Cognitive and behavioral interventions for the management of chronic neuropathic pain in adults - A systematic review

Overcoming Patient Pain Together: Breast Cancer Patients and Caregivers' Pretreatment Psychosocial Distress Linked to Patients' Pain Interference During the First Year of Treatment

Breast cancer patients experience treatment-related pain from surgery, radiation, chemotherapy, and long-term hormonal treatment, which can lead to poorer outcomes. Patient and family caregivers' psychosocial distress exacerbates patient pain interference, but this has not been directly examined among breast cancer patients in dyadic models longitudinally. Guided by a biopsychosocial framework, the Biobehavioral Family Model, we explore how multiple reports of patient pain interference across the first year of treatment are linked to the patient (N = 55) and caregiver (N = 55) pretreatment psychosocial distress (eg, depression, anxiety, marital satisfaction, family relationship quality). Specifically, we find that breast cancer patients' pain interference increases and then decreases over the first year of treatment. Additionally, caregivers' pretreatment anxiety was associated with increased patient pain interference over time (B = .19, SE = .07, P = .008), while patients' pretreatment psychosocial distress was not associated with a change in their pain interference. Yet, looking at clinically specific times during the first year of treatment, we find that caregiver-reported higher marital satisfaction is associated with lower patient-reported pain interference later in treatment (6 months: B = -.58, SE = .24, P = .017; 12 months: B = -.82, SE = .23, P < .001). We conclude that, per the Biobehavioral Family Model, pretreatment patient and caregiver psychosocial distress is linked to patient pain interference during the first year of breast cancer treatment. Thus, caregivers' psychosocial distress (ie, anxiety and marital satisfaction) may be a particularly important target in future dyadic behavioral intervention strategies to reduce breast cancer patient pain. PERSPECTIVE: This article presents the link between breast cancer patients and family caregiver pretreatment psychosocial distress (anxiety, depression, marital satisfaction, and family quality) on patient pain interference during 1 year of breast cancer treatment. Findings suggest that caregiver anxiety and marital satisfaction may be important targets for future dyadic behavioral pain interventions.

Mirogabalin as a Therapeutic Option for Neuropathic Pain Emerging Post-endodontic Treatment: A Two-Case Report

INTRODUCTION

Occlusal and percussion pain may manifest occasionally following endodontic treatment, influencing retreatment decisions. Two cases of periapical neuropathic pain, classified as post-traumatic trigeminal neuropathic pain according to the International Classification of Orofacial Pain, are presented. Although mirogabalin is effective in managing neuropathic pain, there is a lack of clinical reports on its use for occasional post-traumatic trigeminal neuropathic pain after endodontic treatment. These cases highlight clinical symptoms and successful treatment with mirogabalin for post-traumatic trigeminal neuropathic pain after endodontic treatment, providing clinicians a "take-away" lesson for improving patient condition.

METHODS

The patients, referred by their primary dentist due to postendodontic abnormal pain, found no relief with antibiotics or nonsteroidal anti-inflammatory drugs. Although no findings including swelling or periapical radiolucency were observed around the tooth, they experienced occlusal and percussion pain. Local anesthetic testing showed that the pain originated from the peripheral area around the tooth rather than from central sensitization. Dental radiography and cone-beam computed tomography revealed no abnormal findings. Root canal retreatment was performed by a specialist in endodontic treatment. Although endodontic retreatment drastically decreased visual analog scale pain score, pain persisted. Based on the International Classification of Orofacial Pain criteria, diseases other than post-traumatic trigeminal neuropathic pain were excluded. Mirogabalin (10 mg/d) was prescribed once daily before bedtime.

RESULTS

Visual analog scale scores gradually and drastically decreased 2 weeks after mirogabalin therapy. Several months later, no recurrence of postendodontic pain was observed after tapering off and discontinuing mirogabalin.

CONCLUSIONS

These findings suggest the possibility of a new treatment method for post-traumatic trigeminal neuropathic pain after endodontic treatment.

Psychologically based interventions for adults with chronic neuropathic pain: a scoping review

OBJECTIVE

As psychologically based interventions have been shown to have clinical utility for adults with chronic pain generally, a similar benefit might be expected in the management of chronic neuropathic pain (NeuP). However, to date, this has not been established, with existing systematic reviews on this topic being hampered by the scarcity of randomized controlled trials (RCTs). This review aimed to identify the type of psychologically based interventions studied for adults with chronic NeuP. It also aimed to assess whether there are enough RCTs to justify undertaking an updated systematic review.

METHODS

Seven databases and 2 clinical trial registries were searched for NeuP and psychologically based interventions from database inception to December 2021, and the search was updated in February 2023. The search was broadened by reviewing the reference list of included studies and contacting field experts. Predetermined study characteristics were extracted.

RESULTS

Of 4682 records screened, 33 articles (less than 1%) met the eligibility criteria. Four broad intervention approaches were observed, including cognitive-behavioral approaches (n = 16), mindfulness/meditation (n = 10), trauma-focused therapy (n = 4), and hypnosis (n = 3). Thirteen RCTs were identified, and of these, 9 retained 20 participants in each arm after treatment.

CONCLUSIONS

Cognitive-behavioral therapy was the most common therapeutic approach identified, whereas mindfulness/meditation was the most frequently used technique. Almost half to two-thirds of the studies reported significant improvements in pain, disability, or distress, which suggests that psychologically based interventions are potentially beneficial for adults with chronic NeuP. An updated systematic review seems warranted.

STUDY REGISTRATION

Open Science Framework (https://osf.io) (December 6, 2021; DOI: 10.17605/OSF.IO/WNSTM).

Treating neuropathic pain and comorbid affective disorders: Preclinical and clinical evidence

INTRODUCTION

Neuropathic pain (NP) significantly impacts quality of life and often coexists with affective disorders such as anxiety and depression. Addressing both NP and its psychiatric manifestations requires a comprehensive understanding of therapeutic options. This study aimed to review the main pharmacological and non-pharmacological treatments for NP and comorbid affective disorders to describe their mechanisms of action and how they are commonly used in clinical practice.

METHODS

A review was conducted across five electronic databases, focusing on pharmacological and non-pharmacological treatments for NP and its associated affective disorders. The following combination of MeSH and title/abstract keywords were used: "neuropathic pain," "affective disorders," "depression," "anxiety," "treatment," and "therapy." Both animal and human studies were included to discuss the underlying therapeutic mechanisms of these interventions.

RESULTS

Pharmacological interventions, including antidepressants, anticonvulsants, and opioids, modulate neural synaptic transmission to alleviate NP. Topical agents, such as capsaicin, lidocaine patches, and botulinum toxin A, offer localized relief by desensitizing pain pathways. Some of these drugs, especially antidepressants, also treat comorbid affective disorders. Non-pharmacological techniques, including repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and photobiomodulation therapy, modulate cortical activity and have shown promise for NP and mood disorders.

CONCLUSIONS

The interconnection between NP and comorbid affective disorders necessitates holistic therapeutic strategies. Some pharmacological treatments can be used for both conditions, and non-pharmacological interventions have emerged as promising complementary approaches. Future research should explore novel molecular pathways to enhance treatment options for these interrelated conditions.

Evidence Mapping Based on Systematic Reviews of Cognitive Behavioral Therapy for Neuropathic Pain

Objective

This evidence mapping is aimed at identifying, summarizing, and analyzing the available evidence on cognitive behavioral therapy (CBT) for neuropathic pain (NP).

Methods

This study was conducted following the methodology of Global Evidence Mapping (GEM). Searches were conducted in PubMed, Embase, the Cochrane Library, and PsycINFO to identify systematic reviews (SRs) with or without meta-analysis published before February 15, 2022. The authors independently assessed eligibility, extracted data, and evaluated the methodological quality of the included SRs using AMSTAR-2. The results were presented in the tables and a bubble plot based on the identified population-intervention-comparison-outcome (PICO) questions.

Results

A total of 34 SRs met the eligibility criteria. According to the AMSTAR-2, 2 SRs were rated "high," 2 SRs were rated "moderate," 6 SRs were rated "low," and 24 SRs were rated "critically low." The most common study design utilized to evaluate the efficacy of CBT for NP was the randomized controlled trial. In total, 24 PICOs were identified. Migraine was the most studied population. CBT for NP usually reaches the "potentially better" result at follow-up.

Conclusions

Evidence mapping is a useful way to present existing evidence. Currently, the existing evidence on CBT for NP is limited. Overall, the methodological quality of the included SRs was low. Further improvements in the methodological quality of SRs and more research on the most efficient CBT formats for NP are recommended in the future.

Complex Regional Pain Syndrome: Practical Diagnostic and Treatment Guidelines, 5th Edition

There have been some modest recent advancements in the research of Complex Regional Pain Syndrome, yet the amount and quality of the work in this complicated multifactorial disease remains low (with some notable exceptions; e.g., the recent work on the dorsal root ganglion stimulation). The semi-systematic (though in some cases narrative) approach to review is necessary so that we might treat our patients while waiting for "better research." This semi-systematic review was conducted by experts in the field, (deliberately) some of whom are promising young researchers supplemented by the experience of "elder statesman" researchers, who all mention the system they have used to examine the literature. What we found is generally low- to medium-quality research with small numbers of subjects; however, there are some recent exceptions to this. The primary reason for this paucity of research is the fact that this is a rare disease, and it is very difficult to acquire a sufficient sample size for statistical significance using traditional statistical approaches. Several larger trials have failed, probably due to using the broad general diagnostic criteria (the "Budapest" criteria) in a multifactorial/multi-mechanism disease. Responsive subsets can often be identified in these larger trials, but not sufficient to achieve statistically significant results in the general diagnostic grouping. This being the case the authors have necessarily included data from less compelling protocols, including trials such as case series and even in some instances case reports/empirical information. In the humanitarian spirit of treating our often desperate patients with this rare syndrome, without great evidence, we must take what data we can find (as in this work) and tailor a treatment regime for each patient.

Risk of infection within 4 weeks of corticosteroid injection (CSI) in the management of chronic pain during a pandemic: a cohort study in 216 patients

OBJECTIVES

Targeted corticosteroid injections (CSI) are one of the treatments that can provide pain relief and thereby, enhance quality of life in patients with chronic pain. Corticosteroids (CS) are known to impair immune response. The objective was to evaluate the risk of developing post-procedural infection within 4 weeks of receiving depot CSI for chronic pain as part of on going quality improvement project. We hypothesised that interventional treatment with depot steroids will not cause a significant increase in clinical infection in the first 4 weeks.

METHODS

Telephone follow-up was performed as a part of prospective longitudinal audit in a cohort of patients who received interventional treatment for chronic pain at a multidisciplinary pain medicine centre based at a university teaching hospital. Patients who received interventional treatment in the management of chronic pain under a single physician between October 2019 and December 2020 were followed up over telephone as part of on going longitudinal audits. Data was collected on any infection within 4 and 12 weeks of receiving the intervention. Outcomes collected included type of intervention, dose of depot steroids and pain relief obtained at 12 weeks following intervention.

RESULTS

Over a 15 month period, 261 patients received pain interventions with depot CS. There was no loss to follow-up. Nine patients reported an infection within 4 weeks of receiving depot steroids (9/261, 3.4%). None of the patients tested positive for Covid-19. Eight patients (8/261, 3%) reported an infection between 5 and 12 weeks following the corticosteroid intervention. Although none of the patients tested positive for Covid-19, two patients presented with clinical and radiological features suggestive of Covid-19. Durable analgesia was reported by 51% (133/261) and clinically significant analgesia by 30% (78/261) at 12 weeks following the intervention. Failure rate was 19% (50/261).

CONCLUSIONS

Pain medicine interventions with depot steroids do not appear to overtly increase the risk for Covid-19 infection in the midst of a pandemic.

Residual limb pain: An evidence-based review

Acquired limb loss, whether from accident or amputation, occurs with an incidence of greater than 175,000 per year in the United States. Current prevalence is estimated at greater than 1.5 million and is expected to double within 30 years. While many patients with amputations may have no significant pain or sensory issues after healing from the initial loss, one-quarter to one-half of patients may have ongoing difficulties with residual limb pain, phantom limb pain, or phantom limb sensation. This review explores the potential etiologies of those symptoms, as well as a variety of treatment options that a practitioner may consider when approaching this condition.

A Consideration of the Psychological Aspects to Managing Patients with Painful Diabetic Neuropathy: An Insight into Pain Management Services at a Tertiary Centre in the UK

Painful diabetic neuropathy (pDN) is characterised by both sensory and affective disturbances, suggesting a complex bidirectional relationship of neuropathic pain and mood disorders. Data on pDN indicate that neuropathic pain reduces quality of life, including mood and physical and social functioning. Depression and pain coping strategies such as catastrophising and social support predict pain severity. There is a significant and reciprocal relationship between depressed mood and increased pain. The key features of assessing people with neuropathic pain in relation to psychological aspects of their health are discussed in the context of management in a tertiary pain management centre (The Walton Centre, Liverpool, UK) including cognitive behavioural interventions amongst others to improve the quality of life in patients with pDN. We consider psychological issues as a factor influencing treatment and outcome in patients with pDN.

Painful and non-painful chemotherapy-induced peripheral neuropathy and quality of life in colorectal cancer survivors: results from the population-based PROFILES registry

Purpose

This study aims to (1) examine the prevalence of painful versus non-painful chemotherapy-induced peripheral neuropathy (CIPN) among long-term colorectal cancer (CRC) survivors, (2) identify sociodemographic, clinical, and psychological factors associated with painful and non-painful CIPN, and (3) examine the associations of painful CIPN with health-related quality of life (HRQoL) in comparison with non-painful CIPN, i.e., numbness/tingling.

Methods

All CRC survivors diagnosed between 2000 and 2009 as registered by the population-based Netherlands Cancer Registry (Eindhoven region) were eligible for participation. Chemotherapy-treated survivors (n = 477) completed questions on CIPN (EORTC QLQ-CIPN20) and HRQoL (EORTC QLQ-C30).

Results

Painful CIPN was reported by 9% (n = 45) of survivors and non-painful CIPN was reported by 22% (n = 103). Time since diagnosis was related to painful CIPN, and time since diagnosis, a higher disease stage, osteoarthritis, and more anxiety symptoms were related to non-painful CIPN. Finally, survivors with painful CIPN reported a worse global quality of life and worse physical, role, cognitive, and social functioning compared to survivors with non-painful CIPN and those without any sensory CIPN. No differences were found between survivors with non-painful CIPN and those without sensory CIPN.

Conclusions

It seems that painful CIPN must be distinguished from non-painful CIPN, as only painful CIPN was related to a worse HRQoL. Future research is needed to examine whether painful CIPN must be distinguished from non-painful CIPN regarding predictors, mechanisms, and treatment.

Acceptance and Commitment Therapy and Selective Optimization with Compensation for Institutionalized Older People with Chronic Pain

OBJECTIVE

Recent studies support the efficacy of Acceptance and Commitment Therapy (ACT) with people with chronic pain. In addition, Selective Optimization with Compensation strategies (SOC) can help the elderly with chronic pain to accept their chronic condition and increase functional autonomy. Our aim was to analyze the efficacy of an ACT treatment program combined with training in SOC strategies for elderly people with chronic pain living in nursing homes.

METHODS

101 participants (mean age = 82.26; SD = 10.00; 78.6% female) were randomized to the intervention condition (ACT-SOC) or to a minimal support group (MS). Complete data are available for 53 participants (ACT-SOC: n = 27; MS: n = 26). Assessments of functional performance, pain intensity, pain acceptance, SOC strategies, emotional well being and catastrophizing beliefs were done preintervention and postintervention.

RESULTS

Significant time by intervention changes (P = 0.05) were found in acceptance, pain related anxiety, compensation strategies, and pain interference in walking ability. Simple effects changes were found in acceptance (P = 0.01), selection strategies (P = 0.05), catastrophizing beliefs (P = 0.03), depressive symptoms (P = 0.05), pain anxiety (P = 0.01) and pain interference in mood and walking ability (P = 0.03) in the ACT-SOC group. No significant changes were found in the MS group.

CONCLUSIONS

These results suggest that an ACT intervention combined with training in SOC strategies could help older people with pain to improve their emotional well being and their functional capability.

Are some QALYs more equal than others?

Including societal preferences in allocation decisions is an important challenge for the health care sector. Here, we present results of a phased discrete choice experiment investigating the impact of various attributes on respondents' preferences for distribution of health and health care. In addition to the renowned equity principles severity of illness (operationalized as initial health) and fair innings (operationalized as age), some characteristics of beneficiaries (culpability and having dependents) and the disease (rarity) were included in the choice experiment. We used a nested logit model to analyse the data. We found that all selected attributes significantly influenced respondents' choices. The phased inclusion showed that additional attributes affected respondents' preferences for previously-included attributes and reduced unobserved variance. Although not all these attributes may be considered relevant for decision making from a normative perspective, including them in choice experiments contributes to our understanding of societal preferences for each single attribute.

Age moderates response to acceptance and commitment therapy vs. cognitive behavioral therapy for chronic pain

OBJECTIVE

The purpose of this study was to examine age differences in response to different forms of psychotherapy for chronic pain.

METHODS

We performed a secondary analysis of 114 adults (ages 18-89 years) with a variety of chronic, nonmalignant pain conditions randomly assigned to 8 weeks of group-administered acceptance and commitment therapy (ACT) or cognitive behavioral therapy (CBT). Treatment response was defined as a drop of at least three points on the Brief Pain Inventory-interference subscale.

RESULTS

Older adults were more likely to respond to ACT, and younger adults to CBT, both immediately following treatment and at 6-month follow-up. There were no significant differences in credibility, expectations of positive outcome, attrition, or satisfaction, although there was a trend for the youngest adults (ages 18-45 years) to complete fewer sessions.

CONCLUSIONS

These data suggest that ACT may be an effective and acceptable treatment for chronic pain in older adults.

Psychological therapies for the management of chronic neuropathic pain in adults

BACKGROUND

Neuropathic pain is thought to arise from damage to the somatosensory nervous system. Its prevalence is increasing in line with many chronic disorders such as diabetes. All treatments have limited effectiveness. Given the evidence regarding psychological treatment for distress and disability in people with various chronic pain conditions, we were interested to investigate whether psychological treatments have any effects for those with chronic neuropathic pain.

OBJECTIVES

To assess the effects of psychological treatments on pain experience, disability, mood, and health-care use in adults with chronic neuropathic pain.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) published in any language in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and PsycINFO, from database inception to March 2015.

SELECTION CRITERIA

Full publications of RCTs on psychological interventions for neuropathic pain. Trials had to have lasted at least three months, had at least 20 participants in each arm at the end of treatment, and compared a psychological intervention with any active or inactive intervention.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

Two small studies (enrolling a total of 105 participants) met the inclusion criteria. One was a standard cognitive behavioural treatment (CBT) programme for 61 people with pain from spinal cord injury, followed up for three months, and compared with a waiting list. The other was weekly group psychotherapy for 44 people with burning mouth syndrome, compared with a daily placebo tablet. The overall risk of bias was high in both trials.The CBT study assessed participants for pain, disability, mood, and quality of life, with improvement in treatment and control groups. However, there was no more improvement in the treatment group than in the control for any outcome, either post-treatment or at follow-up. The group psychotherapy study only assessed pain, classifying participants by pain severity. There is a lack of evidence on the efficacy and safety of psychological interventions for people with neuropathic pain.

AUTHORS' CONCLUSIONS

There is insufficient evidence of the efficacy and safety of psychological interventions for chronic neuropathic pain. The two available studies show no benefit of treatment over either waiting list or placebo control groups.

Pain and Personality: Do Individuals with Different Forms of Chronic Pain Exhibit a Mutual Personality?

The role of personality in the experience of chronic pain is a growing field, with endless debate regarding the existence of a "pain personality". This study aims to compare different chronic pain types and consolidate the existence of a common personality. Thirty-two females with chronic orofacial pain and 37 age-matched healthy females were assessed with the Temperament and Character Inventory-Revised. Chronic pain subjects had either trigeminal neuropathy (neuropathic pain) or temporomandibular disorders (nociceptive pain). This study revealed that individuals with different chronic pain types exhibit a mutual personality profile encompassing significantly higher scores in Harm Avoidance and significantly lower scores in Self-Directedness when compared to healthy subjects. In fact, this combination is associated with Cluster C personality disorders. In conclusion, our study reveals that irrespective of type, chronic pain may be associated with Cluster C personality disorders. Indeed, there has never been empirical evidence in the past to suggest that chronic pain as an overall concept is associated with any particular personality disorders. Therefore, a potential future avenue of chronic pain treatment may lie in targeting particular personality aspects and shift the target of pain-relieving treatments from sensory and psychologically state focused to psychologically trait focused.

Hypnotic relaxation results in elevated thresholds of sensory detection but not of pain detection

Background

Many studies show an effectiveness of hypnotic analgesia. It has been discussed whether the analgesic effect is mainly caused by the relaxation that is concomitant to hypnosis. This study was designed to evaluate the effects of hypnotic relaxation suggestion on different somatosensory detection and pain thresholds.

Methods

Quantitative sensory testing (QST) measurements were performed before and during hypnosis in twenty-three healthy subjects on the dorsum of the right hand. Paired t-test was used to compare threshold changes. The influence of hypnotic susceptibility was evaluated by calculating correlation coefficients for threshold changes and hypnotic susceptibility (Harvard group scale).

Results

During hypnosis significantly changed somatosensory thresholds (reduced function) were observed for the following sensory detection thresholds: Cold Detection Threshold (CDT), Warm Detection Threshold (WDT), Thermal Sensory Limen (TSL) and Mechanical Detection Threshold (MDT). The only unchanged sensory detection threshold was Vibration Detection Threshold (VDT). No significant changes were observed for the determined pain detection thresholds (Cold Pain Thresholds, Heat Pain Thresholds, Mechanical Pain Sensitivity, Dynamic Mechanical Allodynia, Wind-up Ratio and Pressure Pain Threshold). No correlation of hypnotic susceptibility and threshold changes were detected.

Conclusion

Hypnotic relaxation without a specific analgesic suggestion results in thermal and mechanical detection, but not pain threshold changes. We thus conclude that a relaxation suggestion has no genuine effect on sensory pain thresholds.

Trial Registration

ClinicalTrials.gov, Identifier: NCT02261155 (9^th October 2014).

Management of chronic neuropathic pain: a protocol for a multiple treatment comparison meta-analysis of randomised controlled trials

INTRODUCTION

Chronic neuropathic pain is associated with reduced health-related quality of life and substantial socioeconomic costs. Current research addressing management of chronic neuropathic pain is limited. No review has evaluated all interventional studies for chronic neuropathic pain, which limits attempts to make inferences regarding the relative effectiveness of treatments.

METHODS AND ANALYSIS

We will conduct a systematic review of all randomised controlled trials evaluating therapies for chronic neuropathic pain. We will identify eligible trials, in any language, by a systematic search of CINAHL, EMBASE, MEDLINE, AMED, HealthSTAR, DARE, PsychINFO and the Cochrane Central Registry of Controlled Trials. Eligible trials will be: (1) enrol patients presenting with chronic neuropathic pain, and (2) randomise patients to alternative interventions (pharmacological or non-pharmacological) or an intervention and a control arm. Pairs of reviewers will, independently and in duplicate, screen titles and abstracts of identified citations, review the full texts of potentially eligible trials and extract information from eligible trials. We will use a modified Cochrane instrument to evaluate risk of bias of eligible studies, recommendations from the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) to inform the outcomes we will collect, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to evaluate our confidence in treatment effects. When possible, we will conduct: (1) in direct comparisons, a random-effects meta-analysis to establish the effect of reported therapies on patient-important outcomes; and (2) a multiple treatment comparison meta-analysis within a Bayesian framework to assess the relative effects of treatments. We will define a priori hypotheses to explain heterogeneity between studies, and conduct meta-regression and subgroup analyses consistent with the current best practices.

ETHICS AND DISSEMINATION

We do not require ethics approval for our proposed review. We will disseminate our findings through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

PROSPERO (CRD42014009212).

Effect of intermittent normobaric hyperoxia for treatment of neuropathic pain in Chinese patients with spinal cord injury

STUDY DESIGN

Prospective, randomized and controlled study.

OBJECTIVES

The aim of the study was to investigate the effect of intermittent normobaric hyperoxia (InHO) for treatment of neuropathic pain in patients with spinal cord injury (SCI).

SETTING

The First Affiliated Hospital of Nanhua University, Hengyang, Hunan Province, China.

METHODS

Patients with SCI from Hunan Province were recruited from the First Affiliated Hospital of Nanhua University. History, duration, localization and characteristics of pain were recorded. Visual analog scale (VAS), the Patient Global Impression of Change (PGIC) and Short Form-36 walk-wheel (SF-36ww) was used to investigate the effect of InHO. Patients were randomly assigned to study and control groups. In study group, patients were exposed to pure oxygen via non-rebreathing reservoir mask, which increased the provided oxygen at a rate of 7 l min^-1 for 1 or 4 h daily in 2 weeks. While in control group, patients breathed air via non-rebreathing reservoir mask at the same rate.

RESULTS

A total of 62 SCI patients with neuropathic pain were included in the study. The mean age of the patients was 36.85±10.71 years. Out of 62 patients, 21 were tetraplegic and 41 were paraplegic. Overall, 14 patients had complete SCI while 48 patients had incomplete injuries. Three groups were similar with respect to age, gender, duration, smoker or not, level and severity of injury. In the 4 h per day InHO groups, a statistically significant reduction of the VAS values was observed (P<0.05). Significant difference was also found in SF-36ww pain scores and PGIC (P<0.05). However, such an effect was not evident in the control group.

CONCLUSION

This study revealed that in treatment of neuropathic pain of SCI patients, InHO may be effective.

PERSPECTIVE

This article presents InHO may effectively complement pharmacological treatment in patients with SCI and neuropathic pain.

Pharmacological management of central post-stroke pain: a practical guide

Pain is one of the most troublesome sequelae of stroke. Some of this post-stroke pain is caused by the brain lesion itself; this is called central post-stroke pain (CPSP). Although the prevalence of CPSP is low (1-8 %), persistent, often treatment-resistant, painful sensations are a major problem for stroke patients. The pathogenesis of CPSP remains unknown, but suggested underlying causes include hyperexcitation in the damaged sensory pathways, damage to the central inhibitory pathways, or a combination of the two. For pharmacological treatment, amitriptyline, an adrenergic antidepressant, is currently the first-line drug for CPSP. However, its effect is frequently incomplete and a high dose is commonly not tolerated in stroke patients. Lamotrigine, an antiepileptic, was also found to be effective in a controlled trial and can be used as an alternative or additive therapy. GABAergic drugs with potential calcium channel-blocking effects, such as gabapentin or pregabalin, have recently emerged as a potentially useful therapy. These drugs are effective in various neuropathic pain syndromes, but their effect on CPSP remains to be proven. Pregabalin may improve pain-related anxiety and sleep disturbances. Fluvoxamine and mexiletine may be used adjunctively in some patients. Non-pharmacological treatments such as motor cortex stimulation or deep brain stimulation are used in some centers, but are not proven to be effective. Further well designed clinical trials as well as basic research should be performed to improve our understanding of the pathophysiology of CPSP and to develop better treatment strategies.

Opioid administration following spinal cord injury: implications for pain and locomotor recovery

Approximately one-third of people with a spinal cord injury (SCI) will experience persistent neuropathic pain following injury. This pain negatively affects quality of life and is difficult to treat. Opioids are among the most effective drug treatments, and are commonly prescribed, but experimental evidence suggests that opioid treatment in the acute phase of injury can attenuate recovery of locomotor function. In fact, spinal cord injury and opioid administration share several common features (e.g. central sensitization, excitotoxicity, aberrant glial activation) that have been linked to impaired recovery of function, as well as the development of pain. Despite these effects, the interactions between opioid use and spinal cord injury have not been fully explored. A review of the literature, described here, suggests that caution is warranted when administering opioids after SCI. Opioid administration may synergistically contribute to the pathology of SCI to increase the development of pain, decrease locomotor recovery, and leave individuals at risk for infection. Considering these negative implications, it is important that guidelines are established for the use of opioids following spinal cord and other central nervous system injuries.

Investigation of depression in Greek patients with diabetic peripheral neuropathy

Background:

Considerable studies directly connect the complications in diabetic patients, and especially peripheral neuropathy, with the emergence of depression. Neuropathetic pain may deteriorate the general health status of the diabetic patient and glycaemic regulation.

Purpose:

The purpose of this study was to investigate the appearance and degree of diabetic peripheral neuropathy and its correlation with depression, with other parameters of the disease and also duration.

Methods:

57 diabetic patients participated with diagnosed diabetic peripheral neuropathy (male n=27, female n= 30, mean of age 72.7±6.35 years). The first part of Michigan Neuropathy Screening Instrument and the Zung Depression Rating Scale were used as tools for our study. Data was analysed with the SPSS 18.0 statistic program.

Results:

57.9% of the patients were overweight, 35.1% were obese and only 7% were within normal weight range. The BMI findings between the two genders indicate that male participants are more often obese than females. Women surpassed men in the category of overweight patients (p<0.05). The score based on MNSI was high and between 3 to 12 (mean average of 8.19±2.60 with 8 as intermediate rate). Almost 60% of patients had severe neuropathy, only 2 were found with mild symptoms and the rest had moderate neuropathtic symptoms, based on the score summary from the questionnaire. Investigating in detail the relation of diabetic neuropathy and depression, it derives that a high degree of diabetic neuropathy is related with high score of depression [F(3.160)=9.821, p=0.001]. Moderate and severe neuropathy was found with almost the same levels of depression.

Conclusions:

The correlation between diabetic neuropathy and depression is confirmed, while a very high depression rate was found in patients with severe neuropathy. The issue needs further study by using common instruments to obtain comparative results from the scientific community.

Interventions for treating pain and disability in adults with complex regional pain syndrome

BACKGROUND

There is currently no strong consensus regarding the optimal management of complex regional pain syndrome although a multitude of interventions have been described and are commonly used.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the effectiveness of any therapeutic intervention used to reduce pain, disability or both in adults with complex regional pain syndrome (CRPS).

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of the following databases: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Ovid MEDLINE, Ovid EMBASE, CINAHL, LILACS and PEDro. We included non-Cochrane systematic reviews where they contained evidence not covered by identified Cochrane reviews. The methodological quality of reviews was assessed using the AMSTAR tool.We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes of quality of life, emotional well being and participants' ratings of satisfaction or improvement. Only evidence arising from randomised controlled trials was considered. We used the GRADE system to assess the quality of evidence.

MAIN RESULTS

We included six Cochrane reviews and 13 non-Cochrane systematic reviews. Cochrane reviews demonstrated better methodological quality than non-Cochrane reviews. Trials were typically small and the quality variable.There is moderate quality evidence that intravenous regional blockade with guanethidine is not effective in CRPS and that the procedure appears to be associated with the risk of significant adverse events.There is low quality evidence that bisphosphonates, calcitonin or a daily course of intravenous ketamine may be effective for pain when compared with placebo; graded motor imagery may be effective for pain and function when compared with usual care; and that mirror therapy may be effective for pain in post-stroke CRPS compared with a 'covered mirror' control. This evidence should be interpreted with caution. There is low quality evidence that local anaesthetic sympathetic blockade is not effective. Low quality evidence suggests that physiotherapy or occupational therapy are associated with small positive effects that are unlikely to be clinically important at one year follow up when compared with a social work passive attention control.For a wide range of other interventions, there is either no evidence or very low quality evidence available from which no conclusions should be drawn.

AUTHORS' CONCLUSIONS

There is a critical lack of high quality evidence for the effectiveness of most therapies for CRPS. Until further larger trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult.

Interventions for treating pain and disability in adults with complex regional pain syndrome

BACKGROUND

There is currently no strong consensus regarding the optimal management of complex regional pain syndrome although a multitude of interventions have been described and are commonly used.

OBJECTIVES

To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the effectiveness of any therapeutic intervention used to reduce pain, disability or both in adults with complex regional pain syndrome (CRPS).

METHODS

We identified Cochrane reviews and non-Cochrane reviews through a systematic search of the following databases: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Ovid MEDLINE, Ovid EMBASE, CINAHL, LILACS and PEDro. We included non-Cochrane systematic reviews where they contained evidence not covered by identified Cochrane reviews. The methodological quality of reviews was assessed using the AMSTAR tool.We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes of quality of life, emotional well being and participants' ratings of satisfaction or improvement. Only evidence arising from randomised controlled trials was considered. We used the GRADE system to assess the quality of evidence.

MAIN RESULTS

We included six Cochrane reviews and 13 non-Cochrane systematic reviews. Cochrane reviews demonstrated better methodological quality than non-Cochrane reviews. Trials were typically small and the quality variable.There is moderate quality evidence that intravenous regional blockade with guanethidine is not effective in CRPS and that the procedure appears to be associated with the risk of significant adverse events.There is low quality evidence that bisphosphonates, calcitonin or a daily course of intravenous ketamine may be effective for pain when compared with placebo; graded motor imagery may be effective for pain and function when compared with usual care; and that mirror therapy may be effective for pain in post-stroke CRPS compared with a 'covered mirror' control. This evidence should be interpreted with caution. There is low quality evidence that local anaesthetic sympathetic blockade is not effective. Low quality evidence suggests that physiotherapy or occupational therapy are associated with small positive effects that are unlikely to be clinically important at one year follow up when compared with a social work passive attention control.For a wide range of other interventions, there is either no evidence or very low quality evidence available from which no conclusions should be drawn.

AUTHORS' CONCLUSIONS

There is a critical lack of high quality evidence for the effectiveness of most therapies for CRPS. Until further larger trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult.

Synergistic interaction between total glucosides and total flavonoids on chronic constriction injury induced neuropathic pain in rats

CONTEXT

Shaoyao Gancao Decoction (SGD), a famous herbal medicine, consists of two herbs (Paeoniae Radix and Glycyrrhizae Radix) and is traditionally used for the treatment of pain.

OBJECTIVE

To investigate the synergistic potential of total glucosides of Paeoniae Radix (TGP) and total flavonoids of Glycyrrhizae Radix (TFL).

MATERIALS AND METHODS

Oral administration of TGP and TFL alone at the doses of 60,120 and 240 mg/kg or in combination were given only one time to the neuropathic pain rat induced by chronic constriction injury. Paw pressure and heat immersion tests were performed to assess degrees of mechanical allodynia and thermal hyperalgesia, respectively. Synergistic interactions between TGP and TFL were characterized using isobolographic analysis. Expressions of Sirt1 protein were detected by immunohistochemistry.

RESULTS AND DISCUSSION

On day 14 after surgery, single oral administration of TGP and TFL both produced significant anti-allodynic and anti-hyperalgesic effects in dose-dependent and time-dependent manners. The ED(50) value of TGP was 249.4 ± 10.8 mg/kg while TFL was 871.4 ± 30.5 mg/kg. Isobolographic analysis revealed that the combination of TGP with TFL at the fixed ratios of 3:1 exerted the highest sub-additive (synergistic) interaction, of which the experimental ED(50) value was 95.1 ± 9.0 mg/kg. SGD could also downregulate Sirt1 protein expression, which was 4.2-fold higher than that of model rats in dorsal root ganglion.

CONCLUSION

Analgesic effects of SGD may contribute to simultaneous inhibition of Sirt1 overexpression and could warrant further evaluation as a possible agent for the treatment of neuropathic pain.

Postamputation pain: epidemiology, mechanisms, and treatment

Postamputation pain (PAP) is highly prevalent after limb amputation but remains an extremely challenging pain condition to treat. A large part of its intractability stems from the myriad pathophysiological mechanisms. A state-of-art understanding of the pathophysiologic basis underlying postamputation phenomena can be broadly categorized in terms of supraspinal, spinal, and peripheral mechanisms. Supraspinal mechanisms involve somatosensory cortical reorganization of the area representing the deafferentated limb and are predominant in phantom limb pain and phantom sensations. Spinal reorganization in the dorsal horn occurs after deafferentataion from a peripheral nerve injury. Peripherally, axonal nerve damage initiates inflammation, regenerative sprouting, and increased "ectopic" afferent input which is thought by many to be the predominant mechanism involved in residual limb pain or neuroma pain, but may also contribute to phantom phenomena. To optimize treatment outcomes, therapy should be individually tailored and mechanism based. Treatment modalities include injection therapy, pharmacotherapy, complementary and alternative therapy, surgical therapy, and interventions aimed at prevention. Unfortunately, there is a lack of high quality clinical trials to support most of these treatments. Most of the randomized controlled trials in PAP have evaluated medications, with a trend for short-term Efficacy noted for ketamine and opioids. Evidence for peripheral injection therapy with botulinum toxin and pulsed radiofrequency for residual limb pain is limited to very small trials and case series. Mirror therapy is a safe and cost-effective alternative treatment modality for PAP. Neuromodulation using implanted motor cortex stimulation has shown a trend toward effectiveness for refractory phantom limb pain, though the evidence is largely anecdotal. Studies that aim to prevent PA P using epidural and perineural catheters have yielded inconsistent results, though there may be some benefit for epidural prevention when the infusions are started more than 24 hours preoperatively and compared with nonoptimized alternatives. Further investigation into the mechanisms responsible for and the factors associated with the development of PAP is needed to provide an evidence-based foundation to guide current and future treatment approaches.

Complex regional pain syndrome: practical diagnostic and treatment guidelines, 4th edition

OBJECTIVE

This is the fourth edition of diagnostic and treatment guidelines for complex regional pain syndrome (CRPS; aka reflex sympathetic dystrophy).

METHODS

Expert practitioners in each discipline traditionally utilized in the treatment of CRPS systematically reviewed the available and relevant literature; due to the paucity of levels 1 and 2 studies, less rigorous, preliminary research reports were included. The literature review was supplemented with knowledge gained from extensive empirical clinical experience, particularly in areas where high-quality evidence to guide therapy is lacking.

RESULTS

The research quality, clinical relevance, and "state of the art" of diagnostic criteria or treatment modalities are discussed, sometimes in considerable detail with an eye to the expert practitioner in each therapeutic area. Levels of evidence are mentioned when available, so that the practitioner can better assess and analyze the modality under discussion, and if desired, to personally consider the citations. Tables provide details on characteristics of studies in different subject domains described in the literature.

CONCLUSIONS

In the humanitarian spirit of making the most of all current thinking in the area, balanced by a careful case-by-case analysis of the risk/cost vs benefit analysis, the authors offer these "practical" guidelines.

Health-related quality of life 'well-being' in HIV distal neuropathic pain is more strongly associated with depression severity than with pain intensity

BACKGROUND

Despite modern antiretroviral treatment, HIV-associated distal neuropathic pain (DNP) remains one of the most prevalent and debilitating complications of HIV disease. Neuropathic pain is often accompanied by depressed mood, and both pain and depression have been associated with decreased health-related quality of life (HRQOL) well-being. The relative contribution of depression and pain to worse life quality has not been addressed, however, even though a better understanding might sharpen intervention strategies.

METHODS

We used the Medical Outcomes Study HIV (MOS-HIV) Health Survey and the Beck depression inventory-II and linear regression models to investigate HRQOL well-being in HIV-infected patients with DNP (n = 397) participating in an observational cohort study at six U.S. sites (CNS HIV Antiretroviral Treatment Effects Research Study, CHARTER).

RESULTS

For this sample of patients with HIV DNP, severity of depressed mood was more highly correlated with HRQOL well-being than was pain intensity.

CONCLUSIONS

These results suggest that interventions to improve HRQOL well-being in individuals with HIV-associated DNP may need to address not only pain intensity but mood state as well.

Phantom limb pain and its psychologic management: a critical review

Phantom limb pain is a puzzling phenomenon, from the viewpoints of both the patient experiencing it and the clinician trying to treat it. This review focuses on psychologic aspects in the origin of the PLP and critically evaluates the various psychologic interventions in the management of PLP. Whereas pharmacologic and surgical treatments often fail, psychologic interventions may hold promise in managing PLP. Studies using cognitive-behavioral therapies and hypnotherapy are reviewed. The outcome reports for psychologic therapies have been mainly positive. The results of the majority of these studies show a reduction in PLP. However, the lack of well controlled and randomized trials makes it difficult to draw firm conclusions regarding the effectiveness of these psychologic therapies in the treatment of PLP.

Psychological advances in chronic pain: a concise selective review of research from 2010

PURPOSE OF REVIEW

It is difficult to hold an organized view of psychological research related to chronic pain. There are many different theories and variables and the volume of literature is vast. The purpose of this review is to highlight some key trends in this research in 2010.

RECENT FINDINGS

We conducted a search of the output of four prominent scientific journals in the field of chronic pain management. Five research topics from among those identified are summarized. Identified topics include psychological factors related to analgesic use, efficacy of cognitive behavioral treatments, and contextual approaches (including acceptance and mindfulness).

SUMMARY

The largest number of psychological studies categorized for this review focused on psychological factors in relation to opioid use. These studies include ones to identify risk factors for aberrant drug behavior. This result seems to reflect that the dominant approach to chronic pain remains a pharmacological one. At the same time treatment from within a broadly cognitive behavioral approach seems to have reached a level of relative maturity with questions frequently being addressed with meta-analysis. Otherwise, there are developing and promising trends, such as in new treatment models and uses of information technology.

Phantom limb pain: mechanisms and treatment approaches

The vast amount of research over the past decades has significantly added to our knowledge of phantom limb pain. Multiple factors including site of amputation or presence of preamputation pain have been found to have a positive correlation with the development of phantom limb pain. The paradigms of proposed mechanisms have shifted over the past years from the psychogenic theory to peripheral and central neural changes involving cortical reorganization. More recently, the role of mirror neurons in the brain has been proposed in the generation of phantom pain. A wide variety of treatment approaches have been employed, but mechanism-based specific treatment guidelines are yet to evolve. Phantom limb pain is considered a neuropathic pain, and most treatment recommendations are based on recommendations for neuropathic pain syndromes. Mirror therapy, a relatively recently proposed therapy for phantom limb pain, has mixed results in randomized controlled trials. Most successful treatment outcomes include multidisciplinary measures. This paper attempts to review and summarize recent research relative to the proposed mechanisms of and treatments for phantom limb pain.

Maldynia: pathophysiology and management of neuropathic and maladaptive pain--a report of the AMA Council on Science and Public Health

BACKGROUND

Because of disparate taxonomic arrays for classification, the American Academy of Pain Medicine has proposed categorizing pain on a neurobiologic basis as eudynia (nociceptive pain), Greek for "good pain," or maldynia (maladaptive pain), Greek for "bad pain." The latter has been viewed as maladaptive because it may occur in the absence of ongoing noxious stimuli and does not promote healing and repair.

OBJECTIVE

To address recent findings on the pathogenesis of pain following neural injury and consider whether the development of maladaptive pain justifies its classification as a disease and to briefly discuss the scope of pharmacologic and non-pharmacologic approaches employed in patients with such pain.

METHODS

English language reports on studies using human subjects were selected from a PubMed search of the literature from 1995 to August 2010 and from the Cochrane Library. Further information was obtained from Internet sites of medical specialty and other societies devoted to pain management.

RESULTS

Neural damage to either the peripheral or central nervous system provokes multiple processes including peripheral and central sensitization, ectopic activity, neuronal cell death, disinhibition, altered gene expression, and abnormal sprouting and cellular connectivity. A series of neuro-immune interactions underlie many of these mechanisms. Imaging studies have shown that such damage is characterized by functional, structural, and chemical changes in the brain. Such pain is maladaptive in the sense that it occurs in the absence of ongoing noxious stimuli and does not promote healing and repair.

CONCLUSION

As defined, maldynia is a multidimensional process that may warrant consideration as a chronic disease not only affecting sensory and emotional processing but also producing an altered brain state based on both functional imaging and macroscopic measurements. However, the absolute clinical value of this definition is not established.