The role of mitochondrial dysfunctions due to oxidative and nitrosative stress in the chronic pain or chronic fatigue syndromes and fibromyalgia patients: peripheral and central mechanisms as therapeutic targets?

Abstract:

INTRODUCTION: Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are characterized by persistent pain and fatigue. It is hypothesized that reactive oxygen species (ROS), caused by oxidative and nitrosative stress, by inhibiting mitochondrial function can be involved in muscle pain and central sensitization as typically seen in these patients.

AREAS COVERED: The current evidence regarding oxidative and nitrosative stress and mitochondrial dysfunction in CFS and FM is presented in relation to chronic widespread pain. Mitochondrial dysfunction has been shown in leukocytes of CFS patients and in muscle cells of FM patients, which could explain the muscle pain. Additionally, if mitochondrial dysfunction is also present in central neural cells, this could result in lowered ATP pools in neural cells, leading to generalized hypersensitivity and chronic widespread pain.

EXPERT OPINION: Increased ROS in CFS and FM, resulting in impaired mitochondrial function and reduced ATP in muscle and neural cells, might lead to chronic widespread pain in these patients. Therefore, targeting increased ROS by antioxidants and targeting the mitochondrial biogenesis could offer a solution for the chronic pain in these patients. The role of exercise therapy in restoring mitochondrial dysfunction remains to be explored, and provides important avenues for future research in this area.

 

Source: Meeus M, Nijs J, Hermans L, Goubert D, Calders P. The role of mitochondrial dysfunctions due to oxidative and nitrosative stress in the chronic pain or chronic fatigue syndromes and fibromyalgia patients: peripheral and central mechanisms as therapeutic targets? Expert Opin Ther Targets. 2013 Sep;17(9):1081-9. doi: 10.1517/14728222.2013.818657. Epub 2013 Jul 9. https://www.ncbi.nlm.nih.gov/pubmed/23834645

 

Cognitive performance is of clinical importance, but is unrelated to pain severity in women with chronic fatigue syndrome

Abstract:

In various chronic pain populations, decreased cognitive performance is known to be related to pain severity. Yet, this relationship has not been investigated in patients with chronic fatigue syndrome (CFS). This study investigated the relationship between cognitive performance and (1) pain severity, (2) level of fatigue, and (3) self-reported symptoms and health status in women with CFS. Examining the latter relationships is important for clinical practice, since people with CFS are often suspected to exaggerate their symptoms.

A sample of 29 female CFS patients and 17 healthy controls aged 18 to 45 years filled out three questionnaires (Medical Outcomes Study 36-Item Short-Form Health Survey, Checklist Individual Strength (CIS), and CFS Symptom List) and performed three performance-based cognitive tests (psychomotor vigilance task, Stroop task, and operation span task), respectively.

In both groups, pain severity was not associated with cognitive performance. In CFS patients, the level of fatigue measured with the CFS Symptom List, but not with the CIS, was significantly correlated with sustained attention. Self-reported mental health was negatively correlated with all investigated cognitive domains in the CFS group. These results provide evidence for the clinical importance of objectively measured cognitive problems in female CFS patients.

Furthermore, a state-like measure (CFS Symptom List) appears to be superior over a trait-like measure (CIS) in representing cognitive fatigue in people with CFS. Finally, the lack of a significant relationship between cognitive performance and self-reported pain severity suggests that pain in CFS might be unique.

 

Source: Ickmans K, Meeus M, Kos D, Clarys P, Meersdom G, Lambrecht L, Pattyn N, Nijs J. Cognitive performance is of clinical importance, but is unrelated to pain severity in women with chronic fatigue syndrome. Clin Rheumatol. 2013 Oct;32(10):1475-85. doi: 10.1007/s10067-013-2308-1. Epub 2013 Jun 5. https://www.ncbi.nlm.nih.gov/pubmed/23737111

 

Fear of movement and avoidance behaviour toward physical activity in chronic-fatigue syndrome and fibromyalgia: state of the art and implications for clinical practice

Abstract:

Severe exacerbation of symptoms following physical activity is characteristic for chronic-fatigue syndrome (CFS) and fibromyalgia (FM). These exacerbations make it understandable for people with CFS and FM to develop fear of performing body movement or physical activity and consequently avoidance behaviour toward physical activity. The aims of this article were to review what measures are available for measuring fear of movement and avoidance behaviour, the prevalence fear of movement and avoidance behaviour toward physical activity and the therapeutic options with fear of movement and avoidance behaviour toward physical activity in patients with CFS and FM.

The review revealed that fear of movement and avoidance behaviour toward physical activity is highly prevalent in both the CFS and FM population, and it is related to various clinical characteristics of CFS and FM, including symptom severity and self-reported quality of life and disability. It appears to be crucial for treatment (success) to identify CFS and FM patients displaying fear of movement and avoidance behaviour toward physical activity.

Individually tailored cognitive behavioural therapy plus exercise training, depending on the patient’s classification as avoiding or persisting, appears to be the most promising strategy for treating fear of movement and avoidance behaviour toward physical activity in patients with CFS and FM.

Comment in: Fear of movement and avoidance behaviour toward physical activity in chronic-fatigue syndrome and fibromyalgia: state of the art and implications for clinical practice. [Clin Rheumatol. 2013]

 

Source: Nijs J, Roussel N, Van Oosterwijck J, De Kooning M, Ickmans K, Struyf F, Meeus M, Lundberg M. Fear of movement and avoidance behaviour toward physical activity in chronic-fatigue syndrome and fibromyalgia: state of the art and implications for clinical practice. Clin Rheumatol. 2013 Aug;32(8):1121-9. doi: 10.1007/s10067-013-2277-4. Epub 2013 May 3. https://www.ncbi.nlm.nih.gov/pubmed/23639990

 

Does acetaminophen activate endogenous pain inhibition in chronic fatigue syndrome/fibromyalgia and rheumatoid arthritis? A double-blind randomized controlled cross-over trial

Abstract:

BACKGROUND: Although enhanced temporal summation (TS) and conditioned pain modulation (CPM), as characteristic for central sensitization, has been proved to be impaired in different chronic pain populations, the exact nature is still unknown.

OBJECTIVES: We examined differences in TS and CPM in 2 chronic pain populations, patients with both chronic fatigue syndrome (CFS) and comorbid fibromyalgia (FM) and patients with rheumatoid arthritis (RA), and in sedentary, healthy controls, and evaluated whether activation of serotonergic descending pathways by acetaminophen improves central pain processing.

STUDY DESIGN: Double-blind randomized controlled trial with cross-over design.

METHODS: Fifty-three women (19 CFS/FM patients, 16 RA patients, and 18 healthy women) were randomly allocated to the experimental group (1 g acetaminophen) or the placebo group (1 g dextrose). Participants underwent an assessment of endogenous pain inhibition, consisting of an evaluation of temporal summation with and without conditioned pain modulation (CPM). Seven days later groups were crossed-over. Patients and assessors were blinded for the allocation.

RESULTS: After intake of acetaminophen, pain thresholds increased slightly in CFS/FM patients, and decreased in the RA and the control group. Temporal summation was reduced in the 3 groups and CPM at the shoulder was better overall, however only statistically significant for the RA group. Healthy controls showed improved CPM for both finger and shoulder after acetaminophen, although not significant.

LIMITATIONS: The influence of acetaminophen on pain processing is inconsistent, especially in the patient groups examined.

CONCLUSION: This is the first study comparing the influence of acetaminophen on central pain processing in healthy controls and patients with CFS/FM and RA. It seems that CFS/FM patients present more central pain processing abnormalities than RA patients, and that acetaminophen may have a limited positive effect on central pain inhibition, but other contributors have to be identified and evaluated.

 

Source: Meeus M, Ickmans K, Struyf F, Hermans L, Van Noesel K, Oderkerk J, Declerck LS, Moorkens G, Hans G, Grosemans S, Nijs J. Does acetaminophen activate endogenous pain inhibition in chronic fatigue syndrome/fibromyalgia and rheumatoid arthritis? A double-blind randomized controlled cross-over trial. Pain Physician. 2013 Mar-Apr;16(2):E61-70. http://www.painphysicianjournal.com/linkout?issn=1533-3159&vol=16&page=E61 (Full article available as PDF file)

 

Postural orthostatic tachycardia syndrome as a clinically important subgroup of chronic fatigue syndrome: further evidence for central nervous system dysfunctioning

In this issue of the Journal of Internal Medicine, Lewis and colleagues [1] provide compelling data for a novel subgroup within the chronic fatigue syndrome (CFS) population. They show that approximately 13% (24/179) of CFS patients have postural orthostatic tachycardia syndrome (POTS), a form of dysautonomia implying that when patients change their body position from supine to upright, their heart rate will increase abnormally (tachycardia). POTS is associated with several symptoms often seen in CFS patients: fatigue, lightheadedness, dizziness, neurocognitive deficits and exercise intolerance. Importantly, this was a confirmatory study of a previously published pilot study that found a prevalence rate for POTS of 29% in a smaller sample (n = 63) of CFS patients [2]. Another significant finding is the differences in fatigue severity, depressive thoughts and daytime hypersomnolence between CFS patients with and without POTS, providing evidence for the clinical importance of POTS in CFS.

You can read the full comment here: http://onlinelibrary.wiley.com/doi/10.1111/joim.12034/full

Comment on: Clinical characteristics of a novel subgroup of chronic fatigue syndrome patients with postural orthostatic tachycardia syndrome. [J Intern Med. 2013]

 

Source: Nijs J, Ickmans K. Postural orthostatic tachycardia syndrome as a clinically important subgroup of chronic fatigue syndrome: further evidence for central nervous system dysfunctioning. J Intern Med. 2013 May;273(5):498-500. doi: 10.1111/joim.12034. Epub 2013 Feb 8. http://onlinelibrary.wiley.com/doi/10.1111/joim.12034/full (Full article)

 

Pain in patients with chronic fatigue syndrome: time for specific pain treatment?

Abstract:

BACKGROUND: Besides chronic fatigue, patients with chronic fatigue syndrome (CFS) have debilitating widespread pain. Yet pain from CFS is often ignored by clinicians and researchers.

OBJECTIVES: To examine whether pain is a unique feature of CFS, or does it share the same underlying mechanisms as other CFS symptoms? Second, it is examined whether effective treatments for pain from CFS are currently available.

STUDY DESIGN: Narrative review covering the scientific literature up through December 2011.

SETTING: Several universities.

RESULTS: From the available literature, it is concluded that musculoskeletal factors are unlikely to account for pain from CFS. Pain seems to be one out of many symptoms related to central sensitization from CFS. This idea is supported by the findings of generalized hyperalgesia (including widespread increased responsiveness to painful stimuli) and dysfunctional endogenous analgesia in response to noxious thermal stimuli. Pain catastrophizing and depression partly account for pain from CFS. Pain increases during exercise is probably due to the lack of endogenous analgesia and activation of several genes in response to exercise in CFS. There is currently no evidence in support for the efficacy of complementary medicine in the treatment of pain from CFS. Intensive education about the biology of pain from CFS (within the framework of central sensitization) has positive short-term effects for patients with CFS, and fatigue-targeting cognitive behavioral therapy appears to be effective for pain from CFS as well.

LIMITATIONS: The role of the deficient hypothalamus-pituitary-adrenal axis in relation to pain from CFS, as well as the interactions with immune (dys)functioning require further study.

CONCLUSION: Recent research has increased our understanding of pain from CFS, including its treatment. It is advocated to optimize current CFS treatment protocols by targeting the underlying mechanism for those patients having severe pain.

 

Source: Nijs J, Crombez G, Meeus M, Knoop H, Damme SV, Cauwenbergh V, Bleijenberg G. Pain in patients with chronic fatigue syndrome: time for specific pain treatment? Pain Physician. 2012 Sep-Oct;15(5):E677-86. http://www.painphysicianjournal.com/linkout?issn=1533-3159&vol=15&page=E677 (Full article)

 

How to exercise people with chronic fatigue syndrome: evidence-based practice guidelines

Abstract:

BACKGROUND: Despite the large number of studies emphasizing the effectiveness of graded exercise therapy (GET) and cognitive behavioural therapy (CBT) for people with chronic fatigue syndrome (CFS), clinicians are left wondering how exactly to apply exercise therapy to their patients with CFS. The aim of this literature review is to identify the appropriate exercise modalities (i.e. exercise duration, mode, number of treatment sessions, session length, duration of treatment, exercise intensity and whether or not to apply home exercise program) for people with CFS.

MATERIALS AND METHODS: All studies that were identified through electronic databases (PubMed and PEDro) were assessed for methodological quality by using selection criteria (Delphi score).

RESULTS: In this literature review, 12 studies fulfilled all study requirements. One study had a low methodological quality. The parameters used in the GET and CBT interventions were divided into subgroups: (i) time or symptom contingent, (ii) exercise frequency and (iii) exercise modality.

CONCLUSION: The lack of uniformity in outcome measures and CFS diagnostic criteria make it difficult to compare the findings across studies. Based on the available evidence, exercise therapy for people with CFS should be aerobic and must comprise of 10-11 sessions spread over a period of 4-5 months. A time-contingent approach is preferred over a symptom-contingent way of exercising. In addition, people with CFS can perform home exercises five times a week with an initial duration of 5-15 min per exercise session. The exercise duration can be gradually increased up to 30 min.

© 2012 The Authors. European Journal of Clinical Investigation

© 2012 Stichting European Society for Clinical Investigation Journal Foundation.

Comment in:

Graded exercise therapy (GET)/cognitive behavioural therapy (CBT) is often counterproductive in myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). [Eur J Clin Invest. 2012]

Exercise and chronic fatigue syndrome: maximize function, minimize post-exertional malaise. [Eur J Clin Invest. 2012]

Objective compliance and outcome measures should be used in trials of exercise interventions for Chronic Fatigue Syndrome. [Eur J Clin Invest. 2012]

 

Source: Van Cauwenbergh D De Kooning M, Ickmans K, Nijs J. How to exercise people with chronic fatigue syndrome: evidence-based practice guidelines. Eur J Clin Invest. 2012 Oct;42(10):1136-44. doi: 10.1111/j.1365-2362.2012.02701.x. Epub 2012 Jun 23. https://www.ncbi.nlm.nih.gov/pubmed/22725992

 

Role of psychological aspects in both chronic pain and in daily functioning in chronic fatigue syndrome: a prospective longitudinal study

Abstract:

In addition to fatigue, many patients with chronic fatigue syndrome (CFS) experience chronic musculoskeletal pain. We aimed at examining the role of catastrophizing, coping, kinesiophobia, and depression in the chronic pain complaints and in the daily functioning of CFS patients.

A consecutive sample of 103 CFS patients experiencing chronic widespread musculoskeletal pain completed a battery of questionnaires evaluating pain, daily functioning, and psychological characteristics (depression, kinesiophobia, pain coping, and catastrophizing).

Thirty-nine patients participated in the 6-12-month follow-up, consisting of questionnaires evaluating pain and pressure pain algometry. Correlation and linear regression analyses were performed to identify predictors. The strongest correlations with pain intensity were found for catastrophizing (r = -.462, p < .001) and depression (r = -.439, p < .001). The stepwise multiple regression analysis revealed that catastrophizing was both the immediate main predictor for pain (20.2%) and the main predictor on the longer term (20.1%). The degree of depression was responsible for 10% in the observed variance of the VAS pain after 6-12 months.

No significant correlation with pain thresholds could be revealed. The strongest correlations with daily functioning at baseline were found for catastrophizing (r = .435, p < .001) and depression (r = .481, p < .001). Depression was the main predictor for restrictions in daily functioning (23.1%) at baseline. Pain catastrophizing and depression were immediate and long-term main predictors for pain in patients with CFS having chronic widespread musculoskeletal pain. They were also correlated to daily functioning, with depression as the main predictor for restrictions in daily functioning at baseline.

 

Source: Meeus M, Nijs J, Van Mol E, Truijen S, De Meirleir K. Role of psychological aspects in both chronic pain and in daily functioning in chronic fatigue syndrome: a prospective longitudinal study. Clin Rheumatol. 2012 Jun;31(6):921-9. doi: 10.1007/s10067-012-1946-z. Epub 2012 Feb 16. https://www.ncbi.nlm.nih.gov/pubmed/22349876

 

Kinesiophobia, catastrophizing and anticipated symptoms before stair climbing in chronic fatigue syndrome: an experimental study

Abstract:

PURPOSE: Kinesiophobia and catastrophizing are frequent among people with chronic fatigue syndrome (CFS). This study was aimed at examining (1) whether kinesiophobia, anticipated symptoms and fatigue catastrophizing are related to stair climbing performance in people with CFS; and (2) whether kinesiophobia and fatigue catastrophizing are related to daily physical activity in CFS.

METHOD: Patients with CFS filled in a set of questionnaires, performed a physical demanding task (two floors stair of climbing and descending) with pre-test and post-test heart rate monitoring and immediate post-stair climbing symptom assessment. Real-time activity monitoring was used between the baseline and second assessment day (7 days later).

RESULTS: Kinesiophobia and fatigue catastrophizing were strongly related (ρ = 0.62 and 0.67, respectively) to poorer stair climbing performance (i.e. more time required to complete the threatening activity). Kinesiophobia and fatigue catastrophizing were unrelated to the amount of physical activity on the first day following stair climbing or during the seven subsequent days.

CONCLUSION: These findings underscore the importance of kinesiophobia and fatigue catastrophizing for performing physical demanding tasks in everyday life of people with CFS, but refute a cardinal role for kinesiophobia and fatigue catastrophizing in determining daily physical activity level in these patients.

 

Source: Nijs J, Meeus M, Heins M, Knoop H, Moorkens G, Bleijenberg G. Kinesiophobia, catastrophizing and anticipated symptoms before stair climbing in chronic fatigue syndrome: an experimental study. Disabil Rehabil. 2012;34(15):1299-305. doi: 10.3109/09638288.2011.641661. Epub 2012 Feb 12. https://www.ncbi.nlm.nih.gov/pubmed/22324510

 

Pacing as a strategy to improve energy management in myalgic encephalomyelitis/chronic fatigue syndrome: a consensus document

Abstract:

PURPOSE: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition characterized by a number of symptoms which typically worsen following minimal exertion. Various strategies to manage the limited energy levels have been proposed. Of these, pacing has been consistently rated as one of the most helpful in surveys conducted by patient groups. This review is a response to the paucity of the information on pacing in the scientific literature.

METHOD: We describe the principle of pacing and how this can be adapted to meet individual abilities and preferences. A critical evaluation of the research was conducted to ascertain the benefits and limitations of this strategy.

RESULTS: Based on various studies, it is proposed that pacing can help to stabilize the condition and avoid post-exertional malaise.

CONCLUSION: Pacing offers practitioners an additional therapeutic option which is acceptable to the majority of patients and can reduce the severity of the exertion-related symptoms of ME/CFS.

© 2012 Informa UK, Ltd.

 

Source: Goudsmit EM, Nijs J, Jason LA, Wallman KE. Pacing as a strategy to improve energy management in myalgic encephalomyelitis/chronic fatigue syndrome: a consensus document. Disabil Rehabil. 2012;34(13):1140-7. doi: 10.3109/09638288.2011.635746. Epub 2011 Dec 19. https://www.ncbi.nlm.nih.gov/pubmed/22181560