The Prevalence Rate and the Role of the Spatial Extent of Pain in Nonspecific Chronic Back Pain-A Population-Based Study in the South-West of Germany

Prospective Six-Month Analysis of Multiarea Burst Spinal Cord Stimulation: Correlating Intraoperative Neuromonitoring With Postoperative Programming and Clinical Outcomes

INTRODUCTION

DeRidder burst spinal cord stimulation (SCS) has shown superior relief from overall pain to traditional tonic neurostimulation therapies and a reduction in back and leg pain. However, nearly 80% of patients have two or more noncontiguous pain areas. This affects the ability to effectively program stimulation and deliver long-term efficacy of the therapy. Multiple DeRidder burst region programming is an option to treat multisite pain by interleaving stimulation at multiple areas along the spinal cord. Previous intraoperative neuromonitoring studies have shown that DeRidder burst stimulation provides broader myotomal coverage at a lower recruitment threshold. The goal of this study is to correlate intraoperative electromyogram (EMG) threshold and postsynaptic excitability with postoperative paresthesia thresholds and optimal burst stimulation programming.

MATERIALS AND METHODS

Neuromonitoring was performed during permanent implant of SCS leads in ten patients diagnosed with chronic intractable back and/or leg pain. Each patient underwent the surgical placement of a Penta Paddle electrode through laminectomy at the T8-T11 spinal levels. Subdermal electrode needles were placed into lower extremity muscle groups, in addition to the rectus abdominis muscles, for EMG recording. Evoked responses were compared across multiple trials of burst stimulation in which the number of independent burst areas was varied. After intraoperative data collection, all patients were programmed with single- and multiarea DeRidder burst. Intermittent dosing was delivered at 30:90, 120:360, 120:720, and 120:1440 (seconds ON/OFF) intervals. Numerical rating scale (NRS) and Patient Global Impression of Change scores were evaluated at one, two, three, four, and six months after permanent implant.

RESULTS

The thresholds for EMG recruitment after DeRidder burst differed across all patients owing to anatomical and physiological variations. After a 30-second dose of stimulation, the average decrease in thresholds was 1.25 mA for two-area and 0.9 mA for four-area DeRidder burst. Furthermore, a 30-second dose of multisite DeRidder burst produced a 0.25 mA reduction in the postoperative paresthesia thresholds. Across all patients, the baseline NRS score was 6.5 ± 0.5, and the NRS score after single or multiarea DeRidder burst therapy was 2.87 ± 1.50. Eight of ten patients reported a ≥50% decrease in their pain scores through the six-month follow-up visit. Pain outcomes using intermittent multiarea stimulation with longer OFF times (120:360, 120:720, 120:1440) were comparable to those using single-area DeRidder burst at 30:90 up to six months after implant with patient preference being two-area DeRidder burst.

CONCLUSIONS

This study aims to evaluate the use of intraoperative neuromonitoring to optimize stimulation programming for multisite pain and correlate it with postoperative programming and efficacy. These results suggest that multisite programming can be used to further customize DeRidder burst stimulation to each individual patient and improve outcomes and quality of life for patients receiving SCS therapy for multisite pain.

Digital mapping of shoulder pain in patients with shoulder disorders: a reliability study

INTRODUCTION

Digital body mapping can be used to document and quantify the area and location (distribution) of pain and discomfort and support assessment, monitoring, and treatment in clinical populations. This study determines the test-retest reliability of drawings detailing pain and pins and needles using digital body charts and their relationship to pain intensity and patient-reported shoulder function.

METHODS

Sixty-two participants with shoulder disorder completed pain and pins and needles drawings with test-retest interval of 30 minutes. Pain intensity in the last week and the patient-reported shoulder function questionnaires were completed. Area and radiating extent were determined using customized software. To assess relative and absolute test-retest reliability, the intraclass correlation coefficient (ICC3,1), standard error of measurement (SEM) and minimal detectable change (MDC95) were calculated. Regression analysis evaluated relation between area and radiating extent of pain and pins and needles with patient-reported function questionnaires.

RESULTS

Relative reliability for pain area and radiating extent was excellent (>0.90). Absolute reliability (SEM and MDC95) values for the pain area and radiating extent were 0.20%/34 pixels and 0.57%/94 pixels. Absolute reliability improves for smaller pain areas. Regression analysis revealed the area and radiation extent for both pain and pins and needles are independent constructs to the patient-reported function outcome when adjusted for pain intensity.

CONCLUSIONS

Digital body mapping assessing pain area and radiation extent in patients with shoulder disorders are reliable. The magnitude of absolute reliability suggests other sources of variability on repeat testing in this population. Pain area and radiation extent appear to be independent constructs.

Regional Coverage Differences With Single- and Multi-Area Burst Spinal Cord Stimulation for Treatment of Chronic Pain

INTRODUCTION

Burst spinal cord stimulation (SCS) has shown superior relief from overall pain and a reduction in back and leg pain compared with traditional tonic neurostimulation therapies. However, nearly 80% of patients have two or more noncontiguous pain areas. This can provide challenges in effectively programming stimulation and long-term therapy efficacy. Multiarea DeRidder Burst programming is a new option to treat multisite pain by delivering stimulation to multiple areas along the spinal cord. This study aimed to identify the effect of intraburst frequency, multiarea stimulation, and location of DeRidder Burst on the evoked electromyography (EMG) responses.

MATERIALS AND METHODS

Neuromonitoring was performed during permanent implant of SCS leads in nine patients diagnosed with chronic intractable back and/or leg pain. Each patient underwent the surgical placement of a Penta Paddle electrode via laminectomy at the T8-T10 spinal levels. Subdermal electrode needles were placed into lower extremity muscle groups, in addition to the rectus abdominis muscles, for EMG recording. Evoked responses were compared across multiple trials of burst stimulation in which the number of independent burst areas were varied.

RESULTS

The thresholds for EMG recruitment with DeRidder Burst differed across patients owing to anatomic and physiological variations. The average threshold to evoke a bilateral EMG response using single site DeRidder Burst was 3.2 mA. Multisite DeRidder Burst stimulation on up to four stimulation programs evoked a bilateral EMG response at a threshold of 2.5 mA (∼23% lower threshold). DeRidder Burst stimulation across four electrode pairs resulted in more proximal recruitment (vastus medialis and tibialis anterior) than did stimulation across two pairs. It also resulted in more focal coverage of areas across multiple sites.

CONCLUSIONS

Across all patients, multisite DeRidder Burst provided broader myotomal coverage than did traditional DeRidder Burst. Multisite DeRidder Burst stimulation provided focal recruitment and differential control of noncontiguous distal myotomes. Energy requirements were also lower when multisite DeRidder Burst was used.

Head and Neck Pain Drawing Area Correlates With Higher Psychosocial Burden But Not With Joint Dysfunction in Temporomandibular Disorders: A Cross-Sectional Study

Head and neck pain drawings have been introduced as part of the diagnostic gold standard for temporomandibular disorders (TMD). We aimed to quantify the spatial extent of pain in TMD patients and to analyze its association with further clinical findings. In a cross-sectional study, 90 patients (median age = 38 years; n women = 68) were diagnosed according to the DC/TMD. Intra-articular disorders were either confirmed or rejected by magnetic resonance imaging. The patients shaded all painful areas in a sketch of the left and right side of a face. A grid template was placed over the drawings and each region that contained markings was scored as painful. The correlation between the calculated area and the psychosocial variables (DC/TMD axis II) as well as the influence of pain lateralization were investigated using Spearman correlation, Mann-Whitney-U and chi-square tests. Pain affected all facial areas but concentrated on the regions of the temporomandibular joint and masseter origin. Thirty-nine percent reported purely unilateral pain, which was associated with structural TMJ findings in 77% of cases. Individuals with bilateral pain and those with greater spatial spread of pain had significantly higher scores on all axis II variables, except for functional limitation of the jaw. PERSPECTIVE: Head and neck pain drawings can contribute to a stratification of TMD patients. A greater extent of pain as well as pain bilateralization is associated with higher levels of emotional distress, pain chronicity and somatization, but not with functional impairment. Unilateral reporting of pain is associated with more intra-articular disorders.

Stress-induced hyperalgesia instead of analgesia in patients with chronic musculoskeletal pain

Many individuals with chronic musculoskeletal pain (CMP) show impairments in their pain-modulatory capacity. Although stress plays an important role in chronic pain, it is not known if stress-induced analgesia (SIA) is affected in patients with CMP. We investigated SIA in 22 patients with CMP and 18 pain-free participants. Pain thresholds, pain tolerance and suprathreshold pain ratings were examined before and after a cognitive stressor that typically induces pain reduction (SIA). Whereas the controls displayed a significant increase in pain threshold in response to the stressor, the patients with CMP showed no analgesia. In addition, increased pain intensity ratings after the stressor indicated hyperalgesia (SIH) in the patients with CMP compared to controls. An exploratory analysis showed no significant association of SIA or SIH with spatial pain extent. We did not observe significant changes in pain tolerance or pain unpleasantness ratings after the stressor in patients with CMP or controls. Our data suggest that altered stress-induced pain modulation is an important mechanism involved in CMP. Future studies need to clarify the psychobiological mechanisms of these stress-induced alterations in pain processing and determine the role of contributing factors such as early childhood trauma, catastrophizing, comorbidity with mental disorders and genetic predisposition.

Acupuncture for treating chronic spinal pain: A systematic review and meta-analysis protocol

BACKGROUND

Chronic spinal pain is one of the most leading causes of disability among adults worldwide and is associated with significant health care use. The effect of acupuncture on chronic spinal pain seems controversial based on evidence-based perspective. Thus, we performed a protocol for systematic review and meta-analysis to evaluate the effectiveness of acupuncture for treatment of chronic spinal pain.

METHODS

This systematic review has been registered in PROSPERO (CRD42019120665), which will be conducted in accordance with preferred reporting items for systematic review and meta-analysis protocols 2015 statement. We will search 7 electronic databases to identify relevant studies from inception to November, 2022, which includes PubMed, MEDLINE, Embase, Cochrane Clinical Trials Database, Web of Science, China National Knowledge Infrastructure, and Chinese Biomedical Literature Database. Cochrane "bias risk" tool is used to assess the bias risk of the quality of the included literature. RevMan V.5.3 software will be used to analyze all data.

RESULTS

A synthesis of current evidence of acupuncture for treating chronic spinal pain will be provided in this protocol.

CONCLUSION

This review will provide directions and recommendations for future research and clinical practices of acupuncture for treating chronic spinal pain.

Not just sensitization: sympathetic mechanisms contribute to expand experimental referred pain

Background

Widespread pain partially depends upon sensitization of central pain mechanisms. However, mechanisms controlling pain distribution are not completely known. The present study sought to assess skin temperature variations in the area of experimentally-induced pain and potential sex differences.

Methods

Pressure-pain thresholds (PPTs) were measured on the right infraspinatus muscle. At the end of Day 0, all participants performed an eccentric exercise of the shoulder external rotators to induce muscle soreness 24 hours after. On Day 1, participants indicated on a body chart the area of pain induced by 60 seconds of suprathreshold pressure stimulation (STPS; PPT + 20%) on the right infraspinatus muscle. Skin temperature variations in the area of referred pain were recorded with an infrared thermography camera, immediately before and after the STPS.

Results

Twenty healthy, pain-free individuals (10 females) participated. On Day 0, the pre-STPS temperature was higher than the post-STPS temperature on the arm (P = 0.001) and forearm (P = 0.003). On Day 1, the pre-STPS temperature was higher than the post-STPS temperature on the shoulder (P = 0.015), arm (P = 0.001), and forearm (P = 0.010). On Day 0, the temperature decrease after STPS in females was greater than in males on the forearm (P = 0.039). On Day 1, a greater temperature decrease was found amongst females compared with males at the shoulder (P = 0.018), arm (P = 0.046), and forearm (P = 0.005).

Conclusions

These findings indicate that sympathetic vasomotor responses contribute to expand pressure-induced referred pain, especially among females.

SYSTEMIC CYTOKINE LEVEL DIFFERENCES IN PATIENTS WITH CHRONIC MUSCULOSKELETAL SPINAL PAIN COMPARED TO HEALTHY CONTROLS AND ITS ASSOCIATION WITH PAIN SEVERITY: A SYSTEMATIC REVIEW

OBJECTIVE

Although there has been increasing interest in the role of systemic cytokines in chronic spinal pain (CSP), the evidence on their potential contribution is still unclear. Therefore, the current study systematically reviewed the evidence on systemic cytokine level differences between people with CSP compared to healthy controls (HCs) and the potential associations with pain severity.

METHODS

An electronic search was conducted on PubMed, Web of Science and Embase. All included studies were classified as observational studies, exploring the comparison between a CSP group and a HC group, and the association between systemic cytokine levels and pain severity.

RESULTS

Nine articles were included with a total sample of 400 CSP patients suffering from chronic whiplash associated disorder (CWAD) or chronic low back pain (CLBP). In CLBP, moderate evidence was found for elevated tumor necrosis factor (TNF) α, interleukin (IL) 6, IL-1 receptor antagonist (IL-1RA), and soluble TNF receptor (sTNF-R) type 2, for normal interferon (IFN) γ and IL-2 levels, and for reduced IL-10 levels. No association was found between pain severity and these cytokines in CLBP. In CWAD, moderate evidence was found for elevated CRP and evidence for changes in TNF-α was inconclusive. Evidence for the association between pain severity and CRP was limited, and there is probably no association between pain severity and TNF-α with limited evidence in CWAD.

CONCLUSIONS

Moderate evidence indicates the presence of systemic inflammation in CSP. Evidence regarding the association between pain severity and systemic cytokines is inconclusive and limited.

[A functional approach to disorders of the loco-motor system-a way to a better understanding?]

BACKGROUND

Disorders of the loco-motor system are frequent and expensive. The current method of diagnosing and treating these disorders does not appear to be successful.

DIAGNOSTICS

A functional approach based on the model of the functional system incorporates all aspects relevant to disorders of the loco-motor system. Most disturbances the system can compensate. If compensating mechanisms are not sufficient, the system decompensates, and symptoms develop. It is important to search not only for structural changes but also for somatic dysfunction, psychosocial factors, and changes in neuromodulation. On this basis, treatment strategies can be developed. If there are complex disturbances on different levels, a multimodal interdisciplinary treatment is indicated. The model of the functional system highlights the important role of manual medicine in the diagnostics, treatment, prevention, and rehabilitation of disorders of the loco-motor system.

Management of Chronic Low Back Pain and the Impact on Patients’ Personal and Professional Lives: Results From an International Patient Survey

Objective

Methods

Results

Conclusion

Spatiotemporal patterns of pain distribution and recall accuracy: a dose-response study

OBJECTIVES

Clinical decisions rely on a patient's ability to recall and report their pain experience. Monitoring pain in real-time (momentary pain) may reduce recall errors and optimize the clinical decision-making process. Tracking momentary pain can provide insights into detailed changes in pain intensity and distribution (area and location) over time. The primary aims of this study were (i) to measure the temporal changes of pain intensity, area, and location in a dose-response fashion and (ii) to assess recall accuracy of the peak pain intensity and distribution seven days later, using a digital pain mapping application. The secondary aims were to (i) evaluate the influence of repeated momentary pain drawings on pain recall accuracy and (ii) explore the associations among momentary and recall pain with psychological variables (pain catastrophizing and perceived stress).

METHODS

Healthy participants (N=57) received a low (0.5 ml) or a high (1.0 ml) dose of hypertonic saline (5.8%) injection into the right gluteus medius muscle and, subsequently, were randomized into a non-drawing or a drawing group. The non-drawing groups reported momentary pain intensity every 30-s. Whereas the drawing groups reported momentary pain intensity and distribution on a digital body chart every 30-s. The pain intensity, area (pixels), and distribution metrics (compound area, location, radiating extent) were compared at peak pain and over time to explore dose-response differences and spatiotemporal patterns. All participants recalled the peak pain intensity and the peak (most extensive) distribution seven days later. The peak pain intensity and area recall error was calculated. Pain distribution similarity was determined using a Jaccard index which compares pain drawings representing peak distribution at baseline and recall. The relationships were explored among peak intensity and area at baseline and recall, catastrophizing, and perceived stress.

RESULTS

The pain intensity, area, distribution metrics, and the duration of pain were lower for the 0.5 mL than the 1.0 mL dose over time (p<0.05). However, the pain intensity and area were similar between doses at peak pain (p>0.05). The pain area and distribution between momentary and recall pain drawings were similar (p>0.05), as reflected in the Jaccard index. Additionally, peak pain intensity did not correlate with the peak pain area. Further, peak pain intensity, but not area, was correlated with catastrophizing (p<0.01).

CONCLUSIONS

This study showed differences in spatiotemporal patterns of pain intensity and distribution in a dose-response fashion to experimental acute low back pain. Unlike pain intensity, pain distribution and area may be less susceptible in an experimental setting. Higher intensities of momentary pain do not appear to influence the ability to recall the pain intensity or distribution in healthy participants.

IMPLICATIONS

The recall of pain distribution in experimental settings does not appear to be influenced by the intensity despite differences in the pain experience. Pain distribution may add additional value to mechanism-based studies as the distribution reports do not vary with pain catastrophizing. REC# N-20150052.

Differential sensory and clinical phenotypes of patients with chronic widespread and regional musculoskeletal pain

The differentiation of chronic primary pain syndromes into those with widespread vs regional musculoskeletal pain has been characterized by controversial discussions about common or distinct mechanisms and core clinical and sensory criteria. For example, the recent revision of fibromyalgia criteria has discarded sensory characteristics such as number of "tender points." This study examined empirical evidence related to this diagnostic shift and aimed to identify basic sensory-clinical pain phenotypes in patients with chronic local primary pain (chronic primary back pain [CBP]) and patients with chronic widespread primary pain (fibromyalgia syndrome). Combined sensory-clinical pain phenotypes of 185 patients with previous CBP and fibromyalgia syndrome diagnoses were derived by a stepwise data reduction through descriptive statistical, correlational, principal components and latent class analyses. Clusters were cross-validated by linear discriminant analysis. Four clusters of patients were identified, requiring 4 pressure pain sensitivity markers (number of sensitive tender and control points, pain intensity, and pressure pain threshold at the trapezius) and 2 clinical pain characteristics (pain regions and present pain intensity). Subsequent discriminant analysis revealed that 3 discriminant functions of pressure sensitivity markers sufficed to differentiate the clusters. These sensory-clinical phenotypes differed also in somatic symptoms and impairment but neither in psychopathology nor in psychosocial cofactors. The results highlight the relevance of sensory testing in combination with clinical pain assessment in chronic primary pain syndromes.

Epidemiology of chronic back pain among adults and elderly from Southern Brazil: a cross-sectional study

BACKGROUND

Chronic back pain (CBP) can negatively affect one's quality of life and health condition, posing significant social and economic burdens.

OBJECTIVES

(1) To determine the prevalence of CBP and analyze associated factors in adult and elderly individuals in a municipality in southern Brazil; (2) to verify who sought medical attention or missed work because of back pain; and (3) to estimate the impact of CBP on selected health outcomes.

METHODS

This was a population-based cross-sectional study conducted with individuals aged 18 years and older. CBP was defined as "pain for three consecutive months in the cervical, thoracic, or lumbar regions in the last year." Demographic, socioeconomic, behavioral, and physical and mental health information was collected. The impact of CBP was assessed by the etiological fraction method.

RESULTS

The prevalence of CBP was 20.7% (95% CI: 18.3, 23.0) among the 1300 study participants. The factors associated with CBP were women, elderly, smokers, obesity, and sleeping fewer hours per night, as well as those with higher mental stress levels, history of fracture, arthritis/rheumatism, and work-related musculoskeletal disorder/repetitive strain injury. One-third of those with CBP missed work (31%) and 68% visited the physician over a 12-month period. All health outcomes analyzed (poor or very poor sleep quality, regular or poor health perception, worsened quality of life, depressive symptoms, perceived sadness) were significantly associated with CBP.

CONCLUSION

One in five adults or elderly reported having CBP over the previous 12 months. This condition was associated with poorer health perception, poorer quality of life, and depressive symptoms.

Digital Pain Mapping and Tracking in Patients With Chronic Pain: Longitudinal Study

Background

Digital pain mapping allows for remote and ecological momentary assessment in patients over multiple time points spanning days to months. Frequent ecological assessments may reveal tendencies and fluctuations more clearly and provide insights into the trajectory of a patient’s pain.

Objective

The primary aim of this study is to remotely map and track the intensity and distribution of pain and discomfort (eg, burning, aching, and tingling) in patients with nonmalignant spinal referred pain over 12 weeks using a web-based app for digital pain mapping. The secondary aim is to explore the barriers of use by determining the differences in clinical and user characteristics between patients with good (regular users) and poor (nonregular users) reporting compliance.

Methods

Patients (N=91; n=53 women) with spinal referred pain were recruited using web-based and traditional in-house strategies. Patients were asked to submit weekly digital pain reports for 12 weeks. Each pain report consisted of digital pain drawings on a pseudo–three-dimensional body chart and pain intensity ratings. The pain drawings captured the distribution of pain and discomfort (pain quality descriptors) expressed as the total extent and location. Differences in weekly pain reports were explored using the total extent (pixels), current and usual pain intensity ratings, frequency of quality descriptor selection, and Jaccard similarity index. Validated e-questionnaires were completed at baseline to determine the patients’ characteristics (adapted Danish National Spine Register), disability (Oswestry Disability Index and Neck Disability Index), and pain catastrophizing (Pain Catastrophizing Scale) profiles. Barriers of use were assessed at 6 weeks using a health care–related usability and acceptance e-questionnaire and a self-developed technology-specific e-questionnaire to assess the accessibility and ease of access of the pain mapping app. Associations between total extent, pain intensity, disability, and catastrophizing were explored to further understand pain. Differences between regular and nonregular users were assessed to understand the pain mapping app reporting compliance.

Results

Fluctuations were identified in pain reports for total extent and pain intensity ratings (P<.001). However, quality descriptor selection (P=.99) and pain drawing (P=.49), compared using the Jaccard index, were similar over time. Interestingly, current pain intensity was greater than usual pain intensity (P<.001), suggesting that the timing of pain reporting coincided with a more intense pain experience than usual. Usability and acceptance were similar between regular and nonregular users. Regular users were younger (P<.001) and reported a larger total extent of pain than nonregular users (P<.001).

Conclusions

This is the first study to examine digital reports of pain intensity and distribution in patients with nonmalignant spinal referred pain remotely for a sustained period and barriers of use and compliance using a digital pain mapping app. Differences in age, pain distribution, and current pain intensity may influence reporting behavior and compliance.

Widespread pain is a risk factor for cardiovascular mortality: results from the Framingham Heart Study

AIMS

With the introduction of widespread pain (WSP) as a separate diagnostic code in the ICD-11, WSP has now become an own clinical diagnosis independent of the underlying pathophysiology. Research has reported aetiological associations of WSP and cardiovascular diseases. However, studies on mortality risk in individuals with WSP have reported inconsistent results. This study investigates whether there is increased mortality in WSP individuals and establish potential determinants of mortality risk. Therefore, we evaluates the population-based prospective cohort of the Framingham Heart Study (FHS).

METHODS AND RESULTS

The FHS is a longitudinal multi-generational study. Pain status was assessed uniquely between 1990 and 1994. Cox proportional hazards modelling was used to estimate hazard ratios (HRs) of WSP on all-cause mortality controlling for sex and age, cardiovascular risk factors, cancer history, lifestyle factors and current medication. WSP examination was carried out in 4746 participants of the FHS (60.3 ± 13.5 years, 55.1% women). A total of 678 (14.5%) subjects fulfilled the criteria for WSP, whereas 4011 (85.5%) subjects did not. The follow-up time was 15 years, during which 202 persons died in the WSP group and 1144 in the no-WSP group. When adjusting for age and sex, all-cause mortality was increased by about 16% in WSP subjects. Individuals with WSP had an increased HR particularly for cardiovascular cause of death (HR adjusted by age and sex = 1.46, 95% confidence interval 1.10-1.94).

CONCLUSION

Our data show that in a large population-based cohort, WSP is associated with increased HR for cardiovascular cause of death, underlining the need for pain assessments in cardiovascular practice.

The Reliability and Concurrent Validity of PainMAP Software for Automated Quantification of Pain Drawings on Body Charts of Patients With Low Back Pain

BACKGROUND

The assessment of painful areas through printed body charts is a simple way for clinicians to identify patients with widespread pain in primary care. However, there is a lack in the literature about a simple and automated method designed to analyze pain drawings in body charts in clinical practice.

PURPOSE

To test the inter- and intra-rater reliabilities and concurrent validity of software (PainMAP) for quantification of pain drawings in patients with low back pain.

METHODS

Thirty-eight participants (16 [42.10%] female; mean age 50.24 [11.54] years; mean body mass index 27.90 [5.42] kg/m² ; duration of pain of 94.35 [96.11] months) with a current episode of low back pain were recruited from a pool of physiotherapy outpatients. Participants were instructed to shade all their painful areas on a body chart using a red pen. The body charts were digitized by separate raters using smartphone cameras and twice for one rater to analyze the intra-rater reliability. Both the number of pain sites and the pain area were calculated using ImageJ software (reference method). The PainMAP software used image processing methods to automatically quantify the data from the same digitized body charts.

RESULTS

The reliability analyses revealed that PainMAP has excellent inter- and intra-rater reliabilities to quantify the number of pain sites (intraclass correlation coefficient [ICC]_2,1 : 0.998 [95% confidence interval (CI) 0.996 to 0.999]; ICC_2,1 : 0.995 [95% CI 0.991 to 0.998]) and the pain area [ICC_2,1 : 0.998 (95% CI 0.995 to 0.999); ICC_2,1 : 0.975 (95% CI 0.951 to 0.987)], respectively. The standard error of the measurement was 0.22 (4%) for the number of pain sites and 0.03 cm² (4%) for the pain area. The Bland-Altman analyses revealed no substantive differences between the 2 methods for the pain area (mean difference = 0.007 [95% CI -0.053 to 0.067]).

CONCLUSION

PainMAP software is reliable and valid for quantification of the number of pain sites and the pain area in patients with low back pain.

Pain drawings, interpreter support and clinical findings among immigrant patients on sick leave in Swedish primary health care

Aim:

To evaluate the spread of pain and its correlates among immigrant patients on sick leave.

Background:

Backache, outspread pain and sick-leave questions are problematic to handle primary health care, especially in multicultural settings.

Methods:

Two hundred and thirty-five patients 20–45 years on paid sick leave (59% women, 93% foreign-born, mostly non-Europeans). Many had little formal education. One-third had professional interpreter support. The patients pointed out on their bodies where they felt pain. This information was transferred on a pain drawing [pain drawing fields (PDFs) 0–18] by a doctor. Major depression and psychosocial stressors were assessed using Diagnostic and Statistical Manual of Mental Disorders. Nociceptive locations for pain were established (pain-sites 0–18). Dependent variable was the number of PDFs. Independent variables were social data, sick leave, interpreter, depression, stress levels and number of pain sites. Calculations were done using descriptive methods and multi-variable linear regression in full models, by gender.

Findings:

Many patients had depression (51% women versus 32% men). A majority were exposed to psychosocial stressors. Women had more PDFs, in median 5 [inter-quartile ranges (IQR) 4–8] versus men 3 (IQR 2–5), and also more pain sites, in median 3 (IQR 2–5) versus men in median 2 (IQR 1–3). For men, the regression calculations revealed that numbers of PDFs associated only with increasing numbers of pain sites (B 0.871 P < 0.001). For women, this association was weaker (B 0.364, P < 0.001), with significant values also for age (B 0.103) and sick leave > one year (B 0.767, P = 0.010), and a negative predicting value for interpreter support (B −1.198, P < 0.043). To conclude, PDFs associated often with somatic findings but varied much among the women. This implies potential problems regarding cause, function and sick leave questions. However, support by professional interpreters may facilitate a shared understanding with immigrant women having long-standing pain.

Pain Intensity, Disability, and Quality of Life in Patients with Chronic Low Back Pain: Does Age Matter?

Objective

Nonspecific chronic low back pain (CLBP) is a frequent medical condition among middle-aged and older adults. Its detrimental consequences for functional ability and quality of life are well known. However, less is known about associations of chronological age with disability and well-being among CLBP patients. Coping with pain may be harder with advancing age due to additional age-associated losses of physical, sensory, and other resources, resulting in higher disability and lower quality of life. Alternatively, older patients may feel less impaired and report higher quality of life than younger patients because the experience of chronic pain may be better anticipated and more “normative” in old age.

Methods

We investigated an age-heterogeneous sample of 228 CLBP patients (mean age = 59.1 years, SD = 10.2 years, range 41–82 years). Our outcomes were pain intensity, pain disability (as assessed by self-reported activity restrictions and performance-based tests), and measures of quality of life (health-related quality of life: SF-12 physical and mental health; well-being: anxiety, depression, perceived control over life, affective distress).

Results

Although older patients had higher performance-based disability, they scored higher on mental health and on most measures of well-being than younger patients.

Conclusions

Our findings provide evidence for a “paradoxical” pattern of age effects in CLBP patients and are thus in line with other studies based on nonclinical samples: Although disability in CLBP patients increases with advancing age, indicators of quality of life are equal or even higher in older patients.

Profiles of Subjective Well-being in Patients with Chronic Back Pain: Contrasting Subjective and Objective Correlates

OBJECTIVE

The detrimental impact of nonspecific chronic low back pain (CLBP) on quality of life is well known. However, patients with CLBP represent a remarkably heterogeneous group, and not all of them report compromised well-being.

METHODS

In this study, we investigated this heterogeneity by identifying profiles (or clusters) of well-being and their correlates in 239 CLBP patients. To take the multidimensionality of subjective well-being into account, we included multiple well-being indicators (depression, anxiety, affective distress, perceived control over life). For an in-depth characterization of the well-being profiles, we assessed 1) sociodemographic indicators (age, gender, education, marital status, occupational status), 2) pain-related measures (pain intensity, subjective and objective pain disability, number of pain locations), 3) psychosocial resources (mental health, resilience, perceived support), 4) biographical factors (trauma), and 5) somatosensory profiles based on quantitative sensory testing.

RESULTS

Based on two-step cluster analysis, we identified three distinct well-being profiles, characterized by either generally high well-being (cluster 1, n = 51), moderate well-being (cluster 2, n = 104), or consistently low well-being (cluster 3, n = 77), respectively. Most differences between the derived well-being profiles regarding sociodemographic, psychosocial, and biographical measures were of weak to moderate effect size. Larger effect sizes were observed for differences in pain intensity and subjective, but not objective, pain disability. Finally, the largest effects were found for differences in psychosocial resources.

CONCLUSIONS

Our findings suggest that not only in nonclinical samples, but also in patients with chronic pain, well-being is more closely associated with psychological resources and subjective evaluations than with objective parameters.

Acupuncture for chronic uncomplicated musculoskeletal pain associated with the spine: A systematic review protocol

BACKGROUND

Chronic uncomplicated neck pain, back pain, and lower back pain, with incidences of 18%, 17.7% and 36%, respectively. Although these three conditions occur in different parts of the body, we can summarize them as chronic uncomplicated musculoskeletal pain associated with the spine (CMPS) in accordance with the pathogenesis. Acupuncture is often used to treat them. We aim to conduct a systematic review to evaluate the efficacy of acupuncture for patients experiencing CMPS.

METHODS

The following electronic databases will be searched from inception to Mar 2019: Cochrane Central Register of Controlled Trials, Web of Science, ScienceDirect, PubMed, MEDLINE, EMBASE, Springer, WHO International Clinical Trials Registry Platform, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, VIP Chinese Science and Technology Periodical Database, and Wanfang Database. All randomized controlled trials published in English or Chinese related to acupuncture for CMPS will be included. The primary outcome will be the visual analog scale. Adverse events will be evaluated as secondary outcomes for safety evaluation. Study selection, data extraction, and assessment of study quality will be performed independently by two reviewers. RevMan V.5.3.5 software will be used for the assessment of risk of bias and data synthesis.

RESULTS

This study will provide a high-quality synthesis of current evidence of acupuncture for CMPS from visual analog scale.

CONCLUSION

The conclusion of our study will provide an evidence to judge whether acupuncture is an effective intervention for patients suffered from CMPS.

ETHICS AND DISSEMINATION

Formal ethical approval is not required, as the data are not individualized. The findings of this systematic review will be disseminated in a peer-reviewed publication and/or presented at relevant conferences.

PROSPERO REGISTRATION NUMBER

CRD42018114806.

Distinct patterns of variation in the distribution of knee pain

The patient’s expression of pain using digital-body maps expands analytic opportunities for exploring the spatial variation of bodily pain. A common knee pain condition in adolescents and adults is patellofemoral pain (PFP) and recently PFP was shown to be characterized by a heterogeneous distribution of pain. Whether there are important patterns in these distributions remains unclear. This pioneering study assesses the spatial variation of pain using principal component analysis and a clustering approach. Detailed digital-body maps of knee pain were drawn by 299 PFP patients of mixed sex, age, and pain severity. Three pain distribution patterns emerged resembling an Anchor, Hook, and an Ovate shape on and around the patella. The variations in pain distribution were independent of sex, age, and pain intensity. Bilateral pain associated with a longer duration of pain and the majority characterized by the Hook and Ovate pain distributions. Bilateral and/or symmetrical pain between the left and right knees may represent symptoms associated with longstanding PFP. The distinct patterns of pain location and area suggest specific underlying structures cannot be ruled out as important drivers, although central neuronal mechanisms possibly exemplified by the symmetrical representation of pain may play a role in individuals with longstanding symptoms.

Health-care utilization of patients with chronic back pain before and after rehabilitation

BACKGROUND

Patients with chronic back pain show an increased use of health-care services leading to high direct costs. Multidisciplinary rehabilitation reduces pain intensity, depression, disability and work inability. The study aims to investigate whether health-care utilization in patients with chronic back pain is lower after rehabilitation than before rehabilitation and if, in addition to sociodemographic, medical and psychological characteristics, changes in these characteristics immediately after rehabilitation can predict health-care utilization.

METHODS

N = 688 patients with chronic back pain were asked about their overall health-care services use and the use of general practitioners, specialists, physiotherapy, psychotherapy, complementary therapist, massages, and admission to hospital both 6 months before and 6 months after rehabilitation. In addition, various sociodemographic, medical and psychological variables were assessed. To measure changes due to rehabilitation, differences in pain intensity, disability, impairment and coping, quality of life, and days on sick leave before and after rehabilitation were calculated. Dependent t-tests and hierarchical regression analyses were used to analyse the data.

RESULTS

Health-care utilization 6 months after rehabilitation was, except for physiotherapy and psychotherapy, significantly lower than before. The effect sizes were rather small (Cohens'd =. 01-.34). After rehabilitation between 15.2% and 39.9% of the variance of health-care utilization could be explained. The baseline values of health-care utilization explained between 3.2% and 15.9% of the incremental variances. The changes in psychological impairment and coping as well as in sick leave after rehabilitation could explain between 0.8% and 2.9% of the variance of health-care utilization after rehabilitation. Its influence was significant for the general use of health-care services, general practitioners and specialists.

CONCLUSIONS

The results indicate that use of health-care services after rehabilitation in the present study is slightly lower than before, which has an impact on direct costs due to chronic back pain in Germany. The predictors show the importance in terms of health-care utilization of improving work ability and psychological impairment.

Pain experiences of patients with musculoskeletal pain + central sensitization: A comparative Group Delphi Study

Objectives

Central sensitization (CS) is regarded as an important contributing factor for chronification of musculoskeletal pain (MSP). It is crucial to identify CS, as targeted multimodal treatment may be indicated. The primary objective of this study was therefore to explore pain experience of individuals with MSP+CS in order to gain a better understanding of symptoms in relation to CS from a patient perspective. The secondary objective was to investigate whether pain experiences of patients with MSP+CS differ from those of individuals with neuropathic pain (NP).

Methods

We conducted a comparative Group Delphi Study including patients with MSP+CS and neuropathic pain (NP). 13 guiding questions were used to gather information about sensory discriminatory, affective and associated bodily, mental and emotional phenomena related to the pain experience of patients. Descriptions were categorized using qualitative content analysis. Additionally, patients completed several pain related questionnaires.

Results

Nine participants with MSP+CS and nine participants with NP participated. The Delphi procedure revealed three main themes: psycho-emotional factors, bodily factors and environmental factors. Descriptions of patients with MSP+CS showed a complex picture, psycho-emotional factors seem to have a considerable impact on pain provocation, aggravation and relief. Impairments associated with mental ability and psyche affected many aspects of daily life. In contrast, descriptions of patients with NP revealed a rather mechanistic and bodily oriented pain experience.

Discussion

Patients with MSP+CS reported distinct features in relation to their pain that were not captured with current questionnaires. Insight in patient’s pain experience may help to choose and develop appropriate diagnostic instruments.

Different DHEA-S Levels and Response Patterns in Individuals with Chronic Neck Pain, Compared with a Pain Free Group-a Pilot Study

Objective

To test, in this pilot study, whether DHEA-S (Dehydroepiandrosterone, sulfated form) plasma levels are lower among persons with chronic neck pain, compared to control persons, and to investigate the DHEA-S response after a physical exercise.

Subjects

Included were 12 persons with chronic neck pain and eight controls without present pain, all 18 and 65 years of age. Exclusion criteria for both groups were articular diseases or tendinosis, fibromyalgia, systemic inflammatory and neuromuscular diseases, pain conditions due to trauma, or severe psychiatric diseases.

Design and methods

The participants arm-cycled on an ergometer for 30 minutes. Blood samples were taken before, 60 minutes, and 150 minutes after this standardized physical exercise.

Results

The estimated plasma DHEA-S levels at baseline were 2.0 µmol/L (95% confidence interval [CI] 1.00; 4.01) in the pain group and 4.1 µmol/L (95% CI2.0; 8.6) in the control group, adjusted for sex, age, body mass index (BMI), and Shirom-Melamed Burnout Questionnaire (SMBQ), with a ratio of 0.48 ( P  = 0.094).

Conclusions

In this pilot study, the plasma DHEA-S levels appeared to be lower among the persons with chronic neck pain, compared with the control group. It was indicated that DHEA-S decreased during the physical exercise in the control group, and either increased or was unaffected in the chronic pain group.

[Childhood abuse experiences and chronic low back pain. Direct and mediated effects of childhood abuse in different pain dimensions of nonspecific chronic low back pain]

BACKGROUND

Physical, sexual and emotional abuse in childhood and adolescence is considered to play a role in the etiology and generalization of chronic pain in adulthood. However, it remains unclear whether abuse is specifically associated with different dimensions of nonspecific chronic low back pain (CLBP) and if these associations are mediated by psychological symptoms.

MATERIAL AND METHODS

A total of 103 patients with validated CLBP were assessed by pain drawing, the multidimensional pain questionnaire and the pain experience scale. The childhood trauma questionnaire was used to retrospectively screen for physical, sexual and emotional abuse in childhood and adolescence. Patients were also screened for symptoms of depression, anxiety and dissociation in order to look for possible mediators.

RESULTS

Patients with CLBP who reported childhood abuse showed higher pain intensity, higher spatial extent of pain, higher affective and sensory pain sensation and more pain disability compared to CLBP patients who had not experienced abuse. However, multivariate analyses revealed that only the spatial extent of pain was directly associated with childhood abuse. Furthermore, a significant association between childhood abuse and sensory pain sensation was found to be mediated by symptoms of anxiety and dissociation.

CONCLUSION

The influence of childhood abuse on CLBP is different for specific pain dimensions; therefore, CLBP should be faced as a complex construct that comprises different dimensions. Childhood abuse is suggested as a risk factor for spreading pain in CLBP persons; therefore, CLBP patients reporting additional pain locations might benefit from diagnostic and therapeutic interventions specific for childhood abuse experiences.

Eye Movement Desensitization and Reprocessing vs. Treatment-as-Usual for Non-Specific Chronic Back Pain Patients with Psychological Trauma: A Randomized Controlled Pilot Study

OBJECTIVE

Eye movement desensitization and reprocessing (EMDR)-an evidence-based approach to eliminate emotional distress from traumatic experiences-was recently suggested for the treatment of chronic pain. The aim of this study was to estimate preliminary efficacy of a pain-focused EMDR intervention for the treatment of non-specific chronic back pain (CBP).

DESIGN

Randomized controlled pilot study.

METHODS

40 non-specific CBP (nsCBP) patients reporting previous experiences of psychological trauma were consecutively recruited from outpatient tertiary care pain centers. After baseline assessment, patients were randomized to intervention or control group (1:1). The intervention group received 10 sessions standardized pain-focused EMDR in addition to treatment-as-usual (TAU). The control group received TAU alone. The primary outcome was preliminary efficacy, measured by pain intensity, disability, and treatment satisfaction from the patients' perspective. Clinical relevance of changes was determined according to the established recommendations. Assessments were conducted at the baseline, posttreatment, and at a 6-month follow-up. Intention-to-treat analysis with last observation carried forward method was used. Registered with http://ClinicalTrials.gov (NCT01850875).

RESULTS

Estimated effect sizes (between-group, pooled SD) for pain intensity and disability were d = 0.79 (CI_95%: 0.13, 1.42) and d = 0.39 (CI_95%: -0.24, 1.01) posttreatment, and d = 0.50 (CI_95%: 0.14, 1.12) and d = 0.14 (CI_95%: -0.48, 0.76) at 6-month follow-up. Evaluation on individual patient basis showed that about 50% of the patients in the intervention group improved clinically relevant and also rated their situation as clinically satisfactory improved, compared to 0 patients in the control group.

CONCLUSION

There is preliminary evidence that pain-focused EMDR might be useful for nsCBP patients with previous experiences of psychological trauma, with benefits for pain intensity maintained over 6 months.

Comorbidities, intensity, frequency and duration of pain, daily functioning and health care seeking in local, regional, and widespread pain - a descriptive population-based survey (SwePain)

BACKGROUND

The clinical knowledge of factors related to the spread of pain on the body has increased and understanding these factors is essential for effective pain treatment. This population-based study examines local (LP), regional (RP), and widespread pain (WSP) on the body regarding comorbidities, pain aspects, and impact of pain and elucidates how the spread of pain varies over time.

MATERIAL AND METHODS

A postal questionnaire that addressed pain aspects (intensity, frequency, duration and anatomical spreading on a body manikin), comorbidities and implications of pain (i.e., work situation, physical activity, consumption of health care and experience of hospitality and treatment of health care) was sent to 9000 adults living in southeastern Sweden. Of these, 4774 (53 %) completed and returned the questionnaire. After 9 weeks, a follow-up questionnaire was sent to the 2983 participants who reported pain in the first questionnaire (i.e. 62 % of 4774 subjects). Of these, 1940 completed and returned the questionnaire (i.e. 65 % of 2983 subjects). The follow-up questionnaire included the same items as the first questionnaire.

RESULTS

This study found differences in intensity, frequency and duration of pain, comorbidities, aspects of daily functioning and health care seeking in three pain categories based on spreading of pain: LP, RP and WSP. Compared to the participants with RP and LP, the participants with WSP had lower education and worse overall health, including more frequent heart disease and hypertension. In addition, participants with WSP had more intense, frequent, and long-standing pain, required more medical consultations, and experienced more impact on work. The participants with RP constituted an intermediate group regarding frequency and intensity of pain, and impact on work. The participants with LP were the least affected group regarding these factors. A substantial transition to RP had occurred by the 9-week follow-up.

CONCLUSIONS

This study shows an association between increased spread of pain and prevalence of heart disease, hypertension, more severe pain characteristics (i.e., intensity, frequency and duration), problems with common daily activities and increased health care seeking. The WSP group was the most affected group and the LP group was the least affected group. Regarding these factors, RP was an obvious intermediate group. The transitions between the pain categories warrant research that broadly investigates factors that increase and decrease pain.