Abstract Objectives The purpose of this systematic review is to analyze the available literature on structural and functional brain abnormalities in chronic low back pain (CLBP) using several brain ...magnetic resonance imaging (MRI) techniques. Methods PubMed and Web of Science were systematically screened for relevant literature using different combinations of keywords regarding structural and functional brain imaging techniques in patients with CLBP. Reference lists of included articles were hand-searched for additional literature. Eligible articles were assessed on risk of bias and reviewed by two independent researchers. Results The search query returned 27 articles meeting the inclusion criteria. Methodological quality varied from poor to good. A total of 10 studies evaluated structural gray matter changes. There is conflicting evidence in global gray matter changes, with both increases and decreases shown in different studies. Gray matter changes were demonstrated in specific brain regions. Structural white matter changes were reported in five studies. There is conflicting evidence in total white matter volume due to both increases and unchanged white matter. Several regional differences were identified in which white matter changes were shown. Functional organization during rest was evaluated in 10 studies. CLBP patients showed increased activation in specific regions, together with a disrupted default mode network. A total of six studies evaluated brain activity in response to a nociceptive stimulus. Findings suggest that patients demonstrated increased activity in pain-related regions, and decreased activity in analgesic regions. Conclusions Overall, there is moderate evidence for regional changes in gray and white matter, together with an altered functional connectivity during rest and increased activity in pain-related areas following painful stimulation, evidencing an upregulated pain matrix. More longitudinal research is needed to clarify the temporal relationship regarding pain and neuroplastic changes, and integration of different brain imaging techniques is warranted.
Abstract Objectives The aim of the present study was to systematically review the literature addressing pain-induced changes in the brain related to central sensitization in patients with ...fibromyalgia (FM) using specific functional (rs-fMRI and fMRI) and structural (voxel-based morphometry—VBM) brain MRI techniques. Methods PubMed and Web of Science were searched for relevant literature using different key word combinations related to FM, brain MRI, and central sensitization. Full-text reports fulfilling the inclusion criteria were assessed on risk of bias and reviewed by two independent reviewers. Results From the 61 articles that were identified, 22 met the inclusion criteria and achieved sufficient methodological quality. Overall, eight articles examined structural brain (VBM) changes in patients with FM, showing moderate evidence that central sensitization is correlated with gray matter volume decrease in specific brain regions (mainly anterior cingulate cortex and prefrontal cortex). However, global gray matter volume remains unchanged. A total of 13 articles evaluated brain activity (fMRI) in response to a nociceptive stimulus. Findings suggest a higher but similar pattern of activation of the pain matrix in FM patients compared to controls. There is also evidence of decreased functional connectivity in the descending pain-modulating system in FM patients. Overall, two articles examined intrinsic brain connectivity in FM patients with rs-fMRI. In conclusion, there is moderate evidence for a significant imbalance of the connectivity within the pain network during rest in patients with FM. Conclusions The included studies showed a moderate evidence for region-specific changes in gray matter volume, a decreased functional connectivity in the descending pain-modulating system, and an increased activity in the pain matrix related to central sensitization. More research is needed to evaluate the cause–effect relationship.
Physiologic Effects of Dry Needling Cagnie, Barbara; Dewitte, Vincent; Barbe, Tom ...
Current pain and headache reports,
08/2013, Letnik:
17, Številka:
8
Journal Article
Recenzirano
During the past decades, worldwide clinical and scientific interest in dry needling (DN) therapy has grown exponentially. Various clinical effects have been credited to dry needling, but rigorous ...evidence about its potential physiological mechanisms of actions and effects is still lacking. Research identifying these exact mechanisms of dry needling action is sparse and studies performed in an acupuncture setting do not necessarily apply to DN. The studies of potential effects of DN are reviewed in reference to the different aspects involved in the pathophysiology of myofascial triggerpoints: the taut band, local ischemia and hypoxia, peripheral and central sensitization. This article aims to provide the physiotherapist with a greater understanding of the contemporary data available: what effects could be attributed to dry needling and what are their potential underlying mechanisms of action, and also indicate some directions at which future research could be aimed to fill current voids.
Objective:
To examine the predictive, moderating and mediating role of cognitive, emotional and behavioral factors on pain and disability following shoulder treatment.
Data sources:
Electronic ...databases (PubMed, Web of Science, Embase and PsycINFO) were searched until 14 January 2019.
Study selection:
Studies including persons with musculoskeletal shoulder pain that describe the predictive, moderating or mediating role of baseline cognitive, emotional or behavioral factors on pain or disability following treatment were selected.
Results:
A total of 23 articles, describing 21 studies and involving 3769 participants, were included. Three studies had a high risk of bias. There was no predictive role of baseline depression, anxiety, coping, somatization or distress on pain or disability across types of shoulder treatment. No predictive role of fear-avoidance beliefs was identified in patients receiving physiotherapy, which contrasted to the results found when surgical treatment was applied. Baseline catastrophizing was also not predictive for pain or disability in patients receiving physiotherapy. After conservative medical treatments, results on the predictive role of catastrophizing were inconclusive. Treatment expectations and baseline self-efficacy predicted pain and disability in patients receiving physiotherapy, which was not the case in patients receiving conservative medical treatment. Finally, there was a moderating role for optimism in the relationship between pain catastrophizing and disability in patients receiving physiotherapy.
Conclusion:
There is evidence that expectations of recovery and self-efficacy have a predictive role and optimism a moderating role on pain and/or disability following physiotherapy for musculoskeletal shoulder pain. After surgical treatment, fear-avoidance is a predictor of pain and disability.
Abstract Background Context Heterogeneity exists within the low back pain population. Some patients recover after every pain episode, whereas others suffer daily from LBP complaints. Until now, ...studies rarely make a distinction between recurrent low back pain (RLBP) and chronic low back pain (CLBP), although both are characterized by a different clinical picture. Clinical experiences also indicate that heterogeneity exists within the CLBP population. Muscle degeneration, like atrophy, fat infiltration, alterations in muscle fiber type and altered muscle activity, compromises proper biomechanics and motion of the spinal units in low back pain (LBP) patients. The amount of alterations in muscle structure and muscle function of the paraspinal muscles, might be related to the recurrence or chronicity of LBP. Purpose The aim of this experimental study is to evaluate differences in muscle structure (cross-sectional area and lean muscle fat index) and muscle activity of the multifidus (MF) and erector spinae (ES) during trunk extension, in patients with RLBP, non-continuous CLBP and continuous CLBP. Study Design and Setting This cross-sectional study took place in the University hospital of Ghent, Belgium. Muscle structure characteristics and muscle activity were assessed by magnetic resonance imaging (MRI). Patient Sample Fifty five adults with non-specific low back pain (24 RLBP in remission, 15 non-continuous CLBP, 16 continuous CLBP) participated in this study. Outcome Measures Total cross-sectional area, muscle cross-sectional area, fat cross-sectional area, lean muscle fat index, T2-rest and T2-shift were assessed. Methods A T1-weighted Dixon MRI scan was used to evaluate spinal muscle cross-sectional area and fat infiltration in the lumbar MF and ES. Muscle functional MRI was used to evaluate the muscle activity of the lumbar MF and ES during a lumbar extension exercise. Before and after the exercise, a pain assessment was performed. This study was supported by grants from the Special Research Fund of Ghent University (DEF12/AOP/022) without potential conflict of interest-associated biases in the text of the paper. Results Fat cross-sectional area and lean muscle fat index was significantly higher in MF and ES in continuous CLBP compared to non-continuous CLBP and RLBP (p<0.05). No differences between groups were found for total cross-sectional area and muscle cross-sectional area in MF or ES (p>0.05). Also no significant differences between groups for T2-rest were established. T2-shift, however, was significantly lower in MF and ES in RLBP compared to respectively non-continuous CLBP and continuous CLBP (p<0.05). Conclusion These results indicate a higher amount of fat infiltration in the lumbar muscles, in the absence of clear atrophy, in continuous CLBP compared to RLBP. A lower metabolic activity of the lumbar muscles was seen in RLBP replicating a relative lower intensity in contractions performed by the lumbar muscles in RLBP compared to non-continuous and continuous CLBP. In conclusion, RLBP differ from continuous CLBP for both muscle structure and muscle function, whereas non-continuous CLBP seem comparable with RLBP for lumbar muscle structure and with continuous CLBP for lumbar muscle function. These results underline the differences in muscle structure and muscle function between different LBP populations.
Introduction: Central sensitization is a form of maladaptive neuroplasticity underlying many chronic pain disorders, including neuropathic pain, fibromyalgia, whiplash, headache, chronic pelvic pain ...syndrome and some forms of osteoarthritis, low back pain, epicondylitis, shoulder pain and cancer pain. Brain-derived neurotrophic factor (BDNF) is a driving force behind neuroplasticity, and it is therefore crucial for neural maintenance and repair. However, BDNF also contributes to sensitization of pain pathways, making it an interesting novel therapeutic target.Areas covered: An overview of BDNF's sensitizing capacity at every level of the pain pathways is presented, including the peripheral nociceptors, dorsal root ganglia, spinal dorsal horn neurons, and brain descending inhibitory and facilitatory pathways. This is followed by the presentation of several potential therapeutic options, ranging from indirect influencing of BDNF levels (using exercise therapy, anti-inflammatory drugs, melatonin, repetitive transcranial magnetic stimulation) to more specific targeting of BDNF's receptors and signaling pathways (blocking the proteinase-activated receptors 2-NK-κβ signaling pathway, administration of phencyclidine for antagonizing NMDA receptors, or blockade of the adenosine A2A receptor).Expert opinion: This section focuses on combining pharmacotherapy with multimodal rehabilitation for balancing the deleterious and therapeutic effects of BNDF treatment in chronic pain patients, as well as accounting for the complex and biopsychosocial nature of chronic pain.
Chronic subjective tinnitus is a prevalent symptom, which has many similarities with chronic pain. Central sensitization is considered as a possible underlying mechanism of both symptoms. Central ...sensitization has already been investigated in chronic pain populations but not in patients with chronic subjective tinnitus. Therefore, the main objective of this cross-sectional study was to compare signs and symptoms, indicative for central sensitization, in tinnitus patients with and without chronic idiopathic neck pain, patients with chronic idiopathic neck pain only, and healthy controls. Also, differences in psychological and lifestyle factors, possibly influencing the association between central sensitization and tinnitus, were examined as well as correlations between signs and symptoms of central sensitization, and tinnitus, pain, psychological and lifestyle factors. Differences in signs and symptoms of central sensitization were examined using the self-report Central Sensitization Inventory and QST protocol (local and distant mechanical and heat hyperalgesia, conditioned pain modulation). Tinnitus, pain, psychological and lifestyle factors were evaluated using self-report questionnaires. Symptoms of central sensitization and local mechanical hyperalgesia were significantly more present in both tinnitus groups, compared to healthy controls, but were most extensive in the group with chronic tinnitus+chronic idiopathic neck pain. Distant mechanical hyperalgesia, indicative for central sensitization, was only observed in the group with both chronic tinnitus+chronic idiopathic neck pain. This group also displayed a significantly higher psychological burden and poorer sleep than patients with chronic tinnitus only and healthy controls. Signs and symptoms of central sensitization were also shown to be associated with tinnitus impact, pain-related disability, psychological burden and sleep disturbances. This study shows preliminary evidence for the presence of central sensitization in patients with chronic tinnitus+chronic idiopathic neck pain. This could be explained by the higher perceived tinnitus impact, psychological burden and sleep problems in this group. Trial registration: This study is registered as NCT05186259 (www.clinicaltrials.gov).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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.
Compelling evidence has shown chronic widespread and exaggerated pain experience in chronic musculoskeletal pain (MSKP) conditions. In addition, neuroimaging research has revealed morphological and ...functional brain alterations in these patients. It is hypothesized that brain alterations play a role in the persistent pain complaints of patients with chronic MSKP. Nevertheless, lack of overview exists regarding the relations between brain alterations and clinical measures of pain. The present systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, to investigate the relations between structural or functional brain alterations, using magnetic resonance imaging scans, and clinical pain measures in patients with chronic MSKP. PubMed, Web of Science, Cinahl, and Cochrane databases were searched. First, the obtained articles were screened according to title and abstract. Second, the screening was on the basis of full-text. Risk of bias in included studies was investigated according to the modified Newcastle-Ottawa Scale. Twenty studies met the inclusion criteria. Moderate evidence shows that higher pain intensity and pressure pain sensitivity are related to decreased regional gray matter (GM) volume in brain regions encompassing the cingulate cortex, the insula, and the superior frontal and temporal gyrus. Further, some evidence exists that longer disease duration in fibromyalgia is correlated with decreased total GM volume. Yet, inconclusive evidence exists regarding the association of longer disease duration with decreased or increased regional GM volume in other chronic MSKP conditions. Inconclusive evidence was found regarding the direction of the relation of pain intensity and pressure pain sensitivity with microstructural white matter and functional connectivity alterations. In conclusion, preliminary to moderate evidence demonstrates relations between clinical pain measures, and structural and functional connectivity alterations within brain regions involved in somatosensory, affective, and cognitive processing of pain in chronic MSKP. Nevertheless, inconclusive results exist regarding the direction of these relations. Further research is warranted to unravel whether these brain alterations are positively or negatively correlated to clinical pain measures.
Structural and functional brain alterations within regions involved in somatosensory, affective, and cognitive pain processing play a crucial role in the persistent pain of chronic MSKP patients. Accordingly, these brain alterations have to be taken into account when assessing and treating patients with chronic MSKP.
Abstract
Background
Altered lower back muscle activity is proposed as a contributing factor to the reoccurrence and chronicity of low back pain (LBP). This study compared lumbar muscle activity ...during trunk extension in patients with continuous chronic LBP (CLBP), non-continuous CLBP, recurrent LBP (RLBP) and healthy subjects.
Methods
In 75 subjects (16 continuous CLBP, 15 non-continuous CLBP, 23 RLBP, 21 healthy controls), surface electromyographic (EMG) activity of the lumbar erector spinae (ES), multifidus (MF), latissimus dorsi (LD) and gluteus maximus (GM) was recorded during the concentric, holding and eccentric phase of a modified Biering Sorenson exercise.
Results
Continuous CLBP patients showed higher EMG activity in the ES and MF muscles compared to healthy controls in the concentric (
p
= 0.011;
p
= 0.009 respectively) and the holding phase (
p
= 0.015;
p
= 0.013). Higher EMG activity was observed in continuous CLBP compared to RLBP in the ES and MF muscles in the holding phase (
p
= 0.035;
p
= 0.037), and in the MF in the concentric phase (
p
= 0.046), but not in the ES (
p
= 0.062). No differences in muscle activity were established in either the concentric, holding, and eccentric phase for the LD and GM muscles. No differences were found between non-continuous CLBP and the other groups.
Conclusions
An enhanced muscle activity of the lumbar muscles during the concentric and holding phase was observed during trunk extension in patients with continuous CLBP compared to patients with RLBP and healthy subjects. No differences between groups are present in the GM and LD muscles during concentric and holding phases and for any muscle in the eccentric phase.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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