The Neuropathic Components of Chronic Low Back Pain: A Prospective Multicenter Study Using the DN4 Questionnaire

The usage of a modified straight-leg raise neurodynamic test and hamstring flexibility for diagnosis of non-specific low back pain: A cross-sectional study

OBJECTIVES

The main purpose of this research study was to compare mean modified straight-leg raise test (mSLR) and hamstring muscle length (HL) between chronic non-specific low back pain (LBP) and healthy subjects to understand the possibility of neuropathic causes in LBP population as it may impact the diagnosis and treatment of LBP. Another purpose was to compare mean mSLR between those with lumbar nerve root impingement and those without as determine by magnetic resonance imaging (MRI).

METHODS

The design of the study is cross sectional and included 32 subjects with ages ranging from 18-50 years old. Clinical exam objective measures were collected such as patient questionnaires, somatosensory tests, HL range of motion, and a mSLR test, and were compared to the findings from a structural lumbar spine MRI.

RESULTS

There were no significant differences in mean HL angulation and mSLR angulation between LBP and healthy subjects (p>0.05). There was no significant difference in mean HL by impingement by versus no impingement (38.3±15.6 versus 44.8±9.4, p = 0.08, Cohen's d = 0.50). On the other hand, there was a significant difference in mean mSLR angulation by impingement (57.6.3±8.7 versus 63.8±11.6, p = 0.05, Cohen's d = 0.60).

CONCLUSIONS

The mSLR test was found to be associated with lumbar nerve root compression, regardless of the existence of radiating leg symptoms, and showed no association solely with the report of LBP. The findings highlight the diagnostic dilemma facing clinicians in patients with chronic nonspecific LBP with uncorrelated neuroanatomical image findings. Clinically, it may be necessary to reevaluate the common practice of exclusively using the mSLR test for patients with leg symptoms. This study may impact the way chronic LBP and neuropathic symptoms are diagnosed, potentially improving treatment methods, reducing persistent symptoms, and ultimately improving disabling effects.

Usefulness of the DN4, S-LANSS, and painDETECT screening questionnaires to detect the neuropathic pain components in people with acute whiplash-associated disorders: a cross-sectional study

OBJECTIVE

Although the presence of neuropathic pain (NP) components has been reported in whiplash-associated disorders (WAD), no studies have analyzed the usefulness of NP screening questionnaires to detect NP components in WAD. This study aimed to assess the usefulness of 3 NP screening tools (Douleur Neuropathique 4 [DN4], self-administered Leeds Assessment of Neuropathic Symptoms and Signs [S-LANSS], and painDETECT questionnaire [PDQ]) to detect the presence of NP components in acute WAD.

DESIGN

A cross-sectional study.

SETTING

Hospital.

SUBJECTS

Of 188 eligible individuals, 50 people (68% women, mean age = 40.3 ± 12.5 years) with acute WAD (52% Grade III) were included.

METHODS

Specialized physicians initially screened participants for the presence of NP components according to clinical practice and international recommendations. After physician assessment, blinded investigators used NP screening questionnaires (DN4, S-LANSS, and PDQ) to assess participants within 2 weeks of their accident. The diagnostic accuracy of these tools was analyzed and compared with the reference standard (physicians' assessments).

RESULTS

The 3 screening questionnaires showed excellent discriminant validity (area under the curve: ≥0.8), especially S-LANSS (area under the curve: 0.9; P < .001). DN4 demonstrated the highest sensitivity (87%), followed by S-LANSS (75%), while S-LANSS and PDQ showed the highest specificity (85% and 82%, respectively). These tools demonstrated a strong correlation with the reference standard (S-LANSS: rho = 0.7; PDQ: rho = 0.62; DN4: rho = 0.7; all, P < .001).

CONCLUSIONS

The DN4, S-LANSS, and PDQ show excellent discriminant validity to detect the presence of NP components in acute WAD, especially S-LANSS. Initial screening with these tools might improve management of WAD.

Reliability of a clinical sensory test battery in patients with spine-related leg and arm pain

BACKGROUND

The current standard to evaluate the presence of somatosensory dysfunctions is quantitative sensory testing, but its clinical utility remains limited. Low-cost and time-efficient clinical sensory testing (CST) batteries have thus been developed. Recent studies show moderate to substantial reliability in populations with neuropathic pain. This study evaluates the inter- and intra-tester reliability of people with spine-related leg and arm pain, representing mixed pain mechanisms.

METHODS

Fifty-three patients with spine-related leg (n = 41) and arm pain (n = 12) attended three CST sessions. The CST battery consisted of eleven tests, determining loss and gain of sensory nerve function. CST was performed by the same investigator twice and by an additional investigator to determine inter- and intra-tester reliability. Fleiss' (inter-tester) and Cohen's (intra-tester) kappa were calculated for dichotomized and intraclass correlation coefficients (ICC) for continuous outcomes.

RESULTS

Fleiss' kappa varied among modalities from fair to substantial (κ = 0.23-0.66). Cold, warm, and vibration detection thresholds and cold and pressure pain thresholds reached kappa >0.4 (moderate to substantial reliability). Cohen's kappa ranged from moderate to substantial (κ = 0.45-0.66). The reliability of the windup ratio was poor (ICC <0.18).

CONCLUSION

CST modalities with moderate to substantial inter-tester reliability could be of benefit as a screening tool. The moderate to substantial intra-tester reliability for all sensory modalities (except windup ratio) supports their potential use in clinical practice and research to monitor somatosensory changes over time in patients with spine-related limb pain of mixed pain mechanisms.

SIGNIFICANCE

We already know that most modalities of clinical sensory test (CST) batteries achieve moderate to substantial inter- and intra-tester reliability in populations with neuropathic pain. This study evaluates the reliability of a CST battery in populations with mixed pain mechanisms. We found inter-tester reliability varied from poor to substantial for sensory modalities, questioning the value of some CST modalities. The CST battery showed moderate to substantial intra-tester reliability, suggesting its usefulness to monitor sensory changes over time in this cohort.

Pain quality patterns in delayed onset muscle soreness of the lower back suggest sensitization of fascia rather than muscle afferents: a secondary analysis study

Delayed onset muscle soreness (DOMS) of the lower back is considered a surrogate for acute low back pain (aLBP) in experimental studies. Of note, it is often unquestioningly assumed to be muscle pain. To date, there has not been a study analyzing lumbar DOMS in terms of its pain origin, which was the aim of this study. Sixteen healthy individuals (L-DOMS) were enrolled for the present study and matched to participants from a previous study (n = 16, L-PAIN) who had undergone selective electrical stimulation of the thoracolumbar fascia and the multifidus muscle. DOMS was induced in the lower back of the L-DOMS group using eccentric trunk extensions performed until exhaustion. On subsequent days, pain on palpation (100-mm analogue scale), pressure pain threshold (PPT), and the Pain Sensation Scale (SES) were used to examine the sensory characteristics of DOMS. Pain on palpation showed a significant increase 24 and 48 h after eccentric training, whereas PPT was not affected (p > 0.05). Factor analysis of L-DOMS and L-PAIN sensory descriptors (SES) yielded a stable three-factor solution distinguishing superficial thermal ("heat pain ") from superficial mechanical pain ("sharp pain") and "deep pain." "Heat pain " and "deep pain" in L-DOMS were almost identical to sensory descriptors from electrical stimulation of fascial tissue (L-PAIN, all p > 0.679) but significantly different from muscle pain (all p < 0.029). The differences in sensory description patterns as well as in PPT and self-reported DOMS for palpation pain scores suggest that DOMS has a fascial rather than a muscular origin.

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.

Efficacy of conditioned autologous serum therapy (Orthokine®) on the dorsal root ganglion in patients with chronic radiculalgia: study protocol for a prospective randomized placebo-controlled double-blind clinical trial (RADISAC trial)

BACKGROUND

Pulsed radiofrequency (PRF) treatment on the dorsal root ganglion (DRG) has been proposed as a good option for the treatment of persistent radicular pain based on its effect of neuromodulation on neuropathic pain. Autologous conditioned serum (ACS) therapy is a conservative treatment based on the patient's own blood. The aim of this manuscript is to develop a study protocol using ACS on the DRG as a target for its molecular modulation.

METHODS

We plan to conduct a randomized controlled study to compare the efficacy of PRF therapy plus ACS versus PRF therapy plus physiological saline 0.9% (PhS) on the DRG to reduce neuropathic pain in patients with persistent lower limb radiculalgia (LLR) and to contribute to the functional improvement and quality of life of these patients. Study participants will include patients who meet study the inclusion/exclusion criteria. Eligible patients will be randomized in a 1:1 ratio to one of treatment with PRF plus ACS (experimental group) or PRF plus PhS (placebo group). The study group will consist of 70 patients (35 per group) who have experienced radicular pain symptoms for ≥ 6 months' duration who have failed to respond to any therapy. Both groups will receive PRF on the DRG treatment before the injection of the sample (control or placebo). Patient assessments will occur at baseline, 1 month, 3 months, 6 months, and 12 months after therapy. The primary efficacy outcome measure is Numeric Pain Rating Scale (NPRS) responders from baseline to 12 months of follow-up using validated minimal important change (MIC) thresholds. A reduction of ≥ 2 points in NPRS is considered a clinically significant pain relief. The secondary efficacy outcome measure is the proportion of Oswestry Low Back Pain Disability Scale (ODS) responders from baseline to 12 months of follow-up in the experimental group (PRF plus ACS) versus the placebo group (PRF plus PhS). ODS responders are defined as those patients achieving the validated MIC of ≥ 10-point improvement in ODS from baseline to 12 months of follow-up as a clinically significant efficacy threshold.

DISCUSSION

This prospective, double-blind, randomized placebo-controlled study will provide level I evidence of the safety and effectiveness of ACS on neuropathic symptoms in LLR patients. TRIAL REGISTRATION {2A}{2B}: EUDRACT number: 2021-005124-38. Validation date: 13 November 2021. Protocol version {3}: This manuscript presents the 2nd protocol version.

The PATIENT Approach: A New Bundle for the Management of Chronic Pain

BACKGROUND

Chronic pain is one of the most challenging diseases for physicians as its etiology and manifestations can be extremely varied. Many guidelines have been published and many therapeutic options are nowadays available for the different types of pain. Given the enormous amount of information that healthcare providers must handle, it is not always simple to keep in mind all the phases and strategies to manage pain. We here present the acronym PATIENT (P: patient's perception; A: assessment; T: tailored approach; I: iterative evaluation; E: education; N: non-pharmacological approach; T: team), a bundle which can help to summarize all the steps to follow in the management of chronic pain.

METHODS

We performed a PubMed search with a list of terms specific for every issue of the bundle; only English articles were considered.

RESULTS

We analyzed the literature investigating these topics to provide an overview of the available data on each bundle's issue; their synthesis lead to an algorithm which may allow healthcare providers to undertake every step of a patient's evaluation and management.

DISCUSSION

Pain management is very complex; our PATIENT bundle could be a guide to clinicians to optimize a patient's evaluation and treatment.

Deep RNA-seq of male and female murine sensory neuron subtypes after nerve injury

ABSTRACT

Dorsal root ganglia (DRG) neurons have been well described for their role in driving both acute and chronic pain. Although nerve injury is known to cause transcriptional dysregulation, how this differs across neuronal subtypes and the impact of sex is unclear. Here, we study the deep transcriptional profiles of multiple murine DRG populations in early and late pain states while considering sex. We have exploited currently available transgenics to label numerous subpopulations for fluorescent-activated cell sorting and subsequent transcriptomic analysis. Using bulk tissue samples, we are able to circumvent the issues of low transcript coverage and drop-outs seen with single-cell data sets. This increases our power to detect novel and even subtle changes in gene expression within neuronal subtypes and discuss sexual dimorphism at the neuronal subtype level. We have curated this resource into an accessible database for other researchers ( https://livedataoxford.shinyapps.io/drg-directory/ ). We see both stereotyped and unique subtype signatures in injured states after nerve injury at both an early and late timepoint. Although all populations contribute to a general injury signature, subtype enrichment changes can also be seen. Within populations, there is not a strong intersection of sex and injury, but previously unknown sex differences in naïve states-particularly in Aβ-RA + Aδ-low threshold mechanoreceptors-still contribute to differences in injured neurons.

Does the presence of radiculopathy affect sleep quality and lower extremity functionality in neuropathic low back pain?

OBJECTIVE

Sleep disturbance in chronic neuropathic low back pain is a well-known condition. In this study, we aimed to investigate the effect of lumbar radiculopathy on sleep quality and lower extremity functionality in the presence of neuropathic low back pain.

METHODS

A total of 79 patients diagnosed with disk herniation, needle electromyography, and neuropathic pain were included in the study. Visual Analog Scale, Pittsburg Sleep Quality Index, and Lower Extremity Functionality Scale were applied to the patients.

RESULTS

Of the 79 patients who participated in the study, 34 (43%) were females and 45 (57%) were males. No significant difference was found between the group with and without radiculopathy in terms of sleep quality and lower extremity functionality (p=0.245 and p=0.092, respectively). In our study, a negative correlation was found between night pain and the presence of radiculopathy (p=0.006). The number of lumbar herniated disk levels was higher in the group without radiculopathy and was statistically significant (p=0.023).

CONCLUSION

We found that the presence of radiculopathy did not affect sleep quality and lower extremity functionality in disk herniation patients with neuropathic pain. Although it was not statistically significant in our study, we think that the degree of herniation may affect sleep and lower extremity functionality rather than the number of disk herniation levels with the available data. The fact that neuropathic pain is not limited to disk herniation and radiculopathy, and that neuropathic pain is intertwined with clinical conditions such as anxiety, sleep disorders, and depression are among the conditions that make the studies difficult.

Immediate effect of passive hamstring stretching on flexibility and relationship with psychosocial factors in people with chronic low back pain

Background

Hamstring muscle tightness contributes to disability in people with chronic low back pain (CLBP). HM stretching improves flexibility in healthy individuals, but the immediate effect of stretching is unknown in people with CLBP. Moreover, the stretching effect could be influenced by psychosocial factors.

Objectives

To evaluate the immediate effect of passive HM stretching on flexibility in people with CLBP and the relationships between psychosocial factors and change in hamstring flexibility.

Design

Non-randomized, pilot trial.

Method

One minute of passive stretching was performed in 90 people with CLBP. Change in Active Knee Extension and Straight Leg Raise angles (digital inclinometer), and Fingertips-to-Floor distance (measuring tape) were measured before and immediately after stretching. Correlations between change in flexibility and baseline Fear-Avoidance Beliefs Questionnaire (FABQ) and Hospital Anxiety and Depression Scale (HADS) scores were analyzed.

Results

Hamstring flexibility improved significantly after stretching; Active Knee Extension mean difference was 4° (95% CI, 2.4 to 5.1; p < 0.001, right ES = 0.24, left ES = 0.23); Straight Leg Raise mean difference was 7° (95% CI, 5.5 to 8.6, p < 0.001, right ES = 0.44, left ES = 0.42), Fingertips-to-Floor mean difference was 2 cm (95% CI, 1.7 to 3.0, p < 0.001, ES = 0.20). No correlation was found between improvement in any of the hamstring flexibility measurements and FABQ or HADS scores (p > 0.05).

Conclusions

Passive hamstring stretching induced an immediate, statistically significantly improvement in hamstring flexibility, but only the change in Straight Leg Raise amplitude was clinically important. Psychosocial factors were not related to improvements in flexibility after hamstring stretching.

Diagnosis and Management of Neuropathic Pain in Spine Diseases

Neuropathic pain is generally defined as a non-physiological pain experience caused by damage to the nervous system. It can occur spontaneously, as a reaction to a given stimulus, or independently of its action, leading to unusual pain sensations usually referred to as firing, burning or throbbing. In the course of spine disorders, pain symptoms commonly occur. According to available epidemiological studies, a neuropathic component of pain is often present in patients with spinal diseases, with a frequency ranging from 36% to 55% of patients. Distinguishing between chronic nociceptive pain and neuropathic pain very often remains a challenge. Consequently, neuropathic pain is often underdiagnosed in patients with spinal diseases. In reference to current guidelines for the treatment of neuropathic pain, gabapentin, serotonin and norepinephrine reuptake inhibitors and tricyclic antidepressants constitute first-line therapeutic agents. However, long-term pharmacologic treatment often leads to developing tolerance and resistance to used medications. Therefore, in recent years, a plethora of therapeutic methods for neuropathic pain have been developed and investigated to improve clinical outcomes. In this review, we briefly summarized current knowledge about the pathophysiology and diagnosis of neuropathic pain. Moreover, we described the most effective treatment approaches for neuropathic pain and discussed their relevance in the treatment of spinal pain.

Minimal clinically important difference as a method for assessing the effectiveness of spinal surgery using scales and questionnaires: non-systematic literature review

Objective. To analyze the literature data and to present recommendations on the use of the minimum clinically important difference (MCID) in the practice of spinal surgeon-researcher.

Material and Methods. The article is a non-systematic review of the literature. A search was performed for sources, which describe the calculation and analysis of the MCID parameter on a cohort of patients with degenerative spinal diseases in the PubMed, Scopus and Web of Science databases. Further, the analysis of the literature was carried out on the application of MCID to assess the effectiveness of surgical treatment.

Results. The MCID parameter is illustrated for the most common clinical scales used to assess the effectiveness of treatment in spinal surgery, with their detailed description and discussion of their benefits and drawbacks. The specific MCID values for cervical and lumbar pathologies, first of all degenerative ones, and follow-up periods, which can be used in assessing the results of the treatment, as well as in planning prospective comparative studies are presented.

Conclusion. The MCID parameter is required for sample size calculation and for the analysis of treatment outcomes. The MCID reflects not just the change in the baseline indicator, but also the clinical significance for the patient.

Neuropathic Pain Component in Patients with Cervical Radicular Pain: A Single-Center Retrospective Study

Background and Objectives: Evidence regarding the prevalence of neuropathic pain in patients with cervical radicular pain is limited. This study aimed to investigate the prevalence of neuropathic pain components in patients with cervical radicular pain using established screening tools and identify the relationship between neuropathic pain components and clinical factors. Materials and Methods: Data from 103 patients (aged ≥ 20 years) with cervical radicular pain who visited our pain clinic were analyzed retrospectively. Demographic characteristics, history of neck surgery, pain intensity using numeric rating score, dominant pain site, duration of symptoms, and neck disability index were assessed. The prevalence of neuropathic pain components was defined according to the Douleur Neuropathique 4 questions and painDETECT questionnaire tools. Patient characteristics were compared using the chi-square test or Fisher’s exact test for categorical variables and the independent t-test or Mann−Whitney U test for continuous variables. The correlation between neck disability index and other variables was analyzed using Pearson’s correlation coefficient. Results: Of the 103 patients, 29 (28.1%) had neuropathic pain components. The neck disability index was significantly higher (p < 0.001) for patients in the neuropathic pain group (23.79 ± 6.35) than that in the non- neuropathic pain group (18.43 ± 7.68). The Douleur Neuropathique 4 questions (r = 0.221, p < 0.025) and painDETECT questionnaire (r = 0.368, p < 0.001) scores positively correlated with the neck disability index score. Conclusions: The prevalence of neuropathic pain components in patients with cervical radicular pain was low. The patients in our study showed a strong correlation between functional deterioration and their neuropathic pain screening score. This study may be useful in understanding the characteristics of cervical radicular pain.

Disentangling 'sciatica' to understand and characterise somatosensory profiles and potential pain mechanisms

OBJECTIVES

The study aimed to investigate if patients with lumbar radicular pain only and those with combined lumbar radicular pain + radiculopathy differ in their somatosensory profiles and pain experiences.

METHODS

Quantitative sensory testing (QST) was performed in 26 patients (mean age 47 ± 10 years, 10 females) with unilateral leg pain in the L5 or S1 distribution in their main pain area (MPA) and contralateral mirror side, in the relevant foot dermatome on the symptomatic side and in the hand dorsum. Pain experience was captured on the painDETECT.

RESULTS

Eight patients presented with lumbar radicular pain only and 18 patients with combined radicular pain + radiculopathy. Patients with radicular pain only demonstrated widespread loss of function (mechanical detection) bilaterally in the MPA (p<0.003) and hand (p=0.002), increased heat sensitivity in both legs (p<0.019) and cold/heat sensitivity in the hand (p<0.024). QST measurements in the dermatome did not differ compared to HCs and patients with radiculopathy. Patients with lumbar radiculopathy were characterised by a localised loss of function in the symptomatic leg in the MPA (warm, mechanical, vibration detection, mechanical pain threshold, mechanical pain sensitivity p<0.031) and dermatome (mechanical, vibration detection p<0.001), consistent with a nerve root lesion. Pain descriptors did not differ between the two groups with the exception of numbness (p<0.001). Patients with radicular pain did not report symptoms of numbness, while 78% of patients with radiculopathy did.

CONCLUSIONS

Distinct differences in somatosensory profiles and pain experiences were demonstrated for each patient group, suggesting differing underlying pain mechanisms.

Assessment of the neuropathic component in a chronic low back pain syndrome

Background/Aim. Chronic low back pain syndrome (CLBPS) is the most common cause of functional disability and loss of working ability in developed countries. Some research shows that neuropathic pain (NP) is present in almost 50% of patients with CLPBS. The aim of this study was to determine the characteristics of NP and its impact on quality of life (QoL) in patients with CLBPS. Methods. Patients were tested using three questionnaires for NP: Pain Detect Questionnaire, Leeds Assessment of Neuropathic Symptoms and Signs, and Douleur Neuropathique 4 questions. Thirty-two patients diagnosed with NP based on current clinical criteria and with positive results for NP on all three NP questionnaires formed an experimental group. A control group consisted of 32 patients with CLBPS who did not fulfill clinical criteria for NP and were negative for NP on all three questionnaires. Hamilton depression and anxiety rating scales (Ham-D and Ham-A, respectively) and Short Form (SF)-36 questionnaire were also applied. Results. According to magnetic resonance imaging (MRI), disc herniation was typically detected in the experimental group, while degenerative changes were commonly found in the control group. Patients from the experimental group had significantly greater intensity of pain, pain radiation in the legs, and the pain was usually presented as episodes of sudden attacks with mild pain between them. The most distinctive features of NP were allodynia, electric shock sensation, and hypoesthesia to prick. Patients from the experimental group also had significantly higher depression and anxiety scores, as well as worse QoL compared to the control group, especially in mental domains. Predictors of worse QoL in the patients with CLBPS were a higher level of anxiety and depression. Conclusion. The presence of allodynia, electric shock-like sensations, and hypoesthesia to prick in patients with CLBPS suggest NP. CLBPS patients with NP had worse scores in mental domains of QoL compared to CLPBS patients without NP.

Transforaminal Epidural Steroid Injection Improves Neuropathic Pain in Lumbar Radiculopathy: A Prospective, Clinical Study

Objective

This study aims to evaluate the effects of transforaminal epidural steroid injection (TFESI) on neuropathic pain (NP) in patients with chronic unilateral radiculopathy due to lumbar disc herniation (LDH).

Patients and Methods

Between September 2018 and April 2019, a total of 61 patients who were diagnosed with unilateral/unilevel radiculopathy due to LDH and were scheduled for single-level TFESI were included in this study. The Numeric Rating Scale (NRS), modified Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), and NP-Douleur Neuropathique 4 Questionnaire (DN4) were used before the procedure and at 1 hour, 3 weeks, and 3 months after the procedure.

Results

There was a significant decrease in the NRS and significant improvement in the ODI, BDI, and DN4 scores in all patients at all postprocedural timepoints (P < 0.05). The number of patients with NP decreased from 35 (60.3%) at baseline to 23 (41.2%) at 3 months (P = 0.001). The NRS scores were similar at 3 weeks and 3 months between the patients with and without NP (P > 0.05). The ODI scores were significantly higher at 3 months in the patients with NP than those without NP (P = 0.013). The BDI scores at baseline, 3 weeks, and 3 months were significantly higher in the patients with NP than those without NP (P < 0.001, P = 0.016, and P = 0.016, respectively).

Conclusion

Our study results suggest that TFESI is an effective and safe method to decrease not only nociceptive but also NP component in patients with chronic radiculopathy due to LDH. Clinicians should keep in mind that NP is a risk factor that adversely affects the TFESI success and patients should be evaluated before the procedure.

The frequency of neuropathic pain in Turkish patients with low back pain: a cross-sectional study

The aim of this study was to evaluate the frequency of neuropathic pain (NP) in patients with low back pain (LBP) and the relationship of NP with demographic characteristics and pain duration. Four hundred and forty patients were evaluated with respect to NP. Demographic data were collected and Douleur Neuropathique 4 Questions (DN4) questionnaire was used to identify NP. Any difference in demographic characteristics or duration of pain was investigated between the patients with and without NP. Sociodemographic factors which are independently associated with NP were analyzed. According to DN4, 43.9% of the patients had NP. Mean age of the patients was 44.8 years (± 13.7). 343 (77.9%) of the patients had chronic LBP (more than 3 months). The patients with NP were older (p < 0.001), had higher BMI (p = 0.005) and longer LBP duration (p < 0.001) and had lower educational level (p 0.018). NP was significantly more common in unemployed patients and less common in high-activity employees (p 0.001). Logistic regression analyses identified that high-active workers' risk of having NP was 1.76 times lesser than other groups (office workers, housewives and retired patients). Nearly half of the patients with LBP were accompanied by NP. It was remarkably more common in sedentary patients and patients with low socioeconomic status. High physical activity at work was found to decrease the risk of having NP. Clinicians should emphasize on exercise training as a therapeutic intervention while LBP is being treated.

A comparative study of L4-L5-S1 and L5-S1 vertebral fusion in high-grade L5-S1 spondylolisthesis

Introduction:

One of the most common types of spinal diseases is spondylolisthesis, which in advanced cases requires surgical intervention. This study aimed to compare the results of L4-L5-S1 and L5-S1 vertebral fusion treatment in high-grade L5-S1 spondylolisthesis.

Methods:

A study design that randomized controlled trial. A total of 70 consecutive patients who underwent surgery for the treatment of spondylolisthesis at Al-Zahra Hospital in Isfahan, Iran, were evaluated from July 2020 to February 2021 (35 patients underwent L4-L5-S1 and 35 received L5-S1 vertebral fusion treatment). The radicular and low back pain (LBP) intensity (Vanguard Australian Shares), blood loss, wound infection, reduction, and quality of life (SF-12 scores) were quantified before the surgery, 1, 3, and 6 months after surgery in two groups.

Results:

Patients involved in the two groups had similar baseline demographic characteristics. The percent slip in L4-L5-S1 and L5-S1 group, respectively, postoperative 81.11% and 57.89%, P = 0.0001. Intraoperative blood loss and postoperative were higher in the L4-L5-S1 group when compared to the L5-S1 group (P < 0.05). The wound infection rate of the L4-L5-S1 group was similar to that of the L5-S1 group (8.6% vs. 2.9%, P = 0.303). There was no difference in radicular and LBP intensity, SF-12 scores among patients with L4-L5-S1 and L5-S1 groups (P < 0.05).

Conclusion:

Both L4-L5-S1 and L5-S1 were equally beneficial in improving short-term functional outcomes for patients with high grade L5-S1 spondylolisthesis. However, L4-L5-S1 was associated with statistically significant higher incidences of blood loss, but it was accompanied by a better reduction. Therefore, caution should be exercised when considering L4-L5-S1.

Real-Life Management Pathways for Chronic Peripheral Neuropathic Pain at Tertiary Pain Clinics in France

OBJECTIVE

Peripheral neuropathic pain (PNP) represents a major public health issue. Severe or refractory cases warrant tertiary multidisciplinary management, but little information is available about real-life care pathways. The primary objective of this cross-sectional, observational study was to investigate the pathways of patients with PNP consulting for the first time or followed for less than 1 year in French tertiary specialized pain clinics.

METHODS

PNP was diagnosed with the NeuPSIG algorithm. Data collected included demographics, pain characteristics, and details of management before and after the study visit (e.g., drug and non-drug treatment, nature of medical visits), as well as time to referral to a pain clinic and time to a diagnosis of PNP. Factors associated with delayed referral or diagnosis were analyzed with multivariate analysis.

RESULTS

A total of 404 patients with PNP (age 55.8 ± 15.6 years, 60.3% females, 78.3% retired or unemployed, pain duration 43.4 ± 68.9 months) were enrolled by 84 pain specialists. Pain affected mainly the lower limbs (53.5%) and was predominantly related to surgery or trauma (59.4%). Primary care management was characterized by a high proportion of conventional analgesics (60.7%). Time to referral to a pain clinic was 43.4 ± 68.9 months since pain onset and 20.1 ± 39.4 months since the diagnosis of PNP. Delayed referral to a pain clinic was independently predicted by the clinical specialty of the referring doctor and by male gender.

CONCLUSIONS

This study highlights the need for accessible guidance for non-pain specialists to improve their diagnostic and management skills and for faster referral of patients with PNP to tertiary pain clinics.

Methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system: a systematic review

ABSTRACT

Mechanism-based classification of pain has been advocated widely to aid tailoring of interventions for individuals experiencing persistent musculoskeletal pain. Three pain mechanism categories (PMCs) are defined by the International Association for the Study of Pain: nociceptive, neuropathic, and nociplastic pain. Discrimination between them remains challenging. This study aimed to build on a framework developed to converge the diverse literature of PMCs to systematically review methods purported to discriminate between them; synthesise and thematically analyse these methods to identify the convergence and divergence of opinion; and report validation, psychometric properties, and strengths/weaknesses of these methods. The search strategy identified articles discussing methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system. Studies that assessed the validity of methods to discriminate between categories were assessed for quality. Extraction and thematic analysis were undertaken on 184 articles. Data synthesis identified 200 methods in 5 themes: clinical examination, quantitative sensory testing, imaging, diagnostic and laboratory testing, and pain-type questionnaires. Few methods have been validated for discrimination between PMCs. There was general convergence but some disagreement regarding findings that discriminate between PMCs. A combination of features and methods, rather than a single method, was generally recommended to discriminate between PMCs. Two major limitations were identified: an overlap of findings of methods between categories due to mixed presentations and many methods considered discrimination between 2 PMCs but not others. The results of this review provide a foundation to refine methods to differentiate mechanisms for musculoskeletal pain.

MIS-TLIF versus O-TLIF for single-level degenerative stenosis: study protocol for randomised controlled trial

INTRODUCTION

Patients with symptomatic single-level combination of degenerative stenosis and low-grade spondylolisthesis are often treated by nerve root decompression and spinal fusion. The gold standard is traditional open decompression and fusion, but minimally invasive method is more and more prevailing. However, there is lack of high-quality studies comparing these two techniques in order to obtain the advantages and certain indications to use one of these methods. The current study includes clinical, safety and radiological endpoints to determine the effectiveness of minimally invasive decompression and fusion (MIS-TLIF) over the traditional open one (O-TLIF).

METHODS AND ANALYSIS

All patients aged 40-75 years with neurogenic claudication or bilateral radiculopathy caused by single-level combination of degenerative stenosis and low-grade spondylolisthesis, confirmed by MRI with these symptoms persisting for at least 3 months prior to surgery, are eligible. Patients will be randomised into MIS-TLIF or traditional O-TLIF. The primary outcome measure is Oswestry Disability Index at 3-month follow-up term. The secondary outcomes are patient-reported outcome measures by the number of clinical scales, radiological parameters including sagittal balance parameters, safety endpoints and cost-effectiveness of each method. All patients will be analysed preoperatively, as well as on the 14th day of hospital stay (or on the day of hospital discharge), 3 months, 6 months, 12 months and 24 months postoperatively. The study has the design of a parallel group to demonstrate the non-inferior clinical results of MIS-TLIF compared with the traditional O-TLIF.

ETHICS AND DISSEMINATION

The study will be performed according to Helsinki Declaration. The study protocol was approved by the Local Ethical Committee of Priorov National Medical Research Center of Traumatology and Orthopedics in August 2020. Preliminary and final results will be presented in peer-reviewed journals, especially orthopaedic and spine surgery journals, at national and international congresses.

TRIAL REGISTRATION NUMBER

NCT04594980.

Predictive Value of the Phase Angle for Analgesic Efficacy in Lumbosacral Transforaminal Block

The mechanism of low back and leg pain involves mixed neuropathic and nociceptive components. Spinal neuropathic pain is related to increased levels of inflammatory cytokines and disrupted and increased permeability of the blood-spinal cord barrier, originally composed of tight junctions of capillary endothelial cells surrounded by lamina. The phase angle (PA) estimates cell membrane integrity using bioelectrical impedance analysis. We evaluated the predictive value of the PA for analgesic efficacy in lumbosacral transforaminal block. We retrospectively collected data from 120 patients receiving transforaminal blocks for lumbosacral radicular pain and assessed the PA before and 5 min following the block. Responders (group R) and non-responders (group N) were defined by ≥50% and <50% pain reduction, respectively, on a numerical rating scale, 30 min following the block; clinical data and the PA were compared. Among the 109 included patients, 50 (45.9%) and 59 (54.1%) had ≥50% and <50% pain reduction, respectively. In group N, the PA change ratio showed 88.1% specificity, 32.0% sensitivity, and 62.4% accuracy; a ratio of <0.087 at 5 min following the block predicted non-response. A PA change ratio of <0.087 at 5 min following lumbar transforaminal blocks predicted non-responders with high specificity.

Low back pain in patients with multiple sclerosis: A systematic review and the prevalence in a French multiple sclerosis population

PURPOSE

The prevalence and management of back pain in MS patients was assessed by a systematic review, and the results of a survey on the characteristics of low back pain in a sample of French MS patients are reported.

METHODS

A systematic search was conducted according to the PRISMA guidelines. The outcomes of interest included the prevalence of back pain, severity of pain and impact on daily activities. Moreover, the prevalence of low back pain and its consequences on daily living in a large French MS population were assessed.

RESULTS

Fourteen studies were included in the systematic review. The prevalence of back pain in MS patients ranged from 8.6 to 50%, but that of low back pain in particular ranged from 41.6 to 52.4%. Concerning the survey, 237 patients participated in the online questionnaire. The prevalence of low back pain in the French MS patients was 76.4%. The patients with chronic low back pain had more limitations in their daily life activities than those without chronic low back pain.

CONCLUSION

Patients with MS commonly suffer from low back pain, but it is still an underdiagnosed cause of pain that reduces one's ability to perform activities in daily life.

Sensory descriptors which identify neuropathic pain mechanisms in low back pain: a systematic review

OBJECTIVE

Descriptors provided by patients with neuropathic low back pain (NLBP) with or without spinally referred leg pain are frequently used by clinicians to help to identify the predominant pain mechanisms. Indeed, many neuropathic screening tools are primarily based on subjective descriptors to determine the presence of neuropathic pain. There is a need to systematically review and analyse the existing evidence to determine the validity of such descriptors in this cohort.

METHODS

Ten databases were systematically searched. The review adhered to PRISMA and CRD guidelines and included a risk of bias assessment using QUADAS-2. Studies were included if they contained symptom descriptors from a group of NLBP patients +/- leg pain. Studies had to include a reference test to identity neuropathic pain from other pain mechanisms.

RESULTS

Eight studies of 3099 NLBP patients were included. Allodynia and numbness were found to discriminate between NLBP and nociceptive LBP in four studies. Autonomic dysfunction, (changes in the colour or appearance of the skin), was also found to discriminate between the groups in two studies. Dysesthesia identified NLBP in 5/7 respectively. Results from studies were equivocal regarding pain described as hot/burning cold and paroxysmal pain in people with NLBP.

CONCLUSION

Subjectively reported allodynia and numbness would suggest a neuropathic pain mechanism in LBP. Dysesthesia would raise the suspicion of NLBP. More research is needed to determine if descriptors suggesting autonomic dysfunction can identify NLBP. There is poor consensus on whether other descriptors can identify NLBP.

Nicotine dependence and the International Association for the Study of Pain neuropathic pain grade in patients with chronic low back pain and radicular pain: is there an association?

Background

This study investigated whether current smoking and a higher nicotine dependency were associated with chronic low back pain (LBP), lumbar related leg pain (sciatica) and/or radicular neuropathic pain.

Methods

A cross-sectional study was conducted on 150 patients (mean age, 60.1 ± 13.1 yr). Demographic data, the International Association for the Study of Pain (IASP) neuropathic pain grade, STarT Back tool, and the Fagerström test were completed. A control group (n = 50) was recruited.

Results

There was a significant difference between current smokers and non-smokers in the chronic LBP group in the mean pain score (P = 0.025), total STarT Back score (P = 0.015), worst pain location (P = 0.020), most distal pain radiation (P = 0.042), and in the IASP neuropathic pain grade (P = 0.026). There was a significant difference in the mean Fagerström score between the four IASP neuropathic pain grades (P = 0.005). Current smoking yielded an odds ratio (OR) of 3.071 (P = 0.011) for developing chronic LBP and sciatica, and an OR of 4.028 (P = 0.002) for obtaining an IASP “definite/probable” neuropathic pain grade, for both cohorts. The likelihood for chronic LBP and sciatica increased by 40.9% (P = 0.007), while the likelihood for an IASP neuropathic grade of “definite/probable” increased by 50.8% (P = 0.002), for both cohorts, for every one unit increase in the Fagerström score.

Conclusions

A current smoking status and higher nicotine dependence increase the odds for chronic LBP, sciatica and radicular neuropathic pain.

Evaluation of the Neuropathic Component of Chronic Low Back Pain

OBJECTIVES

Assessment of neuropathic pain in chronic low back syndromes is important. However, there is currently no gold standard for its diagnosis. The aim of this observational cross-sectional study was to assess the neuropathic component of pain in various chronic low back pain syndromes using a range of diagnostic tests.

MATERIALS AND METHODS

Included in this study were 63 patients with chronic axial low back pain (ALBP), 48 patients with chronic radicular syndromes (CRS) comprising 23 with discogenic compression (CDRS) and 25 with lumbar spinal stenosis (LSS), and 74 controls. PainDETECT questionnaire (PDQ), quantitative sensory testing (QST), and skin biopsy with evaluation of intraepidermal nerve fiber density (IENFD) were used to assess the neuropathic pain component.

RESULTS

Positive PDQ (≥19) was obtained more frequently in patients with CDRS and LSS (26.1% and 12.0%, respectively) compared with patients with ALBP (1.6%, P<0.001). The proportion of patients with sensory loss confirmed by QST was lowest in the ALBP subgroup (23.8%) compared with CDRS (47.8%), and LSS (68.0%) subgroups (P<0.001). A reduction in IENFD was disclosed in a proportion of up to 52.0% of affected roots in patients with CRS.

DISCUSSION

Neuropathic pain is quite frequent in CRS, and QST reveals sensory loss as a frequent abnormality in patients with CRS. Using a cut-off value of 19, PDQ identified a neuropathic component in a relatively low proportion of patients with CRS. CRS may be associated with a reduction in IENFD.

Association between neuropathic pain characteristics and DNA methylation of transient receptor potential ankyrin 1 in human peripheral blood

Elucidation of epigenetic mechanisms correlating with neuropathic pain in humans is crucial for the prevention and treatment of this treatment-resistant pain state. In the present study, associations between neuropathic pain characteristics and DNA methylation of the transient receptor potential ankyrin 1 (TRPA1) gene were evaluated in chronic pain patients and preoperative patients. Pain and psychological states were prospectively assessed in patients who suffered chronic pain or were scheduled for thoracic surgery. Neuropathic characteristics were assessed using the Douleur Neuropathique 4 (DN4) questionnaire. DNA methylation levels of the CpG islands in the TRPA1 gene were examined using whole blood. Forty-eight adult patients were enrolled in this study. Increases in DNA methylation rates at CpG -51 showed positive correlations with increases in the DN4 score both in preoperative and chronic pain patients. Combined methylation rates at CpG -51 in these patients also significantly increased together with increase in DN4 scores. Neuropathic pain characteristics are likely associated with methylation rates at the promoter region of the TRPA1 gene in human peripheral blood.

A Novel Algorithm to Identify Predictors of Treatment Response: Tapentadol Monotherapy or Tapentadol/Pregabalin Combination Therapy in Chronic Low Back Pain?

Purpose: High dose monotherapies or drug combinations are used to achieve sufficient analgesia for the treatment of severe chronic low back pain, before invasive therapy options are considered. In order to demonstrate an alternative for an empirical treatment approach, the authors' primary aim was to present an algorithm for the objective identification of treatment predictors. Additionally, the study identified baseline-characteristics in chronic low back pain patients prior to tapentadol PR treatment, as well as scrutinized those patients, either benefitting from a medium/high dose tapentadol PR monotherapy or a combination therapy (medium dose tapentadol PR + pregabalin).

Patients and Methods: The statistical approach included data of a previously published randomized, double blind, phase 3b study which compared the effectiveness and safety of tapentadol PR vs. a combination of tapentadol PR and pregabalin. In total, 46 clinical parameters were included in the statistical prediction models which were applied separately either to 50 patients who already responded well during the titration period (i.e., medium dose tapentadol PR) or to 261 patients with in the comparative treatment period [i.e., monotherapy (high dose tapentadol PR) or combination therapy (medium dose tapentadol PR/pregabalin)].

Results: The first statistical model identified three co-variables (NRS-3, PDQ, SQ) with predictive effects on patients responding well (“optimal responders”) to a medium dose tapentadol PR titration. Those patients presented low baseline pain intensity scores, good sleep quality and high painDETECT scores. The second statistical model identified eight co-variables (PDQ, numbness, SF-12 MCS, SF-12 PCS, VAS, HADS-A, HADS-D, SQ) with predictive effects on patients responding to high dose tapentadol PR monotherapy vs. a combination therapy (tapentadol PR + pregabalin). The high dose tapentadol PR responders indicated high painDETECT scores, little numbness and a good mental health status. Whereas, the combination therapy (tapentadol PR + pregabalin) responders were characterized by severe sleep disturbances and little anxiety.

Conclusion: The statistical analysis characterized chronic low back pain patients and identified factors contributing to a treatment response. Thus, this retrospective statistical algorithm represents an elegant method, which may contribute to future strategies toward a more individualized and improved mechanism based pain therapy.

Prevalence of Chronic Pain, Particularly with Neuropathic Component, and Its Effect on Overall Functioning of Elderly Patients

Background

The prevalence of chronic pain among the elderly is high (estimated at 25–85%) and may adversely affect their everyday functioning, although it is often unrecognized.

Material/Methods

The aim of this study was to assess the prevalence of chronic pain, especially with the neuropathic component, and its effect on overall functioning of elderly patients. We enrolled 145 subjects older than 60 years (nursing home residents, or patients of outpatient geriatric clinic). Information on co-morbidities, functional and mental status, and medications was obtained using a questionnaire. Chronic pain was defined as lasting >3 months and the presence of neuropathic component was detected using the DN4 Questionnaire (Douleur Neuropathique en Questions).

Results

The mean age of patients was 76±9.68 years. Chronic pain was reported by 78% of participants and 32% reported neuropathic pain with neuropathic component (DN4 score ≥4 points). Patients complaining of chronic pain significantly more often presented mood disorders and lower satisfaction with life (particularly those with the highest pain intensity), with no difference in functional status according to the ADL (Activities of Daily Living) tool. Participants with chronic pain were treated with paracetamol (45%), non-steroidal anti-inflammatory drugs (25%), and opioids (24%).

Conclusions

The prevalence of chronic pain, particularly with neuropathic component, in the elderly population seems to be higher than expected based on previous reports, and its treatment appears to be ineffective. This problem requires further research and dissemination of knowledge on the diagnosis and treatment of chronic pain among health care workers caring for elderly patients on a daily basis.

Are painDETECT scores in musculoskeletal disorders associated with duration of daily pain and time elapsed since current pain onset?

Objectives:

We aimed to compare painDETECT scores in outpatients seen in a rheumatology department over a 1-month period and search for correlations between painDETECT scores and the estimated duration of daily pain and time elapsed since the onset of current pain.

Patients and Methods:

A total of 529 of 738 outpatients agreed to complete a set of questionnaires, including painDETECT.

Results:

The mean painDETECT score was 14.14 ± 7.59, and 31% of the patients had painDETECT scores of >18. Fibromyalgia ranked first (21.2 ± 6.0), followed by osteoarthritis of the lower limbs (17.8 ± 8.2), back pain and radiculopathies (16.1 ± 6.8), osteoarthritis of the upper limbs (15.7 ± 8.1), spondylarthrosis (15.1 ± 7.2), entrapment neuropathies (14.1 ± 2.4), rheumatoid arthritis (13.8 ± 7.1), miscellaneous conditions (13.8 ± 8.2), tendinitis (13.4 ± 7.9), connectivitis (11.5 ± 6.7), and osteoporosis (8.5 ± 6.9). The duration of daily pain was much longer in patients with painDETECT scores of >18 (12.41 ± 8.45 vs 6.53 ± 7.45 hours) (t = 0.0000), but very similar painDETECT scores were observed for patients suffering from pain for less than 1 week (13.7 ± 8.2; 38% > 18), for 1 month (14.5 ± 8.2; 25% > 18), several months (12.7 ± 7.3; 23% > 18), 1 year (13.8 ± 7.7; 29% > 18), or several years (14.7 ± 7.4; 33% > 18).

Conclusion:

PainDETECT scores differed little depending on the musculoskeletal condition, strongly correlated with the duration of daily pain, and appeared to be as high in patients with recent pain as in those suffering for years.

Do lumbar magnetic resonance imaging changes predict neuropathic pain in patients with chronic non-specific low back pain?

The aim of this observational, cross-sectional study was to analyse lumbar magnetic resonance imaging (MRI) findings in patients with non-specific chronic low back pain (CLBP), and to evaluate any correlation with pain intensity and their capacity to predict neuropathic pain (NP) in these patients.Fifty-two patients with non-specific CLBP, between 21 and 62 years of age, 50% men, were investigated. Lumbar MRI was employed to assess disc degeneration, endplate changes, Modic changes, disc displacement, facet degeneration, foraminal stenosis and central lumbar spinal stenosis. The characteristics of pain were evaluated and patients were divided into 2 subgroups: with NP (24 patients) and without NP (28 patients), based on the results of a DN4-interview. Correlations between particular MRI changes and their relations to the intensity of pain were evaluated. Logistic regression was used to disclose predictors of NP.Lumbar spine degenerative features were frequent in patients with non-specific CLBP, with L4/5 the most affected level. A significant correlation emerged between the severity of degenerative changes in particular lumbar spine structures (correlation coefficient ranging between 0.325 and 0.573), while no correlation was found between severity of degenerative changes and pain. Multivariate logistic regression revealed only 2 independent predictors of NP - female sex (odds ratio [OR] = 11.9) and a mean pain intensity of ≥4.5 in the previous 4 weeks (OR = 13.1).Degenerative changes in the lumbar spine are frequent MRI findings, but do not correlate with the intensity of pain and do not predict NP. However, female sex and pain intensity do predict NP.

Optimizing the Management and Outcomes of Failed Back Surgery Syndrome: A Consensus Statement on Definition and Outlines for Patient Assessment

Failed back surgery syndrome (FBSS) is a controversial term for identifying patients affected by new, recurrent, or persistent pain in the low back and/or legs following spinal surgery. The lack of a comprehensive standardized care pathway compromises the appropriate management of FBSS patients, which is associated with a heavy financial burden. An international panel of spine surgeons, neurosurgeons, and pain specialists with a particular interest in FBSS established the chronic back and leg pain (CBLP) network with the aim of addressing the challenges and barriers in the clinical management of FBSS patients by building a common transdisciplinary vision. Based on literature reviews, additional input from clinical expertise of multiple professional disciplines, and consensus among its members, the network attempted to provide recommendations on the management of patients with FBSS utilizing a multidisciplinary team (MDT) approach. The presentation of this work has been divided in two separate parts to enhance its clarity. This first paper, in favour of selecting appropriate validated tools to improve the FBSS patient assessment, focuses on FBSS taxonomy and its clinical implications for evaluation. Concise recommendations for assessment, treatment, and outcome evaluation using a MDT approach would be an important resource for specialists and nonspecialist clinicians who manage patients with FBSS, to improve decision-making, reduce variation in practice, and optimize treatment outcomes in this difficult-to-treat population.

The neuropathic pain component among patients with chronic low back-radicular pain

OBJECTIVES

Determining neuropathic pain component (NPC) among patients with chronic low back pain-radicular pain (CLBP-RP) and the adjustment between scales of neuropathic pain.

MATERIAL-METHODS

One hundred and one patients with CLBP-RP were included in the study. The severity of CLBP-RP was evaluated by visual analogue scale (VAS). The Douleur Neuropathique 4 Questions (DN4) and Leeds Assessment of Neuropathic Symptoms and Signs Scales (LANSS) were used to evaluate the NPC.

RESULTS

The mean score of CLBP-RP assessed by VAS was 80 mm. NPC was detected a rate of 65.3% by DN4 and 40.6% by LANSS. NPC was 75.4% in females and 47.2% in males according to DN4, and 52.3% in females and 19.4% in males according to LANSS. The female gender, occupation, and VAS scores were determined to be significant factors contributing to presence of NPC according to logistic regression analyses (p< 0.01, p< 0.05, p< 0.05). A medium degree accordance was established between DN4 and LANSS scales according to kappa coefficient (Kappa = 0.532, p< 0.05).

CONCLUSION

CLBP is among the diseases causing mixed type pain accompanied by nociceptive and neuropathic pain. NPC was detected in a considerable part of patients with radicular pain. Identifying the character of radicular pain is significant to develop proper management strategies.

Proportion of neuropathic pain in the back region in chronic low back pain patients -a multicenter investigation

Neuropathy can contribute to low back pain (LBP) in the region of the back. Our study investigated the proportion of neuropathic pain (NP) in low back region in chronic LBP patients from multicenter and clinics in China and identified associated factors. Assessment was made using a questionnaire and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS, only tested in low back region), as well as Quantitative Sensory Testing (QST, merely applied to the low back region), the Hospital Anxiety and Depression Scale (HADS) and the Oswestry Disability Index (ODI). Our questionnaire collected demographic information, behavioral habits and medical records. 2116 outpatients over 18 years old complaining of LBP lasting more than 3 months were enrolled in this study. The NP proportion in low back region in chronic LBP patients was 2.8%. Multivariable logistic regression analysis showed that histories of lumbar surgery, abdominal or pelvic surgery, and drinking alcohol were independent positive predictors for LBP of predominantly neuropathic origin (LBNPO), while history of low back sprain and frequently carrying weight as independent negative predictor. Using these parameters may help the identification of patients with chronic LBP likely to develop NP leading to improved treatment outcomes.

Difference between subjects in early chronic phase of low back pain with and without neuropathic component: observational cross-sectional study

BACKGROUND

Neuropathic pain in early chronic low back pain is insufficiently recognized and treated.

AIM

The aim of this study was to establish if there is a difference among chronic low back pain subjects with and without neuropathic pain and healthy subjects, in clinical characteristic and the level of trunk muscle activation.

DESIGN

Cross sectional observational study.

SETTING

Rehabilitation clinic, inpatient and outpatient.

POPULATION

Thirty-three subjects in early chronic phase of low back pain and 26 healthy subjects were included in this research.

METHODS

Clinical characteristics and relative thickness change of lumbar multifidus and transversal abdominal muscle, measured by ultrasound, in neuropathic, non-neuropathic chronic low back pain and healthy subjects were analyzed.

RESULTS

Chronic low back pain subjects with neuropathic pain reported higher level of pain on Visual Analog Scale (VAS) (back pain P=0.016, leg pain P=0.006), had higher Oswestry Disability Score (P=0.029), had lower motor (P=0.001) and sensory leg scores (P=0.000), and decreased level of activation of transversal abdominal muscle (P=0.000) comparing to chronic low back pain group without neuropathic pain. Low back pain subjects with leg pain ≥5 on VAS were 11.2 times more prone to develop neuropathic pain. Motor leg score ≤47 increases this chance 35 times. Sensory leg score ≤25 increases this chance 14 times. Reduced activation of transversal abdominal muscle for 40-50% increases this chance 7-24 times.

CONCLUSIONS

Chronic low back pain subjects with neuropathic pain were more painful and disabled, had lower motor and sensory scores, and lower relative thickness change of transversal abdominal muscle comparing to the low back pain group without neuropathic pain. Self -reported leg pain intensity of 5 or more on VAS, motor score of 47 and less, sensory scores of 25 and less and diminished activation of transversal abdominal muscle significantly increase the chance that chronic low back pain subject has neuropathic component of pain.

CLINICAL REHABILITATION IMPACT

Neuropathic pain in early chronic low back pain subjects might be more readily recognized if patients with radiculopathy and diminished activation of transversal abdominal muscle were regularly screened for neuropathic pain.

Neuropathic Pain after Shoulder Arthroplasty: Prevalence, Impact on Physical and Mental Function, and Demographic Determinants

Purpose: The objectives of this survey study were to provide an estimate of the prevalence of neuropathic pain (NP) and to explore the cross-sectional and longitudinal group differences postoperatively. Method: A cohort of consecutive patients who had undergone total shoulder arthroplasty (TSA), reverse shoulder arthroplasty (RSA), or humeral head replacement (HHR) were surveyed within an average of 3.8 years after surgery. Questionnaires completed at the time of the survey were the Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) pain scale, the visual analogue scale (VAS) for pain, the Western Ontario Osteoarthritis of the Shoulder (WOOS) index, the Patient Health Questionnaire-9 (PHQ-9), and a satisfaction questionnaire. Results: Of the 141 candidates who were invited to participate in the study, 115 patients participated (85 TSA, 21 HHR, and 9 RSA), for an 82% response rate. Five patients (4%) met the criteria for NP, of whom one had a loosening of the prosthesis and required further surgery. Having NP was associated with greater pain (VAS; p=0.001), greater depression (PHQ-9; p=0.001), more disability (WOOS; p=0.030), and less satisfaction with the surgery (p=0.014). There was no relationship between the presence of NP and patients' age, sex, preoperative pain, range of motion results, or WOOS scores (p>0.05). Conclusions: Persistent pain of neuropathic origin is not common after shoulder arthroplasty, but it is a significant contributor to poor mental and physical well-being and thus warrants further research.

Cannabinoids and spinal cord stimulation for the treatment of failed back surgery syndrome refractory pain

Objective

This study aimed to evaluate pain and its symptoms in patients with failed back surgery syndrome (FBSS) refractory to other therapies, treated with a combination of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), in association with spinal cord stimulation (SCS).

Settings

Outpatients referred at Pain Unit of San Vincenzo Hospital in Taormina (Italy), between September 2014 and January 2016.

Subjects

Eleven FBSS patients diagnosed with neuropathic pain using the Douleur Neuropathique 4 questionnaire and suffering from moderate to severe chronic refractory pain, and undergoing treatment with SCS and a combination of THC/CBD for 12 consecutive months.

Materials and methods

All the included patients discontinued previous unsuccessful therapy at least 2 months before the beginning of the cannabinoid therapy, with the exception of the SCS that was continued. Patients received a fixed dosage of cannabinoid agonists (THC/CBD) that could be increased subjective to pain control response. A Brief Pain Inventory questionnaire was administered to measure pain and its interference with characteristic dimensions of feelings and functions. The duration of treatment with SCS and THC/CBD combination was 12 months.

Results

Effective pain management as compared to baseline result was achieved in all the cases studied. The positive effect of cannabinoid agonists on refractory pain was maintained during the entire duration of treatment with minimal dosage titration. Pain perception, evaluated through numeric rating scale, decreased from a baseline mean value of 8.18±1.07–4.72±0.9 by the end of the study duration (12 months) (P<0.001).

Conclusion

The results indicate that cannabinoid agonists (THC/CBD) can have remarkable analgesic capabilities, as adjuvant of SCS, for the treatment of chronic refractory pain of FBSS patients.

The appropriate management of persisting pain after spine surgery: a European panel study with recommendations based on the RAND/UCLA method

PURPOSE

Management of patients with persisting pain after spine surgery (PPSS) shows significant variability, and there is limited evidence from clinical studies to support treatment choice in daily practice. This study aimed to develop patient-specific recommendations on the management of PPSS.

METHODS

Using the RAND/UCLA appropriateness method (RUAM), an international panel of 6 neurosurgeons, 6 pain specialists, and 6 orthopaedic surgeons assessed the appropriateness of 4 treatment options (conservative, minimally invasive, neurostimulation, and re-operation) for 210 clinical scenarios. These scenarios were unique combinations of patient characteristics considered relevant to treatment choice. Appropriateness had to be expressed on a 9-point scale (1 = extremely inappropriate, 9 = extremely appropriate). A treatment was considered appropriate if the median score was ≥ 7 in the absence of disagreement (≥ 1/3 of ratings in each of the opposite sections 1-3 and 7-9).

RESULTS

Appropriateness outcomes showed clear and specific patterns. In 48% of the scenarios, exclusively one of the 4 treatments was appropriate. Conservative treatment was usually considered appropriate for patients without clear anatomic abnormalities and for those with new pain differing from the original symptoms. Neurostimulation was considered appropriate in the case of (predominant) neuropathic leg pain in the absence of conditions that may require surgical intervention. Re-operation could be considered for patients with recurrent disc, spinal/foraminal stenosis, or spinal instability.

CONCLUSIONS

Using the RUAM, an international multidisciplinary panel established criteria for appropriate treatment choice in patients with PPSS. These may be helpful to educate physicians and to improve consistency and quality of care. These slides can be retrieved under Electronic Supplementary Material.

Pharmacological target therapy of neuropathic pain and patient-reported outcomes in patients with chronic low back pain in Korea: Results from the NLBP Outcomes Research

A number of studies have demonstrated an association of neuropathic pain and chronic low back pain (CLBP), but the outcome difference in each medical management is poorly understood. This study is aimed to investigate treatment patterns of neuropathic pain in CLBP patients and to explore patient-reported outcomes (PROs) including quality of life (QoL) and functional disability by treatment patterns.Data were extracted from the neuropathic low back pain (NLBP) outcomes research. It was a multicenter and cross-sectional study in which 1200 patients were enrolled at 27 general hospitals, from 2014 to 2015. Of total, 478 patients classified as neuropathic pain were used for this subgroup analysis. The patients were divided into 2 groups according to treatment patterns (with vs. without the targeted therapy [TT] of neuropathic pain). Demographic and clinical features were collected by chart reviews and PROs were measured by patient's survey. QoL was assessed by EuroQoL 5-dimension (EQ-5D) questionnaire. Functional disability was measured by the Quebec Back Pain Disability Scale (QBPDS). Multiple linear regression analyses were conducted to compare the PROs between TT group and non-targeted therapy (nTT) group.Among the NLBP patients (mean age 63years, female 62%), EQ-5D index, EuroQoL-Visual Analog Scale (EQ-VAS), and QBPDS Scores (mean ± standard deviation) were 0.40 ± 0.28, 54.98 ± 19.98, and 46.03 ± 21.24, respectively. Only 142 (29.7%) patients had pharmacological TT of neuropathic pain. Univariate analyses revealed no significant mean differences between TT group and nTT group in the EQ-5D index (0.41 ± 0.27 and 0.39 ± 0.28), EQ-VAS (56.43 ± 18.17 and 54.37 ± 20.69), and QBPDS (45.31 ± 21.32 and 46.31 ± 21.24). After adjustment with covariates, TT group had higher scores of EQ-5D index (β = 0.07; P < 0.01) and EQ-VAS (β = 4.59; P < 0.05) than the nTT group. The TT group's QBPDS score was lower than the nTT group, although its statistical significance still has not been reached (β = -4.13; P = 0.07).We found that considerable proportion of the NLBP patients remains untreated or undertreated. Although TT group had significantly better QoL than nTT group, only 29.7% of NLBP patients had pharmacological TT. Therefore, clinicians should consider using TT for better QoL of neuropathic pain patients.

Combination Drug Therapy for the Management of Low Back Pain and Sciatica: Systematic Review and Meta-Analysis

Combining medicines may give greater pain relief and/or improved tolerability. We conducted a systematic review to investigate the effects of combination drug therapy in patients with low back pain and/or sciatica on pain, disability, and adverse events. Databases and trial registers were searched from inception to July 27, 2017, for randomized trials of (sub)acute or chronic back pain or sciatica participants that were administered combination drug therapy compared with monotherapy or placebo. Of the 27 studies included, most combinations (21 of 23) consisted of single trials. Most combinations had no or small effect on pain and disability. A clinically important difference was found in one combination, buprenorphine plus pregabalin versus buprenorphine for chronic back pain at immediate (mean difference = -23.30; 95% confidence interval = -27.68 to -18.92) and short (mean difference = -27.60; 95% confidence interval = -31.70 to -23.50) terms; however, the quality of evidence was low. There was no statistically significant increased risk of serious adverse events. When the risk of adverse events was statistically significant, it favored monotherapy or placebo. There is no clear evidence to support any combination drug therapy for the management of low back pain and sciatica due to the limited number of studies and overall low quality of evidence. Perspective: Combining medicines may give greater pain relief and/or improved tolerability compared with single-ingredient medicines. However, the lack of studies and overall low quality of evidence limit the recommendation of combination drug therapy for the management of low back pain and sciatica.

Assessment of pain quality reveals distinct differences between nociceptive innervation of low back fascia and muscle in humans

Introduction/Objectives

Verbal descriptors are an important pain assessment parameter. The purpose of this study was to explore the ability to discriminate deep muscle pain and overlying fascia pain according to verbal descriptors and compare the pattern with skin stimulation (from previously published data).

Methods

In 16 healthy human subjects, electrical stimulation was chosen to excite a broad spectrum of nociceptive primary afferents innervating the respective tissues. The 24-item Pain Perception Scale (Schmerzempfindungsskala [SES]) was used to determine the induced pain quality.

Results

Overall, affective (P = 0.69) and sensory scores (P = 0.07) were not significantly different between muscle and fascia. Factor analysis of the sensory descriptors revealed a stable 3-factor solution distinguishing superficial thermal ("heat pain" identified by the items "burning," "scalding," and "hot") from superficial mechanical ("sharp pain" identified by the items "cutting," "tearing," and "stinging") and "deep pain" (identified by the items "beating," "throbbing," and "pounding"). The "deep pain" factor was more pronounced for muscle than fascia (P < 0.01), whereas the other 2 factors were more pronounced for fascia (both P < 0.01). The patterns of skin and fascia matched precisely in sensory factors and on single-item level.

Conclusion

The differences in sensory descriptor patterns between muscle and fascia may potentially guide treatment towards muscle or fascia in low back pain physiotherapeutic regimes. The similarity of descriptor patterns between fascia and skin, both including the terms "burning" and "stinging," opens the possibility that neuropathic back pain (when the dorsal ramus of the spinal nerve is affected) may be confused with low back pain of fascia origin.

Prevalence of Neuropathic Pain and Patient-Reported Outcomes in Korean Adults with Chronic Low Back Pain Resulting from Neuropathic Low Back Pain

Study Design

A noninterventional, multicenter, cross-sectional study.

Purpose

We investigated the prevalence of neuropathic pain (NP) and patient-reported outcomes (PROs) of the quality of life (QoL) and functional disability in Korean adults with chronic low back pain (CLBP).

Overview of Literature

Among patients with CLBP, 20%–55% had NP.

Methods

Patients older than 20 years with CLBP lasting for longer than three months, with a visual analog scale (VAS) pain score higher than four, and with pain medications being used for at least four weeks before enrollment were recruited from 27 general hospitals between December 2014 and May 2015. Medical chart reviews were performed to collect demographic/clinical features and diagnosis of NP (douleur neuropathique 4, DN4). The QoL (EuroQoL 5-dimension, EQ-5D; EQ-VAS) and functional disability (Quebec Back Pain Disability Scale, QBPDS) were determined through patient surveys. Multiple linear regression analyses were performed to compare PROs between the NP (DN4≥4) and non-NP (DN4<4) groups.

Results

A total of 1,200 patients (females: 65.7%; mean age: 63.4±13.0 years) were enrolled. The mean scores of EQ-5D, EQ-VAS, and QBPDS were 0.5±0.3, 55.7±19.4, and 40.4±21.1, respectively. Among all patients, 492 (41.0%; 95% confidence interval, 38.2%–43.8%) suffered from NP. The prevalence of NP was higher in male patients (46.8%; p<0.01), in patients who had pain based on radiological and neurological findings (59.0%; p<0.01), and in patients who had severe pain (49.0%; p<0.01). There were significant mean differences in EQ-5D (NP group vs. non-NP group: 0.4±0.3 vs. 0.5±0.3; p<0.01) and QBPDS (NP group vs. non-NP group: 45.8±21.2 vs. 36.3±20.2; p<0.01) scores. In the multiple linear regression, patients with NP showed lower EQ-5D (β=−0.1; p<0.01) and higher QBPDS (β=7.0; p<0.01) scores than those without NP.

Conclusions

NP was highly prevalent in Korean patients with CLBP. Patients with CLBP having NP had a lower QoL and more severe dysfunction than those without NP. To enhance the QoL and functional status of patients with CLBP, this study highlights the importance of appropriately diagnosing and treating NP.

Investigating the validity of the DN4 in a consecutive population of patients with chronic pain

Neuropathic pain is clinically described as pain caused by a lesion or disease of the somatosensory nervous system. The aim of this study was to assess the validity of the Dutch version of the DN4, in a cross-sectional multicentre design, as a screening tool for detecting a neuropathic pain component in a large consecutive, not pre-stratified on basis of the target outcome, population of patients with chronic pain. Patients' pain was classified by two independent (pain-)physicians as the gold standard. The analysis was initially performed on the outcomes of those patients (n = 228 out of 291) in whom both physicians agreed in their pain classification. Compared to the gold standard the DN4 had a sensitivity of 75% and specificity of 76%. The DN4-symptoms (seven interview items) solely resulted in a sensitivity of 70% and a specificity of 67%. For the DN4-signs (three examination items) it was respectively 75% and 75%. In conclusion, because it seems that the DN4 helps to identify a neuropathic pain component in a consecutive population of patients with chronic pain in a moderate way, a comprehensive (physical-) examination by the physician is still obligate.

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

This systematic review synthesizes literature describing prevalence, characteristics, and prognosis of low back-related leg pain (LBLP) patients with neuropathic pain in primary care and/or similar settings. Inclusion and exclusion criteria were developed and used by independent reviewers to screen citations for eligibility. The initial search yielded 24,948 citations; after screening 12 studies were included. Neuropathic pain was identified using case ascertainment tools (n = 5), clinical history with examination (n = 4), and using LBLP samples assumed neuropathic (n = 3). Neuropathic pain prevalence varied from 19% to 80%. There was consistent evidence for higher back-related disability (n = 3), poorer health-related quality of life (n = 2), and some evidence for more severe depression (n = 2), anxiety (n = 3), and pain intensity (n = 4) in patients with neuropathic pain. Results were less consistent when cases were identified through clinical history with examination than those identified using case ascertainment tools. Prognosis (n = 1) of LBLP patients with neuropathic pain was worse compared with those without, in all outcomes (leg pain intensity, leg and back-related disability, self-reported general health) except back pain intensity. No studies described prognostic factors. This systematic review highlights the evidence gap in neuropathic pain in LBLP in primary care, especially with respect to prognosis.

PERSPECTIVE

Patients with LBLP may have neuropathic pain. This systematic review emphasizes the paucity of evidence describing the characteristics and prognosis of neuropathic pain in this patient population. Future research investigating prognosis of these patients with neuropathic pain is likely to contribute to better understanding and management.