Human Studies

Myofascial pain syndrome (MPS) has a high global prevalence and is associated with myofascial trigger points (MTrPs) in taut bands or nodules. Little is known about the aetiology. The current study assessed the pathophysiological characteristics of MTrPs in MPS patients.

Objectives Complex regional pain syndrome (CRPS) is a rare chronic pain condition for which no curative treatment exists. Patients in tertiary centres are often required to make decisions about treatment options. This study was conducted to explore how prior attendance of a pain management program might alter patients' decision making processes. Methods This qualitative study uses focus groups to gather patient views on an immunosuppressant drug treatment (mycophenolate) for the management of CRPS. Participants were allocated to one of three focus groups based on their treatment journey; Group 1 (n=3) were involved in a recent mycophenolate drug trial; Group 2 (n=5) were neither involved in the trial nor attended a Pain Management Programme (PMP); Group 3 (n=6) were not involved in the trial but had attended a PMP. Outcomes were considered within the framework of Leventhal's Common Sense Model (CSM) in relation to the decision making process. Results Thematic analysis identified differing themes for each group. Group 1: (1) Medication as a positive form of treatment, (2) The trial/drug and (3) Pacing. Group 2: (1) Medication as form of treatment, (2) Other forms of support/treatment and (3) Side effects of mycophenolate. Group 3: (1) Varied view of medication, (2) Consideration of other forms of support and (3) Side effects. Conclusions Attendance on a PMP might provide patients with skills to better manage uncertainty when faced with various treatment options. Leventhal's model goes some way to explaining this. The specific importance of, and benefit from understanding pacing when commencing an effective drug treatment for chronic pain became apparent.

Little is known about the epidemiology of neuropathic pain in primary care patients consulting with low back-related leg pain. We aimed to describe prevalence, characteristics and clinical course of low back-related leg pain patients with and without neuropathic pain, consulting with their family doctor in the UK.

Objectives Cooled radiofrequency (cRF) is an effective treatment for sacroiliac pain. In contrast to conventional radiofrequency denervation, this technique allows enlarging the area of denervation by cooling the radiofrequency probe. However, there is sparse knowledge about the impact of interventional procedures like cRF treatment of sacroiliac joint pain on psychological comorbidities. The aim of this retrospective study was to evaluate the outcome of cRF in chronic pain patients regarding the psychological outcomes anxiety, depression, sleep quality and pain related disability. Methods In this retrospective observational study 29 interventions were performed over a period of two years in 28 patients. Pre- and post-interventional pain levels, depression and anxiety scores, pain-related disability, treatment satisfaction and sleep quality were assessed by standardized and validated questionnaires. Pain medication was recorded prior to the intervention and at follow-up. Results Hospital Anxiety and Depression Scale (HADS-D) scores for depression showed a statistically significant reduction after therapy which did not remain significant after Bonferroni-Holm correction. Anxiety as measured by the HADS-A score did not show a statistically significant change. No statistically significant improvement was observed in the pain disability index. Patients reported fewer sleep disorders after treatment. Mean pain (NRS) was statistically significantly reduced 1 week post intervention and at time of follow-up. There was no clear reduction of analgesic medication. Conclusions Besides pain reduction, our data show a positive influence on sleep quality, possibly on depression, but not on anxiety and pain disability.

Fibromyalgia (FM) is a chronic condition characterized by widespread pain of unknown etiology associated with alterations in the central nervous system. Although previous studies demonstrated altered patterns of brain activity during pain processing in patients with FM, alterations in spontaneous brain oscillations, in terms of functional connectivity or microstates, have been barely explored so far. Here we recorded the EEG from 43 patients with FM and 51 healthy controls during open-eyes resting-state. We analyzed the functional connectivity between different brain networks computing the phase lag index after ໿group Independent Component Analysis, and also performed an EEG microstates analysis. Patients with FM showed increased beta band connectivity between different brain networks and alterations in some microstates parameters (specifically lower occurrence and coverage of microstate class C). We speculate that the observed alterations in spontaneous EEG may suggest the dominance of endogenous top-down influences; this could be related to limited processing of novel external events and the deterioration of flexible behavior and cognitive control frequently reported for FM. These findings provide the first evidence of alterations in long-distance phase connectivity and microstate indices at rest, and represent progress towards the understanding of the pathophysiology of fibromyalgia and the identification of novel biomarkers for its diagnosis.