Malignancy as a possible complication of complex regional pain syndrome: a case report.

A synovial sarcoma presented in the knee of a young woman 20 years after the onset of pain which was attributed to complex regional pain syndrome (CRPS). Was this a chance occurrence, or could there be any link between the two conditions? Did the pain itself and the persistent inflammatory and immunological response to pain contribute to the development of malignancy, or could the malignancy have been present subclinically for many years and have contributed to the ongoing pain syndrome? This case report looks into the diagnosis of synovial sarcoma and CRPS and the relationship between the neurogenic inflammation seen in CRPS and that seen in malignancies. The diagnosis of CRPS is a diagnosis of exclusion. Constant vigilance of patients with this unpleasant condition is necessary.

Cancer pain: part 1: Pathophysiology; oncological, pharmacological, and psychological treatments: a perspective from the British Pain Society endorsed by the UK Association of Palliative Medicine and the Royal College of General Practitioners.

OBJECTIVE: This discussion document about the management of cancer pain is written from the pain specialists' perspective in order to provoke thought and interest in a multimodal approach to the management of cancer pain, not just towards the end of life, but pain at diagnosis, as a consequence of cancer therapies, and in cancer survivors. It relates the science of pain to the clinical setting and explains the role of psychological, physical, interventional and complementary therapies in cancer pain. METHODS: This document has been produced by a consensus group of relevant health care professionals in the United Kingdom and patients' representatives making reference to the current body of evidence relating to cancer pain. In the first of two parts, pathophysiology, oncological, pharmacological, and psychological treatment are considered. CONCLUSIONS: It is recognized that the World Health Organization (WHO) analgesic ladder, while providing relief of cancer pain towards the end of life for many sufferers worldwide, may have limitations in the context of longer survival and increasing disease complexity. To complement this, it is suggested that a more comprehensive model of managing cancer pain is needed that is mechanism-based and multimodal, using combination therapies including interventions where appropriate, tailored to the needs of an individual, with the aim to optimize pain relief with minimization of adverse effects.

Cancer pain: part 2: physical, interventional and complimentary therapies; management in the community; acute, treatment-related and complex cancer pain: a perspective from the British Pain Society endorsed by the UK Association of Palliative Medicine and the Royal College of General Practitioners.

OBJECTIVE: This discussion document about the management of cancer pain is written from the pain specialists' perspective in order to provoke thought and interest in a multimodal approach to the management of cancer pain, not just towards the end of life, but pain at diagnosis, as a consequence of cancer therapies, and in cancer survivors. It relates the science of pain to the clinical setting and explains the role of psychological, physical, interventional and complementary therapies in cancer pain. METHODS: This document has been produced by a consensus group of relevant healthcare professionals in the United Kingdom and patients' representatives making reference to the current body of evidence relating to cancer pain. In the second of two parts, physical, invasive and complementary cancer pain therapies; treatment in the community; acute, treatment-related and complex cancer pain are considered. CONCLUSIONS: It is recognized that the World Health Organization (WHO) analgesic ladder, whilst providing relief of cancer pain towards the end of life for many sufferers world-wide, may have limitations in the context of longer survival and increasing disease complexity. To complement this, it is suggested that a more comprehensive model of managing cancer pain is needed that is mechanism-based and multimodal, using combination therapies including interventions where appropriate, tailored to the needs of an individual, with the aim to optimize pain relief with minimization of adverse effects.

Chronic pain syndrome associated with health anxiety: a qualitative thematic comparison between pain patients with high and low health anxiety.

OBJECTIVES: Based on the high prevalence of health anxiety among patients with chronic pain and the conceptual overlap between the diagnostic criteria for hypochondriasis and pain disorder, it has been suggested that the cognitive-behavioural theory of severe and persistent health anxiety can be applied to understand the problems presented by a subgroup of chronic pain patients. This study aimed to provide qualitative data to complement the progress of the existing experimental research and theory development. DESIGN: A cross-sectional design with two groups was adopted. METHOD: In-depth semi-structured interviews were conducted with 60 chronic pain patients seeking medical treatment from a specialist clinic, and theoretical thematic analysis was performed on a subset of interview transcripts drawn from the five most health anxious and the five least health anxious of this sample. RESULTS: Five themes emerged from the analysis, and they concerned (1) pain appraisal, (2) pain preoccupation, (3) coping strategies, (4) self-identity, and (5) suicidal ideation. Differences were observed between the health anxious and non-health anxious pain patients consistently across all these themes. CONCLUSIONS: The phenomenological information both informs and supports the idea that the cognitive-behavioural model of health anxiety can be adapted for the understanding of and development of treatments for pain patients with health anxiety. The findings also challenge the common practice of 'lumping' pain patients into a single group and underline the importance of matching treatments to the patients' psychological characteristics.

Diabetic painful neuropathy: current and future treatment options.

Diabetic painful neuropathy (DPN) is one of the most common causes of neuropathic pain. The management of DPN consists of excluding other causes of painful peripheral neuropathy, maximising diabetic control and using medications to alleviate pain. The precise relationship between glycaemic control and the development and severity of DPN remains controversial. In this context, drugs such as aldose reductase inhibitors, ACE inhibitors, lipid-lowering agents and alpha-lipoic acid (thioctic acid) may have a useful role to play. There is also evidence that a successful pancreatic transplant may improve symptoms over time, but the mainstay of management continues to be symptomatic control of pain with drugs. Evidence from placebo-controlled studies has shown that opioids, antiepileptic and antidepressant drugs together with capsaicin are effective for alleviating DPN. Tramadol and oxycodone have been shown to be effective in studies of limited duration but their adverse effects, such as constipation and physical dependency, may limit their usefulness as a first-line treatment for DPN. Of the antidepressant drugs, the tricyclic antidepressants have been shown to be effective for alleviating DPN. These medications are widely used but their anticholinergic and sedative properties may not be well tolerated by patients. There is also good evidence that the serotonin-noradrenaline reuptake inhibitor antidepressant drugs venlafaxine and duloxetine are effective for treating DPN. However, venlafaxine may cause cardiac dysrhythmias, and patients using this medication require careful cardiac monitoring. Duloxetine appears to be less cardiotoxic and is licensed in the US and EU for alleviating DPN. The gabapentinoid group of drugs, gabapentin and pregabalin, appear to be the most evidence-based of the antiepileptic drugs for treating DPN. Large placebo-controlled studies have been performed with both of these agents. For many patients, it is still unclear what advantages pregabalin has over gabapentin for DPN. Until better evidence emerges, the potential availability of less expensive generic formulations of gabapentin, together with greater experience with its use, favour gabapentin as the main antiepileptic drug for alleviating DPN. Topiramate, lamotrigine, sodium valproate and oxcarbazepine have been shown to be effective in smaller studies but do not have the same evidence base as the gabapentinoid group of drugs. Of the newer antiepileptic drugs, lacosamide appears to be the most promising for alleviating DPN. Capsaicin has the best evidence base of all the topical agents, but local anaesthetic patches may also have a useful therapeutic role. It is not possible to nominate a single drug as the first-line treatment for DPN and there is evidence that a low-dose combination of two or more drugs rather than a single agent may provide better symptomatic relief with fewer adverse effects. Further studies are necessary to clarify the best combination(s) of treatment for DPN.

Increased use of safety-seeking behaviors in chronic back pain patients with high health anxiety.

Many patients with chronic pain also exhibit elevated levels of health anxiety. This study examined the effect of health anxiety on the use of safety-seeking behaviors (SSBs) in pain-provoking situations. Participants were 20 chronic back pain patients with high health anxiety (Group H), 20 with low health anxiety (Group L) and 20 pain-free controls (Group C). Two physical tasks were video recorded, and compared both for overt pain behavior (identified by blind observers following a standardized procedure) and for the occurrence of SSB (identified by showing the participants video playback and asking them to specify motivation for all actions/behaviors displayed during the tasks). While there were no differences in the display of overt pain behaviors, Group H deployed a greater number of SSBs than Groups L and C. This finding held true for both tasks and remained significant when concurrent pain and mood ratings were statistically controlled for. SSB was correlated with catastrophizing thoughts but not pain intensity; pain intensity was correlated with overt pain behavior but not catastrophizing. Taken together, these findings suggest that SSB is distinct from overt pain behavior and may be a defining characteristic of chronic pain patients reporting high levels of health anxiety.

Guidelines for providing acupuncture treatment for cancer patients--a peer-reviewed sample policy document.

Clinical guidelines are statements that have been systematically developed and which aim to assist clinicians in making decisions about treatment for specific conditions, and promote best practice. They are linked to evidence and are meant to facilitate good medical practice. We are not aware of any guidelines for the safe practice of acupuncture in a conventional healthcare setting, yet they are necessary as acupuncture may be performed in a variety of settings and by a variety of healthcare professionals: doctors, nurses, physiotherapists, midwives, and non medically trained practitioners. These guidelines were developed for use in cancer patients, mainly for pain but also for some non-pain indications such as hot flushes. They are presented here as a template for other acupuncturists who are requested to provide policies for acupuncture treatment for cancer patients. This article includes a general review of the evidence on mechanisms, effectiveness and safety of acupuncture that is intended to be used in conjunction with the guidelines; and the guidelines themselves. An appendix includes instructions for self acupuncture. The guidelines contain sections on roles and responsibilities, criteria for acupuncture practice, indications for acupuncture, contraindications and cautions, acupuncture treatment, and review and audit. These guidelines set basic, minimum standards of care, and need re-assessment and ongoing validation as further data and evidence accumulate.

Recent advances in cancer pain management.

Pain is the most feared symptom of cancer. New oncological cancer treatments are improving survival, but advanced cancer presents challenges that have not been seen before, often with pain that is very difficult to manage because of a recurrent tumour that is invading the central nervous system. In some of the older interventional techniques of destroying nerve pathways, expertise has diminished or has been deemed unnecessary with the development of specialist palliative care. Not all pain is managed adequately with the analgesic ladder. Knowledge of pain mechanisms, careful assessment and selection of the right technique at the right time will enhance cancer pain management. New techniques include intrathecal drug therapy, vertebroplasty, cordotomy, ultra-sound guided nerve blocks, neuromodulation and advances in drug therapies.

Opioids and endocrine dysfunction.

The endocrine effects of opioids used for the management of persistent pain are poorly understood by clinicians and patients, and hormone levels are rarely measured. It is recognized that opioids exert this effect via the hypothalamic-pituitary-gonadal axis. Additional effects on adrenal hormones, weight, blood pressure and bone density may also occur. Symptoms and signs of sex hormone deficiency occur in both men and women but are under-reported and are often clinically unrecognized. The potential effects of long term opioid therapy on the endocrine system should be explained to patients before opioid therapy is commenced. Monitoring of sex hormones is recommended; if there are deficiencies opioids should be tapered and withdrawn, if this is clinically acceptable. If opioid therapy has to continue, hormone replacement therapy should be initiated and monitored by an endocrinologist.

Pain-related insomnia versus primary insomnia: a comparison study of sleep pattern, psychological characteristics, and cognitive-behavioral processes.

BACKGROUND: Recent applications of cognitive-behavior therapy for primary insomnia in the management of pain-related insomnia are based on the implicit assumption that the 2 types of insomnia share the same presentation and maintaining mechanisms. The objectives of this study were to compare the characteristics of patients who have pain-related insomnia with those reporting primary insomnia and to identify psychological factors that predict pain-related insomnia. METHODS: Chronic pain patients with concomitant insomnia (n=137; Pain-related Insomnia Group) completed a selection of questionnaires that measure sleep patterns, psychological attributes, and cognitive-behavioral processes associated with the persistence of insomnia. Their responses were compared with those of primary insomnia patients (n=33; Primary Insomnia Group), using 3 sets of multivariate analyses of covariance that took account of demographic differences. Hierarchical regression analyses were performed to identify predictors of insomnia severity among the chronic pain patients. RESULTS: The Pain-related Insomnia Group did not differ from the Primary Insomnia Group in their pattern and severity of sleep disturbance. The 2 groups were largely comparable in terms of their psychological characteristics, except that the Primary Insomnia Group was distinguishable from the Pain-related Insomnia Group by their greater tendency to worry. Patients in the Pain-related Insomnia Group reported levels of sleep-related anxiety and presleep somatic arousal that matched with those reported by patients in the Primary Insomnia Group. However, relative to patients in the Pain-related Insomnia Group, those in the Primary Insomnia Group reported more dysfunctional sleep beliefs and presleep cognitive arousal. In addition to pain intensity, depression, and presleep cognitive arousal were significant predictors of insomnia severity within the Pain-related Insomnia Group. CONCLUSIONS: There are more similarities than differences between the 2 types of insomnia. Besides pain, mood, and presleep, thought processes also seem to have a role in the manifestation of pain-related insomnia. It is suggested that hybrid treatments that seek to simultaneously address factors across these domains may represent more effective treatments than 1-dimensional interventions.

Mental defeat is linked to interference, distress and disability in chronic pain.

Mental defeat is a psychological construct that has recently been applied to characterize the experience of chronic pain. Elevated levels of mental defeat have been identified in patients with chronic pain, and while its presence distinguishes treatment seeking from non-treatment seeking individuals, the link between mental defeat and disability in chronic pain is yet to be established. The current study investigated the extent to which mental defeat is associated with pain-related interference, distress and disability. A total of 133 participants completed the Pain Self Perception Scale that assessed mental defeat in relation to pain. Moreover, the participants were asked to complete a set of questionnaires that measured pain interference, distress, disability and other demographic (age, body mass index), clinical (pain intensity) and psychological (catastrophizing, worry, rumination and health anxiety) predictors of disability. Mental defeat was found to be strongly correlated with pain interference, sleep disturbance, anxiety, depression, functional disability and psychosocial disability. These correlations remained significant even when pain intensity and demographic variables were partialled out. Relative to chronic pain patients with lower levels of mental defeat, those with higher levels of mental defeat reported greater degree of pain interference, distress and disability. In a series of regression analyses, mental defeat emerged as the strongest predictor of pain interference, depression and psychosocial disability, whereas catastrophizing was the best predictor of sleep interference, anxiety and functional disability. These findings suggest that mental defeat may be an important mediator of distress and disability in chronic pain. Theoretical and clinical implications are discussed.

Perioperative pain relief.

Perioperative pain relief has taken on a new dimension in recent years; that of helping to prevent chronic pain after surgery. Knowledge of pain mechanisms, the importance of both peripheral and central sensitisation and descending inhibitory and facilitatory pathways from the midbrain to spinal cord, have advanced our understanding of how pain may persist after surgery. There is advancing knowledge about the up-regulation and down-regulation of opioid receptors, opioid tolerance and hyperalgesia, and its similarities to neuropathic pain.

Effects of mood on pain responses and pain tolerance: an experimental study in chronic back pain patients.

Although chronic pain and depression commonly co-occur, causal relationships have yet to be established. A reciprocal relationship, with depression increasing pain and vice versa, is most frequently suggested, but experimental evidence is needed to validate such a view. The most straightforward approach would be a demonstration that increasing or decreasing depressed mood predictably modifies pain responses. The current experiment tested whether experimentally induced depressed and happy mood have differential effects on pain ratings and tolerance in 55 patients suffering from chronic back pain. Participants were randomly assigned to depressed, neutral (control) or elated mood induction conditions. They completed a physically passive baseline task prior to receiving mood induction, then a clinically relevant physically active task (holding a heavy bag) to elicit pain responses and tolerance. Measures were taken immediately after the baseline task and immediately after the mood induction to assess the changes in mood, pain ratings and tolerance before and after the experimental manipulation. Results indicate that the induction of depressed mood resulted in significantly higher pain ratings at rest and lower pain tolerance, whilst induced happy mood resulted in significantly lower pain ratings at rest and greater pain tolerance. Correlations between changes in mood on the one hand and changes in pain response and pain tolerance on the other hand were consistent with these findings. It is concluded that, in chronic back pain patients, experimentally induced negative mood increases self-reported pain and decreases tolerance for a pain-relevant task, with positive mood having the opposite effect.