Preoperative factors affecting the two-year postoperative patient-reported outcome in single-level lumbar grade I degenerative spondylolisthesis.

Background: The choice of operative method for lumbar spinal stenosis with Meyerding grade I degenerative spondylolisthesis remains controversial. The purpose of this study was to identify the preoperative factors affecting the 2-year postoperative patient-reported outcome in Meyerding grade I degenerative spondylolisthesis. Methods: Seventy-two consecutive patients who had minimally invasive decompression alone (D group; 28) or with fusion (DF group; 44) were enrolled. The parameters investigated were the Japanese Orthopaedic Association back pain evaluation questionnaire as patient-reported assessment, and L4 slippage (L4S), lumbar lordosis (LL), and lumbar axis sacral distance (LASD) as an index of sagittal alignment for radiological evaluation. Data collected prospectively at 2 years postoperatively were examined by statistical analysis. Results: Sixty-two cases (D group; 25, DF group; 37) were finally evaluated. In multiple logistic regression analysis, preoperative L4S and LASD were extracted as significant preoperative factors affecting the 2-year postoperative outcome. Patients with preoperative L4S of 6 mm or more have a lower rate of improvement in lumbar spine dysfunction due to low back pain (risk ratio=0.188, p=.043). Patients with a preoperative LASD of 30 mm or more have a higher rate of improvement in lumbar dysfunction due to low back pain (risk ratio=11.48, p=.021). The results of multiple logistic analysis by operative method showed that there was a higher rate of improvement in lumbar spine dysfunction due to low back pain in patients with preoperative LASD of 30 mm or more in DF group (risk ratio=172.028, p=.01). Conclusions: Preoperative L4S and LASD were extracted as significant preoperative factors affecting patient-reported outcomes at 2 years postoperatively. Multiple logistic analyses by the operative method suggested that DF may be advantageous in improving lumbar dysfunction due to low back pain in patients with preoperative LASD of 30 mm or more.

Systemically Acting Diclofenac Sodium Patch for Control of Low Back Pain: A Randomized, Double-Blind, Placebo-Controlled Study in Japan.

INTRODUCTION: Nonsteroidal antiinflammatory drugs (NSAIDs) are commonly used for pain disorders such as low back pain and exist in multiple formulations; however, no systemically acting transdermal formulations are available for low back pain. Transdermal formulations can be safely administered even to patients with trouble swallowing or at risk of aspiration, and without regard to the effect of food on drug absorption. Unlike locally acting formulations, systemically acting transdermal formulations need not be applied at the target site, so dosing is simple and the burden is not on one area of the skin. A patch with the systemically acting NSAID diclofenac sodium is approved in Japan for treatment of cancer-related pain, and we hypothesized that it would be useful for controlling low back pain. METHODS: This randomized, double-blind, placebo-controlled study aimed to evaluate the efficacy and safety of diclofenac sodium patch in Japanese patients with low back pain. Eligible patients were randomized to receive diclofenac sodium patch 75 mg or 150 mg or placebo once daily for 2 weeks. The primary endpoint was pain intensity assessed on a visual analog scale (VAS). RESULTS: Primary analysis of the primary endpoint showed that both doses of the diclofenac sodium patch (150 mg and 75 mg) were superior to placebo in terms of absolute change from baseline in mean 3-day VAS score after 2 weeks' treatment; the mean difference between the active and placebo treatments in this variable was -5.67 [95% confidence interval (CI) -9.34 to -2.00] mm in the 150 mg group and -5.68 (95% CI -9.34 to -2.01) mm in the 75 mg group. Most adverse events were mild. No serious adverse events occurred. CONCLUSION: In Japanese patients, diclofenac sodium patch is effective for the relief of low back pain and is well tolerated. TRIAL REGISTRATION: JPRN number, JPRN-JapicCTI-205134.

The Relationship between Numbness and Quality of Life.

BACKGROUND: Numbness is a term commonly used in clinical practice to describe an abnormal sensory experience that is produced by a stimulus or is present even without a stimulus. However, there is still much that remains obscure in this field, and also, few reports have focused on its symptoms. In addition, while pain itself is known to have a significant impact on quality of life (QOL), the relationship between numbness and QOL is often unclear. Therefore, we conducted an epidemiological survey and analyzed the relationship between painless numbness and QOL, using type, location, and age as influencing factors, respectively. METHODS: A nationwide epidemiological survey was conducted by mail using a survey panel designed by the Nippon Research Center. Questionnaires were sent to 10,000 randomly selected people aged 18 and over from all over Japan. Out of the 5682 people who responded, the relationship between numbness and QOL was analyzed using the EuroQol 5 Dimension-3L (EQ5D-3L) for patients who are currently experiencing painless numbness. FINDINGS: The results suggest that painless numbness affects QOL and that QOL decreases as its intensity increases. Furthermore, the two factors of numbness of feet and numbness among the young may be less likely to affect QOL. This study may be of great significance in the field of numbness research.

Comparison of the Effectiveness of Pharmacological Treatments for Patients with Chronic Low Back Pain: A Nationwide, Multicenter Study in Japan.

INTRODUCTION: Chronic low back pain (CLBP) is a leading cause of disability, yet there is limited high-quality evidence to identify the most suitable pharmacological therapy. The purpose of this Japanese nationwide, multicenter, prospective study was to compare the effectiveness of four representative drug therapies-acetaminophen, celecoxib, loxoprofen, and a tramadol and acetaminophen (T+A) combination drug-to establish evidence for a drug of choice for CLBP. METHODS: Patients with CLBP (N=471) received one of the four treatments and were evaluated, prospectively and comprehensively, once every month for six months using a visual analog scale (VAS) for LBP, the Japanese Orthopedic Association (JOA) score, the JOA Back Pain Evaluation Questionnaire (JOABPEQ), the Roland-Morris Disability Questionnaire (RDQ), the EuroQol five-dimensions three-levels (EQ-5D-3L), and the Short Form-8 item health survey (SF-8). We conducted multivariable linear regression analyses of the four drugs at 1 and 6 months after drug allocation. Differences with P<0.05 were considered statistically significant. RESULTS: Patients who received acetaminophen showed a significant improvement from baseline in the mental health subscale of the JOABPEQ at one month (P=0.02) and the JOA score at six months (P<0.01). None of the other outcome measures among the four drugs differed significantly. Across groups, all outcome measures, except the mental component summary (MCS) score of the SF-8, improved equivalently, although most measurements showed no obvious cumulative effect over six months. The MCS score of the SF-8 decreased gradually over six months in all groups. CONCLUSIONS: Most of the outcome measures among the treated groups were not significantly different, indicating similar treatment effects of the four drugs for CLBP. Our study indicated the limit of each outcome measure for evaluating the patient status, suggesting that a single outcome measure is insufficient to reflect treatment effectiveness.

Three-dimensional analysis of the characteristics of joint motion and gait pattern in a rodent model following spinal nerve ligation.

BACKGROUND: The spinal nerve ligation (SNL) rat is well known as the most common rodent model of neuropathic pain without motor deficit. Researchers have performed analyses using only the von Frey and thermal withdrawal tests to evaluate pain intensity in the rat experimental model. However, these test are completely different from the neurological examinations performed clinically. We think that several behavioral reactions must be observed following SNL because the patients with neuropathic pain usually have impaired coordination of the motions of the right-left limbs and right-left joint motion differences. In this study, we attempted to clarify the pain behavioral reactions in SNL rat model as in patients. We used the Kinema-Tracer system for 3D kinematics gait analysis to identify new characteristic parameters of each joint movement and gait pattern. RESULTS: The effect of SNL on mechanical allodynia was a 47 ± 6.1% decrease in the withdrawal threshold during 1-8 weeks post-operation. Sagittal trajectories of the hip, knee and ankle markers in SNL rats showed a large sagittal fluctuation of each joint while walking. Top minus bottom height of the left hip and knee that represents instability during walking was significantly larger in the SNL than sham rats. Both-foot contact time, which is one of the gait characteristics, was significantly longer in the SNL versus sham rats: 1.9 ± 0.15 s vs. 1.03 ± 0.15 s at 4 weeks post-operation (p = 0.003). We also examined the circular phase time to evaluate coordination of the right and left hind-limbs. The ratio of the right/left circular time was 1.0 ± 0.08 in the sham rats and 0.62 ± 0.15 in the SNL rats at 4 weeks post-operation. CONCLUSIONS: We revealed new quantitative parameters in an SNL rat model that are directly relevant to the neurological symptoms in patients with neuropathic pain, in whom the von Frey and thermal withdrawal tests are not used at all clinically. This new 3D analysis system can contribute to the analysis of pain intensity of SNL rats in detail similar to human patients' reactions following neuropathic pain.

Direct and Indirect Pathways for Health-Related Quality of Life Change from Pain Improvement in Neuropathic Pain Patients with Spine Diseases: Path Analysis with Structural Equation Modeling Using Non-Interventional Study Results of Pregabalin.

BACKGROUND: Chronic low back pain or chronic cervical pain often has a neuropathic pain (NeP) component and patients with these conditions complain of sleep deprivation, loss of physical function, and reduced productivity due to pain. The objective of this study was to clarify the pathway by which pain, sleep disturbance due to pain, and physical function status influence QOL measures in chronic low back pain patients with NeP associated with lumbar spine diseases (CLBP-NeP) and in chronic cervical pain patients with NeP associated with cervical spine diseases (CCP-NeP). METHODS: A model assuming pain numeric rating scale (NRS), pain-related sleep interference scale (PRSIS), and functional indices (Roland Morris Disability Questionnaire [RMDQ], Neck Disability index [NDI]) as factors that can affect outcomes such as QOL (calculated using EuroQoL 5 Dimensions (EQ-5D)), the Patient Global Impression of Change (PGIC), and the Clinical Global Impression of Change (CGIC) was developed using structural equation modeling. RESULTS: Overall trends were frequently observed in both patients with CLBP-NeP and CCP-NeP. Pain NRS had the largest comprehensive direct impact on QOL based on EQ-5D and an overall impression of changing symptoms. The effects of pain NRS on each outcome were largely due to direct pain-related effects; however, for EQ-5D, an indirect effect via functional improvement was the primary factor. CONCLUSION: Although the results of this study suggest that the indirect functional improvement of pain relief may not be recognized as a significant component of therapeutic effects by both physicians and patients, the pain-relieving intervention contributes directly to improvement of patients' overall QOL and also indirectly via functional improvement in Japanese primary care settings. Accordingly, to achieve the therapeutic goal for patients with NeP and minimize the impact of pain burden, our findings indicate that pain relief interventions are also crucial from the perspective of the patient's HRQOL.

Effectiveness of Pregabalin Treatment for Neuropathic Pain in Patients with Spine Diseases: A Pooled Analysis of Two Multicenter Observational Studies in Japan.

PURPOSE: Neuropathic pain (NeP) is common among patients with chronic pain associated with spine diseases. Practical effectiveness of pregabalin, one of the first-line treatments for NeP, has not been evaluated in an entire population of patients with spine diseases, including various pathophysiological conditions. This pooled analysis aimed to evaluate the therapeutic value of pregabalin for chronic pain with NeP component in patients with spine diseases in routine primary care settings. PATIENTS AND METHODS: We pooled data from two 8-week prospective observational cohort studies for patients with chronic low back pain with accompanying lower limb pain (NeP component), and patients with chronic cervical pain and accompanying upper limb radiating pain (NeP component) in routine primary care settings in Japan. For both studies, patients were treated for 8 weeks with pregabalin (alone/with other analgesics) or usual care with conventional analgesics (eg, non-steroidal anti-inflammatory drugs). Changes in pain numerical rating scale (NRS), Pain-Related Sleep Interference Scale (PRSIS), and EuroQol 5-dimension 5-level (EQ-5D-5L) scores from baseline to week 8 were summarized and compared between the pregabalin and usual care groups, and also for subgroups of primary diagnosis. Safety was evaluated by adverse events (AEs) in the pregabalin group. RESULTS: The pooled dataset comprised 700 patients (pregabalin group: 302; usual care group: 398). All patient-reported outcomes (PRO) scores significantly improved from baseline to week 8 in the pregabalin than in the usual care group (NRS: P<0.0001; PRSIS: P<0.0001, and EQ-5D-5L: P=0.0006). Overall, all three PRO measures showed greater improvement in the pregabalin than in the usual care group, irrespective of the primary diagnosis. AEs were reported in 36.1% of the pregabalin group. CONCLUSION: This analysis suggested multi-faceted effectiveness of treatment with pregabalin from the patient's perspectives under a "real-world" practice in all patients with chronic NeP from various spine diseases.

Impact of background factors on outcomes of pharmacological therapy for chronic low back pain: A nationwide multicenter prospective study.

BACKGROUND: Chronic low back pain (CLBP) is a major cause of chronic pain with nociceptive, neuropathic or both pain components, and a leading cause of disability. The objectives of this study were to determine the impact of background factors including previous use of drugs on outcomes of pharmacological therapy for CLBP in a nationwide multicenter prospective study. METHODS: The subjects were 474 patients (male: 41.9%, median age: 73.0) with CLBP. Background factors that could influence outcomes after pharmacological treatment for 6 months were examined: age, gender, body mass index (BMI), duration of CLBP, osteoporosis, history of spinal surgery, history of malignant tumor, smoking habit, employment status (yes or no), exercise habit (frequency), number of live-in family members, having something to do for pleasure, Center for Epidemiologic Studies depression scale (CES-D) score, and medication at baseline. Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) for LBP, JOA Back Pain Evaluation Questionnaire (JOABPEQ), Roland-Morris Disability Questionnaire (RDQ), Short-form 8-item health survey (SF-8), and EQ-5D were used for evaluation at baseline and after 6 months. Multivariate linear regression models were used in statistical analysis. RESULTS: Drugs for neuropathic pain at baseline (p < 0.001), Tramacet® at baseline (p < 0.05), weak opioids at baseline (p < 0.05), older age (p < 0.001), long disease duration (p < 0.005), history of spinal surgery (p < 0.001), and smoking habit (p < 0.001) had significant negative effects on outcomes. Employment (p < 0.05), exercise habit (p < 0.05), and CED-D at baseline (p < 0.001) had positive effects on outcomes. CONCLUSIONS: This is the first study to identify significant prognostic factors for outcomes of pharmacological treatment of CLBP. The neuropathic pain component of CLBP at baseline is a major significant negative factor for most outcomes involving improved pain, activities of daily life, and quality of life. Treatment strategies developed with consideration of these factors may be advantageous for recovery from CLBP.

A systematic review and meta-analysis comparing anterior decompression with fusion and posterior laminoplasty for cervical spondylotic myelopathy.

BACKGROUND: The optimal surgical procedure for the treatment of cervical spondylotic myelopathy (CSM) remains controversial because there are few comprehensive studies that have investigated the surgical methods. Therefore, we conducted a systematic review and meta-analysis to evaluate evidence in the literature and to compare the surgical outcomes between anterior decompression with fusion (ADF) and laminoplasty, which are representative procedures for CSM. METHODS: An extensive literature search was performed using PubMed, Embase, and the Cochrane Library to identify comparative studies of ADF and laminoplasty for CSM. The language was restricted to English, and the publication period was from January 2001 to July 2019. We only included studies of CSM and excluded studies that involved patients with ossification of the posterior longitudinal ligament and treatments with posterior instrumented fusion. We extracted outcomes from the studies, such as preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, cervical alignment, surgical complications and reoperation rates. Then, a meta-analysis was performed on these surgical outcomes. RESULTS: Nine studies were obtained, and the quality of the studies was acceptable. In the meta-analysis, the preoperative JOA score was similar between the ADF and laminoplasty groups. The postoperative JOA scores and neurological recovery rates were not different between the ADF and laminoplasty groups. ADF exhibited more favorable results than laminoplasty in terms of postoperative cervical alignment. In contrast, overall complications were more frequently observed in the ADF group than in the laminoplasty group, leading to higher rates of reoperation. However, postoperative neck pain was more frequently observed in the laminoplasty group than in the ADF group. CONCLUSIONS: This systematic review and meta-analysis showed both the merits and shortcomings of ADF and laminoplasty. ADF and laminoplasty showed similar results in terms of neurological recovery. Postoperative cervical lordosis was better preserved with ADF than with laminoplasty. However, ADF was associated with a higher incidence of surgical complications than laminoplasty.

Assessment of spinal cord relative vulnerability in C4-C5 compressive cervical myelopathy using multi-modal spinal cord evoked potentials and neurological findings.

Objective: The correlation between the progression of spinal cord lesions using spinal cord evoked potentials (SCEPs) and neurological findings are unclear. The purpose is to electrophysiologically evaluate relative vulnerability of spinal cord in patients with compressive cervical myelopathy (CCM) at C4-C5 intervertebral level using SCEPs and correlate the progression of spinal cord lesions with neurological findings.Design: Retrospective study.Setting: Yamaguchi University Hospital.Participants: 36 patients.Methods: SCEPs following median nerve stimulation (MN-SCEPs), ulnar nerve stimulation (UN-SCEPs), transcranial electric stimulation (TCE-SCEPs), and spinal cord stimulation (SC-SCEPs) were intraoperatively recorded. MN-SCEPs are mediated by posterior horns (4, 5 layers), UN-SCEPs by the Burdach tract, TCE-SCEPs by the lateral corticospinal tract, and SC-SCEPs by the Goll tract. We evaluated the neurological findings (numbness, tactile sense and pain sense in the C6 area, tactile sense in the lower extremities, and triceps tendon reflex [TTR]).Results: The incidence of electrophysiological and clinical abnormalities decreased in the order of UN-SCEPs (100%), TCE-SCEPs (94.4%), MN-SCEPs (77.8%), and SC-SCEPs (69.4%), and in the order of numbness (100%), pain sense (97.2%), TTR (91.7%), tactile sense in the C6 area (83.3%), and tactile sense in the lower extremities (70.0%), respectively.Conclusions: The relative vulnerability of spinal cord occurred in the order of the Burdach tract, the lateral corticospinal tract, posterior horns (4, 5 layers), and the Goll tract in most patients with CCM at the C4-C5 intervertebral level.

Impact of Consultation Length on Satisfaction in Patients with Chronic Low Back Pain: A Nationwide Multicenter Study in Japan.

INTRODUCTION: Chronic low back pain (CLBP) is a major health burden worldwide and requires patient satisfaction with treatment. Consultation length can be an important factor in patient satisfaction, but few studies have investigated the impact of consultation length on satisfaction in patients with CLBP. This study tried to elucidate the impact of consultation length on clinical outcomes in patients with CLBP. METHODS: This study is part of an analysis using the database of the nationwide, multicenter cohort for CLBP performed by the Project Committee of the Japanese Society for Spine Surgery and Related Research. A total of 427 patients aged 20-85 years (median age, 73.0 years; female, 58.6%) with CLBP were prospectively followed-up monthly for 6 months. Multivariable nonlinear regression analyses were performed to assess the effect of consultation length on outcome measures including subjective satisfaction score, EuroQol 5-dimension, Japanese Orthopaedic Association (JOA) score, Roland-Morris Disability Questionnaire, JOA Back Pain Evaluation Questionnaire, visual analog scale (VAS) and Medical Outcome Survey short-form 8-item health survey that evaluated at the next phase. Furthermore, we assessed whether the effect of consultation length on patient satisfaction was modified by the baseline Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP) score for patient and physician versions. RESULTS: VAS for CLBP was the only score that correlated significantly with consultation length (P = 0.018). Satisfaction score showed a significant positive correlation with consultation length in patients with the highest baseline BS-POP scores (P < 0.2). Moreover, consultation lengths more than 7.6 min and 15.1 min offered increase of satisfaction if patients show the highest BS-POP scores on patient and physician versions, respectively. CONCLUSIONS: These findings suggest that a sufficiently long consultation is an important factor for subjective satisfaction in the patients with CLBP, particularly in patients with psychological problems.

Clinically significant changes in pain along the Pain Intensity Numerical Rating Scale in patients with chronic low back pain.

Low back pain (LBP) is the most common cause of chronic pain. Numerous clinical scales are available for evaluating pain, but their objective criteria in the management of LBP patients remain unclear. This study aimed to determine an objective cutoff value for a change in the Pain Intensity Numerical Rating Scale (ΔPI-NRS) three months after LBP treatment. Its utility was compared with changes in six commonly used clinical scales in LBP patients: Pain Disability Assessment Scale (PDAS), Pain Self-Efficacy Questionnaire (PSEC), Pain Catastrophizing Scale (PCS), Athens Insomnia Scale (AIS), EuroQoL 5 Dimension (EQ5D), and Locomo 25. We included 161 LBP patients treated in two representative pain management centers. Patients were partitioned into two groups based on patient's global impression of change (PGIC) three months after treatment: satisfied (PGIC = 1, 2) and unsatisfied (3-7). Multivariate logistic regression analysis was performed to explore relevant scales in distinguishing the two groups. We found ΔPI-NRS to be most closely associated with PGIC status regardless of pre-treatment pain intensity, followed by ΔEQ5D, ΔPDAS, ΔPSEC, and ΔPCS. The ΔPI-NRS cutoff value for distinguishing the PGIC status was determined by ROC analysis to be 1.3-1.8 depending on pre-treatment PI-NRS, which was rounded up to ΔPI-NRS = 2 for general use. Spearman's correlation coefficient revealed close relationships between ΔPI-NRS and the six other clinical scales. Therefore, we determined cutoff values of these scales in distinguishing the status of ΔPI-NRS≥2 vs. ΔPI-NRS<2 to be as follows: ΔPDAS, 6.71; ΔPSEC, 6.48; ΔPCS, 6.48; ΔAIS, 1.91; ΔEQ5D, 0.08; and ΔLocomo 25, 9.31. These can be used as definitive indicator of therapeutic outcome in the management of chronic LBP patients.

Comparison of anterior decompression with fusion and posterior decompression with fusion for cervical spondylotic myelopathy-A systematic review and meta-analysis.

BACKGROUND: The optimal surgical procedure for the treatment of cervical spondylotic myelopathy (CSM) remains controversial. Recently, laminectomy/laminoplasty with instrumented fusion (LAMF) has been increasingly applied to treat CSM. However, few comprehensive studies have compared anterior decompression with fusion (ADF) and LAMF. Therefore, we conducted a meta-analysis to evaluate the evidence in the literature and to compare the surgical outcomes between the 2 procedures. Since the surgical outcomes and risks differ between patients with CSM and ossification of the posterior longitudinal ligament (OPLL) and between only posterior decompression and decompression with fusion treatments, we excluded patients with OPLL and patients with only posterior decompression in this review. METHODS: An extensive literature search was performed using PubMed, Embase, and the Cochrane Library to identify comparative studies of ADF and LAMF for the treatment of CSM. The language was restricted to English, and the publication period was from January 2001 to July 2019. We only included studies about CSM and excluded studies that involved patients with ossification of the posterior longitudinal ligament and with the treatment of posterior decompression without fusion. We extracted outcomes from the studies, such as preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, neck disability index (NDI) scores, cervical alignment data, and surgical complications. Then, a meta-analysis was performed on these surgical outcomes. RESULTS: Eleven studies were obtained, and the quality of the studies was acceptable. In the meta-analysis, the pre- and postoperative JOA scores were similar between the ADF and LAMF groups. The ADF group exhibited more favorable results than the LAMF group in terms of postoperative cervical alignment and the NDI. Overall complications were similar between the ADF and LAMF groups; however, C5 palsy was more frequently observed in the LAMF group than in the ADF group. CONCLUSIONS: While the ADF and LAMF groups demonstrated similar results in terms of neurological recovery, postoperative cervical lordosis and NDI scores were more favorable with ADF than with LAMF. The overall complication rate was similar between the ADF and LAMF groups. Surgeons should understand the merits and shortcomings of both procedures when deciding on a surgical procedure.

Relationship Between Cauda Equina Conduction Time and Type of Neurogenic Intermittent Claudication due to Lumbar Spinal Stenosis.

INTRODUCTION: This study investigated whether the prolongation of the cauda equina conduction time (CECT) was related to the type of neurogenic intermittent claudication due to lumbar spinal stenosis. METHODS: In total, 149 patients who underwent surgery due to lumbar spinal stenosis with neurogenic intermittent claudication were classified into three groups as follows: cauda equina-type(n = 67), radicular-type(n = 29), and mixed-type(n = 53). Cauda equina conduction time was measured by placing disc electrodes on the abductor hallucis muscle, electrically stimulating the tibial nerve of the ankle and recording the compound muscle action potentials and F-waves. Motor evoked potentials from the abductor hallucis muscle were measured after magnetically stimulating the lumbosacral spine. Cauda equina conduction time was calculated from the latencies of compound muscle action potentials, F-waves, and motor evoked potentials. The measurement of the dural sac cross-sectional area were assessed using computed tomography myelography or MRI. RESULTS: The values of CECT were as follows: cauda equina-type, 5.6 ± 1.1 ms; mixed-type, 5.1 ± 0.9 ms; and radicular-type, 4.0 ± 0.9 ms. The values of dural sac cross-sectional area were as follows: cauda equina-type, 42.8 ± 18.7 mm; mixed-type, 49.6 ± 20.9 mm; and radicular-type, 75.3 ± 19.1 mm. In the cauda equina-type and mixed-type patients, CECT was significantly prolonged and there were negative correlations between CECT and dural sac cross-sectional area. CONCLUSIONS: Cauda equina conduction time differed according to the type of lumbar spinal stenosis. The prolongation of CECT may be caused by the demyelination of the CE. Cauda equina conduction time may be a useful measure for evaluating the dysfunction of the CE rather than radiculopathy for patients with lumbar spinal stenosis.

Factors associated with an excellent outcome after conservative treatment for patients with proximal cervical spondylotic amyotrophy using electrophysiological, neurological and radiological findings.

Objective: To investigate factors associated with excellent outcomes after conservative treatment in patients with proximal cervical spondylotic amyotrophy (CSA) using electrophysiological, radiological, and neurological findings. Design: Retrospective study. Setting: Yamaguchi University Hospital. Participants: Seventy-seven patients. Interventions: Erb-point-stimulated compound muscle action potentials (CMAP) were recorded in deltoid and biceps. The percentages of CMAP amplitudes on the affected side compared to the normal side in deltoid (PD) and biceps brachii (PB) were calculated. Central motor conduction time was calculated by subtracting peripheral motor conduction time from the onset latency of motor evoked potentials. Cervical lordotic angles, the diameter of C5 canal, and the intervertebral range at C4-C5 and C5-C6 levels were assessed on plain radiographs. Magnetic resonance imaging was used to assess the width of the intervertebral foramen (WIF) at C4-C5 and C5-C6 levels in the axial views. First visit and final follow-up strengths of most atrophic muscles were evaluated using manual muscle testing (MMT). Improvements in strength were classified as excellent (five grades recovered), good (more than one grade recovered), unchanged (no improvement), or poor (worsened). Results: The outcomes were excellent in 27 patients (35.1%), good in 22 (28.6%), unchanged in 26 (33.8%), and poor in two (2.5%). Factors associated with excellent outcomes were WIF at C4-C5 and C5-C6 on the normal side, PB, and CMAP amplitudes of the deltoid on the normal side. Conclusions: Patients with excellent outcomes originally had wide WIF at C4-C5 and C5-C6 levels and the absence of symptomatic spinal cord compression at C3-C4 and C4-C5 levels.

A Cost-Effectiveness Analysis Of Pregabalin For The Treatment Of Patients With Chronic Cervical Pain With A Neuropathic Component In Japan.

PURPOSE: To evaluate the cost-effectiveness of pregabalin versus other analgesics among patients with chronic cervical pain with neuropathic components during routine clinical practice in Japan. PATIENTS AND METHODS: The analysis considered patients with chronic cervical pain with a neuropathic pain component (radiating pain to the upper limb) and who were treated with pregabalin with or without other analgesics (pregabalin-containing treatments) or other analgesics alone (usual care) for 8 weeks. Other analgesics included non-steroidal anti-inflammatory drugs (NSAIDs), weak opioids, antidepressants, and antiepileptic drugs. A Markov cohort simulation model was constructed to estimate costs and effectiveness (in terms of quality-adjusted life-years, QALYs) of each treatment over a 12-month time horizon. In the model, patients transitioned among three states of pain severity (no/mild, moderate, and severe). Data were derived from a previous observational study (pregabalin-containing treatments, n = 138; usual care, n = 211). Cost inputs included medical costs and productivity losses. QALYs were calculated using the EuroQol five-dimensional, five-level questionnaire. The cost-effectiveness was evaluated using incremental cost-effectiveness ratios (ICERs). Sensitivity analyses were conducted to assess the robustness of results. RESULTS: From the payer's perspective, pregabalin-containing treatments were more costly (JPY 61,779 versus JPY 26,428) but also more effective (0.763 QALYs versus 0.727 QALYs) than the usual care, with an ICER of JPY 970,314 per QALY gained. From the societal perspective, which also included productivity losses, the ICER reduced to JPY 458,307 per QALY gained. One-way sensitivity analyses demonstrated the robustness of the results. Given a hypothetical threshold value of one additional QALY of JPY 5,000,000, the probability of pregabalin-containing treatments being cost-effective was 100%. CONCLUSION: Compared with using other analgesics alone, the use of pregabalin, alone or in addition to other analgesics, was cost-effective for the treatment of chronic cervical pain with a neuropathic pain component in Japan.

Cost-effectiveness analysis of the pharmacological management of chronic low back pain with four leading drugs.

BACKGROUND: Chronic low back pain is a major health problem that has a substantial effect on people's quality of life and places a significant economic burden on healthcare systems. However, there has been little cost-effectiveness analysis of the treatments for it. Therefore, the purpose of this prospective observational study was to evaluate the cost-effectiveness of the pharmacological management of chronic low back pain. METHODS: A total of 474 patients received pharmacological management for chronic low back pain using four leading drugs for 6 months at 28 institutions in Japan. Outcome measures, including EQ-5D, the Japanese Orthopaedic Association (JOA) score, the JOA back pain evaluation questionnaire (BPEQ), the Roland-Morris Disability Questionnaire, the Medical Outcomes Study SF-8, and the visual analog scale, were investigated at baseline and every one month thereafter. The incremental cost-utility ratio (ICUR) was calculated as drug cost over the quality-adjusted life years. An economic estimation was performed from the perspective of a public healthcare payer in Japan. Stratified analysis based on patient characteristics was also performed to explore the characteristics that affect cost-effectiveness. RESULTS: The ICUR of pharmacological management for chronic low back pain was JPY 453,756. Stratified analysis based on patient characteristics suggested that the pharmacological treatments for patients with a history of spine surgery or cancer, low frequency of exercise, long disease period, low scores in lumbar spine dysfunction and gait disturbance of the JOA BPEQ, and low JOA score at baseline were not cost-effective. CONCLUSIONS: Pharmacological management for chronic low back pain is cost-effective from the reference willingness to pay. Further optimization based on patient characteristics is expected to contribute to the sustainable development of a universal insurance system in Japan.

Effectiveness of pregabalin for treatment of chronic cervical radiculopathy with upper limb radiating pain: an 8-week, multicenter prospective observational study in Japanese primary care settings.

Background: Despite high prevalence of chronic neck pain in Japan and the negative impact pain has on patient's quality of life (QoL), the therapeutic value of pregabalin for chronic neck pain with a neuropathic pain (NeP) component has not been assessed in a typical Japanese health care setting. Methods: An 8-week, non-interventional, multicenter, observational study of Japanese adults (≥20 years) with chronic refractory cervical pain including a NeP element (for ≥12 weeks) and sleep disturbance on the Pain-Related Sleep-Interference Scale (PRSIS) ≥1 (from 0 "does not interfere with sleep" to 10 "completely interferes"). Patients received either usual care with conventional analgesics or pregabalin (150-600 mg/day) for 8 weeks. "Usual care" with analgesics or other treatment(s) was determined based on physician's best clinical judgment. Primary endpoint was change from baseline to week 8 in PRSIS. Secondary endpoints included: change from baseline to week 4 in PRSIS, and to week 4 and 8 in pain Numerical Rating Scale (NRS; from 0 "no pain" to 10 "worst possible pain"), and on the Neck Disability Index (NDI). Other assessments of QoL were undertaken. Safety was monitored. Results: Overall, 369 patients received pregabalin (n=145) or usual care (n=224). The median (range) dose of pregabalin was 49.6 (25.0-251.5) mg/day. Least-squares mean change in PRSIS from baseline to week 8 favored pregabalin (-1.167 vs -0.269; treatment difference -0.898 [95% CI -1.262, -0.535], P<0.001). Similar observations were seen at week 4 in favor of pregabalin versus usual care (P<0.001). Pregabalin significantly improved pain NRS and NDI scores at weeks 4 and 8 (all P<0.001). Improvements in QoL versus usual care were also observed. Pregabalin was generally well tolerated. Conclusion: In this open-label study, pregabalin improved PRSIS and resulted in clinically meaningful reductions in pain in Japanese patients with NeP associated with chronic cervical pain. ClinicalTrials.gov identifier: NCT02868359.