Michael Peolsson

Increase in muscle nociceptive substances and anaerobic metabolism in patients with trapezius myalgia: microdialysis in rest and during exercise.

&NA; Local metabolic changes are suggested to be involved in muscle pain development in humans. Nineteen women with chronic work‐related trapezius myalgia (TM) and 20 healthy female controls (CON) were studied during baseline rest, 20 min repetitive low‐force exercise, and 120 min recovery. Interstitial serotonin (5‐HT), glutamate, lactate, pyruvate, and blood flow were determined by microdialysis in the trapezius muscle. Baseline pressure pain threshold (PPT) was lower (143±18 (TM) vs. 269±17 (CON) kPa) (mean±SEM), pain intensity (visual analogue scale, VAS) higher (33±5 vs. 2±1 mm), muscle 5‐HT higher (22.9±6.7 vs. 3.8±1.3 nmol/l), and glutamate higher (47±3 vs. 36±4 μmol/l) in TM than in CON (all P<0.05), whereas muscle blood flow was similar in groups. Furthermore, muscle pyruvate was higher (180±15 vs. 135±12 μmol/l) and lactate higher (4.4±0.3 vs. 3.1±0.3 mmol/l) in TM than in CON (P<0.001). In response to exercise, VAS and glutamate increased in both TM and CON (all P<0.05). In TM only, lactate and pyruvate increased significantly (P<0.02), whereas blood flow increased to similar levels in both groups. During the initial 20 min recovery period, blood flow remained increased in TM (P<0.005) whereas it decreased to baseline levels in CON. In conclusion, patients with chronic work‐related TM have increased levels of muscle 5‐HT and glutamate that were correlated to pain intensity (r=0.55, P<0.001) and PPT (r=−0.47, P<0.001), respectively. In addition, TM was associated with increased anaerobic metabolism, whereas a normal rise in blood flow was seen with exercise. These findings indicate that peripheral nociceptive processes are active in work‐related TM.

CATASTRoPHIZING, dEPRESSIoN, ANd PAIN: CoRRELATIoN WITH ANd INFLuENCE oN QuALITY oF LIFE ANd HEALTH - A STudY oF CHRoNIC WHIPLASH-ASSoCIATEd dISoRdERS

OBJECTIVE The aims of this study were: (i) to classify subgroups according to the degree of pain intensity, depression, and catastrophizing, and investigate distribution in a group of patients with chronic whiplash-associated disorders; and (ii) to investigate how these subgroups were distributed and inter-related multivariately with respect to consequences such as health and quality of life outcome measures. DESIGN Descriptive cross-sectional study. PATIENTS A total of 275 consecutive chronic pain patients with whiplash-associated disorders who were referred to a university hospital. METHODS The following data were obtained by means of self-report questionnaires: pain intensity in neck and shoulders, background history, Beck Depression Inventory, the catastrophizing scale of Coping Strategy Questionnaire, Life Satisfaction Checklist, the SF-36 Health Survey, and the EuroQol. RESULTS Principal component analysis was used to recognize subgroups according to the degree of pain intensity, depression, and catastrophizing. These subgroups have specific characteristics according to perceived health and quality of life, and the degree of depression appears to be the most important influencing factor. CONCLUSION From a clinical point of view, these findings indicate that it is important to assess patients for intensity of pain, depression, and catastrophizing when planning a rehabilitation programme. Such an evaluation will help individualize therapy and intervention techniques so as to optimize the efficiency of the programme.

Biochemical alterations in the trapezius muscle of patients with chronic whiplash associated disorders (WAD) – A microdialysis study

The mechanisms behind the development of chronic trapezius myalgia in patients with whiplash associated disorders (WAD) appear to involve both peripheral and central components, but the specific contribution of alterations in muscle is not clear. Female patients with WAD and involvement of trapezius (N=22) and female controls (N=20; CON) were studied during an experiment compromised of rest (baseline), 20min repetitive low‐force exercise and 120min recovery. Their interstitial concentrations of serotonin (5‐HT), glutamate, lactate, pyruvate, potassium, interleukin‐6 (IL‐6), and blood flow were determined in the trapezius muscle using a microdialysis technique. Pressure pain thresholds (PPT) over trapezius and tibialis anterior muscles were also assessed. In WAD, we found signs of generalized hypersensitivity according to PPT. The WAD group had significantly higher interstitial [IL‐6] and [5‐HT] in the trapezius than the CON. [Pyruvate] was overall significantly lower in WAD, and with lactate it showed another time‐pattern throughout the test. In the multivariate regression analysis of pain intensity [5‐HT] was the strongest regressor and positively correlated with pain intensity in WAD. In addition, blood flow, [pyruvate], and [potassium] influenced the pain intensity in a complex time dependent way. These findings may indicate that peripheral nociceptive processes are activated in WAD with generalized hypersensitivity for pressure and they are not identical with those reported in chronic work‐related trapezius myalgia, which could indicate different pain mechanisms.

Impact of the interaction between self-efficacy, symptoms and catastrophising on disability, quality of life and health in with chronic pain patients

Purpose. To investigate the interactions between self-efficacy – including subcomponents – and symptoms (pain, depression and anxiety), catastrophising, disability, quality of life and health in a population of patients with chronic pain. Method. The study used 433 patients with chronic pain including 47 patients with spinal cord injury-related pain, 150 patients with chronic whiplash-associated disorders and 236 patients with fibromyalgia. The participants answered a postal questionnaire that provided background data, pain intensity and duration and psychological- and health-related variables. Results. In the multivariate context, depression, anxiety, catastrophising and disability were intercorrelated. Self-efficacy correlated positively with variables of quality of life and general health. These two groups of variables were negatively correlated. The pain variables – duration of pain, pain intensity and spreading of pain – formed a third group of variables. Self-efficacy function was negatively correlated to these three pain variables. When regressing disability, quality of life and health, we found that self-efficacy had a positive impact whereas symptoms, catastrophising and pain had a negative influence on these aspects. Different patterns of influencing variables were discerned for the three different analyses, and specific patterns of the subscales of self-efficacy corresponded to specific patterns of negative factors for the outcome of disability, quality of life and health. Conclusion. There is a complex interaction of psychological factors and symptoms and their positive and negative influence on disability, quality of life and health. The results indicate that it might be important to assess and influence both enhancing and detoriating factors to ensure an effective pain management programme.

The complex interplay between pain intensity, depression, anxiety and catastrophising with respect to quality of life and disability

Purpose. To identify subgroups of patients with chronic pain based on the occurrence of depression, anxiety and catastrophising and the duration of pain and pain intensity. In addition to this, the relationship between the subgroups with respect to background variables, diagnosis, pain-related disability and perceived quality of life are investigated. Methods. This study used 433 patients with chronic pain including 47 patients with spinal cord injury-related pain, 150 with chronic whiplash associated disorders and 236 with fibromyalgia. The participants answered a postal questionnaire that provided background data, pain intensity and duration and psychological and health-related items. Results. On the basis of depression, anxiety, catastrophising, pain intensity and duration, we identified subgroups of patients with chronic pain that differed with respect to perceived quality of life, disability and diagnosis. The psychological factors, especially depression, significantly influenced perceived quality of life and disability. Pain intensity and duration play a minor role with respect to quality of life, although pain intensity is associated to perceived disability. Conclusions. The results of this study highlight the importance of not looking at patients with chronic pain as a homogenous entity. A detailed assessment, including psychological factors with emphasis on depressive symptoms, might be essential for planning and carrying through treatment and rehabilitation.

Increased levels of interstitial potassium but normal levels of muscle IL-6 and LDH in patients with trapezius myalgia

Abstract The mechanisms behind the development of work‐related trapezius pain are suggested to involve both peripheral and central components, but the specific contribution of alterations in muscle nociceptive and other substances is not clear. Female patients with chronic trapezius myalgia (N=19; TM) and female controls (N=20; CON) were studied at rest, during 20 min repetitive low‐force exercise and recovery, and had their interstitial concentrations of potassium (K+), lactate dehydrogenase (LDH), interleukin‐6 (IL‐6) and collagen turnover determined in the trapezius muscle by the microdialysis technique. K+ levels were at all time points higher in TM than in CON (P<0.0001). Baseline levels of LDH and IL‐6 were similar in both groups. In response to exercise pain intensity, rated perceived exertion, and the concentrations of K+, LDH and IL‐6 increased significantly in both groups. [K+] immediately decreased to baseline levels in CON but remained elevated during the first 20 min of recovery in TM (P<0.01) whereafter it returned to baseline level. In all subjects taken together mean [K+] correlated negatively with pressure pain threshold of trapezius (P<0.001), positively with mean pain intensity VAS (P<0.001) and mean perceived exertion (P<0.001). Rises in muscle LDH and IL‐6 as well as the anabolic ratio for collagen type I was not significantly different between groups. In conclusion, patients with chronic pain in the trapezius muscle had increased levels of interstitial potassium. This finding could be causally related to myalgia or secondary to pain due to deconditioned muscle or altered muscle activity pattern.

Generalized pain is associated with more negative consequences than local or regional pain : A study of chronic whiplash-associated disorders

OBJECTIVE The main aims of this study were: (i) to determine, for chronic whiplash-associated disorders, whether widespread pain has more severe consequences for other symptoms and different aspects of perceived health than does local/regional pain; (ii) to investigate whether pain, depression, and symptoms not directly related to pain are intercorrelated and to what extent these symptoms correlate with catastrophizing according to the Coping Strategy Questionnaire. DESIGN Descriptive cross-sectional study. PATIENTS A total of 275 consecutive chronic pain patients with whiplash-associated disorders who were referred to a university hospital. METHODS Background history, Beck Depression Inventory, Coping Strategy Questionnaire, Life Satisfaction Checklist, the SF-36 Health Survey and EuroQol were used to collect data. RESULTS Spreading of pain was associated with negative consequences with respect to pain intensity and prevalence of other symptoms, life satisfaction/quality and general health. The subjects differ with respect to the presence of symptoms not directly related to pain. A minor part of the variation in Back Depression Inventory was explained by direct aspects of pain, indicating that, to some extent, generalization of pain is related to catastrophizing thoughts. CONCLUSION Widespread pain was associated with negative consequences with respect to pain intensity, prevalence of other symptoms including depressive symptoms, some aspects of coping, life satisfaction and general health.

Pain Gestures: The Orchestration of Speech and Body Gestures

This article is about the use and function of gestures in pain communication. More specifically how we can communicate an internal bodily experience like pain with the help of gestures. This is of great importance both in everyday situations and in medical consultations of various types. Our focus in this article is on the issues of the gesture as a communicative resource, how verbal and nonverbal communicative resources are related to each other and in what way gestures contribute to the structure of different types of pain. Thirty-seven patients have been interviewed about their pain experiences and the main result is that several communicative modalities are interwoven in the pain accounts. Three different functions of gestures were identified: the pointing, iconic and symbolic functions. The clinical relevance of this approach to gestures in pain communication is to take note of the intricate interplay of different communicative resources used in the pain description, and to emphasize both verbal and nonverbal interaction in the clinical conversation as a resource in the care situation.

Living with Chronic Pain: A Dynamic Learning Process

This study focuses on how patients describe and manage their pain in their everyday life. The data consist of interviews with 37 patients undergoing treatment for chronic pain. The study focuses on ...This study focuses on how patients describe and manage their pain in their everyday life. The data consist of interviews with 37 patients undergoing treatment for chronic pain. The study focuses on how experiences of pain are mediated and interpreted with the help of the individuals discursive resources. It is argued that this kind of resource is important in constituting a structure of relations between a suffering person, pain and context. In the analysis of the material a four-step procedure was used, including both formal and content-related aspects. It was found that the patients describe chronic pain as a dynamic phenomenon. Patients learn about their pain by actively constituting relations among themselves, the pain and their activities. For the patients, chronic pain is a structured phenomenon. Patients often describe how pain is initiated, worsens and is alleviated. Patients thereby learn to distinguish different figures in their pain, which they are able to relate to in their management of pain. This suggests that a life in pain could be seen as an apprenticeship process. The heart of the matter in this process is learning to become sensitive to and flexible towards variations in the pain and potential pain triggers in the environment. This knowledge is important, as mastering pain is a balancing act between inner resources and environmental circumstances.

Modelling human musculoskeletal functional movements using ultrasound imaging

BackgroundA widespread and fundamental assumption in the health sciences is that muscle functions are related to a wide variety of conditions, for example pain, ischemic and neurological disorder, exercise and injury. It is therefore highly desirable to study musculoskeletal contributions in clinical applications such as the treatment of muscle injuries, post-surgery evaluations, monitoring of progressive degeneration in neuromuscular disorders, and so on.The spatial image resolution in ultrasound systems has improved tremendously in the last few years and nowadays provides detailed information about tissue characteristics. It is now possible to study skeletal muscles in real-time during activity.MethodsThe ultrasound images are transformed to be congruent and are effectively compressed and stacked in order to be analysed with multivariate techniques. The method is applied to a relevant clinical orthopaedic research field, namely to describe the dynamics in the Achilles tendon and the calf during real-time movements.ResultsThis study introduces a novel method to medical applications that can be used to examine ultrasound image sequences and to detect, visualise and quantify skeletal muscle dynamics and functions.ConclusionsThis new objective method is a powerful tool to use when visualising tissue activity and dynamics of musculoskeletal ultrasound registrations.