Pregabalin for Refractory Radicular Leg Pain due to Lumbar Spinal Stenosis: A Preliminary Prospective Study

Nonsurgical therapy for lumbar spinal stenosis caused by ligamentum flavum hypertrophy: A review

Lumbar spinal stenosis (LSS) can cause a range of cauda equina symptoms, including lower back and leg pain, numbness, and intermittent claudication. This disease affects approximately 103 million people worldwide, particularly the elderly, and can seriously compromise their health and well-being. Ligamentum flavum hypertrophy (LFH) is one of the main contributing factors to this disease. Surgical treatment is currently recommended for LSS caused by LFH. For patients who do not meet the criteria for surgery, symptom relief can be achieved by using oral nonsteroidal anti-inflammatory drugs (NSAIDs) and epidural steroid injections. Exercise therapy and needle knife can also help to reduce the effects of mechanical stress. However, the effectiveness of these methods varies, and targeting the delay in LF hypertrophy is challenging. Therefore, further research and development of new drugs is necessary to address this issue. Several new drugs, including cyclopamine and N-acetyl-l-cysteine, are currently undergoing testing and may serve as new treatments for LSS caused by LFH.

Recovery of the Japanese orthopedic association back pain evaluation questionnaire score and walking ability following lumbar spinal stenosis surgery

PURPOSE

We investigated the recovery of the Japanese orthopedic association back pain evaluation questionnaire (JOABPEQ) scores and 6 min walk distance (6MWD) in patients after surgery for lumbar spinal stenosis and identified the items among 25 questions of JOABPEQ that showed recovery.

METHODS

A total of 227 patients (average age 71.5 years; SD: 7.5; 121 men) were included from a single center. The outcome measures were JOABPEQ, visual analog scale (VAS), and 6MWD and obtained preoperatively and at 1, 3, 6, and 12 months postoperatively. Mixed-model repeated measures were used to compare the variables at each time point between the surgery groups.

RESULTS

The JOABPEQ, VAS, and 6MWD scores generally improved at 1 month postoperatively compared with those obtained preoperatively, and some parameters further improved at 3 months. However, improvement in the lumbar spine dysfunction item of JOABPEQ was delayed, showing improvement at 3 months postoperatively for decompression surgery (average score: pre, 64.6; 3 months, 78.5) and 6 months postoperatively for fusion surgery (average score: Pre, 64.3; 6 months, 77.1). Responses to the individual JOABPEQ questions generally improved after surgery. No significant changes in lumbar spine dysfunction occurred in the fusion group.

CONCLUSION

Our results demonstrated the early postoperative recovery course of JOABPEQ and 6MWD. In the fusion group, significant changes in lumbar spine dysfunction started at 6 months postoperatively. These findings could help medical staff explain postoperative recovery to patients after lumbar spinal stenosis surgery and in their decision making regarding surgery.

Pain Management Interventions in Lumbar Spinal Stenosis: A Literature Review

Lumbar spinal stenosis (LSS) occurs due to the narrowing of the space within the vertebral canal and or intervertebral foramina. This results in the compression of the spinal cord and possibly the roots of the spinal nerves. Lower back pain and neurogenic claudication (NC) are major symptoms of spinal stenosis. This is a literature review that summarizes the important findings pertaining to pain management of spinal stenosis. Twenty-four original articles were assessed. Pain can be treated through non-invasive or surgical methods. Conservative techniques include physical exercises, epidural corticosteroid injection, local anesthetic injection therapy, and oral analgesics. Surgical intervention deals with the decompression of the affected spinal region, with or without vertebral fusion surgery. Other novel surgical techniques include implantation of specific equipment, known as interspinous spacer devices and minimally invasive lumbar decompression (MILD). Most studies offering a comparative analysis have demonstrated that surgical intervention is more efficacious than non-surgical interventions to manage pain associated with spinal stenosis.

Somnolence and Dizziness During Mirogabalin Treatment in Patients With Neuropathic Pain Related to Lumbar Disease Who Switched From Pregabalin: A Retrospective Study

STUDY DESIGN

Multicenter retrospective study.

OBJECTIVES

To investigate adverse events (AEs) in patients with neuropathic pain related to lumbar disease who switched to mirogabalin from pregabalin.

METHODS

This study surveyed the records of 82 patients with peripheral neuropathic leg pain related to lumbar disease who switched to mirogabalin from pregabalin. We evaluated AEs associated with pregabalin and mirogabalin, the continuation rate of mirogabalin, and the pain-relieving effect at 4 weeks after switching from pregabalin to mirogabalin. We compared patients who switched due to lack of efficacy (LoE group) and patients who switched due to AEs (AE group).

RESULTS

The incidence rates of somnolence and dizziness with pregabalin were 12.2% and 14.6%, respectively, while the incidence rates with mirogabalin were reduced to 7.3% for somnolence and 4.9% for dizziness. The incidence of AEs with pregabalin was significantly higher in the AE group (LoE group: 11.1%, AE group 100%), especially for somnolence (LoE group: 3.2%, AE group: 47.1%) and dizziness (LoE group: 4.8%, AE: 52.9%). After switching, the incidences of AEs with mirogabalin were not significantly different between the 2 groups (LoE group: 15.9%, AE group: 23.5%), including for somnolence (LoE group: 7.9%, AE group: 5.9%) and dizziness (LoE group: 4.8%, AE group: 5.9%). There were no significant differences in continuation rate of mirogabalin or the pain-relieving effect between groups.

CONCLUSIONS

The patients who experience somnolence and dizziness with pregabalin might be able to continue safely receiving treatment for their pain by switching to mirogabalin.

Minimal Clinically Important Difference of the 6-Minute Walk Distance in Patients Undergoing Lumbar Spinal Canal Stenosis Surgery: 12 Months Follow-Up

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

We evaluated the responsiveness of the 6-minute walk distance (6MWD) and determined the threshold of the minimal clinically important difference (MCID) in patients who underwent lumbar spinal stenosis (LSS) surgery.

SUMMARY OF BACKGROUND DATA

Little evidence exists on the MCID of 6MWD after LSS surgery. The 6MWD is an objective gait assessment that can be measured quickly.

MATERIALS AND METHODS

In total, 126 patients (74 men; average age, 72.2 ± 6.5 yr) were included and assessed preoperatively and at 12 months postoperatively. We used the Oswestry Disability Index (ODI), as an anchor to calculate the MCID for the 6MWD and measured internal and external responsiveness of the 6MWD. The external responsiveness was assessed in 2 ways: (1) One based on the anchoring questionnaire and (2) another based on the scale distribution. The anchor-based approach was evaluated using the Spearman rank correlation coefficient and receiver-operating characteristic curve. The distribution-based approach was evaluated using the minimal detectable change.

RESULTS

The ODI scores and 6MWD for each anchor significantly improved postoperatively. The change in the 6MWD was significantly correlated with change in the ODI (6 mo, r = -0.45; 12 mo, r = -0.49). The receiver-operating characteristic analysis demonstrated good discriminative properties for the 6MWD using the ODI anchor (6 mo, 0.72; 12 mo, 0.78). The cutoff values for 6MWD were 102.3 and 57.5 at 6 and 12 months, respectively. In the distribution-based approach, the minimal detectable change for the 6MWD was 95.7 m.

CONCLUSIONS

We validated both the internal and external responsiveness of the 6MWD using the ODI and estimated the MCID in the 6MWD for patients undergoing LSS surgery. However, there was lower validity for the MCID among those participants with the high walking ability and low disability at baseline.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lumbar spinal stenosis, 2021 - Secondary publication

BACKGROUND

The Japanese Orthopaedic Association (JOA) guideline for the management of lumbar spinal stenosis (LSS) was first published in 2011. Since then, the medical care system for LSS has changed and many new articles regarding the epidemiology and diagnostics of LSS, conservative treatments such as new pharmacotherapy and physical therapy, and surgical treatments including minimally invasive surgery have been published. In addition, various issues need to be examined, such as verification of patient-reported outcome measures, and the economic effect of revised medical management of patients with lumbar spinal disorders. Accordingly, in 2019 the JOA clinical guidelines committee decided to update the guideline and consequently established a formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline, incorporating the recent advances of evidence-based medicine.

METHODS

The JOA LSS guideline formulation committee revised the previous guideline based on the method for preparing clinical guidelines in Japan proposed by the Medical Information Network Distribution Service in 2017. Background and clinical questions were determined followed by a literature search related to each question. Appropriate articles based on keywords were selected from all the searched literature. Using prepared structured abstracts, systematic reviews and meta-analyses were performed. The strength of evidence and recommendations for each clinical question was decided by the committee members.

RESULTS

Eight background and 15 clinical questions were determined. Answers and explanations were described for the background questions. For each clinical question, the strength of evidence and the recommendation were both decided, and an explanation was provided.

CONCLUSIONS

The 2021 clinical practice guideline for the management of LSS was completed according to the latest evidence-based medicine. We expect that this guideline will be useful for all medical providers as an index in daily medical care, as well as for patients with LSS.

A targeted literature review of the burden of illness for spine-related neuropathic pain in Japan

BACKGROUND

Neuropathic pain (NeP) is pain provoked by damage or disease in the nervous system and about one in three Japanese patients with spinal disorders are highly likely to have NeP. The humanistic and economic burden of illness (BOI) of spine-related NeP represents unmet medical needs that should be addressed. The purpose of this targeted literature review was to synthesize the available evidence on the BOI of spine-related NeP in Japanese patients.

METHODS

PubMed and ICHUSHI were searched for relevant studies published between January 2010 and December 2020, in English or Japanese. The population included patients with one or more of prespecified spinal disorders and NeP, and outcomes of interest were data related to humanistic or economic burden.

RESULTS

Out of 32 studies that assessed the BOI of spine-related disorders in Japan, only six specifically assessed spine-related NeP. Among these studies, five different validated questionnaires were used to measure humanistic burden. Spine-related NeP was consistently shown to be related with a poorer health-related quality of life and higher levels of anxiety and depression compared to the general population as well as patients with nociceptive pain. No articles directly evaluating economic burden were identified in this search, so an exploratory analysis was conducted. Reduction in work productivity by people experiencing spine-related NeP in the whole of Japan were estimated to total JPY 172,266,780,480 per year.

CONCLUSIONS

The humanistic burden of spine-related NeP on Japanese patients is considerable, not only physically but also mentally. Exploratory analysis of the economic burden illustrates the possibility of substantial societal costs associated with NeP. In order to better understand the depth of BOI and the unmet medical need caused by spine-related NeP, further studies on real-world outcomes are recommended.

Efficacy and Safety of Add-on Mirogabalin to NSAIDs in Lumbar Spinal Stenosis with Peripheral Neuropathic Pain: A Randomized, Open-Label Study

Introduction

In Japan, conservative therapy for patients with lumbar spinal stenosis (LSS) includes non-steroidal anti-inflammatory drugs (NSAIDs), prostaglandin E1, tramadol, physical/exercise therapy, and nerve blocks. Mirogabalin, a selective oral α2δ ligand, is approved for treating peripheral neuropathic pain, though data regarding visual analog scores (VAS) for pain in patients with LSS are limited. We investigated the efficacy and safety of mirogabalin as an add-on treatment in patients with LSS taking NSAIDs compared with patients taking NSAIDs only.

Methods

This multicenter, randomized, open-label study (MiroTAS) was conducted at 32 centers in Japan between June 2020 and October 2021. Patients were randomly assigned to mirogabalin and NSAIDs or NSAIDs alone in a 1:1 ratio. NSAIDs were administered according to their Japanese package inserts; mirogabalin was administered based on renal function [creatinine clearance (CrCL) ≥ 60 mL/min, 5 mg twice daily (BID) in Weeks 1–2, 10 mg BID in Weeks 3–4, and 15 or 10 mg BID after Week 5; CrCL 30 to < 60 mL/min, 2.5 mg BID Weeks 1–2, 5 mg BID Weeks 3–4, and 7.5 or 5 mg BID after Week 5]. The primary endpoint was the change in VAS score for leg pain from baseline to Week 12. Secondary endpoints were quality of life, evaluated using the EuroQol five-dimensional descriptive system (EQ-5D-5L) (at baseline and Week 12) and Patient Global Impression of Change (PGIC) (at Week 12), and safety. Change in VAS score at Week 12 was calculated using a linear mixed model for repeated measures. The safety endpoints were treatment-emergent adverse events (TEAEs) and adverse drug reactions.

Results

In total, 220 patients who met the eligibility criteria were enrolled. In the mirogabalin and NSAIDs and NSAIDs groups, mean ages (67.8 vs. 70.9 years), proportions of female patients (54.5% vs. 49.0%), mean body weights (63.9 vs. 62.0 kg), mean CrCL values (81.5 vs. 70.7 mL/min), proportions of patients with CrCL 30 to < 60 mL/min (27.3% vs. 33.7%), mean VAS scores (63.8 vs. 62.8 mm), and proportions of patients with VAS score ≥ 60 (53.6% vs. 52.9%) at enrollment were similar. The median durations of LSS were 9.0 and 11.0 months and the spine pain DETECT questionnaire (SPDQ) scores were 6.8 and 7.8, respectively. The least square (LS) mean change in VAS score from baseline to Week 12 was − 24.1 mm in the mirogabalin and NSAIDs group and − 14.2 mm in the NSAIDs group (both P < 0.0001 vs. baseline). The difference in LS mean was − 9.9 [95% confidence interval (CI), − 18.0, − 1.8] (P = 0.0174). The improvement in EQ-5D-5L score at Week 12 was significantly greater in the mirogabalin and NSAIDs group versus the NSAIDs group [mean difference, 0.0529 (95% CI, 0.0036, 0.1022), P = 0.0357]. At Week 12, the proportions of patients with PGIC scores ≤ 3 and ≤ 2 were higher in the mirogabalin and NSAIDs group vs. the NSAIDs group (76.2% vs. 50.0%, P = 0.0006, and 47.6% vs. 32.4%, P = 0.0523). In the mirogabalin and NSAIDs group, the incidences of TEAEs and adverse drug reactions were 60.9% and 57.3%, respectively, and the most common TEAEs were somnolence (30.0%) and dizziness (25.5%).

Conclusions

The addition of mirogabalin to NSAIDs improved VAS, EQ-5D-5L, and PGIC. The main TEAEs were somnolence and dizziness. The addition of mirogabalin to NSAIDs improved peripheral neuropathic pain associated with LSS and raised no new safety concerns.

Trial Registration

Japan Registry of Clinical Trials (jRCTs021200007).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-022-00410-z.

Pharmacotherapy for Spine-Related Pain in Older Adults

As the population ages, spine-related pain is increasingly common in older adults. While medications play an important role in pain management, their use has limitations in geriatric patients due to reduced liver and renal function, comorbid medical problems, and polypharmacy. This review will assess the evidence basis for medications used for spine-related pain in older adults, with a focus on drug metabolism and adverse drug reactions. A PubMed/OVID search crossing common spine, neck, and back pain terms with key words for older adults and geriatrics was combined with common drug classes and common drug names and limited to clinical trials and age over 65 years. The results were then reviewed with identification of commonly used drugs and drug categories: nonsteroidal anti-inflammatories (NSAIDs), acetaminophen, corticosteroids, gabapentin and pregabalin, antispastic and antispasmodic muscle relaxants, tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tramadol, and opioids. Collectively, 138 double-blind, placebo-controlled trials were the focus of the review. The review found a variable contribution of high-quality studies examining the efficacy of medications for spine pain primarily in the geriatric population. There was strong evidence for NSAID use with adjustments for gastrointestinal and renal risk factors. Gabapentin and pregabalin had mixed evidence for neuropathic pain. SNRIs had good evidence for neuropathic pain and a more favorable safety profile than TCAs. Tramadol had some evidence in older patients, but more so in persons aged < 65 years. Rational therapeutic choices based on geriatric spine pain diagnosis are helpful, such as NSAIDs and acetaminophen for arthritic and myofascial-based pain, gabapentinoids or duloxetine for neuropathic and radicular pain, antispastic agents for myofascial-based pain, and combination therapy for mixed etiologies. Tramadol can be well tolerated in older patients, but has risks of cognitive and classic opioid side effects. Otherwise, opioids are typically avoided in the treatment of spine-related pain in older adults due to their morbidity and mortality risk and are reserved for refractory severe pain. Whenever possible, beneficial geriatric spine pain pharmacotherapy should employ the lowest therapeutic doses with consideration of polypharmacy, potentially decreased renal and hepatic metabolism, and co-morbid medical disorders.

Movement disorders associated with antiseizure medications: A systematic review

New-onset movement disorders have been frequently reported in association with the use of antiseizure medications (ASMs). The frequency of specific motor manifestations and the spectrum of their semiology for various ASMs have not been well characterized. We carried out a systematic review of literature and conducted a search on CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus from inception to April 2021. We compiled the data for all currently available ASMs using the conventional terminology of movement disorders. Among 5123 manuscripts identified by the search, 437 met the inclusion criteria. The largest number of reports of abnormal movements were in association with phenobarbital, valproic acid, lacosamide, and perampanel, and predominantly included tremor and ataxia. The majority of attempted interventions for all agents were discontinuation of the offending drug or dose reduction which led to the resolution of symptoms in most patients. Familiarity with the movement disorder phenomenology previously encountered in relation with specific ASMs facilitates early recognition of adverse effects and timely institution of targeted interventions.

Responsiveness and Minimal Clinically Important Difference of the 6-minute Walk Distance in Patients Undergoing Lumbar Spinal Canal Stenosis Surgery

STUDY DESIGN

This was a retrospective review of prospectively collected data.

OBJECTIVE

We aimed to evaluate the responsiveness of the 6-minute walk distance (6MWD) and determine the threshold of the minimal clinically important difference (MCID) in the 6MWD in patients who underwent surgery for lumbar spinal canal stenosis (LSS) surgery.

SUMMARY OF BACKGROUND DATA

The 6MWD rapidly and objectively assesses the walking distance in patients with LSS. To date, no study has assessed the MCID in the 6MWD in patients who underwent LSS surgery.

MATERIALS AND METHODS

A total of 41 patients (16 women; average age: 69.4 y, SD: 7.8 y) were included and assessed preoperatively and at 6 months postoperatively. We evaluated the 6MWD and Oswestry Disability Index (ODI), which is a health-related patientrReported outcome, used as an anchor to calculate the MCID for in the 6MWD. We used 2 different approaches to examine the responsiveness of the 6MWD: internal and external responsiveness. The external responsiveness was assessed in 2 ways: one based on the anchoring questionnaire and the other based on the scale distribution of the scale. The anchor-based approach was evaluated using the Spearman rank correlation coefficient and the receiver operating characteristic curve. The distribution-based approach was evaluated using the minimal detectable change.

RESULTS

The ODI scores and 6MWD for each anchor significantly improved postoperatively. The correlation coefficient between changes in the 6MWD and ODI was r=-0.58. The area under the receiver operating characteristic curve for the ODI anchor was 0.70 (95% confidence interval: 0.52-0.89), and the cutoff value for the ODI anchor was 50 m (sensitivity=0.57, specificity=0.71). In the distribution-based approach, the minimal detectable change for the 6MWD was 105.9 m.

CONCLUSIONS

Both the internal and the external responsiveness of the 6MWD were validated using the ODI. Therefore, the MCID in the 6MWD in patients undergoing LSS surgery ranges from 50 to 105.9 m.

LEVEL OF EVIDENCE

Level III.

Therapeutic Effect of Mirogabalin on Peripheral Neuropathic Pain due to Lumbar Spine Disease

Study Design

Retrospective study.

Purpose

This study aims to evaluate the effectiveness of mirogabalin in treatment of peripheral neuropathic pain due to lumbar spine disease.

Overview of Literature

Mirogabalin is a novel selective ligand for the α2δ subunit of voltage-gated Ca channels.

Methods

Between April and December 2019, we used mirogabalin to treat 60 consecutive patients (mean age, 67.6 years) with leg symptoms due to lumbar disease. The treatment outcome after 8 weeks of mirogabalin therapy was evaluated by comparing the preand post-administration Numerical Rating Scale (NRS) for leg symptoms and sleep disturbance, the NRS and Roland–Morris Disability Questionnaire for low back pain (LBP), and the quality of life (QOL) score (based on EuroQol five-dimension five-level scale).

Results

Mirogabalin treatment was stopped at less than eight weeks in eight patients. The remaining 52 patients for evaluation were divided as group 1 (17 patients who presented with leg symptoms that lasted for less than 3 months) and group 2 (35 patients with leg symptoms that lasted longer than 3 months). The leg symptoms and LBP in both groups significantly improved at 4 and 8 weeks of treatment, and sleep disturbance and QOL were improved at 8 weeks as well. Compared to group 2, the pretreatment leg symptoms and QOL were significantly worse in group 1, and their improvement after 8 weeks of mirogabalin treatment was significantly better (p<0.05). Of the 60 original patients, 17 suffered adverse effects, which were mild in 16 patients and required treatment cessation due to excessive weight gain in one patient.

Conclusions

We have validated the effect of mirogabalin on neuropathic pain due to lumbar spine disease, which has effectively addressed the associated leg symptoms, LBP, and sleep disturbance.

Usefulness of the Inferior Articular Process's Cross-Sectional Area as a Morphological Parameter for Predicting Central Lumbar Spinal Stenosis

Hypertrophy of facet joints is associated with a high risk of central lumbar spinal stenosis (CLSS). However, no research has reported the effect of inferior articular process hypertrophy in CLSS. We hypothesize that the inferior articular process’s cross-sectional area (IAPCSA) is larger in patients with CLSS compared to those without CLSS. Data on IAPCSA were obtained from 116 patients with CLSS. A total of 102 control subjects underwent lumbar spine magnetic resonance imaging (LS-MRI) as part of a routine medical examination. Axial T1-weighted images were obtained from the two groups. Using an imaging analysis system, we investigated the cross-sectional area of the inferior articular process. The average IAPCSA was 70.97 ± 13.02 mm² in control subjects and 88.77 ± 18.52 mm² in patients with CLSS. CLSS subjects had significantly greater levels of IAPCSA (p < 0.001) than controls. A receiver operating characteristic (ROC) curve was plotted to determine the validity of IAPCSA as a predictor of CLSS. The most suitable cut-off point of IAPCSA for predicting CLSS was 75.88 mm², with a sensitivity of 71.6%, a specificity of 68.6%, and an area under the curve (AUC) of 0.78 (95% CI: 0.72–0.84). Greater IAPCSA levels were associated with a higher incidence of CLSS. These results demonstrate that IAPCSA is a useful morphological predictor in the evaluation of CLSS.

Numbness and Weakness Recovered at a Less Extent in Patients with Lumbar Disc Herniation after Percutaneous Endoscopic Lumbar Discectomy

Background

Patients with lumbar disc herniation (LDH) may present with motor disorders and various sensory disorders, among which pain and numbness are the most common ones. Percutaneous endoscopic lumbar discectomy (PELD) is reported to be both safe and effective. However, most of the previous studies focused on the recovery of pain, and the relief extent of numbness and weakness has rarely been reported. The Sciatica Bothersomeness Index (SBI) is a self-assessment tool for LDH patients. It has demonstrated acceptable reliability, construct validity, and responsiveness.

Objectives

Our aim was to explore the curative effect of percutaneous endoscopic lumbar discectomy and to compare the various extent of relief among pain, numbness, and weakness.

Methods

The medical records of patients admitted for LDH from September 2016 to December 2018 were collected, and the patients were followed up for 3 months to evaluate the relief of their clinical symptoms. Preoperative and postoperative total scores and subitem scores of SBI were compared to evaluate the relief of pain, numbness, and weakness. Surgical outcomes of PELD were evaluated by the Nakai score, and patients were divided into two groups accordingly, which were the relief group (excellent and good in the Nakai score) and the less relief group (fair and poor in the Nakai score). Risk factors for PELD outcomes and preoperative presence of numbness and/or weakness were analyzed by the logistic model, and p value less than 0.05 was considered significant.

Results

A total of 86 patients met the inclusion criteria and acquired 3 months follow-up. Relief extent of pain, numbness, and weakness, was 82%, 41%, and 21%, respectively. There were 71 cases in the relief group and 15 cases in the less relief group. Results of the logistic regression analysis showed that the preoperative pain score of SBI (p=0.002; OR: 1.647 (1.199-2.261)) was a relatively independent risk factor for PELD outcomes, and multiplicativity of duration of preoperative symptoms and imaging grade [p=0.004; OR: 1.015 (1.005-1.026)] was a relatively independent risk factor for preoperative presence of numbness and/or weakness.

Conclusions

PELD had a good curative effect in the treatment of LDH. Patients of LDH recovered best from pain, followed by numbness and weakness after PELD. Higher level of patients self-reported preoperative pain indicated a better surgical outcome for LDH patients, and preoperative long duration of symptoms together with a severe compression of nerve root significantly increased the risk of presenting numbness and/or weakness.

Alteration of the lysophosphatidic acid and its precursor lysophosphatidylcholine levels in spinal cord stenosis: A study using a rat cauda equina compression model

Cauda equina compression (CEC) is a major cause of neurogenic claudication and progresses to neuropathic pain (NP). A lipid mediator, lysophosphatidic acid (LPA), is known to induce NP via the LPA₁ receptor. To know a possible mechanism of LPA production in neurogenic claudication, we determined the levels of LPA, lysophosphatidylcholine (LPC) and LPA-producing enzyme autotaxin (ATX), in the cerebrospinal fluid (CSF) and spinal cord (SC) using a CEC as a possible model of neurogenic claudication. Using silicon blocks within the lumbar epidural space, we developed a CEC model in rats with motor dysfunction. LPC and LPA levels in the CSF were significantly increased from day 1. Importantly, specific LPA species (16:0, 18:2, 20:4) were upregulated, which have been shown to produce by ATX detected in the CSF, without changes on its level. In SC, the LPC and LPA levels did not change, but mass spectrometry imaging analysis revealed that LPC was present in a region where the silicon blocks were inserted. These results propose a model for LPA production in SC and CSF upon neurogenic claudication that LPC produced locally by tissue damages is converted to LPA by ATX, which then leak out into the CSF.

Predictors of walking ability after surgery for lumbar spinal canal stenosis: a prospective study

BACKGROUND CONTEXT

Few studies have investigated predictors of objective walking distance in patients with lumbar spinal stenosis (LSS).

PURPOSE

This study aimed to clarify objective predictors of postoperative 6-minute walk distance (6MWD) in patients with LSS and to develop prediction equations.

STUDY DESIGN

This was a prospective study. Data were analyzed by multiple linear regression analyses.

PATIENT SAMPLE

Patients with LSS were enrolled.

OUTCOME MEASURES

Predictors of 6MWD after surgery were evaluated, including patient characteristics (sex, age, height, and body weight), pain (visual analog scale; low back pain, lower limb pain, and lower limb numbness), surgical factors (number of operation segments [1 or ≥2], surgery type [fusion or decompression], and minimum area of the dural sac), and objective physical function (6MWD and trunk muscle strength).

METHODS

Patients with LSS were consecutively included and assessed preoperatively (n=113) and 6 months postoperatively (n=78). Simple and multiple linear regression analyses were performed with 6MWD at 6 months postoperation as the dependent variable. We have study funding sources (Nagono Medical Foundation) and no study-specific conflicts of interest-associated biases.

RESULTS

At 6-month follow-up, 6MWD (457.7±105.5 m) improved significantly compared with preoperative 6MWD (275.0±157.2 m; p<.01). Trunk muscle strength and pain improved significantly compared with the preoperative score (p<.01). The predictors of postoperative 6MWD were age, body weight, number of operation segments (1 or ≥2), surgery type (fusion or decompression), preoperative trunk extensor strength, and preoperative 6MWD (adjusted R²=0.65, p<.01). The proposed prediction equation was as follows: postoperative 6MWD (m)=549.5-5.3×age (years)-1.8×body weight (kg)-68.3×surgery type (0: decompression, 1: fusion)-58.6×operation segment (0: one segment, 1: ≥2 segments)+3.5×trunk extensor strength (kg)+0.2×preoperative 6MWD (m).

CONCLUSIONS

Younger age, lower body weight, one level operative segment, decompression surgery, and better preoperative scores for trunk extensor strength and 6MWD predicted better scores for 6 months postoperative 6MWD. Preoperative reduction in body weight and increase of trunk extensor strength might be associated with improved postoperative 6MWD scores.

Is Pregabalin Effective Against Acute Lumbar Radicular Pain ?

Introduction

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the first-line treatment for acute lumbar radicular pain accompanying lumbar disc herniation (LDH), but their effects are minimal. The purpose of this study was to evaluate the efficacy and safety of pregabalin (PGB) as an alternative therapy for this condition.

Methods

Patients with acute lumbar radicular pain accompanying LDH were randomly administered either NSAIDs plus PGB (30 patients) or NSAIDs alone (30 patients) for up to 4 weeks. The primary outcome was leg pain at 2 and 4 weeks. Secondary outcomes were reduction in sleep disturbances and patient global impressions of change (PGIC) at 2 and 4 weeks.

Results

Four patients in the NSAIDs plus PGB group were deemed ineligible and excluded from the study. Fewer sleep disturbances were reported by patients administered NSAIDs plus PGB compared with the NSAID monotherapy group at both 2 and 4 weeks. Additionally, the NSAIDs plus PGB group showed greater improvement in pain than the NSAID monotherapy group at 4 weeks, although this difference was not significant. PGIC was also significantly better in the NSAIDs plus PGB group than in the NSAID monotherapy group at 4 weeks. The incidence of adverse events was significantly greater in the NSAIDs plus PGB group than in the NSAID monotherapy group.

Conclusions

The combination of NSAIDs plus PGB is more effective against sleep disturbance than NSAIDs alone in patients with acute LDH, although the control of sciatic pain is minimal. Patients reported satisfactory recoveries could also be obtained, and thus, this combination therapy could be a good option for the conservative treatment of acute lumbar radicular pain, including LDH.

Optimal treatment for lumbar spinal stenosis: an update

PURPOSE OF REVIEW

Our review of current literature within the past 12-24 months for the treatment of lumbar spinals stenosis (LSS) serves to update providers on recent advances and comparisons regarding therapy spanning lifestyle modification, pharmacologic therapy, minimally invasive interventions, and surgical interventions.

RECENT FINDINGS

Current literature supporting the inclusion of physical therapy and gabapentin/pregabalin within an initial treatment regimen have been positive. A recent randomized, double-blinded clinical trial of adding calcitonin to epidural steroid injections have shown improvement in pain and function up to 1 year. The minimally invasive lumbar decompression (mild) procedure is showing ongoing beneficial results in pain and function. Spinal cord stimulation (SCS) may have a role for select patients with lumbar spinal stenosis. Finally, the benefits of surgical treatment versus nonsurgical treatment is ultimately inconclusive because of the nature of data collection, inconsistencies with the clinical definition of LSS, and a lack of standardized treatment guidelines.

SUMMARY

Our review of current research demonstrates there is a positive role for the current conservative therapies, with favorable results for interventions such as minimally invasive decompression and SCS. Pharmacologic interventions such as systemic prostaglandin analogues and epidural agents such as calcitonin demonstrate early promise, but need to undergo additional safety testing and confirmatory trials. Further long-term research with validated, objective measurements for the aforementioned treatments are needed to draw any definitive conclusions for clinical practice.

A comparative study of three conservative treatments in patients with lumbar spinal stenosis: lumbar spinal stenosis with acupuncture and physical therapy study (LAP study)

Background

Although the efficiency of conservative management for lumbar spinal stenosis (LSS) has been examined, different conservative management approaches have not been compared. We have performed the first comparative trial of three types of conservative management (medication with acetaminophen, exercise, and acupuncture) in Japanese patients with LSS.

Methods

Patients with L5 root radiculopathy associated with LSS who visited our hospital for surgical treatment were enrolled between December 2011 and January 2014. In this open-label study, patients were assigned to three treatment groups (medication, exercise, acupuncture) according to the visit time. The primary outcomes were Zurich claudication questionnaire (ZCQ) scores before and after 4 weeks of treatment. Least square mean analysis was used to assess the following dependent variables in the treatment groups: changes in symptom severity and physical function scores of the ZCQ and the ZCQ score of patient’s satisfaction after treatment.

Results

Thirty-eight, 40, and 41 patients were allocated to the medication, exercise, and acupuncture groups, respectively. No patient underwent surgical treatment during the study period. The symptom severity scores of the ZCQ improved significantly after treatment in the medication (p = 0.048), exercise (p = 0.003), and acupuncture (p = 0.04) groups. The physical function score improved significantly in the acupuncture group (p = 0.045) but not in the medication (p = 0.20) and exercise (p = 0.29) groups. The mean reduction in the ZCQ score for physical function was significantly greater for acupuncture than for exercise. The mean ZCQ score for treatment satisfaction was significantly greater for acupuncture than for medication.

Conclusions

Acupuncture was significantly more effective than physical exercise according to the physical function score of the ZCQ and than medication according to the satisfaction score. The present study provides new important information that will aid decision making in LSS treatment.

Trial registration

This study was registered with the UMIN Clinical Trials Registry (UMIN000006957).

Limaprost or Pregabalin: Preoperative and Postoperative Medication for Pain due to Lumbar Spinal Stenosis

PURPOSE

We aimed to evaluate the incidence of (and risk factors for) postoperative pregabalin and/or limaprost to treat persistent numbness and/or pain of the lower extremities after lumbar spinal stenosis (LSS) surgery.

METHODS

Medical records of 329 patients (168 men, 161 women; average age 70 years) were retrospectively reviewed for data on the duration of LSS diagnosis; LSS disease; preoperative medication (limaprost, pregabalin, or combined limaprost/pregabalin; duration); symptoms; preoperative/postoperative intermittent claudication (IC); operation type; and postoperative medication and period.

RESULTS

Limaprost, pregabalin, and combined limaprost/pregabalin were prescribed preoperatively for 43%, 7%, and 5% of patients, respectively. At an average of 21 months postoperatively, limaprost, pregabalin, and combined therapy were prescribed in 11%, 8%, 4% of patients, respectively. Medication requirement was significantly lower postoperatively than preoperatively (P < 0.0001). Significant risk factors for required postoperative medication were required preoperative medication (odds ratio [OR] 3.088, 95% confidence interval [CI] 1.679 to 5.681]; postoperative period (OR 1.063, 95% CI 1.031 to 1.096); and postoperative IC (OR 3.868, 95% CI 1.481 to 10.103). A negative impact from postoperative medication was seen in patients who had undergone decompression surgery (OR 0.589, 95% CI 0.377 to 0.918).

CONCLUSIONS

Overall, 23% of LSS patients required medication for pain and/or numbness at 21 months postoperatively. Significant factors portending required postoperative medication were preoperative medication, longer postoperative period, and postoperative IC. A negative influence from postoperative medication was seen in patients who had undergone decompression surgery without fusion.

Benefits and safety of gabapentinoids in chronic low back pain: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Chronic Low Back Pain (CLBP) is very common, with a lifetime prevalence between 51% and 80%. In majority, it is nonspecific in nature and multifactorial in etiology. Pregabalin (PG) and Gabapentin (GB) are gabapentinoids that have demonstrated benefit in neuropathic pain conditions. Despite no clear rationale, they are increasingly used for nonspecific CLBP. They necessitate prolonged use and are associated with adverse effects and increased cost. Recent guidelines from the National Health Service (NHS), England, expressed concerns on their off-label use, in addition to the risk of misuse. We aimed to assess the effectiveness and safety of gabapentinoids in adult CLBP patients.

METHODS

Electronic databases of MEDLINE, EMBASE, and Cochrane were searched from their inception until December 20th, 2016. We included randomized control trials reporting the use of gabapentinoids for the treatment of CLBP of >3 months duration, in adult patients. Study selection and data extraction was performed independently by paired reviewers. Outcomes were guided by Initiative on Methods, Measurement and Pain Assessment in Clinical Trials guidelines, with pain relief and safety as the primary outcomes. Meta-analyses were performed for outcomes reported in 3 or more studies. Outcomes were reported as mean differences (MDs) or risk ratios (RRs) with their corresponding 95% confidence intervals (CIs), and I2 in percentage representing the percentage variability in effect estimates that could be explained by heterogeneity. GRADE (Grading of Recommendations Assessment, Development, and Evaluation) was used to assess the quality of evidence.

RESULTS

Out of 1,385 citations, eight studies were included. Based on the interventions and comparators, studies were analyzed in 3 different groups. GB compared with placebo (3 studies, n = 185) showed minimal improvement of pain (MD = 0.22 units, 95% CI [-0.5 to 0.07] I2 = 0%; GRADE: very low). Three studies compared PG with other types of analgesic medication (n = 332) and showed greater improvement in the other analgesic group (MD = 0.42 units, 95% CI [0.20 to 0.64] I2 = 0; GRADE: very low). Studies using PG as an adjuvant (n = 423) were not pooled due to heterogeneity, but the largest of them showed no benefit of adding PG to tapentadol. There were no deaths or hospitalizations reported. Compared with placebo, the following adverse events were more commonly reported with GB: dizziness-(RR = 1.99, 95% CI [1.17 to 3.37], I2 = 49); fatigue (RR = 1.85, 95% CI [1.12 to 3.05], I2 = 0); difficulties with mentation (RR = 3.34, 95% CI [1.54 to 7.25], I2 = 0); and visual disturbances (RR = 5.72, 95% CI [1.94 to 16.91], I2 = 0). The number needed to harm with 95% CI for dizziness, fatigue, difficulties with mentation, and visual disturbances were 7 (4 to 30), 8 (4 to 44), 6 (4 to 15), and 6 (4 to 13) respectively. The GRADE evidence quality was noted to be very low for dizziness and fatigue, low for difficulties with mentation, and moderate for visual disturbances. Functional and emotional improvements were reported by few studies and showed no significant improvements.

CONCLUSIONS AND RELEVANCE

Existing evidence on the use of gabapentinoids in CLBP is limited and demonstrates significant risk of adverse effects without any demonstrated benefit. Given the lack of efficacy, risks, and costs associated, the use of gabapentinoids for CLBP merits caution. There is need for large high-quality trials to more definitively inform this issue.

TRIAL REGISTRATION

PROSPERO CRD42016034040.