Neuropathic Pain in Low Back-Related Leg Pain Patients: What Is the Evidence of Prevalence, Characteristics, and Prognosis in Primary Care? A Systematic Review of the Literature

Association between the dietary inflammatory index and pain in US adults from NHANES

OBJECTIVES

The growing global burden of pain is gradually expanding from the medical field to public health. Dietary inflammatory potential correlates with inflammatory markers, and inflammation is one of the main mechanisms of pain.

METHODS

This study explored the association between dietary inflammatory index (DII) and pain from the NHANES database on DII and pain (neck pain, low back pain, joint pain, and headache or migraine) using logistic regression and stratified analysis.

RESULTS

The results show a stronger association between DII and joint pain (Q4 of DII adjusted-OR = 1.23, 95% CI = 1.08-1.40, P = 0.003) and headache or migraine (Q4 of DII adjusted-OR = 1.31, 95% CI = 1.15-1.48, P < 0.001), but no association is found in neck pain (Q4 of DII adjusted-OR = 1.03, 95% CI = 0.89-1.20, P = 0.65) and low back pain (Q4 of DII adjusted-OR = 1.04, 95% CI = 0.92-1.17, P = 0.54). After stratifying the data according to demographics, differences in the relationship between DII and pain are found at different levels of the population.

DISCUSSION

This study identifies high DII as a risk factor for joint pain and headache or migraine.

Prognosis of Patients With Neuropathic Low Back-Related Leg Pain: An Exploratory Study Using Prospective Data From UK Primary Care

This prospective cohort study investigates the prognosis of patients with neuropathic low back-related leg pain consulting in UK primary care. Data from 511 patients were collected using standardised baseline clinical examinations (including magnetic resonance imaging scan findings), self-report questionnaires at baseline, 4 months, 12 months, and 3 years. Cases of possible neuropathic pain (NP) and persistent-NP were identified using either of 2 definitions: 1) clinical diagnosis of sciatica, 2) self-report version of leeds assessment for neurological symptoms and signs (s-LANSS). Mixed-effects models compared pain intensity (highest of mean leg or mean back pain [0-10 Numerical Rating Scale]) over 3-years between persistent-NP versus non-persistent-NP based on 1) clinical diagnosis, 2) s-LANSS. Logistic regression examined associations between potential prognostic factors and persistent-NP at 4 months based on the 2 NP definitions. At 4-months, using both definitions: 1) approximately 4 out of 10 patients had persistent-NP, 2) mean pain intensity was higher for patients with persistent-NP at all follow-up points compared to those without, 3) only pain self-efficacy was significantly associated with persistent-NP (s-LANSS: OR .98, sciatica: .98), but it did not predict cases of persistent-NP in either multivariable model. Based on factors routinely collected from self-report and clinical examination, it was not possible to predict persistent-NP in this population. PERSPECTIVE: This study provides evidence that neuropathic back-related leg pain in patients consulting in primary care is not always persistent. Patients with persistent neuropathic pain had worse outcomes than those without. Neither leg pain intensity, pain self-efficacy nor MRI scan findings predicted cases of persistent neuropathic pain in this patient population.

Predictors of neuropathic pain and related functional disability in sciatica patients: a cross-sectional study

PURPOSE

The aim of the present paper was to assess neuropathic pain and its predictors among patients with sciatica. In addition, we sought to investigate the predictors of functional disability in sciatica patients with neuropathic pain.

METHODS

A cross-sectional study was carried out on a sample of 100 sciatica patients aged 18 years and older with a radiating pain from the lower back down to the leg below the knee. Information about socio-demographic characteristics, duration of symptoms, being treated or not, type of treatment, side of sciatica, presence of back pain, leg pain occurrence, leg pain intensity, functional disability and pain catastrophizing were collected.

RESULTS

Of the total patients, 57% had neuropathic pain. Multivariable analysis showed that leg pain intensity was higher in the neuropathic pain group as compared to the non-neuropathic pain group. Also, patients with left sciatica were less likely to have neuropathic pain than patients with right sciatica. Patients with neuropathic pain having high levels of pain catastrophizing and being on bed rest for at least one week were at a higher risk of developing functional disability as compared to their counterparts.

CONCLUSION

Low levels of pain catastrophizing and less bed rest should be considered in interventions aimed at improving the functional ability for sciatica patients with neuropathic pain.

Diagnostic Value of an Additional Sequence (Large-Field Coronal Stir) in a Routine Lumbar Spine MR Imaging Protocol to Investigate Lumbar Radiculopathy

OBJECTIVE

Lumbar radiculopathy mainly originates in the spine (lumbar disc herniation or spine osteoarthritis) but can sometimes be explained by extra-spinal nerve compression or confused with referred pain mimicking radiculopathy. Our main objective was to demonstrate the clinical benefit of the large-field coronal STIR (coroSTIR) sequence in the etiological assessment of lumbar radiculopathy with a duration of more than six weeks.

MATERIALS AND METHODS

Six hundred consecutive lumbar MRI scans performed using the same protocol were retrospectively reviewed. Two musculoskeletal radiologists independently assessed the coroSTIR sequence for the presence of extra-spinal anomalies (ESA) that could explain or contribute to the lumbar radiculopathy. The presence of an ESA was then correlated with sex, age, topography and lateralization of radiculopathy, history of vertebral surgery, as well as the presence of a spinal cause explaining the symptoms. Extra-spinal incidentalomas (ESI) with potential clinical impact visible only on the coroSTIR sequence were also systematically reported.

RESULTS

An extra-spinal cause was detected on the coroSTIR sequence in 68 cases (11.3%), mainly gluteal tendinobursitis (30.9%), congestive hip osteoarthritis (25%), degenerative sacroiliac arthropathy (14.7%), or inflammatory sacroilitis (7.3%). Their prevalence was significantly correlated in multivariate regression with age (58 years vs. 53 years, p = 0.01), but not with the type of radiating pain (sciatica or cruralgia). The presence of ESI was also frequent (70 cases, 11.7%), including some potentially severe diagnoses (38% of tumor or pseudo-tumor mass requiring further assessment or monitoring).

CONCLUSIONS

Considering its acceptable acquisition time, the detection of a significant number of potentially symptom-related extra-spinal anomalies, and the discovery of a non-negligible number of extra-spinal incidentalomas with potential clinical impact, the coronal STIR should be performed systematically in routine MRI for lumbar radiculopathy.

Recommendations for terminology and the identification of neuropathic pain in people with spine-related leg pain. Outcomes from the NeuPSIG working group

ABSTRACT

Pain radiating from the spine into the leg is commonly referred to as "sciatica," "Sciatica" may include various conditions such as radicular pain or painful radiculopathy. It may be associated with significant consequences for the person living with the condition, imposing a reduced quality of life and substantial direct and indirect costs. The main challenges associated with a diagnosis of "sciatica" include those related to the inconsistent use of terminology for the diagnostic labels and the identification of neuropathic pain. These challenges hinder collective clinical and scientific understanding regarding these conditions. In this position paper, we describe the outcome of a working group commissioned by the Neuropathic Pain Special Interest Group (NeuPSIG) of the International Association for the Study of Pain (IASP) which was tasked with the following objectives: (1) to revise the use of terminology for classifying spine-related leg pain and (2) to propose a way forward on the identification of neuropathic pain in the context of spine-related leg pain. The panel recommended discouraging the term "sciatica" for use in clinical practice and research without further specification of what it entails. The term "spine-related leg pain" is proposed as an umbrella term to include the case definitions of somatic referred pain and radicular pain with and without radiculopathy. The panel proposed an adaptation of the neuropathic pain grading system in the context of spine-related leg pain to facilitate the identification of neuropathic pain and initiation of specific management in this patient population.

Low-back related leg pain: is the nerve guilty? How to differentiate the underlying pain mechanism

Low back pain (LBP) that radiates to the leg is not always related to a lesion or a disease of the nervous system (neuropathic pain): it might be nociceptive (referred) pain. Unfortunately, patients with low-back related leg pain are often given a variety of diagnoses (e.g. 'sciatica'; 'radicular pain'; pseudoradicular pain"). This terminology causes confusion and challenges clinical reasoning. It is essential for clinicians to understand and recognize predominant pain mechanisms. This paper describes pain mechanisms related to low back-related leg pain and helps differentiate these mechanisms in practice using clinical based scenarios. We illustrate this by using two clinical scenarios including patients with the same symptoms in terms of pain localization (i.e. low-back related leg pain) but with different underlying pain mechanisms (i.e. nociceptive versus neuropathic pain).

Pain-related interference and pain-related psychosocial factors of three different subgroups of patients with chronic low back pain

BACKGROUND

Low back pain (LBP) subgroup identification and management are a research priority. The clarification of subgroup differences could assist clinicians in clinical decisions contributing to a tailored treatment.

OBJECTIVES

To compare pain-related interference and pain-related psychosocial factors among subgroups of chronic low back pain (localised low back pain, peripheral neuropathic back pain, and widespread pain).

DESIGN

Cross-sectional study.

METHODS

A cross-sectional study was conducted on 444 participants with chronic low back pain. Pain-related interference was investigated by the Brief Pain Inventory and Patient-Specific Functional Scale. Pain-related psychosocial factors assessment included psychosocial factors from Brief Screening Questions and maladaptive beliefs from Back Beliefs Questionnaire, self-efficacy, and expectation questions. Participants' characteristics, pain-related interference, and pain-related psychosocial factors were compared among the three groups.

RESULTS

A one-way ANCOVA presented statistically significant differences among the groups for current pain intensity [F(2,441) = 6.77, p = 0.001], pain duration [F(2,425) = 9.83, p < 0.001], pain-related interference by Brief Pain Inventory [F(2,441) = 11.97, p < 0.001], and pain-related psychosocial factors regarding symptoms of anxiety [F(2,441) = 3.85, p = 0.022], symptoms of depression [F(2,441) = 6.74, p = 0.001], social isolation [F(2,441) = 6.54, p = 0.002], catastrophising [F(2,441) = 9.72, p < 0.001], perceived stress [F(2,441) = 3.93, p = 0.020], maladaptive beliefs [F(2,441) = 6.89, p = 0.001], and expectation [F(2,441) = 6.66, p = 0.001].

CONCLUSION

Participants with widespread pain presented higher pain-related interference and pain-related psychosocial factors compared to the localised low back pain group. Participants with peripheral neuropathic back pain and widespread pain presented with similar characteristics.

Reliability of the straight leg raise test for suspected lumbar radicular pain: A systematic review with meta-analysis

BACKGROUND

The passive straight leg raise (SLR) and crossed SLR are recommended tests for lumbar radicular pain. There are no recent reviews of test reliability.

OBJECTIVES

To summarize SLR and crossed SLR reliability in patients with suspected lumbar radicular pain.

DESIGN

Systematic review with meta-analysis.

METHOD

MEDLINE and CINAHL were searched for studies published before April 2021 that reported SLR or crossed SLR reliability in patients with low back-related leg pain. Supplemental analyses also included patients with low back pain only. Study selection, risk of bias assessment (QAREL), and data extraction were performed in duplicate. Kappa, intraclass correlation coefficients, and smallest detectable difference (SDD₉₅) quantified reliability. Meta-analysis was performed when appropriate. Confidence in the evidence was determined by applying GRADE principles.

RESULTS/FINDINGS

Fifteen studies met selection criteria. One-hundred-eighty-nine participants had low back-related leg pain. Four-hundred-thirty-nine were included in supplemental analyses. Meta-analyses showed at least fair inter-rater reliability when a positive SLR required provocation of lower extremity symptoms or pain. SLR reliability was at least moderate when testing included structural differentiation (e.g., ankle dorsiflexion). A low prevalence of positive crossed SLR tests led to wide-ranging reliability estimates. Confidence in the evidence for identifying a positive SLR or crossed SLR was moderate to very low. SDD₉₅ values for different raters measuring SLR range of motion ranged from 13 to 20°.

CONCLUSIONS

Reliability data support testing SLR with structural differentiation manoeuvres. Crossed SLR reliability data are inconclusive. Measurement error likely prohibits using SLR range of motion for clinical decision-making.

Global prevalence of sarcopenia and severe sarcopenia: a systematic review and meta-analysis

BACKGROUND

Sarcopenia is defined as the loss of muscle mass and strength. Despite the seriousness of this disease, a single diagnostic criterion has not yet been established. Few studies have reported the prevalence of sarcopenia globally, and there is a high level of heterogeneity between studies, stemmed from the diagnostic criteria of sarcopenia and the target population. The aims of this systematic review and meta-analysis were (i) to identify and summarize the diagnostic criteria used to define sarcopenia and severe sarcopenia and (ii) to estimate the global and region-specific prevalence of sarcopenia and severe sarcopenia by sociodemographic factors.

METHODS

Embase, MEDLINE, and Web of Science Core Collections were searched using relevant MeSH terms. The inclusion criteria were cross-sectional or cohort studies in individuals aged ≥18 years, published in English, and with muscle mass measured using dual-energy x-ray absorptiometry, bioelectrical impedance, or computed tomography (CT) scan. For the meta-analysis, studies were stratified by diagnostic criteria (classifications), cut-off points, and instruments to assess muscle mass. If at least three studies reported the same classification, cut-off points, and instrument to measure muscle mass, they were considered suitable for meta-analysis. Following this approach, 6 classifications and 23 subgroups were created. Overall pooled estimates with inverse-variance weights obtained from a random-effects model were estimated using the metaprop command in Stata.

RESULTS

Out of 19 320 studies, 263 were eligible for the narrative synthesis and 151 for meta-analysis (total n = 692 056, mean age: 68.5 years). Using different classifications and cut-off points, the prevalence of sarcopenia varied between 10% and 27% in the studies included for meta-analysis. The highest and lowest prevalence were observed in Oceania and Europe using the European Working Group on Sarcopenia in Older People (EWGSOP) and EWGSOP2, respectively. The prevalence ranged from 8% to 36% in individuals <60 years and from 10% to 27% in ≥60 years. Men had a higher prevalence of sarcopenia using the EWGSOP2 (11% vs. 2%) while it was higher in women using the International Working Group on Sarcopenia (17% vs. 12%). Finally, the prevalence of severe sarcopenia ranged from 2% to 9%.

CONCLUSIONS

The prevalence of sarcopenia and severe sarcopenia varied considerably according to the classification and cut-off point used. Considering the lack of a single diagnostic for sarcopenia, future studies should adhere to current guidelines, which would facilitate the comparison of results between studies and populations across the globe.

Development of a clinical prediction model to inform clinical decision making for classification of patients with sciatica, based on their clinical characteristics, in the Greek health system: protocol for a prospective predictive exploratory study

INTRODUCTION

Sciatica is one of the most common reasons for seeking healthcare for musculoskeletal pain. Sciatica is primarily considered as neuropathic in nature when neural tissue in the low back is compromised, but sometimes other non-neural structures may be involved. Appropriate assessment and management are important for patients with sciatica. Therapists use several outcome measures to assess patients to inform selection of the most suitable treatment. There is limited evidence for the best treatment of sciatica, and this is likely contributed to by having no reliable algorithm to categorise patients based on their clinical characteristics to inform physiotherapy treatment. The purpose of this study is to develop a clinical prediction model to categorise patients with sciatica, in terms of early clinical outcome, based on their initial clinical characteristics.

METHODS AND ANALYSIS

A prospective observational multicentre design will recruit consecutive patients (n=467) with sciatica referred for physiotherapy. Each patient will be evaluated to determine whether or not they will be accepted into the study by answering some questions that will confirm the study's eligibility criteria. Patients' basic characteristics, patient-reported outcome measures and performance-based measures will be collected at baseline from multiple sites in the Greek territory using this same protocol, prior to commencement of treatment. The main researcher of this study will be responsible for data collection in all sites. On completion of the standard referred physiotherapy treatment after 3 weeks' time, participants will be asked by telephone to evaluate their outcome using the Global Perceived Effect Scale. For the descriptive statistical analysis, the continuous variables will be expressed in the form of 'mean' and 'SD'. In order to assess the prognostic value of each predictor, in terms of the level of improvement or worsening of the symptoms, multiple variable regression analysis will be used.

ETHICS AND DISSEMINATION

Τhis study is approved from the Ethics and Deontology Committee of the University of West Attica, Athens, Greece, protocol number: 38313-09/06/2020, 10226-10/02/2021. The study's findings will be published in a peer-reviewed journal and disseminated at national and international conferences and through social media.

PROSPERO REGISTRATION NUMBER

CRD42020168467.

Effect of Neural Mobilization Exercises in Patients With Low Back-Related Leg Pain With Peripheral Nerve Sensitization: A Prospective, Controlled Trial

Objective

The aim of this study was to investigate the short-term effect of slider and tensioner exercises on pain and range of motion (ROM) of straight leg raise (SLR) and slump tests in patients with low back-related leg pain with peripheral nerve sensitization.

Methods

In this prospective, controlled trial, 51 patients with low back-related leg pain with peripheral nerve sensitization were divided into 3 treatment groups: slider (slider neural mobilization exercise + transcutaneous electric nerve stimulation [TENS]), tensioner (tensioner neural mobilization exercise + TENS), and control (only TENS). Each patient received 6 sessions over 2 weeks. The following outcomes were measured at baseline and after the first, third, and sixth sessions: visual analog scale (VAS) for pain and ROM of SLR and slump tests were performed for the symptomatic side.

Results

Compared with controls, patients receiving the slider and tensioner exercises showed a greater decrease in pain at the third and sixth sessions (mean difference: ≥1.54 cm; 95% CI, 0.1-3.9). There was a significant difference in the ROM of the SLR test between the slider and controls at only the sixth session (mean difference: 16.7°; 95% CI, -29.2 to -4.3). Patients in the slider and tensioner groups demonstrated greater improvements in the ROM of slump test at all sessions compared with controls (mean difference: ≥12.5°; 95% CI, -32.1 to -6.4). There were no significant differences between the slider and tensioner groups in any outcome at any session.

Conclusion

Patients in both slider and tensioner neural mobilization exercise groups demonstrated improvements in pain and ROM in patients with low back-related leg pain with peripheral nerve sensitization compared to those in the control group.

Frequency-Specific Blood Oxygen Level Dependent Oscillations Associated With Pain Relief From Ankle Acupuncture in Patients With Chronic Low Back Pain

Objective: Recent advances in brain imaging have deepened our knowledge of the neural activity in distinct brain areas associated with acupuncture analgesia. However, there has not been conclusive research into the frequency-specific resting-state functional changes associated with acupuncture analgesia in patients with chronic pain. Here, we aimed to characterize changes across multiple frequencies of resting-state cortical activity associated with ankle acupuncture stimulation (AAS) in patients with chronic low back pain (CLBP) and healthy controls.

Methods: Twenty seven patients with CLBP and Twenty five age- and gender-matched healthy volunteers were enrolled in the study. Participants received tactile sham acupuncture (TSA) and AAS, respectively. The whole-brain amplitude of low-frequency fluctuation (ALFF) in the range 0.01–0.25 Hz was assessed for changes associated with each intervention. Further, a visual analog scale (VAS) was used to collect subjective measures of pain intensity in patients. Linear mixed-effect modeling (LME) was used to examine the mean ALFF values of AAS and TSA between patients and healthy controls.

Results: The ALFF was modulated in the default mode network (an increase in the medial prefrontal cortex, and a decrease in the cerebellum/posterior ingulate/parahippocampus, P < 0.01, corrected) in both patients and controls. Decreased ALFF in the bilateral insular was frequency-dependent. Modulations in the cerebellum and right insular were significantly correlated with VAS pain score after AAS (P < 0.01).

Conclusion: Hence, frequency-specific resting-state activity in the cerebellum and insular was correlated to AAS analgesia. Our frequency-specific analysis of ALFF may provide novel insights related to pain relief from acupuncture.

A qualitative exploration of patient experiences of medication for sciatica

BACKGROUND

Sciatica is often a painful and disabling condition, with medication routinely the first line of management. It is important to describe patients experiences of taking medication for sciatica, the reasons for commencing and reasons for cessation, the effects of the medication in symptom management and any other potential positive or deleterious effects.

OBJECTIVES

To describe patient experiences of medication for the relief of symptoms of sciatica.

STUDY DESIGN

Qualitative analysis of data from a mixed-methods randomised controlled pilot study.

METHODS

A total of 46 semi-structured interviews were conducted with 33 consenting participants (19 female) recruited from 14 GP practices. A purposive sampling strategy ensured a range of age, severity of pain and disability. Interviews were recorded and transcribed verbatim prior to thematic analysis, which aimed to identify the important, interesting or divergent views within the data.

FINDINGS

Participant experiences of pain were often severe with significant disability and fear. The use of a combination of medications was common, including the use of opioids and other medication inconsistent with national (NICE) guidance. Most participants found medication ineffective and reported significant side-effects, often necessitating cessation of the drugs or the use of alternatives. Despite the regularity of participants stopping all medication for sciatica, their pain levels still significantly eased over the 6-month period of the study.

CONCLUSIONS

The study highlighted a lack of perceived effectiveness for prescribed medication, often with concomitant side-effects. Clinicians should be cognisant of the fears that patients hold in terms of the cause and severity of sciatica, as well as fears of prescribed medication.

Axially Loaded Magnetic Resonance Imaging Identification of the Factors Associated with Low Back-Related Leg Pain

This retrospective observational study was conducted to identify factors associated with low back-related leg pain (LBLP) using axially loaded magnetic resonance imaging (AL-MRI). Ninety patients with low back pain (LBP) underwent AL-MRI of the lumbar spine. A visual analog scale and patient pain drawings were used to evaluate pain intensity and location and determine LBLP cases. The values of AL-MRI findings were analyzed using a logistic regression model with a binary dependent variable equal to one for low back-related leg pain and zero otherwise. Logistic regression results suggested that intervertebral joint effusion (odds ratio (OR) = 4.58; p = 0.035), atypical ligamenta flava (OR = 5.77; p = 0.003), and edema of the lumbar intervertebral joint (OR = 6.41; p = 0.003) were more likely to be present in LBLP patients. Advanced disc degeneration (p = 0.009) and synovial cysts (p = 0.004) were less frequently observed in LBLP cases. According to the AL-MRI examinations, the odds of having LBLP are more likely if facet effusion, abnormal ligamenta flava, and lumbar facet joint edema are present on imaging than if not. The assessment of lumbar spine morphology in axial loaded MRI adds value to the potential understanding of LBLP, but further longitudinal and loaded–unloaded comparative studies are required to determine the role of acute dynamic changes and instability in LBLP development.

Prevalence, Characteristics, and Clinical Course of Neuropathic Pain in Primary Care Patients Consulting With Low Back-related Leg Pain

OBJECTIVES

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

MATERIALS AND METHODS

This was a prospective cohort study. Data were collected using a standardized baseline clinical examination and self-report questionnaires at baseline, 4, 12, and 36 months. We identified cases of neuropathic pain using 3 definitions: 2 based on clinical diagnosis (sciatica, with and without evidence of nerve root compression on magnetic resonance imaging), one on the self-report version of Leeds Assessment for Neurological Symptoms and Signs. Differences between patients with and without neuropathic pain were analyzed comparing each definition. Clinical course (mean pain intensity measured as the highest of leg or back pain intensity: mean of 3 Numerical Rating Scales, each 0 to 10) was investigated using linear mixed models over 36 months.

RESULTS

Prevalence of neuropathic pain varied from 48% to 74% according to definition used. At baseline, patients with neuropathic pain had more severe leg pain intensity, lower pain self-efficacy, more patients had sensory loss than those without. Distinct profiles were apparent depending on neuropathic pain definition. Mean pain intensity reduced after 4 months (6.1 to 3.9 [sciatica]), most rapidly in cases defined by clinical diagnosis.

DISCUSSION

This research provides new information on the clinical course of neuropathic pain and a better understanding of neuropathic pain in low back-related leg pain patients consulting in primary care.

Self-efficacy as a prognostic factor and treatment moderator in chronic musculoskeletal pain patients attending pain management programmes: A systematic review

OBJECTIVE

Evidence on the effectiveness of pain management programmes (PMPs) for chronic pain patients is mixed. Self-efficacy may be associated with outcome of PMPs. The purpose of this systematic review was to assess the role of self-efficacy as a (i) prognostic factor and (ii) moderator of treatment, in chronic musculoskeletal pain (CMP) patients attending a PMP.

METHODS

A systematic review of the literature and qualitative synthesis was carried out. Six electronic databases were searched (1989-2020). Studies that measured pain self-efficacy as a prognostic factor or treatment moderator in patients with CMP, who participated in a multidisciplinary PMP were included. Study quality was appraised using the Quality in Prognosis Studies (QUIPS) tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

Six studies investigating self-efficacy as a prognostic factor were included with a total of 1881 participants. No studies were found assessing self-efficacy as a treatment moderator. Self-efficacy was a prognostic factor for physical functioning in two studies. There was weak evidence for self-efficacy as a prognostic factor for disability, health-related quality of life and pain outcomes and no evidence for psychological variables, disease severity and tender point index following PMPs. Quality of evidence was very low using the GRADE system for each outcome measure.

CONCLUSION

Baseline self-efficacy may play a role in physical function outcomes in CMP patients attending a PMP. Higher quality evidence is needed to determine the influence of self-efficacy on outcomes in this setting.

Clinical indicators to identify neuropathic pain in low back related leg pain: a modified Delphi study

BACKGROUND

Neuropathic pain (NP) is common in patients presenting with low back related leg pain. Accurate diagnosis of NP is fundamental to ensure appropriate intervention. In the absence of a clear gold standard, expert opinion provides a useful methodology to progress research and clinical practice. The aim of this study was to achieve expert consensus on a list of clinical indicators to identify NP in low back related leg pain.

METHODS

A modified Delphi method consisting of three rounds was designed in accordance with the Conducting and Reporting Delphi Studies recommendations. Recruitment involved contacting experts directly and through expressions of interest on social media. Experts were identified using pre-defined eligibility criteria. Priori consensus criteria were defined for each round through descriptive statistics. Following completion of round 3 a list of clinical indicators that achieved consensus were generated.

RESULTS

Thirty-eight participants were recruited across 11 countries. Thirty-five participants completed round 1 (92.1%), 32 (84.2%) round 2 and 30 (78.9%) round 3. Round 1 identified consensus (Kendall's W coefficient of concordance 0.456; p < 0.001) for 10 clinical indicators out of the original 14, and 9 additional indicators were added to round 2 following content analysis of qualitative data. Round 2 identified consensus (Kendall's W coefficient of concordance 0.749; p < 0.001) for 10 clinical indicators out of 19, and 1 additional indicator was added to round 3. Round 3 identified consensus for 8 indicators (Kendall's W coefficient of concordance 0.648; p < 0.001). Following completion of the third round, an expert derived consensus list of 8 items was generated. Two indicators; pain variously described a burning, electric shock like and/or shooting into leg and pain in association with other neurological symptoms (e.g. pins and needles, numbness, weakness), were found to have complete agreement amongst expert participants.

CONCLUSIONS

Good agreement was found for the consensus derived list of 8 clinical indicators to identify NP in low back related leg pain. This list of indicators provide some indication of the criteria upon which clinicians can identify a NP component to low back related leg pain; further research is needed for stronger recommendations to be made.

Diagnostic utility of patient history, clinical examination and screening tool data to identify neuropathic pain in low back related leg pain: a systematic review and narrative synthesis

BACKGROUND

Low back-related leg pain (LBLP) is a challenge for healthcare providers to manage. Neuropathic pain (NP) is highly prevalent in presentations of LBLP and an accurate diagnosis of NP in LBLP is essential to ensure appropriate intervention. In the absence of a gold standard, the objective of this systematic review was to evaluate the diagnostic utility of patient history, clinical examination and screening tool data for identifying NP in LBLP.

METHODS

This systematic review is reported in line with PRISMA and followed a pre-defined and published protocol. CINAHL, EMBASE, MEDLINE, Web of Science, Cochrane Library, AMED, Pedro and PubMed databases, key journals and the grey literature were searched from inception to 31 July 2019. Eligible studies included any study design reporting primary diagnostic data on the diagnostic utility of patient history, clinical examination or screening tool data to identify NP in LBLP, in an adult population. Two independent reviewers searched information sources, assessed risk of bias (QUADAS-2) and used GRADE to assess overall quality of evidence.

RESULTS

From 762 studies, 11 studies were included. Nine studies out of the 11 were at risk of bias. Moderate level evidence supports a cluster of eight signs (age, duration of disease, paroxysmal pain, pain worse in leg than back, typical dermatomal distribution, worse on coughing/sneezing/straining, finger to floor distance and paresis) for diagnosing lumbosacral nerve root compression, demonstrating moderate/high sensitivity (72%) and specificity (80%) values. Moderate level evidence supports the use of the StEP tool for diagnosing lumbar radicular pain, demonstrating high sensitivity (92%) and specificity (97%) values.

CONCLUSIONS

Overall low-moderate level evidence supports the diagnostic utility of patient history, clinical examination and screening tool data to identify NP in LBLP. The weak evidence base is largely due to methodological flaws and indirectness regarding applicability of the included studies. The most promising diagnostic tools include a cluster of 8 patient history/clinical examination signs and the StEP tool. Low risk of bias and high level of evidence diagnostic utility studies are needed, in order for stronger recommendations to be made.

The influence of nociceptive and neuropathic pain states on the processing of acute electrical nociceptive stimulation: A dynamic causal modeling study

INTRODUCTION

Despite the worldwide increase in prevalence of chronic pain and the subsequent scientific interest, researchers studying the brain and brain mechanisms in pain patients have not yet clearly identified the exact underlying mechanisms. Quantifying the neuronal interactions in electrophysiological data could help us gain insight into the complexity of chronic pain. Therefore, the aim of this study is to examine how different underlying pain states affect the processing of nociceptive information.

METHODS

Twenty healthy participants, 20 patients with non-neuropathic low back-related leg pain and 20 patients with neuropathic failed back surgery syndrome received nociceptive electrical stimulation at the right sural nerve with simultaneous electroencephalographic recordings. Dynamic Causal Modeling (DCM) was used to infer hidden neuronal states within a Bayesian framework.

RESULTS

Pain intensity ratings and stimulus intensity of the nociceptive stimuli did not differ between groups. Compared to healthy participants, both patient groups had the same winning DCM model, with an additional forward and backward connection between the somatosensory cortex and right dorsolateral prefrontal cortex.

DISCUSSION

The additional neuronal connection with the prefrontal cortex as seen in both pain patient groups could be a reflection of the higher attention towards pain in pain patients and might be explained by the higher levels of pain catastrophizing in these patients.

CONCLUSION

In contrast to the similar pain intensity ratings of an acute nociceptive electrical stimulus between pain patients and healthy participants, the brain is processing these stimuli in a different way.

Clinical indicators to identify neuropathic pain in low back-related leg pain: protocol for a modified Delphi study

INTRODUCTION

Neuropathic low back-related leg pain (LBLP) can be a challenge to healthcare providers to diagnose and treat. Accurate diagnosis of neuropathic pain is fundamental to ensure appropriate intervention is given. However, to date there is no gold standard to diagnose neuropathic LBLP. A Delphi study will therefore be conducted to obtain an expert-derived consensus list of clinical indicators to identify a neuropathic component to LBLP.

METHODS/ANALYSIS

Included participants will be considered experts within the field as measured against a predefined eligibility criterion. Through an iterative multistage process, participants will rate their agreement with a list of clinical indicators and suggest any missing clinical indicators during each round. Agreement will be measured using a 5-point Likert scale. Descriptive statistics will be used to measure agreement; median, IQR and percentage of agreement. A priori consensus criteria will be defined for each round. Data analysis at the end of round three will enable a list of clinical indicators to be derived.

ETHICS AND DISSEMINATION

Ethical approval was gained from the University of Birmingham (ERN_19-1142). On completion of the study, findings will be disseminated in a peer-reviewed journal and presented at relevant conferences.

Diagnostic utility of patient history, clinical examination and screening tool data to identify neuropathic pain in low back-related leg pain: protocol for a systematic review

INTRODUCTION

Neuropathic low back-related leg pain (LBLP) can be a challenge to healthcare providers to diagnose and treat. Accurate diagnosis of neuropathic pain is fundamental to ensure appropriate intervention is given. However, to date there is no gold standard to diagnose neuropathic LBLP. Patient examination guidelines and screening tools have been developed and validated for the purpose of diagnosing neuropathic pain in LBLP; however, there has been no systematic review conducted to compare the diagnostic validity of these methods. Therefore, this systematic review will investigate the diagnostic utility of patient history, clinical examination and screening tool data to identify neuropathic pain in LBLP.

METHODS AND ANALYSIS

This protocol is informed and reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis-Protocols. CINAHL, EMBASE, MEDLINE, Web of Science, Cochrane Library, AMED, Pedro, PubMed, key journals and grey literature will be searched rigorously to find diagnostic accuracy studies investigating patient examination data to identify neuropathic pain in LBLP patients. Two independent reviewers will conduct the search, extract the data and assess risk of bias for included studies using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. The overall quality of included studies will be evaluated using Grading of Recommendations, Assessment, Development and Evaluation guidelines. A meta-analysis will be conducted if deemed appropriate. Otherwise, a narrative synthesis will be conducted.

ETHICS AND DISSEMINATION

No research ethics is required for this systematic review since patient data will not be collected. This review will help to inform healthcare professionals and researchers on the most effective means in which to diagnose neuropathic pain in LBLP. Results of this review will be submitted for publication in a peer-review journal and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42019140861.

Animal models for studying the etiology and treatment of low back pain

Chronic low back pain is a major cause of disability and health care costs. Effective treatments are inadequate for many patients. Animal models are essential to further understanding of the pain mechanism and testing potential therapies. Currently, a number of preclinical models have been developed attempting to mimic aspects of clinical conditions that contribute to low back pain (LBP). This review focused on describing these animal models and the main behavioral tests for assessing pain in each model. Animal models of LBP can be divided into the following five categories: Discogenic LBP, radicular back pain, facet joint osteoarthritis back pain, muscle-induced LBP, and spontaneous occurring LBP models. These models are important not only for enhancing our knowledge of how LBP is generated, but also for the development of novel therapeutic regimens to treat LBP in patients. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1305-1312, 2018.