of the clinical disorders. Targets of antibody-binding and downstream effects vary between conditions, and more research is needed to elucidate the molecular and cellular details.

The central nervous system appears largely unaffected by antibody binding, suggesting that the clinically evident CNS symptoms associated with CPP might arise downstream of peripheral processes. In this narrative review pertinent findings are described, and it is suggested that additional symptom-based disorders might be examined for the contribution of antibody-mediated autoimmune mechanisms.

Source: Goebel A, Andersson D, Helyes Z, Clark JD, Dulake D, Svensson C. The autoimmune aetiology of unexplained chronic pain. Autoimmun Rev. 2022 Mar;21(3):103015. doi: 10.1016/j.autrev.2021.103015. Epub 2021 Dec 10. PMID: 34902604. https://www.sciencedirect.com/science/article/abs/pii/S1568997221002974 (Full text)