Prevalence and Location of Neuropathic Pain in Lumbar Spinal Disorders: Analysis of 1804 Consecutive Patients With Primary Lower Back Pain

Pain Neuroscience Education for Acute Pain

In musculoskeletal and sports medicine, pain has traditionally been linked to tissue injury, often assuming a linear correlation between tissue damage and pain intensity. However, modern pain science has illuminated the complexity of the human pain experience, incorporating psychosocial elements, nervous system sensitization, immune responses, and structural changes in the brain as factors. This contemporary understanding of pain has proven highly beneficial for both clinicians treating individuals in pain and those experiencing pain. Pain neuroscience education (PNE) provides individuals in pain with an understanding of the underlying neurobiology and neurophysiology of their pain experience, which has been shown to result in decreased self-reported pain, reduced disability, the alleviation of fear and fear-avoidance behaviors, diminished pain catastrophizing, and improved movement. Currently, research on PNE predominantly focuses on interventions with individuals with persistent or chronic pain conditions. However, those who experience acute, sub-acute, and perioperative pain also have the potential for elevated levels of fear, fear-avoidance, and pain catastrophizing, indicating potential benefits from PNE. This invited commentary seeks to inform readers about the latest advancements in pain science and propose a conceptual model for delivering PNE in acute pain experiences.

Level of Evidence

5.

Prevalence and predisposing factors of neuropathic pain in patients with rotator cuff tears

BACKGROUND

The management of pain in patients with rotator cuff tears can be challenging. Neuropathic pain is reportedly associated with pain occurrence in musculoskeletal diseases. However, to date, few studies have reported on the prevalence of neuropathic pain in patients with rotator cuff tears or identified the factors associated with neuropathic pain in a multicenter study.

METHODS

A total of 391 patients (205 males and 186 females; median age, 67.7 years; range, 27-92 years) with rotator cuff tears were included in this study. The prevalence of neuropathic pain in rotator cuff tears was investigated using the Japanese version of the painDETECT questionnaire for all patients. In addition, factors significantly associated with the occurrence of neuropathic pain were examined using multivariate logistic regression analysis.

RESULTS

Twenty-eight patients (7.2%) were classified into the neuropathic pain group (score ≥19), 97 (24.8%) into the uncertainty regarding neuropathy group (score 13-18), and 266 (68.0%) into the nociceptive pain group (score ≤12). According to the multivariate logistic regression analysis, the independent predictors of neuropathic pain were the VAS score (most severe pain during the past 4 weeks; odds ratio, 1.55; 95% confidence interval [CI], 1.23-2.09) and UCLA shoulder score (odds ratio, 0.81; 95% CI, 0.65-0.97).

CONCLUSIONS

Based on the study findings, the prevalence of neuropathic pain in patients with rotator cuff tear was 7.2%. It is important to investigate the presence or absence of neuropathic pain when treating patients with painful rotator cuff tears, because neuropathy associated with rotator cuff tears may adversely affect patient outcomes.

Association between chiropractic spinal manipulation and gabapentin prescription in adults with radicular low back pain: retrospective cohort study using US data

OBJECTIVES

Radicular low back pain (rLBP) is often treated off-label with gabapentin or by chiropractors using chiropractic spinal manipulative therapy (CSMT). To date, no studies have examined the association between these interventions. We hypothesised that adults under 50 years of age receiving CSMT for newly diagnosed rLBP would have reduced odds of receiving a gabapentin prescription over 1 year-follow-up.

DESIGN

Retrospective cohort study.

SETTING

US network including linked medical records, medical claims and pharmacy claims of >122 million patients attending large healthcare organisations (TriNetX), queried 15 June 2023, yielding data from 2017 to 2023.

PARTICIPANTS

Adults aged 18-49 were included at their first occurrence of rLBP diagnosis. Exclusions were severe pathology, other spinal conditions, on-label gabapentin indications and gabapentin contraindications. Propensity score matching controlled for variables associated with gabapentin use and receipt of prescription medication over the preceding year.

INTERVENTIONS

Patients were divided into CSMT or usual medical care cohorts based on the care received on the index date of rLBP diagnosis.

PRIMARY AND SECONDARY OUTCOME MEASURES

OR for gabapentin prescription.

RESULTS

After propensity matching, there were 1635 patients per cohort (mean age 36.3±8.6 years, 60% women). Gabapentin prescription over 1-year follow-up was significantly lower in the CSMT cohort compared with the usual medical care cohort, with an OR (95% CI) of 0.53 (0.40 to 0.71; p<0.0001). Sensitivity analyses revealed early divergence in cumulative incidence of prescription; and no significant between-cohort difference in a negative control outcome (gastrointestinal medication) suggesting adequate control for pharmacological care preference.

CONCLUSIONS

Our findings suggest that US adults receiving CSMT for newly diagnosed rLBP have significantly reduced odds of receiving a gabapentin prescription over 1-year follow-up compared with those receiving usual medical care. Results may not be generalisable and should be replicated in other healthcare settings and corroborated by a prospective study to reduce confounding.

Characterization of neuropathic component of back pain in patients with osteoporotic vertebral fractures

BACKGROUND:

Osteoporotic vertebral fractures (OVFs) are often followed by chronic back pain which may have a nociceptive, neuropathic, or mixed component. However, literature on this topic is lacking.

OBJECTIVE:

The objective of this cross-sectional study is to characterize the neuropathic component of chronic back pain in patients with OVFs.

METHODS:

Spine fractures were detected by morphometric examination. Pain severity and its impact on activities of daily living (ADL) were evaluated through the Brief Pain Inventory (BPI). Neuropathic pain was investigated through the Italian versions of the Leeds Assessment of Neuropathic Symptoms and Signs pain scale (LANSS) and the painDETECT questionnaire (PD-Q).

RESULTS:

We included 72 patients, mainly women (88.8%), with mean age of 69.2 years. The 70.8% of patients had multiple OVFs, of which 47% located at the thoracic spine, 43.1% at the thoracic and at lumbar spine, and 9.8% at the lumbar spine. The BPI showed moderate back pain in 23.6% of cases and severe in 8.3% of cases, with high interference with ADL in 38.9% of patients. The PD-Q revealed the presence of neuropathic pain in 5.5% of cases, while the LANSS in 23.6% of cases.

CONCLUSIONS:

In our study, the prevalence of neuropathic component of chronic back pain ranged from 5.5% to 23.6%, according to PD-Q and LANSS respectively, in patients with OVFs. Further studies should investigate if the characterization of chronic back pain might contribute to appropriateness of interventions for this population.

MRI grading of spinal stenosis is not associated with the severity of low back pain in patients with lumbar spinal stenosis

Background

Although lumbar spinal stenosis (LSS) often coexists with other degenerative conditions, few studies have fully assessed possible contributing factors for low back pain (LBP) in patients with LSS. The purpose of this study was to identify factors associated with the severity of LBP in patients with LSS.

Methods

The patients with neurogenic claudication caused by LSS, which was confirmed by magnetic resonance imaging (MRI) were included in this cross-sectional study. Data included ratings of LBP, buttock and leg pain, and numbness on a numerical rating scale (NRS), 36-item Short-Form Survey (SF-36) scores, muscle mass measured by bioelectrical impedance analysis, and radiographic measurements including lumbopelvic alignment and slippage. The severity of LSS, endplate defects, Modic endplate changes, intervertebral disc degeneration, and facet joint osteoarthritis were evaluated on MRI. Spearman correlation and multivariate linear regression analyses were used to examine the factors associated with the severity of LBP (NRS score).

Results

A total of 293 patients (135 male and 158 female, average age 72.6 years) were analyzed. LBP was moderately correlated with buttock and leg pain, and buttock and leg numbness. Significant but weak correlations were observed between LBP and body mass index, appendicular and trunk muscle mass, all domains of SF-36, pelvic tilt, total number of endplate defects and Modic endplate changes, and summary score of disc degeneration grading, but not severity or number of spinal stenoses. In the multivariate regression analysis, age, female sex, trunk muscle mass, diabetes, NRS buttock and leg pain, NRS buttock and leg numbness, SF-36 vitality, pelvic tilt, and total number of endplate defects were associated with the severity of LBP.

Conclusions

Trunk muscle mass, lumbopelvic alignment, and endplate defects, but not severity of stenosis are partly associated with severity of LBP, but buttock and leg pain and buttock and leg numbness have strongest relationships with LBP in patients with LSS.

Comparing what the clinician draws on a digital pain map to that of persons who have greater trochanteric pain syndrome

OBJECTIVES

To assess the agreements and differences in pain drawings (pain area, shape and location) between individuals who have greater trochanteric pain syndrome (GTPS) and their clinician.

METHODS

In this study, 23 patients with GTPS (21 female, pain duration range 8-24 months) underwent clinical evaluation by a registered physiotherapist. Digital 2d full body pain drawings were independently performed by the clinician during the subjective examination and by the patient following the physical examination. Levels of agreement [LoA] in the pain area were assessed with Bland-Altman plots. Differences in pain drawings were assessed visually by overlaying images, and by quantifying the differences in shape and location with the bounding box, and Jaccard index, respectively.

RESULTS

Pain areas (/total pixels of the charts) did not differ in size (LoA mean difference less than -0.5%; range -2.35-1.56%) or shape (bounding box p>0.17). However, there was minimal overlap in location (Jaccard index range 0.09-0.18/1 for perfect overlap).

CONCLUSIONS

Patients and the clinician displayed differences in location of pain areas, but not size or shape, when they independently performed digital pain drawings. The reasons that underlie and the clinical impact of these differences remains unclear.

The Effect of Preoperative Neuropathic Pain and Nociceptive Pain on Postoperative Pain Intensity in Patients with the Lumbar Degenerative Disease Following Lateral Lumbar Interbody Fusion

OBJECTIVE

The purpose of this study was to analyze whether the type of preoperative pain affects the improvement in postoperative pain intensity in patients with a lumbar degenerative disease (LDD).

METHODS

We retrospectively reviewed 93 patients who underwent lateral lumbar interbody fusion (LLIF) without direct decompression. All patients were evaluated using Numeric Rating Scale (NRS) scores for low back pain (NRS_LBP), leg pain (NRS_LP), and leg numbness (NRS_LN) and imaging data before and after LLIF surgery. Based on the Japanese version of the painDETECT scores, patients were classified into 3 groups: a neuropathic pain (NeP) group, a nociceptive pain (NocP) group, and an intermediate mixed pain group.

RESULTS

The Japanese version of the painDETECT identified NeP in 20.4% of patients with LDD prior to LLIF. Preoperative NRS_LBP, NRS_LP, and NRS_LN scores were higher in the NeP group than those in the NocP group. All types of pain improved after LLIF surgery. The NRS_LBP score 12 months after surgery was higher in the NeP group (3.8 ± 2.8) than that in the NocP group (1.9 ± 2.2) (P = 0.008). Similar results were obtained with NRS_LP (NeP group = 3.1 ± 2.8, NocP group = 1.5 ± 2.0, P = 0.010).

CONCLUSIONS

Although LLIF was useful for relieving all types of preoperative pain in LDD patients, the NRS scores for preoperative pain were higher in the NeP group than those in the NocP group, and the postoperative NRS_LBP and NRS_LP score was significantly higher in the NeP group. Thus, controlling preoperative NeP may improve therapeutic efficacy.

Endplate defects, not the severity of spinal stenosis, contribute to low back pain in patients with lumbar spinal stenosis

BACKGROUND CONTEXT

It is controversial whether lumbar spinal stenosis (LSS) itself contributes to low back pain (LBP). Lower truncal skeletal muscle mass, spinopelvic malalignment, intervertebral disc degeneration, and endplate abnormalities are thought to be related to LBP. However, whether these factors cause LBP in patients with LSS is unclear.

PURPOSE

To identify factors associated with LBP in patients with LSS.

STUDY DESIGN/SETTING

Cross-sectional design.

PATIENT SAMPLE

A total of 260 patients (119 men and 141 women, average age 72.8 years) with neurogenic claudication caused by LSS, as confirmed by magnetic resonance imaging (MRI).

OUTCOME MEASURES

Ratings of LBP, buttock and leg pain, and numbness on a numerical rating scale (NRS), 36-Item Short Form Survey (SF-36) scores, muscle mass measured by bioelectrical impedance analysis, and radiographic measurements including slippage and lumbopelvic alignment. The severity of LSS, endplate defects, Modic endplate changes, intervertebral disc degeneration, and facet joint osteoarthritis were assessed on MRI.

METHODS

The presence of LBP was defined as an NRS score ≥3. The demographic data, patient-reported outcomes, and radiological and MRI findings were compared between patients with and without LBP. Multivariate logistic regression analysis was used to identify the factors that were independently associated with the presence of LBP.

RESULTS

There were significant differences between patients with and without LBP for buttock and leg pain and numbness on the NRS, general health on the SF-36, presence of endplate defects, presence of Modic changes, disc degeneration grading, and disc height grading (all p < .05). Multivariate logistic regression analysis showed significant associations between LBP and diabetes (OR 2.43; 95% CI 1.07-5.53), buttock and leg numbness on the NRS (OR 1.34; 95% CI 1.17-1.52), general health on the SF-36 (OR 0.97; 95% CI 0.95-0.99), and the presence of erosive endplate defects (OR 3.04; 95% CI 1.51-6.11) (all p < .05).

CONCLUSIONS

These results suggest that LBP in patients with LSS should be carefully assessed not only for spinal stenosis but also clinical factors and endplate defects.

PROMIS Neuropathic and Nociceptive Pain Quality in Musculoskeletal Pain Presentations

OBJECTIVE

Musculoskeletal pain is a significant contributor to the global disease burden. Management of musculoskeletal pain where a neuropathic component is present can be challenging. This study evaluated the internal structure of the Patient-Reported Outcome Measures Information System (PROMIS) pain quality scales, explored the prevalence of neuropathic and nociceptive pain, and identified health demographics and behaviors related to musculoskeletal pain presentations.

METHODS

Patients presenting to the Victoria University Osteopathy Clinic (Melbourne, Vic., Australia) were invited to complete a health demographics and behaviors questionnaire, and the PROMIS Neuropathic (NeuroPQ) and Nociceptive (NociPQ) pain quality scales, before their initial consultation. Descriptive, inferential, and correlation statistics were used to evaluate the PROMIS scales, health demographics, and behaviors. Mokken scale analysis was used to evaluate the internal structure and dimensionality of the NeuroPQ and NociPQ scales.

RESULTS

Three hundred eighty-three (N=383) patients completed the measures. Mokken scaling suggested the PROMIS scales demonstrated acceptable internal structure and were unidimensional. Over 22% of patients demonstrated cutoff scores above 50, suggesting a substantive neuropathic pain component to their musculoskeletal presentation. Patients who reported cigarette smoking, not being born in Australia or not speaking English at home, demonstrated higher NeuroPQ scores. Females demonstrated significantly higher NociPQ scores than males. Pain intensity demonstrated small to medium correlations with NeuroPQ and NociPQ scores.

DISCUSSION

This study provides support for the use of the NeuroPQ and NociPQ scales in musculoskeletal pain patients. Associations with health demographics and behaviors were identified, and patients typically experienced a combination of neuropathic and nociceptive pain.

Risk Factors for Neuropathic Pain in Middle-Aged and Elderly People: A Five-Year Longitudinal Cohort in the Yakumo Study

OBJECTIVE

To determine the risk factors for new neuropathic pain (NeP) after five years in healthy middle-aged and elderly volunteers.

DESIGN

Prospective longitudinal cohort study (Yakumo study).

SETTING

Clinical evaluation in a health checkup.

SUBJECTS

A total of 366 people (male N = 146, female N = 220, average age = 63.5 years) who did not have NeP in 2013 were examined.

METHODS

NeP was diagnosed based on a painDETECT questionnaire score ≥13. Body mass index (BMI), comorbidity, low back pain (LBP), sciatica, physical ability, grip and back muscle strength, osteoporosis, sarcopenia, frailty, spinal alignment, and quality of life (QOL) with the SF36 in 2013 were compared between NeP(+) and NeP(-) subjects in 2018 using multivariate logistic regression analysis.

RESULTS

The NeP(+) rate in 2018 was 5.2%, with no significant differences in age and gender. NeP(+) subjects had significantly lower BMI, severe sciatica, poor gait ability, higher rates of osteoporosis and sarcopenia, greater lumbar kyphosis and spinal inclination, and poorer mental health in 2013. Poor gait ability (odds ratio [OR] = 8.05), low BMI (OR = 2.31), lumbar kyphosis (OR = 1.38), low percentage of the young adult mean (OR = 1.15), and low mental QOL (OR = 1.06) were identified as significant and independent risk factors for new NeP after five years.

CONCLUSIONS

This longitudinal cohort study identified five independent risk factors for development of new NeP after five years, with related factors of spinal inclination, sarcopenia, and sciatica. New NeP may be prevented by intervention or treatment of these factors at an early stage in relatively healthy middle-aged and elderly people.

Percutaneously-quantified advanced glycation end-products (AGEs) accumulation associates with low back pain and lower extremity symptoms in middle-aged low back pain patients

Advanced glycation end-products (AGEs) have been reported as a possible biomarker of ageing and metabolic diseases; however, its role in the clinical progression of these diseases remains unclear. We aimed to evaluate how AGEs are associated with clinical symptoms and comorbidities in lower back pain (LBP) patients. This prospective cohort study enrolled 636 LBP patients. They were subjected to quantified AGE (qAGE) analysis using skin autofluorescence, and their clinical symptoms and comorbidities, such as diabetes, renal failure with haemodialysis treatment, and osteoporosis, were measured. LBP, lower extremity pain, and numbness were evaluated using a visual analogue scale (VAS). The measured qAGE was significantly higher in subjects with any comorbidity. Age also showed a strong positive correlation with qAGE. qAGE and VAS for leg numbness were positively correlated. Furthermore, in LBP patients under 50-years-old, qAGE was positively correlated with VAS for LBP, lower extremity pain, and numbness. In conclusion, qAGE, as measured by skin autofluorescence measurement, was significantly higher in LBP patients with diabetes and dialysis, as well as in osteoporosis patients. Furthermore, qAGE showed potential as a biomarker for LBP, lower extremity pain, and numbness in patients under 50-years-old. If accumulated AGEs are identified at a young age, researchers should be vigilant for the development of osteoporosis and LBP-related clinical symptoms later in life.

Prevalence of lumbar spinal stenosis in general and clinical populations: a systematic review and meta-analysis

PURPOSE

To estimate the prevalence of degenerative lumbar spinal stenosis (LSS) in adults, identified by clinical symptoms and/or radiological criteria.

METHODS

Systematic review of the literature. Pooled prevalence estimates by care setting and clinical or radiological diagnostic criteria were calculated and plotted [PROSPERO ID: CRD42018109640].

RESULTS

In total, 41 papers reporting on 55 study samples were included. The overall risk of bias was considered high in two-thirds of the papers. The mean prevalence, based on a clinical diagnosis of LSS in the general population, was 11% (95% CI 4-18%), 25% (95% CI 19-32%) in patients from primary care, 29% (95% CI 22-36%) in patients from secondary care and 39% (95% CI 39-39%) in patients from mixed primary and secondary care. Evaluating the presence of LSS based on radiological diagnosis, the pooled prevalence was 11% (95% CI 5-18%) in the asymptomatic population, 38% (95% CI - 10 to 85%) in the general population, 15% (95% CI 13-18%) in patients from primary care, 32% (95% CI 22-41%) in patients from secondary care and 21% (95% CI 16-26%) in a mixed population from primary and secondary care.

CONCLUSIONS

The mean prevalence estimates based on clinical diagnoses vary between 11 and 39%, and the estimates based on radiological diagnoses similarly vary between 11 and 38%. The results are based on studies with high risk of bias, and the pooled prevalence estimates should therefore be interpreted with caution. With an growing elderly population, there is a need for future low risk-of-bias research clarifying clinical and radiological diagnostic criteria of lumbar spinal stenosis. These slides can be retrieved under Electronic Supplementary Material.

The Relationship Between Neuropathic Pain and Spinal Alignment: Independent Risk Factors for Low Quality of Life in Middle-Aged and Elderly People

STUDY DESIGN

Prospective research in middle-aged and elderly people.

OBJECTIVE

To investigate low back pain (LBP) and neuropathic pain (NeP); spinal alignment and range of motion (ROM); spinal degenerative changes in plain radiography; osteoporosis; muscle strength; and physical ability as possible risk factors for poor quality of life (QOL).

SUMMARY OF BACKGROUND DATA

The aging of society has led to an increase in elderly people with chronic pain, including LBP and NeP. However, there has been no analysis of NeP and spinal sagittal alignment as potential risk factors for decreased QOL in the healthy general population.

METHODS

The subjects were 1128 people (male 473, female 655, average age: 64.3 yrs) who attended an annual health checkup in Yakumo study. The prevalence of LBP and sciatica were investigated using a visual analogue scale (VAS), and NeP was defined as more than or equal to 13 points on the painDETECT questionnaire. Sagittal spinal alignment with spinal ROM was also measured. Body mass index, muscle strength, physical ability, osteoporosis, and lumbar degenerative changes were measured, and 36-item short-form health survey (SF-36) was used for QOL analysis.

RESULTS

NeP was present in 113 people (10%). The NeP (+) subjects had significantly more severe pain, lower gait speed, higher osteoporosis rate, lumbar kyphosis, and larger spinal inclination (P < 0.01) compared with NeP (-) subjects. On SF-36, physical and mental QOL were significantly lower for NeP (+) subjects (P < 0.0001). In multivariate logistic regression analysis adjusted for age and sex, NeP (+) (odds ratio [OR]: 3.01), positive spinal inclination (OR: 1.14), and high VAS for LBP (OR: 1.04) were identified as risk factors for low physical QOL, and NeP (+) (OR: 5.32) was the only significant risk factor for low mental QOL.

CONCLUSION

These results suggest that interventions for NeP and other identified risk factors may contribute to improvement of low physical and mental QOL in middle-aged and elderly people.

LEVEL OF EVIDENCE

2.

Shoulder pain has most impact on poor quality of life among various types of musculoskeletal pain in middle-aged and elderly people: Yakumo study

Objectives: To investigate the severity and effect on quality of life (QOL) of various types of pain in healthy volunteers.Methods: A total of 384 subjects (male: 158, female: 226, average age: 63 years) were included in a prospective cohort study (Yakumo study). Shoulder pain, low back pain (LBP), sciatica, knee pain, and the American Shoulder and Elbow Surgeons (ASES) shoulder score were evaluated with SF-36.Results: The prevalence of shoulder pain, LBP, sciatica, and knee pain was 42%, 44%, 16%, and 48%, respectively, with similar severities of pain. Shoulder pain visual analogue scale (VAS) and ASES shoulder scores were significantly correlated with SF-36 domains. Subjects with poor physical QOL had significantly higher VAS scores for all pain types and a lower ASES shoulder score. Shoulder pain VAS was also significantly related to poor mental QOL. Multivariate regression analysis adjusted for age and gender showed that shoulder pain VAS (OR: 1.25, p < .05) and 10-m gait speed (OR: 1.82, p < .05) were significant independent risk factors for poor physical QOL.Conclusion: Only shoulder pain of similar severity to other pain and shoulder complaints impacted on both physical and mental QOL. The severity of shoulder pain was an independent risk factor for poor physical QOL.

Prevalence of Neuropathic Pain Symptoms in Foot and Ankle Patients

BACKGROUND

The management of pain in patients with foot and ankle pathology can be challenging. Cumulative data suggest that, in addition to nociceptive mechanisms, other neuropathic mechanisms can contribute to pain in a subset of people with orthopedic conditions, and can be found in 10.5% to 53% of patients with chronic pain, depending on the location of the pathology. Preoperative diagnosis of neuropathic pain (NP) can potentially change decision making and management of foot and ankle pathologies.

METHODS

We used a validated patient-reported pain questionnaire (painDETECT) as a cross-sectional study to investigate the prevalence of NP symptoms in a population of patients undergoing foot and ankle surgery. A total of 533 patients were prospectively included and completed the painDETECT questionnaire.

RESULTS

Sixty-six patients (12.4%) were classified as having a component of NP symptoms according to their painDETECT score. Current smokers (23.2%) had a significantly higher rate of developing NP symptoms than current nonsmokers (11.1%) ( P = .016). The location of the pathology and obesity had a moderate effect on the prevalence of NP symptoms. Patients with ankle-level pathology, excluding tarsal tunnel syndrome, had a marginally increased risk of having NP symptoms (15.4%) compared to patients with forefoot pathologies, excluding Morton's neuroma (7.5%, P = 0.06). Obesity also had a moderate effect on the NP risk, with 15.6% risk of NP symptoms for patients with BMI of 30 or more compared to 10% risk for patients with a BMI of less than 30 ( P = .06). Patients with NP symptoms reported significantly higher levels of current pain (7.2 vs 4.6, P < .001).

CONCLUSION

A considerable number of patients with foot and ankle problems requiring surgery had a neuropathic component of pain. Evaluation of their risk factors and level of pain may help with the diagnosis, decision making, and pain control. Further research is needed to evaluate the effect of preoperative NP on the short- and long-term results of surgeries.

LEVEL OF EVIDENCE

Level II, prospective cohort survey study.

Unilateral laminectomy for bilateral decompression improves low back pain while standing equally on both sides in patients with lumbar canal stenosis: analysis using a detailed visual analogue scale

BACKGROUND

Unilateral laminectomy for bilateral decompression (ULBD) for lumbar spinal stenosis (LSS) is a less invasive technique compared to conventional laminectomy. Recently, several authors have reported favorable results of low back pain (LBP) in patients of LSS treated with ULBD. However, the detailed changes and localization of LBP before and after ULBD for LSS remain unclear. Furthermore, unsymmetrical invasion to para-spinal muscle and facet joint may result in the residual unsymmetrical symptoms. To clarify these points, we conducted an observational study and used detailed visual analog scale (VAS) scores to evaluate the characteristics and bilateral changes of LBP and lower extremity symptoms.

METHODS

We included 50 patients with LSS treated with ULBD. A detailed visual analogue scale (VAS; 100 mm) score of LBP in three different postural positions: motion, standing, and sitting, and bilateral VAS score (approached side versus opposite side) of LBP, lower extremity pain (LEP), and lower extremity numbness (LEN) were measured. Oswestry Disability Index (ODI) was used to quantify the clinical improvement.

RESULTS

Detailed LBP VAS score before surgery was 51.5 ± 32.5 in motion, 63.0 ± 30.1 while standing, and 37.8 ± 31.8 while sitting; and showed LBP while standing was significantly greater than LBP while sitting (p < 0.01). After surgery, LBP while standing was significantly improved relative to that while sitting (p < 0.05), and levels of LBP in the three postures became almost the same with ODI improvement. Bilateral VAS scores showed significant improvement equally on both sides (p < 0.01).

CONCLUSIONS

ULBD improves LBP while standing equally on both sides in patients with LCS. The improvement of LBP by the ULBD surgery suggests radicular LBP improved because of decompression surgery. Furthermore, the symmetric improvement of LBP by the ULBD surgery suggests unsymmetrical invasion of the paraspinal muscles and facet joints is unrelated to residual LBP.

Analysis of Neuropathic Pain Using Magnetic Resonance Imaging T2 Mapping of Intervertebral Disc in Chronic Low Back Pain

Study Design

Cross sectional study.

Purpose

The study aimed to analyze mechanisms underlying chronic low back pain (CLBP) using magnetic resonance imaging (MRI) T2 mapping of the intervertebral disc (IVD).

Overview of Literature

MRI T2 mapping utilizes the T2 values for quantifying moisture content and collagen sequence breakdown. We previously used MRI T2 mapping for quantifying the extent of IVD degeneration (IVDD) and showed a correlation between the degeneration of the posterior annulus fibrosus (AF) and CLBP.

Methods

We enrolled 40 patients with CLBP (17 males, 23 females; mean age, 50.8±1.6 years; range, 22–60 years). IVDs were categorized as the anterior AF, nucleus pulposus (NP), and posterior AF, and T2 value for each disc was measured. T2 values, assessed using the Japanese neuropathic pain (NeP) screening questionnaire, of the NeP and nociceptive pain (NocP) groups were compared.

Results

T2 values of the NocP and NeP groups were 64.7±5.6 ms and 58.1±2.3 ms for the anterior AF; 67.0±4.6 ms and 59.6±2.1 ms for NP; and 70.7±4.6 ms and 51.0±1.2 ms for the posterior AF, respectively. T2 values for IVDD were significantly lower in the NeP group than those in the NocP group (p<0.01).

Conclusions

The results indicate a correlation between the degeneration of posterior AF and NeP. MRI T2 mapping may be beneficial for detecting NeP caused by IVDD and can help formulate targeted analgesic therapies.

Chemotherapy-Induced Neuropathy in Cancer Survivors

CONTEXT

Evidence suggests that chemotherapy-induced neuropathy (CIN) is a significant problem for cancer survivors. However, a detailed phenotypic characterization of CIN in cancer survivors is not available.

OBJECTIVES

To evaluate between-group differences in demographic and clinical characteristics, as well as in measures of sensation, function, and postural control, in a sample of cancer survivors who received a platinum and/or a taxane-based CTX regimen and did (n = 426) and did not (n = 197) develop CIN.

METHODS

Survivors completed self-report questionnaires and underwent objective testing (i.e., light touch, pain sensation, cold sensation, vibration, muscle strength, grip strength, Purdue Pegboard test, Timed Get Up and Go test, Fullerton Advanced Balance test). Parametric and nonparametric statistics were used to compare between-group differences in study outcomes.

RESULTS

Of the 426 survivors with CIN, 4.9% had CIN only in their upper extremities, 27.0% only in their lower extremities, and 68.1% in both their upper and lower extremities. Demographic and clinical characteristics associated with CIN included the following: older age, lower annual income, higher body mass index, a higher level of comorbidity, being born prematurely, receipt of a higher cumulative dose of chemotherapy, and a poorer functional status. Survivors with CIN had worse outcomes for all of the following objective measures: light touch, pain, temperature, vibration, upper and lower extremity function, and balance.

CONCLUSIONS

This study is the first to provide a detailed phenotypic characterization of CIN in cancer survivors who received a platinum and/or a taxane compound. These data can serve as a benchmark for future studies of CIN in cancer survivors.

Prevalence and associations of neuropathic pain in a cohort of multi-ethnic Asian low back pain patients

The prevalence of neuropathic low back pain differs in different ethnic populations. The aims of the study are to determine its frequency and associations in a multi-ethnic cohort of Asian low back pain patients. This was a cross-sectional study of low back patients seen at the University of Malaya Medical Centre, Kuala Lumpur, Malaysia. Neuropathic low back pain patients were identified using the painDETECT questionnaire and compared with non-neuropathic (unclear or nociceptive) low back pain patients, in terms of socio-demographic and clinical factors, pain severity (numerical pain rating scale, NPRS), disability (Roland Morris Disability Questionnaire, RMDQ), as well as anxiety and depression (Hospital Anxiety and Depression Scale, HADS). Of 210 patients, 26 (12.4%) have neuropathic low back pain. Neuropathic pain is associated with non-Chinese ethnicity, higher body mass index and pain radiation below the knee. Patients with neuropathic pain have significantly higher NPRS and RMDQ scores, and there are more subjects with anxiety on HADS. However, there are no differences between the groups in age, gender, pain duration or underlying diagnosis of low back pain. The prevalence of neuropathic low back pain in a multi-ethnic Malaysian cohort is lower than previously reported in other populations with possible differences between ethnic groups. It is associated with greater pain severity, disability and anxiety.