Pain In Chronic Fatigue Syndrome Research Articles

The Process of Change in Pain During Cognitive-Behavior Therapy for Chronic Fatigue Syndrome.

Cognitive-behavior therapy (CBT) leads to a reduction of fatigue and pain in chronic fatigue syndrome. The processes underlying the reduction in pain have not been investigated. Recently, it was shown that increased self-efficacy, decreased focusing on symptoms, increased physical functioning, and a change in beliefs about activity contribute to the decrease in fatigue. The present study has 2 objectives: (1) to determine the relationship between the reduction of fatigue and pain during CBT; (2) test to what extent the model for change in fatigue is applicable to the reduction in pain. One hundred forty-two patients meeting United States centers for Disease Control and Prevention criteria for chronic fatigue syndrome, currently reporting pain, and starting CBT were included. A cross-lagged analysis was performed to study the causal direction of change between pain and fatigue. Pain and process variables were assessed before therapy, 3 times during CBT, and after therapy. Actual physical activity was also assessed. The model was tested with multiple regression analyses. The direction of change between pain and fatigue could not be determined. An increase in physical functioning and decrease in focusing on symptoms explained 4% to 14% of the change in pain. Pain and fatigue most probably decrease simultaneously during CBT. Pain reduction can partly be explained by a reduction of symptom focusing and increased physical functioning. Additional, yet unknown cognitive-behavioral factors also play a role in the reduction of pain.

Associations Between Cognitive Performance and Pain in Chronic Fatigue Syndrome: Comorbidity with Fibromyalgia Does Matter

Background: In addition to the frequently reported pain complaints, performance-based cognitive capabilities in patients with chronic fatigue syndrome (CFS) with and without comorbid fibromyalgia (FM) are significantly worse than those of healthy controls. In various chronic pain populations, cognitive impairments are known to be related to pain severity. However, to the best of our knowledge, the association between cognitive performance and experimental pain measurements has never been examined in CFS patients. Objectives: This study aimed to examine the association between cognitive performance and self-reported as well as experimental pain measurements in CFS patients with and without FM. Study Design: Observational study. Setting: The present study took place at the Vrije Universiteit Brussel and the University of Antwerp. Methods: Forty-eight (18 CFS-only and 30 CFS+FM) patients and 30 healthy controls were studied. Participants first completed 3 performance-based cognitive tests designed to assess selective and sustained attention, cognitive inhibition, and working memory capacity. Seven days later, experimental pain measurements (pressure pain thresholds [PPT], temporal summation [TS], and conditioned pain modulation [CPM]) took place and participants were asked to fill out 3 questionnaires to assess self-reported pain, fatigue, and depressive symptoms. Results: In the CFS+FM group, the capacity of pain inhibition was significantly associated with cognitive inhibition. Self-reported pain was significantly associated with simple reaction time in CFS-only patients. The CFS+FM but not the CFS-only group showed a significantly lower PPT and enhanced TS compared with controls. Limitations: The cross-sectional nature of this study does not allow for inferences of causation. Conclusions: The results underline disease heterogeneity in CFS by indicating that a measure of endogenous pain inhibition might be a significant predictor of cognitive functioning in CFS patients with FM, while self-reported pain appears more appropriate to predict cognitive functioning in CFS patients without FM. Key words: Chronic fatigue syndrome, cognitive function, cognitive inhibition, chronic pain, fibromyalgia, pain inhibition, pain-related cognitive impairment, working memory

Associations between cognitive performance and pain in chronic fatigue syndrome: comorbidity with fibromyalgia does matter

In addition to the frequently reported pain complaints, performance-based cognitive capabilities in patients with chronic fatigue syndrome (CFS) with and without comorbid fibromyalgia (FM) are significantly worse than those of healthy controls. In various chronic pain populations, cognitive impairments are known to be related to pain severity. However, to the best of our knowledge, the association between cognitive performance and experimental pain measurements has never been examined in CFS patients.This study aimed to examine the association between cognitive performance and self-reported as well as experimental pain measurements in CFS patients with and without FM.Observational study.The present study took place at the Vrije Universiteit Brussel and the University of Antwerp.Forty-eight (18 CFS-only and 30 CFS+FM) patients and 30 healthy controls were studied. Participants first completed 3 performance-based cognitive tests designed to assess selective and sustained attention, cognitive inhibition, and working memory capacity. Seven days later, experimental pain measurements (pressure pain thresholds [PPT], temporal summation [TS], and conditioned pain modulation [CPM]) took place and participants were asked to fill out 3 questionnaires to assess self-reported pain, fatigue, and depressive symptoms.In the CFS+FM group, the capacity of pain inhibition was significantly associated with cognitive inhibition. Self-reported pain was significantly associated with simple reaction time in CFS-only patients. The CFS+FM but not the CFS-only group showed a significantly lower PPT and enhanced TS compared with controls.The cross-sectional nature of this study does not allow for inferences of causation.The results underline disease heterogeneity in CFS by indicating that a measure of endogenous pain inhibition might be a significant predictor of cognitive functioning in CFS patients with FM, while self-reported pain appears more appropriate to predict cognitive functioning in CFS patients without FM.

A chronic fatigue syndrome model demonstrates mechanical allodynia and muscular hyperalgesia via spinal microglial activation.

Patients with chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FMS) display multiple symptoms, such as chronic widespread pain, fatigue, sleep disturbance, and cognitive dysfunction. Abnormal pain sensation may be the most serious of these symptoms; however, its pathophysiology remains unknown. To provide insights into the molecular basis underlying abnormal pain in CFS and FMS, we used a multiple continuous stress (CS) model in rats, which were housed in a cage with a low level of water (1.5 cm in depth). The von Frey and Randall-Seritto tests were used to evaluate pain levels. Results showed that mechanical allodynia at plantar skin and mechanical hyperalgesia at the anterior tibialis (i.e., muscle pain) were induced by CS loading. Moreover, no signs of inflammation and injury incidents were observed in both the plantar skin and leg muscles. However, microglial accumulation and activation were observed in L4-L6 dorsal horn of CS rats. Quantification analysis revealed a higher accumulation of microglia in the medial part of Layers I-IV of the dorsal horn. To evaluate an implication of microglia in pain, minocycline was intrathecally administrated (via an osmotic pump). Minocycline significantly attenuated CS-induced mechanical hyperalgesia and allodynia. These results indicated that activated microglia were involved in the development of abnormal pain in CS animals, suggesting that the pain observed in CFS and FMS patients may be partly caused by a mechanism in which microglial activation is involved.

Functional Improvement Is Accompanied by Reduced Pain in Adolescent Chronic Fatigue Syndrome

Dear Editor: Chronic fatigue syndrome (CFS) in adolescents is a complex, disabling condition characterized by severe and unexplained fatigue lasting more than 6 months, and often accompanied by pain symptoms. CFS in adolescents has substantial long-term consequences for educational and social development ⇓. Chronic pain symptoms in CFS are disabling and affect physical and social functioning ⇓. Adult patients with CFS show lower pain thresholds than healthy subjects ⇓. In a recently published review about pain in patients with CFS, Nijs et al. stated that pain appears to be one out of many symptoms related to central sensitization in adult CFS ⇓. They concluded that pain-catastrophizing thoughts and depression partly account for these pain symptoms. They suggested that it is important to understand the symptoms of pain in CFS better in order to assess whether it requires a specific treatment approach other than the main treatment focused on fatigue ⇓. Previous research has suggested to view the pathophysiological state of pain in CFS as an increase in the excitability and synaptic efficacy of neurons in central nociceptive pathways ⇓. We present original data on pain symptoms in adolescent CFS and their relation to treatment focused on fatigue. We hypothesized that adolescent CFS patients have a lowered pain threshold at the time of diagnosis and that both pain experience and pain threshold improve when CFS is successfully treated. Between November 2008 and February 2010, 83 adolescents (12–18 years) participating in the Fatigue In Teenagers on the interNET (FITNET) trial ⇓ were invited to participate in this longitudinal study on pain in adolescents with CFS, when attending their initial assessment at the University Medical Center Utrecht for the original FITNET trial ⇓. All patients agreed to participate (100%). They all complied with the U.S. Centers …

Pain in chronic fatigue syndrome: response to rehabilitative treatments in the PACE trial

Pain is a common symptom of chronic fatigue syndrome (CFS). We investigated the effects of the treatments used in the PACE trial [cognitive behavioural therapy (CBT), graded exercise therapy (GET), adaptive pacing therapy (APT) and specialist medical care (SMC)] on pain in CFS. We compared pain outcomes including individual painful symptoms, taken from the CDC criteria for CFS and co-morbid fibromyalgia. We modelled outcomes adjusting for baseline variables with multiple linear regression. Significantly less frequent muscle pain was reported by patients following treatment with CBT compared to SMC (mean difference = 0.38 unit change in frequency, p = 0.02), GET versus SMC (0.42, p = 0.01) and GET versus APT (0.37, p = 0.01). Significantly less joint pain was reported following CBT versus APT (0.35, p = 0.02) and GET versus APT (0.36, p = 0.02). Co-morbid fibromyalgia was less frequent following GET versus SMC (0.03, p = 0.03). The effect sizes of these differences varied between 0.25 and 0.31 for muscle pain and 0.24 and 0.26 for joint pain. Treatment effects on pain were independent of 'change in fatigue'. CBT and GET were more effective in reducing the frequency of both muscle and joint pain than APT and SMC. When compared to SMC, GET also reduced the frequency of co-morbid fibromyalgia; the size of this effect on pain was small.

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

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.

The relationship between posttraumatic stress disorder, illness cognitions, defence styles, fatigue severity and psychological well-being in chronic fatigue syndrome

This study investigated, firstly, the rate of posttraumatic stress disorder (PTSD) and the level of psychological well-being amongst people with chronic fatigue syndrome (CFS); and secondly, the extent to which illness cognitions, defence styles and PTSD symptom severity related to fatigue severity and psychological well-being. Seventy-eight participants with a diagnosis of CFS completed the Chalder Fatigue Scale, the General Health Questionnaire-28, the Posttraumatic Stress Diagnostic Scale, the Illness Cognition Questionnaire and the Defence Style Questionnaire. Fifty-nine participants were recruited from the general public to form the non-fatigued control group. CFS participants had significantly higher levels of PTSD symptoms, lower levels of psychological well-being and more traumatic life events compared to the non-fatigued controls. Trauma exposure and PTSD severity both predicted CFS status. However, regression analyses demonstrated no significant relationship between PTSD symptoms and fatigue severity or the degree of psychological well-being. ‘Helplessness’ predicted both physical and mental fatigue and psychological well-being, whilst the ‘mature’ defence styles predicted fatigue severity only. The results offer support to previous research showing that the rate of traumatic life events and PTSD are significantly higher amongst the CFS population. The lack of relationship between PTSD symptoms and fatigue severity or psychological well-being indicates that these processes may operate independently of one another, via different appraisal processes. This study focused on fatigue severity, but it may be that the role of pain in CFS is a key element in the previously reported association between PTSD and CFS.

Response to: Exercise Performance and Chronic Pain in Chronic Fatigue Syndrome: The Role of Pain Catastrophizing

Nijs and colleagues [1] have found various correlations; however, they have not proven the direction of causation or shown what can be done with the information. As is well known, pain can have a protective effect; conditions involving a lack of sensitivity to pain can cause all sorts of extra complications. Knowledge of why patients with …

Exercise Performance and Chronic Pain in Chronic Fatigue Syndrome: The Role of Pain Catastrophizing

This study aimed to examine the associations between bodily pain, pain catastrophizing, depression, activity limitations/participation restrictions, employment status, and exercise performance in female patients with chronic fatigue syndrome (CFS) who experience widespread pain. Cross-sectional observational study. A university-based clinic. Thirty-six female CFS patients who experienced widespread pain. Patients filled in the Medical Outcomes Short-Form 36 Health Status Survey, the Chronic Fatigue Syndrome Activities and Participation Questionnaire, the Beck Depression Inventory, and the Pain Catastrophizing Scale, and underwent a maximal exercise stress test with continuous monitoring of electrocardiographic and ventilatory parameters. Pain catastrophizing was related to bodily pain (r = -0.70), depression (r = 0.55), activity limitations/participation restrictions (r = 0.68), various aspects of quality of life ( r varied between -0.51 and -0.64), and exercise capacity (r varied between -0.41 and -0.61). Based on hierarchical multiple regression analysis, pain catastrophizing accounted for 41% of the variance in bodily pain in female CFS patients who experience chronic widespread musculoskeletal pain. Among the three subscale scores of the Pain Catastrophizing Scale, helplessness and rumination rather than magnification were strongly related to bodily pain. Neither pain catastrophizing nor depression was related to employment status. These data provide evidence favoring a significant association between pain catastrophizing, bodily pain, exercise performance, and self-reported disability in female patients with CFS who experience widespread pain. Further prospective longitudinal studying of these variables is required.

Diffuse noxious inhibitory control is delayed in chronic fatigue syndrome: An experimental study

Deficient endogenous pain inhibition, e.g. Diffuse noxious inhibitory controls (DNIC), or hormonal abnormalities like hypocortisolism, could be responsible for chronic widespread pain in Chronic Fatigue Syndrome (CFS). Thirty-one CFS-patients with chronic pain and 31 healthy controls were subjected to spatial summation of thermal noxious stimuli by gradual immersion (ascending or descending) of the arm in warm water (46 °C). They rated pain intensity every 15 s. Every immersion took 2 min, alternated with 5 min rest. Before and after immersion, salivary cortisol was assessed. Overall pain ratings were higher in CFS-patients, but the evolution was not different between patients and controls, during both ascending and descending immersion. Pain intensity and immersed surface were only correlated during the descending session in both patients ( r = .334) and controls ( r = .346). When comparing the first and the last 15 s of every emersion, it was found that pain inhibition starts slower for CFS-patients in comparison to healthy subjects. Both pre- or post-values and cortisol response did not differ between controls and patients. The drop in cortisol was significantly correlated to pain intensity in CFS ( r between .357 and .402). In addition to the hyperalgesia in CFS, DNIC react slower to spatial summation of thermal noxious stimuli. We found no evidence for hypocortisolism in CFS, and the cortisol response to nociception was not different in CFS compared to healthy subjects. In conclusion, delayed pain inhibition may play a role in chronic widespread pain in CFS but further research is required.

Chronic musculoskeletal pain in chronic fatigue syndrome: Recent developments and therapeutic implications

Patients with chronic fatigue syndrome (CFS) experience chronic musculoskeletal pain which is even more debilitating than fatigue. Scientific research data gathered around the world enables clinicians to understand, at least in part, chronic musculoskeletal pain in CFS patients. Generalized joint hypermobility and benign joint hypermobility syndrome appear to be highly prevalent among CFS sufferers, but they do not seem to be of any clinical importance. On the other hand, pain catastrophizing accounts for a substantial portion of musculoskeletal pain and is a predictor of exercise performance in CFS patients. The evidence concerning pain catastrophizing is supportive of the indirect evidence of a dysfunctional pain processing system in CFS patients with musculoskeletal pain. CFS sufferers respond to incremental exercise with a lengthened and accentuated oxidative stress response, explaining muscle pain, postexertional malaise, and the decrease in pain threshold following graded exercise in CFS patients. Applying the scientific evidence to the manual physiotherapy profession, pacing self-management techniques and pain neurophysiology education are indicated for the treatment of musculoskeletal pain in CFS patients. Studies examining the effectiveness of these strategies for CFS patients are warranted.

Pain in patients with chronic fatigue syndrome: Does nitric oxide trigger central sensitisation?

Previous studies have provided evidence supportive of the clinical importance of widespread pain in patients with chronic fatigue syndrome (CFS): pain severity may account for 26-34% of the variability in the CFS patient's activity limitations and participation restrictions. The etiology of widespread pain in CFS remains to be elucidated, but sensitisation of the central nervous system has been suggested to take part of CFS pathophysiology. It is hypothesised that a nitric oxide (NO)-dependent reduction in inhibitory activity of the central nervous system and consequent central sensitisation accounts for chronic widespread pain in CFS patients. In CFS patients, deregulation of the 2',5'-oligoadenylate synthetase/RNase L pathway is accompanied by activation of the protein kinase R enzyme. Activation of the protein kinase R and subsequent nuclear factor-kappaB activation might account for the increased production of NO, while infectious agents frequently associated with CFS (Coxsackie B virus, Epstein-Barr Virus, Mycoplasma) might initiate or accelerate this process. In addition, the evidence addressing behavioural changes in CFS patients fits the central sensitisation-hypothesis: catastrophizing, avoidance behaviour, and somatization may result in, or are initiated by sensitisation of the central nervous system.

The localization of pain in chronic fatigue syndrome on a pain drawing according to grid areas.

23 women with chronic symptoms of fatigue and pain used a gridded form to localize pain. Most frequent experiences of pain were in the neck and right buttock (44% of subjects), upper parts of the chest, left calf, and lower back by 40%.