Effect of mechanical compression on the lumbar nerve root: localization and changes of intraradicular inflammatory cytokines, nitric oxide, and cyclooxygenase

6. Persistent spinal pain syndrome type 2

INTRODUCTION

Persistent Spinal Pain Syndrome (PSPS) refers to chronic axial pain and/or extremity pain. Two subtypes have been defined: PSPS-type 1 is chronic pain without previous spinal surgery and PSPS-type 2 is chronic pain, persisting after spine surgery, and is formerly known as Failed Back Surgery Syndrome (FBSS) or post-laminectomy syndrome. The etiology of PSPS-type 2 can be gleaned using elements from the patient history, physical examination, and additional medical imaging. Origins of persistent pain following spinal surgery may be categorized into an inappropriate procedure (eg a lumbar fusion at an incorrect level or for sacroiliac joint [SIJ] pain); technical failure (eg operation at non-affected levels, retained disk fragment, pseudoarthrosis), biomechanical sequelae of surgery (eg adjacent segment disease or SIJ pain after a fusion to the sacrum, muscle wasting, spinal instability); and complications (eg battered root syndrome, excessive epidural fibrosis, and arachnoiditis), or undetermined.

METHODS

The literature on the diagnosis and treatment of PSPS-type 2 was retrieved and summarized.

RESULTS

There is low-quality evidence for the efficacy of conservative treatments including exercise, rehabilitation, manipulation, and behavioral therapy, and very limited evidence for the pharmacological treatment of PSPS-type 2. Interventional treatments such as pulsed radiofrequency (PRF) of the dorsal root ganglia, epidural adhesiolysis, and spinal endoscopy (epiduroscopy) might be beneficial in patients with PSPS-type 2. Spinal cord stimulation (SCS) has been shown to be an effective treatment for chronic, intractable neuropathic limb pain, and possibly well-selected candidates with axial pain.

CONCLUSIONS

The diagnosis of PSPS-type 2 is based on patient history, clinical examination, and medical imaging. Low-quality evidence exists for conservative interventions. Pulsed radiofrequency, adhesiolysis and SCS have a higher level of evidence with a high safety margin and should be considered as interventional treatment options when conservative treatment fails.

Predictive Factors Associated with Successful Response to Percutaneous Adhesiolysis in Chronic Lumbar Radicular Pain

Percutaneous adhesiolysis (PEA) is of interest in the treatment of lumbar radicular pain. This study aimed to assess the effectiveness of PEA in patients with chronic lumbar radicular pain refractory to epidural steroid injections and to determine predictive factors, including demographic, clinical, and procedural data, to provide superior treatment efficacy. One hundred and ninety-three patients were reviewed. Successful treatment outcome was described as a 50% reduction in the visual analog scale score. Among the 193 patients, 109 (56.2%) exhibited a positive treatment response at 12 months. In multivariate logistic regression analysis, no depression (OR, 3.105; 95% CI, 1.127-8.547; p = 0.028), no spondylolisthesis (OR, 2.976; 95% CI, 1.246-7.092; p = 0.014), no previous lumbar surgery (OR, 2.242; 95% CI, 1.067-4.716; p = 0.033), mild foraminal stenosis (OR, 3.460; 95% CI, 1.436-8.333; p = 0.006), no opioid use (OR, 1.782; 95% CI, 0.854-3.717; p = 0.123), and baseline pain scores (OR, 0.787; 95% CI, 0.583-1.064; p = 0.120) were the predictive factors significantly associated with unsuccessful treatment outcome. PEA is a useful treatment option for patients with chronic lumbar radicular pain refractory to epidural steroid injections. A history of lumbar surgery, spondylolisthesis, depression, and severe foraminal stenosis could be associated with a poor prognosis.

Clinical Effectiveness of Single Lumbar Periradicular Infiltration in Patients with Sciatica

Periradicular therapy (PRT) is a minimally invasive radiological procedurein patients with chronic lumbar pain.The aim of the study is to identify clinical and radiological predictive factors for treatment success after a single PRT treatment in patients with sciatica.The study includes a prospective follow-up of 166 patients treated with PRT. The pain intensity is determined according to the VAS scale and the degree of improvement is presented as excellent (over 75%), good (50-70%), moderate (25-49%), and weak (less than 25%). The follow up of the treated patients was done at 2 weeks, 3 and 6 months. In patients with pain duration up to 3 months, the improvement was excellent in n=32 (58.18%) after 2 weeks, after 3 months n=41 (74.55%) and after 6 months n=41 (74.55%). This stands in contrast to patients with pain over 1 year. The percentage of improvement after 6 months, post-intervention, was highest in patients without nerve root compression (86.25±19.2),and the highest improvement after 6 months was in patients with localization of pain at the L4-L5 level (69.69±29.7), the greatest improvement after six months was in patients with extraforaminal hernia (62.82±34.3), and the lowest in patients with central stenosis (40.21±30.7).Our study results suggest that the shorter a pain duration, low-grade root compression, injection level and type of herniation area predictor the more favourable response patients have to transforaminal epidural steroid injection in patients with sciatica.

[The use of a fixed combination of diclofenac and orphenadrine in the treatment of acute pain syndrome in patients with discogenic lumbosacral radiculopathy and lumboischialgia]

Acute pain syndromes caused by discogenic lumbosacral radiculopathy and lumboischialgia are not uncommon in clinical practice and characterized by a high risk of becoming chronic. The pathogenetic aspects, features of the clinical picture, existing approaches to conservative treatment of these conditions are analyzed in this paper. Data on the efficacy and safety of a fixed combination of diclofenac and orphenadrine (Neodolpasse) use in the treatment of vertebrogenic pain syndromes based on the NEODOLEX study results are presented, and the authors' own clinical observations are given. Possible reasons for the high efficacy of Neodolpasse in patients with discogenic radiculopathies and nonspecific back and neck pain are discussed.

Intravenous Corticosteroid Therapy for Acute Lumbar Radicular Pain

Introduction: The efficacy of pharmacological interventions for acute lumbar radicular pain (ALRP) is limited, and systemic steroid use remains controversial. We evaluated the effectiveness and tolerance of systemic steroid use in a cohort of patients with ALRP. Methods: A retrospective cohort of 56 patients (including 24 females) were admitted with intractable ALRP resistance to conservative treatment of NSAIDs and opiates between the years 2016 and 2018. Medical records were studied for demographics, physical examination findings, Visual Analogue Score (VAS), IV steroids side effects, and recent imaging findings. All patients received a daily dose of IV 24 mg Dexamethasone until discharge, SNRB, or surgery. Results: The average IV steroid treatment was 3.9 (±2.8) days, with most patients showing significant pain relief allowing discharge (69.7%). SNRB was required in 19.6% and surgical intervention in 10.7% within the same admission. Multivariate analysis did not find any parameter to predict treatment failure (age, gender, motor/sensory deficit, CT/MRI findings). The motor deficit, positive straight leg raising (SLR), and dural sac compression on CT were higher in the intervention group but did not reach statistical significance. One patient required discontinuation of IV steroids due to elevated blood pressure. Conclusions: Despite the insufficient evidence in the literature, IV steroid treatment is still a viable option in ALRP treatment, with pain relief allowing discharge in 70% of patients and a low complication rate. Our study found daily 24 mg IV dexamethasone for ALRP to be an effective treatment and helpful in most patients admitted. This study supports the common practice used by spine units.

Inhibiting spinal secretory phospholipase A2 after painful nerve root injury attenuates established pain and spinal neuronal hyperexcitability by altering spinal glutamatergic signaling

Neuropathic injury is accompanied by chronic inflammation contributing to the onset and maintenance of pain after an initial insult. In addition to their roles in promoting immune cell activation, inflammatory mediators like secretory phospholipase A₂ (sPLA₂) modulate nociceptive and excitatory neuronal signaling during the initiation of pain through hydrolytic activity. Despite having a known role in glial activation and cytokine release, it is unknown if sPLA₂ contributes to the maintenance of painful neuropathy and spinal hyperexcitability later after neural injury. Using a well-established model of painful nerve root compression, this study investigated if inhibiting spinal sPLA₂ 7 days after painful injury modulates the behavioral sensitivity and/or spinal dorsal horn excitability that is typically evident. The effects of sPLA₂ inhibition on altered spinal glutamatergic signaling was also probed by measuring spinal intracellular glutamate levels and spinal glutamate transporter (GLAST and GLT1) and receptor (mGluR5, GluR1, and NR1) expression. Spinal sPLA₂ inhibition at day 7 abolishes behavioral sensitivity, reduces both evoked and spontaneous neuronal firing in the spinal cord, and restores the distribution of neuronal phenotypes to those of control conditions. Inhibiting spinal sPLA₂ also increases intracellular glutamate concentrations and restores spinal expression of GLAST, GLT1, mGluR5, and GluR1 to uninjured expression with no effect on NR1. These findings establish a role for spinal sPLA₂ in maintaining pain and central sensitization after neural injury and suggest this may be via exacerbating glutamate excitotoxicity in the spinal cord.

Vertebral Endplate Changes Correlate with Presence of Cartilaginous Endplate in the Herniated Disc Tissue: Factor Predicting Failure of Conservative Treatment

Study Design

Cross-sectional comparative.

Purpose

To characterize the scores of disc degeneration, inflammation, and nerve density in herniated disc samples and associate findings with the presence of vertebral endplate (VEP) changes on magnetic resonance imaging (MRI).

Overview of Literature

Considering the role of disc composition in spontaneous regression and persistence of pain during conservative management, it is important to identify the influencing factors. VEP changes are highly associated with disc degeneration, but their correlation with herniated disc composition has not yet been reported.

Methods

Fifty-one discs were obtained from patients undergoing surgery for herniated disc. Their ages ranged from 19–65 years, and 31/51 were male. Pre-surgical T1 and T2 weighted lumbar-spine MRIs were analyzed to observe Pfirrmann grade, VEP defects, herniation type, Modic changes, and high-intensity zones (HIZ) at the affected level. Five-micron thick sections were stained with hematoxylin and eosin, Alcian blue periodic acid–Schiff stain; examined for histological degeneration scores (HDS; 0–15), inflammation (0 [absence]–3 [severe]), and presence of cartilaginous endplate (CEP). Three-micron thick sections were stained with protein-gene-product 9.5 and expression was counted/mm². Data was analyzed, and p<0.05 was considered to indicate statistical significance.

Results

VEP defects, Modic changes, and HIZ were respectively observed in 30/51, 16/51, and 6/51 of the samples. CEP was observed in 26/51 samples and in 23/51 with endplate defects. Discs with adjacent VEP defects showed increased HDS (p<0.001) and inflammation (p<0.001). Discs with adjacent Modic changes also revealed increased HDS (p=0.01). Histological sections with CEP showed increased HDS (p<0.001) and inflammation (p<0.001), and nerve density was significantly positively correlated with HDS (r=0.27, p=0.02).

Conclusions

VEP changes can modulate degeneration and inflammation of herniated discs. Presence of these changes is highly predictive of the occurrence of CEP in herniated discs, which leads to slow resorption and persistent clinical symptoms.

A 3D-printed microfluidic platform for simulating the effects of CPAP on the nasal epithelium

Obstructive sleep apnoea (OSA) is a chronic disorder that involves a decrease or complete cessation of airflow during sleep. It occurs when the muscles supporting the soft tissues in the throat relax during sleep, causing narrowing or closure of the upper airway. Sleep apnoea is a serious medical condition with an increased risk of cardiovascular complications and impaired quality of life. Continuous positive airway pressure (CPAP) is the most effective treatment for moderate to severe cases of OSA and is effective in mild sleep apnoea. However, CPAP therapy is associated with the development of several nasal side effects and is inconvenient for the user, leading to low compliance rates. The effects of CPAP treatment on the upper respiratory system, as well as the pathogenesis of side effects, are incompletely understood and not adequately researched. To better understand the effects of CPAP treatment on the upper respiratory system, we developed an in vitro 3D-printed microfluidic platform. A nasal epithelial cell line, RPMI 2650, was then exposed to certain conditions to mimic the in-vivo environment. To create these conditions, the microfluidic device was utilized to expose nasal epithelial cells grown and differentiated at the air-liquid interface. The airflow was similar to what is experienced with CPAP, with pressure ranging between 0-20 cm of H20. Cells exposed to pressure showed decreased barrier integrity, change in cellular shape, and increased cell death (lactate dehydrogenase release into media) compared to unstressed cells. Stressed cells also showed increased secretions of inflammatory markers IL-6 and IL-8 and had increased production of ATP. Our results suggest that stress induced by airflow leads to structural, metabolic, and inflammatory changes in the nasal epithelium, which may be responsible for developing nasal side-effects following CPAP treatment.

Excessive swelling of nerve roots : Important factor for recurring sciatica after lumbar surgery

OBJECTIVE

The aim of the study was to investigate the occurrence of unexpectedly swollen nerve roots and to investigate the relationship between nerve root edema and recurrent radicular pain.

METHODS

During the period from August 2010 to August 2015, a total of 462 patients with degenerative lumbar disease underwent surgery in this study group. Magnetic resonance imaging (MRI) was used to evaluate the details of the nerve root. Of the patients with recurring radiating pain 13 met the inclusion criteria of the study group and 24 patients without any complications volunteered as the control group. The visual analog scale (VAS), Oswestry Disability Index (ODI), and medical outcomes study item short form health survey (SF-36) were used to evaluate the clinical outcomes.

RESULTS

The preoperative diameter of the nerve root showed no significant difference between the two groups (P = 0.28). The postoperative nerve diameter of the study group was larger than that of the control group (P < 0.01). The initial operation improved the symptoms and the VAS was significantly decreased (P < 0.01). After recurrence of the neuralgia, the VAS score significantly increased (P < 0.01). The pain of the study group improved to the same level as that of the control group 4 weeks after subsequent surgery (P = 0.47), while the quality of life was still lower than that of the control group (P < 0.05). The scores collected 3 months after surgery showed that the clinical outcomes were not different between the two groups (P > 0.05).

CONCLUSION

In surgery for degenerative lumbar disease accompanied by nerve root edema, excessive nerve root swelling is an important factor for recurrent radiating pain. With a properly carried out intervention in the re-exploration, the recurrent symptoms can be gradually relieved.

Clinical side effects of continuous positive airway pressure in patients with obstructive sleep apnoea

CPAP is considered the gold standard treatment in OSA and is highly efficacious in controlling OSA symptoms. However, treatment effectiveness is limited because of many factors including low adherence due to side effects. This review highlights the range of side effects associated with CPAP therapy in patients with OSA. This information is important for the initiation of patients onto CPAP as well as their continued care while on treatment, given the increase in non-medically supervised CPAP care models in use globally.

The expression of P16 and S100 associated with elastin degradation and fibrosis of the Ligamentum Flavum hypertrophy

BACKGROUND

One of the characteristics of lumbar spinal stenosis (LSS) is elastin degradation and fibrosis in the ligamentum flavum (LF). However, the biochemical factors that cause these histologic changes is unclear. P16 and S100 participate in scar formation and collagen development in wound healing and fibrosis diseases. In this study, we investigate the association between P16 and S100 expression and the fibrosis of the hypertrophic LF in LSS.

METHODS

The LF specimens were surgically obtained from 30 patients with single-segment LSS (SLSS), 30 patients with double-segment LSS (DLSS) and 30 patients with L4/5 lumbar disc herniation (LDH). The LF thickness was measured by axial T1-weighted MRI. The extent of LF elastin degradation and fibrosis were graded based on hematoxylin-eosin (HE) and Verhoff's Van Gieson's (VVG) stain, respectively. The localization of P16 and S100 was determined by immunohistochemistry.

RESULTS

The Absolute and relative LF thickness were greater in the DLSS group compared with the SLSS and LDH groups (p <  0.05). The elastic tissue from the dorsal aspect to the dural aspect in SLSS and DLSS groups was significantly increased. The amount of collagen deposition and elastic tissue is significantly higher in the DLSS group compared with the SLSS and LDH groups (p <  0.05). The specimens in the DLSS group showed positive staining of P16, especially in the dorsal layer. Almost all samples in the SLSS group were partially positive for P16. The LDH group showed negative staining of P16 in both the dural and dorsal layers. All the three groups were stained with S100 in the dorsal layer of the LF. On the contrary, S100 staining was absent in the dural layer of the LF in the three groups.

CONCLUSIONS

Elastin degradation and fibrosis of the LF in the DLSS patients is more severe compared with the SLSS and LDH patients. Increased expression of P16 associated with LF fibrosis and thickness, suggested that the expression of P16 may related to LF hypertrophy in the patients who suffer with LSS. LF hypertrophy process may not be associated with high expression of S100.

Relationship of Success Rate for Balloon Adhesiolysis with Clinical Outcomes in Chronic Intractable Lumbar Radicular Pain: A Multicenter Prospective Study

Combined balloon decompression and epidural adhesiolysis has been reported to be effective in refractory lumbar spinal stenosis. Many cases of intractable stenosis have symptom-related multiple target sites for interventional treatment. In this situation it may not be possible to perform balloon adhesiolysis, or even only epidural adhesiolysis, for all target sites. Therefore, this multicenter prospective observational study aimed to evaluate the relationship of successful ballooning rate for multiple target sites with clinical outcome. Based on the ballooning success rate of multiple target sites, the patients were divided into three groups: below 50%, 50-85%, and above 85% ballooning. A greater ballooning success rate for multiple target sites provided a more decreased pain intensity and improved functional status in patients with chronic refractory lumbar spinal stenosis, and the improvement was maintained for 6 months. The estimated proportions of successful responders according to a multidimensional approach in the below 50%, 50-85%, and above 85% balloon success groups at 6 months after the procedure were 0.292, 0.468, and 0.507, respectively (p = 0.038). Our study suggests the more successful balloon adhesiolysis procedures for multiple target lesions are performed, the better clinical outcome can be expected at least 6 months after treatment.

Does the presence of the fibronectin-aggrecan complex predict outcomes from lumbar discectomy for disc herniation?

BACKGROUND CONTEXT

Protein biomarkers associated with lumbar disc disease have been studied as diagnostic indicators and therapeutic targets. Recently, a cartilage degradation product, the fibronectin-aggrecan complex (FAC) identified in the epidural space, has been shown to predict response to lumbar epidural steroid injection in patients with radiculopathy from herniated nucleus pulposus (HNP).

PURPOSE

Determine the ability of FAC to predict response to microdiscectomy for patients with radiculopathy due to lumbar disc herniation STUDY DESIGN/SETTING: Single-center prospective consecutive cohort study.

PATIENT SAMPLE

Patients with radiculopathy from HNP with concordant symptoms to MRI who underwent microdiscectomy.

OUTCOMES MEASURES

Oswestry disability index (ODI) and visual analog scores (VAS) were noted at baseline and at 3-month follow-up. Primary outcome of clinical improvement was defined as patients with both a decrease in VAS of at least 3 points and ODI >20 points.

METHODS

Intraoperative sampling was done via lavage of the excised fragment by ELISA for presence of FAC. Funding for the ELISA was provided by Cytonics, Inc.

RESULTS

Seventy-five patients had full complement of data and were included in this analysis. At 3-month follow-up, 57 (76%) patents were "better." There was a statistically significant association of the presence of FAC and clinical improvement (p=.017) with an 85% positive predictive value. Receiver-operating-characteristic (ROC) curve plotting association of FAC and clinical improvement demonstrates an area under the curve (AUC) of 0.66±0.08 (p=.037). Subset analysis of those with weakness on physical examination (n=48) plotting the association of FAC and improvement shows AUC on ROC of 0.81±0.067 (p=.002).

CONCLUSIONS

Patients who are "FAC+" are more likely to demonstrate clinical improvement following microdiscectomy. The data suggest that the inflammatory milieu plays a significant role regarding improvement in patients undergoing discectomy for radiculopathy in lumbar HNP, even in those with preoperative weakness. The FAC represents a potential target for treatment in HNP.

[A neuropathic component of lumboischialgia: mechanisms of development and treatment approaches]

Low back pain (LBP) is accompanied by the development of pain syndrome that spreads into the leg in 25-57% of patients. This is an important factor predicting the risk of transition of pain from acute to chronic and is an indirect indicator of disease severity. It is often impossible to specify the primary mechanism facilitated pain irradiation in lumboischialgia because many structures can cause analogous symptoms. Mechanisms of development of LBP are represented by nociceptive, neuropathic and psychogenic components. Currently, the term 'neuropathic back pain' remains rather ambiguous. Existing data suggest that the term 'neuropathic LBP is not confined to classic radiculopathy and is realized through several pathophysiological mechanisms. Lumboischialgia is a clinical appearance of these mechanisms. The authors present main mechanisms of the development of lumboischialgia, discuss clinical markers of neuropathic component of LBP, approaches to its diagnosis and treatment.

Effectiveness and Factors Associated with Epidural Decompression and Adhesiolysis Using a Balloon-Inflatable Catheter in Chronic Lumbar Spinal Stenosis: 1-Year Follow-Up

OBJECTIVES

This study aimed to investigate the efficacy of the combined balloon decompression with a balloon-inflatable catheter (ZiNeu) in addition to conventional epidural adhesiolysis, and to identify factors that predict patient responses.

STUDY DESIGN

An institutional single-armed prospective observational study.

SUBJECTS

Chronic refractory lumbar spinal stenosis.

METHODS

This study was performed in 61 patients with spinal stenosis who suffered from chronic (at least 3 months) lumbar radicular pain with or without lower back pain. Patients had failed to maintain improvement for more than 1 month with conventional epidural injection. The numeric rating scale (NRS) and Oswestry disability index (ODI) were each measured at 1, 3, 6, and 12 months after percutaneous epidural adhesiolysis and balloon decompression with a ZiNeu catheter.

RESULTS

The percentage of successful responders was 72.1%, 60.7%, 57.4%, and 36.1% of patients at 1, 3, 6, and 12 months, respectively. A single combined treatment of percutaneous epidural adhesiolysis and balloon decompression with a ZiNeu catheter provided sufficient pain relief and functional improvement in patients with chronic refractory lumbar spinal stenosis, and the improvement was maintained for 12 months (P < 0.001). Multivariate logistic regression analysis showed that absence of diabetes independently predicted successful response at 12 months after percutaneous epidural decompression and adhesiolysis with the balloon catheter (Odds ratio = 0.080; 95% confidence interval = 0.009-0.676; P = 0.020).

CONCLUSIONS

The combined epidural adhesiolysis and balloon decompression with a ZiNeu catheter led to significant pain relief and functional improvement in a subset of patients with refractory spinal stenosis.

Neuropathic Pain Components in Patients with Lumbar Spinal Stenosis

PURPOSE

To determine the prevalence and characteristics of neuropathic pain (NP) in patients with lumbar spinal stenosis (LSS) according to subgroup analysis of symptoms.

MATERIALS AND METHODS

We prospectively enrolled subjects with LSS (n=86) who were scheduled to undergo spinal surgery. The patients were divided into two groups according to a chief complaint of radicular pain or neurogenic claudication. We measured patient's pain score using the visual analog scale (VAS), Oswestry Disability Index (ODI) and Leads Assessment of Neuropathic Symptoms and Signs (LANSS). According to LANSS value, the prevalence of NP component pain in patients with LSS was assessed. Statistical analysis was performed to find the relationship between LANSS scores and the other scores.

RESULTS

From our sample of 86 patients, 31 (36.0%) had a NP component, with 24 (63.4%) in the radicular pain group having NP. However, only seven patients (15.6%) in the neurogenic claudication group had NP. The LANSS pain score was not significantly correlated with VAS scores for back pain, but did correlate with VAS scores for leg pain (R=0.73, p<0.001) and with ODI back pain scores (R=0.54, p<0.01).

CONCLUSION

One-third of the patients with LSS had a NP component. The presence of radicular pain correlated strongly with NP. The severity of leg pain and ODI score were also closely related to a NP component. This data may prove useful to understanding the pain characteristics of LSS and in better designing clinical trials for NP treatment in patients with LSS.

Oral steroids for acute radiculopathy due to a herniated lumbar disk: a randomized clinical trial

IMPORTANCE

Oral steroids are commonly used to treat acute sciatica due to a herniated disk but have not been evaluated in an appropriately powered clinical trial.

OBJECTIVE

To determine if oral prednisone is more effective than placebo in improving function and pain among patients with acute sciatica.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, double-blind, placebo-controlled clinical trial conducted from 2008 to 2013 in a large integrated health care delivery system in Northern California. Adults (n=269) with radicular pain for 3 months or less, an Oswestry Disability Index (ODI) score of 30 or higher (range, 0-100; higher scores indicate greater dysfunction), and a herniated disk confirmed by magnetic resonance imaging were eligible.

INTERVENTIONS

Participants were randomly assigned in a 2:1 ratio to receive a tapering 15-day course of oral prednisone (5 days each of 60 mg, 40 mg, and 20 mg; total cumulative dose = 600 mg; n = 181) or matching placebo (n = 88).

MAIN OUTCOMES AND MEASURES

The primary outcome was ODI change at 3 weeks; secondary outcomes were ODI change at 1 year, change in lower extremity pain (measured on a 0-10 scale; higher scores indicate more pain), spine surgery, and Short Form 36 Health Survey (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores (0-100 scale; higher scores better).

RESULTS

Observed baseline and 3-week mean ODI scores were 51.2 and 32.2 for the prednisone group and 51.1 and 37.5 for the placebo group, respectively. The prednisone-treated group showed an adjusted mean 6.4-point (95% CI, 1.9-10.9; P = .006) greater improvement in ODI scores at 3 weeks than the placebo group and a mean 7.4-point (95% CI, 2.2-12.5; P = .005) greater improvement at 52 weeks. Compared with the placebo group, the prednisone group showed an adjusted mean 0.3-point (95% CI, -0.4 to 1.0; P = .34) greater reduction in pain at 3 weeks and a mean 0.6-point (95% CI, -0.2 to 1.3; P = .15) greater reduction at 52 weeks. The prednisone group showed an adjusted mean 3.3-point (95% CI, 1.3-5.2; P = .001) greater improvement in the SF-36 PCS score at 3 weeks, no difference in the SF-36 PCS score at 52 weeks (mean, 2.5; 95% CI, -0.3 to 5.4; P = .08), no change in the SF-36 MCS score at 3 weeks (mean, 2.2; 95% CI, -0.4 to 4.8; P = .10), and an adjusted 3.6-point (95% CI, 0.6-6.7; P = .02) greater improvement in the SF-36 MCS score at 52 weeks. There were no differences in surgery rates at 52-week follow-up. Having 1 or more adverse events at 3-week follow-up was more common in the prednisone group than in the placebo group (49.2% vs 23.9%; P < .001).

CONCLUSIONS AND RELEVANCE

Among patients with acute radiculopathy due to a herniated lumbar disk, a short course of oral steroids, compared with placebo, resulted in modestly improved function and no improvement in pain.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00668434.

A novel balloon-inflatable catheter for percutaneous epidural adhesiolysis and decompression

Epidural adhesions cause pain by interfering with the free movement of the spinal nerves and increasing neural sensitivity as a consequence of neural compression. To remove adhesions and deliver injected drugs to target sites, percutaneous epidural adhesiolysis (PEA) is performed in patients who are unresponsive to conservative treatments. We describe four patients who were treated with a newly developed inflatable balloon catheter for more effective PEA and relief of stenosis. In the present patients, treatments with repetitive epidural steroid injection and/or PEA with the Racz catheter or the NaviCath did not yield long-lasting effects or functional improvements. However, PEA and decompression with the inflatable balloon catheter led to maintenance of pain relief for more than seven months and improvements in the functional status with increases in the walking distance. The present case series suggests that the inflatable balloon catheter may be an effective alternative to performing PEA when conventional methods fail to remove adhesions or sufficiently relieve stenosis.

Epiduroscopy for patients with lumbosacral radicular pain

Lumbosacral radicular pain is a pain in the distribution area of one of the nerves of the lumbosacral plexus, with or without sensory and/or motor impairment. A major source of lumbosacral radicular pain is failed back surgery, which is defined as persistent or recurrent pain, mainly in the region of the lower back and legs even after technically, anatomically successful spine surgeries. If lumbosacral radicular neuropathic pain fails to respond to conservative or interventional treatments, epiduroscopy can be performed as part of a multidisciplinary approach. Epiduroscopy aids in identifying painful structures in the epidural space, establishing a diagnosis and administering therapy. The novelty consists in the use of an epiduroscope to deliver therapies such as adhesiolysis and targeted administration of epidural medications. Clinical trials report favorable treatment outcomes in 30% to 50% of patients. Complications are rare and related to the rate or volume of epidural fluid infusion or inadvertent dural puncture. In patients with lumbosacral radicular pain, especially after back surgery, epiduroscopy with adhesiolysis may be considered (evidence rating 2 B+).

Clinical effectiveness of percutaneous adhesiolysis and predictive factors of treatment efficacy in patients with lumbosacral spinal stenosis

OBJECTIVE

Patients with lumbosacral spinal stenosis (LSS) do not always obtain satisfactory pain relief from transforaminal epidural steroid injection (TFESI) because perineural/epidural adhesions prevent the spread of injectate into the epidural space. Percutaneous adhesiolysis (PA) can eliminate the deleterious effects of adhesion. This study was to evaluate the effectiveness of PA among patients with LSS refractory to TFESI and to ascertain the prognostic factors determining PA efficacy.

DESIGN

Retrospective study.

SETTING

Spine hospital.

SUBJECTS

Sixty-five patients with LSS refractory to TFESI who underwent PA with NaviCath® were reviewed.

METHODS

We recorded Numeric Rating Scale for back pain (NRS back) and leg pain (NRS leg), and Oswestry Disability Index (ODI), at pretreatment, 2 weeks, and 3 months after treatment. Successful pain relief and functional improvement were described as a 50% and 40% or more reduction in NRS and ODI, respectively. Clinical data and radiological findings were obtained to assess the possible predictive factors for PA efficacy.

RESULTS

Among the 65 patients, 45 (69.2%), 40 (61.5%), and 39 (60.0%) patients showed successful outcomes in NRS back, NRS leg, and ODI at 2 weeks, respectively. Among 63 patients who were followed up at 3 months, 34 (54.0%), 32 (50.8%), and 30 (47.6%) patients showed successful results, respectively. Spondylolisthesis, previous lumbar surgery, and foraminal stenosis were associated with a significantly higher proportion of unsuccessful result in NRS and ODI (%).

CONCLUSION

PA may be a useful treatment in patients with LSS refractory to TFESI and reduce the surgical requirement. Previous surgery, spondylolisthesis, and foraminal stenosis may be associated with poor prognosis.

Immediate pain response does not predict long-term outcome of CT-guided cervical transforaminal epidural steroid injections

BACKGROUND AND PURPOSE

Imaging-guided cervical transforaminal epidural steroid injections have been shown to decrease verbal numerical pain scores and improve functionality (Roland Morris Disability Index). These injections are often administered in combination with local anesthetic. The purpose of this study was to determine if the immediate postprocedure VNPS predicts the long-term effectiveness of the injection.

MATERIALS AND METHODS

A quality assurance data base review of 247 patient records was used to document the VNPS and RMDI of patients undergoing a single CT-guided CTESI. Pain scores were recorded before the procedure, immediately after the procedure, at 2 weeks, and at 2 months. The RMDI was recorded before the procedure, at 2 weeks, and at 2 months. Spearman rank correlation analysis and logistic regression models were used to determine if the immediate postprocedure or 2-week VNPS correlated with or predicted the longer-term VNPS and RMDI as measured at 2 weeks and 2 months.

RESULTS

There was not a strong correlation between the pain score obtained immediately after the procedure and the 2-month outcome of the VNPS or RMDI. The pain scores at 2 weeks did correlate with the 2-month outcomes. The 2-week VNPS also was a significant predictor of patients who would achieve a >50% improvement in VNPS or RMDI at 2 months.

CONCLUSIONS

Pain scores obtained immediately after completion of a single CT-guided CTESI do not predict the long-term effectiveness of this procedure. However, patient response at 2 weeks does correlate with the long-term effectiveness of these injections as measured by the VNPS and the RMDI.

A morphometric cadaver study of the anterior lumbar epidural space

INTRODUCTION

Free disc fragments end often up in the concavity of the anterior epidural space. This space consists of two compartments. The discrepancy between the impressive magnetic resonance imaging findings, clinical symptoms in patients and the problem of treatment options led us to the anatomical determination of anterior epidural space volumes.

MATERIALS AND METHODS

For the first time, the left and right anterior epidural volume between the peridural membrane and the posterior concavity of the lumbar vertebral bodies L3-S1 were determined for each segment. A CT scan and a polyester resin injection were used for the in vitro measurements.

RESULTS

The volumes determined in human cadavers using this method ranged from 0.23 ccm for L3 to 0.34 ccm for L5. The CT concavity volume determination showed this increase in volume from cranial to caudal, as well.

CONCLUSION

This volume is large enough to hold average-sized slipped discs without causing neurological deficits. A better understanding of the anterior epidural space may allow a better distinction of patient treatment options.

Identifying inflammatory targets for biologic therapies for spine pain

The costs associated with treating spine-related conditions are enormous and are trending upward. Current methods employed to treat inflammatory-mediated pain are targeted at alleviating symptoms, rather than correcting the underlying cause of disease. It is clear that a biochemical basis for inflammatory-mediated intervertebral disk, facet joint, and nerve pain exists. Biologic therapies that address the underlying cause of pain could potentially decrease the costs associated with treating spine pathology. MMPs, IL-1, TNF- α, IL-6, NGF, bradykinin, prostaglandins, and nitric oxide are implicated in much of the catabolic effects seen in the pathogenesis of inflammatory-mediated pain and are good targets for inhibition. The anticatabolic and anabolic effects of TIMPs, BMPs, TGF- β, and IGF-1 are targets already shown to favorably impact disk matrix homeostasis. With rapid advances in biomedical technology, these interventions may be available for clinical use in the near future.

How can animal models inform on the transition to chronic symptoms in whiplash?

STUDY DESIGN

A nonsystematic review of the literature.

OBJECTIVE

The objective was to present general schema for mechanisms of whiplash pain and review the role of animal models in understanding the development of chronic pain from whiplash injury.

SUMMARY OF BACKGROUND DATA

Extensive biomechanical and clinical studies of whiplash have been performed to understand the injury mechanisms and symptoms of whiplash injury. However, only recently have animal models of this painful disorder been developed based on other pain models in the literature.

METHODS

A nonsystematic review was performed and findings were integrated to formulate a generalized picture of mechanisms by which chronic whiplash pain develops from mechanical tissue injuries.

RESULTS

The development of chronic pain from tissue injuries in the neck due to whiplash involves complex interactions between the injured tissue and spinal neuroimmune circuits. A variety of animal models are beginning to define these mechanisms.

CONCLUSION

Continued work is needed in developing appropriate animal models to investigate chronic pain from whiplash injuries and care must be taken to determine whether such models aim to model the injury event or the pain symptoms.

Percutaneous treatment of intervertebral disc herniation

Interventional radiology plays a major role in the management of symptomatic intervertebral disc herniations. In the absence of significant pain relief with conservative treatment including oral pain killers and anti-inflammatory drugs, selective image-guided periradicular infiltrations are generally indicated. The precise control of needle positioning allows optimal distribution of steroids along the painful nerve root. After 6 weeks of failure of conservative treatment including periradicular infiltration, treatment aiming to decompress or remove the herniation is considered. Conventional open surgery offers suboptimal results and is associated with significant morbidity. To achieve minimally invasive discal decompression, different percutaneous techniques have been developed. Their principle is to remove a small volume of nucleus, which results in an important reduction of intradiscal pressure and subsequently reduction of pressure inside the disc herniation. However, only contained disc herniations determined by computed tomography or magnetic resonance are indicated for these techniques. Thermal techniques such as radiofrequency or laser nucleotomy seem to be more effective than purely mechanical nucleotomy; indeed, they achieve discal decompression but also thermal destruction of intradiscal nociceptors, which may play a major role in the physiopathology of discal pain. The techniques of image-guided spinal periradicular infiltration and percutaneous nucleotomy with laser and radiofrequency are presented with emphasis on their best indications.

The efficacy of transforaminal injection of steroids for the treatment of lumbar radicular pain

BACKGROUND

Transforaminal injection of steroids is used to treat lumbar radicular pain. Not known is whether the route of injection or the agent injected is significant.

STUDY DESIGN

A prospective, randomized study compared the outcomes of transforaminal injection of steroid and local anesthetic, local anesthetic alone, or normal saline, and intramuscular injection of steroid or normal saline. Patients and outcome evaluators were blinded as to agent administered.

METHODS

The primary outcome measure was the proportion of patients who achieved complete relief of pain, or at least 50% relief, at 1 month after treatment. Secondary outcome measures were function, disability, patient-specified functional outcomes, use of other health care, and duration of relief beyond 1 month.

RESULTS

A significantly greater proportion of patients treated with transforaminal injection of steroid (54%) achieved relief of pain than did patients treated with transforaminal injection of local anesthetic (7%) or transforaminal injection of saline (19%), intramuscular steroids (21%), or intramuscular saline (13%). Relief of pain was corroborated by significant improvements in function and disability, and reductions in use of other health care. Outcomes were equivalent for patients with acute or chronic radicular pain. Over time, the number of patients who maintained relief diminished. Only some maintained relief beyond 12 months. The proportions of patients doing so were not significantly different statistically between groups.

DISCUSSION

Transforaminal injection of steroids is effective only in a proportion of patients. Its superiority over other injections is obscured when group data are compared but emerges when categorical outcomes are calculated. Over time, the proportion of patients with maintained responses diminishes.

Upper Limb Neurodynamic Test 1 and symptoms reproduction in carpal tunnel syndrome. A validity study

The aim of this study was to estimate the validity of the Upper Limb Neurodynamic Test 1 (ULNT1) for the diagnosis of Carpal Tunnel Syndrome (CTS) with blind comparison to a reference criterion of a compatible clinical presentation and abnormal nerve conduction. 47 subjects with suspected CTS were enrolled. All patients were tested with nerve conduction studies and ULNT1. Considering results as positive in the presence of reproduction of symptoms on affected upper limb, or side-to-side differences in elbow extension, or symptoms modified by lateral neck side-bending, we estimated sensitivity as 91.67%, specificity as 15%, positive likelihood ratio as 1.0784, negative likelihood ratio as 0.5556, and post-test probability for negative test as 40%. Using a new criterion, i.e. the reproduction of symptoms only in the first three digits of the affected hand, we estimated sensitivity as 54.17%, specificity as 70%, positive and negative likelihood ratios as 1.8056 and 0.6548, respectively, and post-test probability for positive test as 68%. Our investigation suggests that the reproduction of the typical current CTS symptoms in the affected hand during ULNT1 testing, improves estimation of the probability of the presence of this condition, even if this test alone cannot be used to diagnose CTS.

Uterine fibroid mimicking lumbar radiculopathy: a case report

STUDY DESIGN

Case report.

OBJECTIVE

To present the case of a patient with low back and lower extremity pain suspected to result from lumbar radiculopathy but who was discovered to have symptomatic uterine fibroid (UF).

SUMMARY OF BACKGROUND DATA

UFs are usually asymptomatic but at times can produce symptoms such as excessive menstrual bleeding, intermenstrual bleeding, dysmenorrhea, pelvic pain, pelvic pressure, bloating, dyspareunia, urinary and bowel disturbance, subfertility, and pregnancy-related complications. In rare cases, they can cause neural impingement leading to lower extremity pain, which can be mistaken for lumbar radiculopathy.

METHODS

The patient was a 44-year-old woman who presented with low back pain and left leg pain. Examination suggested lumbar radiculopathy but lumbar magnetic resonance imaging was negative with the exception of a large mass in the pelvis. Pelvic magnetic resonance imaging confirmed this to be a large UF.

RESULTS

The patient's symptoms completely resolved following hysterectomy.

CONCLUSION

In a female patient with suspected radiculopathy, in whom lumbar imaging is negative, or who does not respond as expected to treatment, UF should be considered.

Pathomechanisms of sciatica in lumbar disc herniation: effect of periradicular adhesive tissue on electrophysiological values by an intraoperative straight leg raising test

STUDY DESIGN

This study is aimed to investigate the changes of nerve root functions during the straight leg raising (SLR) test in vivo.

OBJECTIVE

To investigate the relationship between nerve root movement and the electrophysiological values during an intraoperative SLR test.

SUMMARY OF BACKGROUND DATA

The SLR test is one of the most significant signs for making a clinical diagnosis of lumbar disc herniation. A recent study showed that intraradicular blood flow apparently decreased during the SLR test in patients with disc herniation.

METHODS

The study included 32 patients who underwent microdiscectomy. During the surgery, the nerve root motion affected by the hernia was observed during the SLR test. The patients' legs were allowed to hang down to the angle at which sciatica had occurred and the change of nerve root action potentials was measured. After removal of the hernia, a similar procedure was repeated. The periradicular specimens collected during surgery were examined by light and electron microscope.

RESULTS

In all patients intraoperative microscopy revealed that the hernia was adherent to the dura mater of the nerve roots. During the SLR test, the limitation of nerve root movement occurred by periradicular adhesive tissue and amplitude of action potential showed a sharp decrease at the angle that produced sciatica. After removal of the hernia, all the patients showed smooth gliding of the nerve roots during the test, and there was no marked decrease of amplitude. Our data suggest that temporary ischemic changes in the nerve root cause transient conduction disturbances. Pathologic examination showed that the periradicular tissue consisted of the granulation with vascularization and many inflammatory cell infiltrations.

CONCLUSION

The presence of periradicular fibrosis will compound the nerve root pain by fixing the nerve in one position, thereby increasing the susceptibility of the nerve root to tension or compression.

Changes in blood flow, oxygen tension, action potentials, and vascular permeability induced by arterial ischemia or venous congestion on the lumbar dorsal root ganglia in dogs

It is generally believed that radiculopathy associated with the degenerative conditions of the spine may result from both mechanical compression and circulatory disturbance. However, the basic pathophysiology of circulatory disturbance induced by ischemia and congestion is not fully understood. This study investigated the effect of ischemia and congestion on the dorsal root ganglion (DRG) using an in vivo model. The sixth and seventh lumbar laminae were removed and the seventh lumbar DRG was exposed using adult dogs. The aorta was clamped as an ischemic model in the DRG, and the inferior vena cava was clamped as a congestion model at the sixth costal level for 30 min using forceps transpleurally. Measurements of blood flow, partial oxygen pressure, and action potentials in the DRG were recorded over a period of 1 h after clamp release. Finally, we examined the status of intraganglionic blood permeability under a fluorescence microscope following injection of Evans blue albumin into the cephalic vein to determine the type of circulatory disturbance occurring in the DRG. Immediately after inferior vena cava clamping, the central venous pressure increased approximately four times and marked extravasation of protein tracers was induced in the lumbar DRG. Blood flow, partial oxygen pressures, and action potentials within the DRG were more severely affected by the aorta clamping; however, this ischemic model did not reveal any permeability changes in the DRG. The permeability change in the DRG was more easily increased via venous congestion than by arterial ischemia. The intraganglionic venous flow was stopped with compression at much lower pressures than that needed to impact arterial flow. From a clinical perspective, intraganglionic edema formation, rather than arterial ischemia, may be an earlier phenomenon inducing DRG dysfunction.

Effect of ligamenta flava hypertrophy on lumbar disc herniation with contralateral symptoms and signs: a clinical and morphometric study

INTRODUCTION

The purpose of this study was to determine whether ligamentum flavum hypertrophy among disc herniated patients causes contralateral pain symptoms. For this reason we measured the thickness of the ligament in disc herniated patients with ipsilateral or contralateral symptoms.

MATERIAL AND METHODS

Two hundred disc herniated patients with ipsilateral symptoms as group I were compared with five disc herniated patients with only contralateral symptoms as group II. Ligamenta flava thicknesses and spinal canal diameters of both groups were measured on magnetic resonance imaging (MRI) with a micro-caliper.

RESULTS

Both groups underwent surgery only on the disc herniated side. The total thicknesses of the ligamenta flava in group II was thicker than in group I. There was no spinal stenosis in either group and no significance difference between the groups. Statistically significant differences were found for both ipsilateral and contralateral thickness of the ligament flava in both groups. We also compared thickness of the ligamenta flava for each level of disc herniation in group I; ligamenta flava hypertrophy was more common at L3-L4 and L4-L5 levels of vertebrae in females.

CONCLUSIONS

Aetiology of contralateral sciatica among disc herniated patients may be related to hypertrophy of the ligamenta flava, especially on the opposite side. Surgical approaches of the disc herniated side alone may be sufficient for a good outcome.

Sciatica

Sciatica is a symptom rather than a specific diagnosis. Available evidence from basic science and clinical research indicates that both inflammation and compression are important in order for the nerve root to be symptomatic. Tumour necrosis factor-alpha (TNF-alpha) is a key mediator in animal models, but its exact contribution in human radiculopathy is still a matter of debate. Sciatica is mainly diagnosed by history taking and physical examination. In general, the clinical course of acute sciatica is considered to be favourable. In the first 6-8 weeks, there is consensus that treatment of sciatica should be conservative. We review and comment on the levels of evidence of the efficacy of patient information, advice to stay active, physical therapy analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), epidural corticosteroid injections and transforaminal peri-radicular injections of corticosteroid. There is good evidence that discectomy is effective in the short term. but, in the long term, it is not more effective than prolonged conservative care. Shared decision making with regard to surgery is necessary in the absence of severe progressive neurological symptoms. Although the term sciatica is simple and easy to use, it is, in fact, an archaic and confusing term. For most researchers and clinicians, it refers to a radiculopathy, involving one of the lower extremities, and related to disc herniation (DH). As such, the term 'sciatica' is too restrictive as nerve roots from L1 to L4 may also be involved in the same process. However, even more confusing is the fact that patients, and many clinicians alike, use sciatica to describe any pain arising from the lower back and radiating down to the leg. The majority of the time, this painful sensation is referred pain from the lower back and is neither related to DH nor does it result from nerve-root compression. Although differentiating the radicular pain from the referred pain may be challenging for the clinician, it is of primary importance. This is because the epidemiology, clinical course and, most importantly, therapeutic interventions are different for these two conditions. It should, however, be emphasised that the quality of the available evidence is rather limited due to a considerable heterogeneity in the study populations included in the trials. This makes generalisation of findings across studies, and to routine clinical practice, a challenge. Prevalence estimates of radicular pain related to DH also vary considerably between studies, which is, in part, due to differences in the definitions used. A recent review showed that the prevalence of sciatic symptoms is rather variable, with values ranging from 1.6% to 43%. If stricter definitions of sciatica were used, for example, in terms of pain distribution and/or pain duration, lower prevalence rates were reported. Studies in working populations with physically demanding jobs consistently report higher rates of sciatica compared with studies in the general population.

Microvascular system of the lumbar dorsal root ganglia in rats. Part II: neurogenic control of intraganglionic blood flow

OBJECT

The dorsal root ganglion (DRG) should not be overlooked when considering the mechanism of low-back pain and sciatica, so it is important to understand the morphological features of the vascular system supplying the DRG. However, the neurogenic control of intraganglionic blood flow has received little attention in the past. The authors used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerves in blood vessels of the DRG.

METHODS

Ten Wistar rats were used. To investigate the mechanism of vasomotion on the lumbar DRG, the authors used immunohistochemical methods. Sections were incubated overnight with antisera to tyrosine hydroxylase (TH), aromatic L-amino-acid decarboxylase (AADC), 5-hydroxytryptamine, substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP), somatostatin (SOM), neuropeptide Y (NPY), leucine-enkephalin, and cholineacetyl transferase (Ch-E). The avidin-biotin complex method was used as the immunohistochemical procedure, and the sections were observed under a light microscope.

RESULTS

In the immunohistochemical study, TH-, AADC-, SP-, CGRP-, VIP-, SOM-, NPY-, and Ch-E-positive fibers were seen within the walls of blood vessels in the DRG. This study revealed the existence of a comprehensive perivascular adrenergic, cholinergic, and peptidergic innervation of intraganglionic blood vessels, with a possible role in neurogenic regulation (autoregulation) of intraganglionic circulation.

CONCLUSIONS

The presence of perivascular nerve plexuses around intraganglionic microvessels suggests that autonomic nerves play an important role in intraganglionic circulation.

Emerging technologies for degenerative disk disease: potential synergy between biochemical signaling and spinal biomechanics

Interventional spinal procedures are performed with increasing frequency, and they remain an important tool for physiatrists treating patients with spine pain. As the potential treatment options expand with novel technologies on the horizon, such as gene- and cell-based therapies, the physiatrist will be uniquely poised to deliver such treatments in conjunction with exercise-based therapies. Therefore, the development of novel technologies requires particular attention to the potential synergy between biochemical signaling and spinal biomechanics. It is hoped that such insight will result in improved treatment options for patients with pain related to degenerative disk disease, leading to improved nonoperative outcomes. This article reviews the current knowledge of precipitants of disk degeneration, the effects of beneficial and traumatic levels of disk loading, and how each of these can be impacted by novel treatment options.

Detection of anti-TNFalpha activity in canine hyperimmune serum using a TNFalpha inhibition assay

BACKGROUND

Increased serum tumor necrosis factor-alpha (TNFalpha) activity has been associated with onset of serious inflammatory diseases in dogs. Development of treatment with TNFalpha-antagonists has been limited by the unavailability of suitable reagents and potency assays for TNFalpha.

OBJECTIVES

The objectives of this study were to optimize a cell-based assay to measure anti-TNFalpha activity in serum and plasma from hyperimmune (vaccinated with an Escherichia coli J5 bacterin) and unvaccinated canine donors; to use the assay to determine whether hyperimmune serum inhibits TNFalpha activity in vivo; and to determine whether soluble TNF receptor-1 (sTNFR1, a naturally occurring TNFalpha antagonist) contributes to anti-TNFalpha activity.

METHODS

Commercial plasma and serum from hyperimmune-frozen plasma (HFP) donors and unvaccinated fresh-frozen plasma (FFP) donors were used in the study. An L929-cell TNFalpha-inhibition assay (LTIA) was optimized to measure anti-TNFalpha activity. Using a rat subcutaneous pouch model of inflammation, the effects of HFP, FFP, a synthetic TNFalpha antagonist (Etanercept), and carprofen on TNFalpha activity were compared in vivo. Immunofluorescence was used to measure soluble sTNFR1 concentration.

RESULTS

Using the optimized LTIA, HFP serum but not FFP serum decreased canine TNFalpha activity (P<.01). HFP plasma and Etanercept (but not FFP plasma or carprofen) significantly decreased TNFalpha activity in pouch exudates (P<.05). A significantly higher concentration of sTNFR1 was found in HFP than FFP serum.

CONCLUSIONS

Using the LTIA, anti-TNFalpha activity is readily measured in canine serum and inflammatory exudates. sTNFR1 appears to contribute to anti-TNFalpha activity in HFP serum. These results suggest HFP should be investigated further as a potential immunotherapeutic agent for controlling canine diseases in which TNFalpha is implicated.

Localization of COX-1 and COX-2 in the intracranial dura mater of the rat

Primary headaches such as migraine can be aborted by systemic administration of non-steroidal anti-inflammatory drugs (NSAIDs), potentially through the non-selective inhibition of cyclooxygenase (COX) activity in the intracranial meninges. In this study we have used single and double labeling immunohistochemistry to examine the distribution of the COX-1 and COX-2 isoforms in the intracranial dura mater of the rat and identify cell types that express them. COX-1 immunoreactivity was found in medium and small dural blood vessels and was co-expressed with the endothelial cell markers vimentin and the endothelial isoform of nitric oxide synthase (ecNOS). COX-1 was also found to be present in most dural mast cells. COX-2 was mainly expressed in ED2-positive resident dural macrophages. Constitutive COX-2 expression was also found in some axonal profiles, many of which were co-labeled with the nociceptor peptide marker CGRP. The findings suggest that NSAIDs may abort headache, at least in part, by inhibiting either neuronal or non-neuronal COX activity in the dura mater.

The bothersomeness of sciatica: patients' self-report of paresthesia, weakness and leg pain

The objective of the study was to investigate how patients with sciatica due to disc herniation rate the bothersomeness of paresthesia and weakness as compared to leg pain, and how these symptoms are associated with socio-demographic and clinical characteristics. A cross-sectional study was conducted on 411 patients with clinical signs of radiculopathy. Items from the Sciatica Bothersomeness Index (0 = none to 6 = extremely) were used to establish values for paresthesia, weakness and leg pain. Associations with socio-demographic and clinical variables were analyzed by multiple linear regression. Mean scores (SD) were 4.5 (1.5) for leg pain, 3.4 (1.8) for paresthesia and 2.6 (2.0) for weakness. Women reported higher levels of bothersomeness for all three symptoms with mean scores approximately 10% higher than men. In the multivariate models, more severe symptoms were associated with lower physical function and higher emotional distress. Muscular paresis explained 19% of the variability in self-reported weakness, sensory findings explained 10% of the variability in paresthesia, and straight leg raising test explained 9% of the variability in leg pain. In addition to leg pain, paresthesia and weakness should be assessed when measuring symptom severity in sciatica.

Intramuscular oxygen-ozone therapy in the treatment of acute back pain with lumbar disc herniation: a multicenter, randomized, double-blind, clinical trial of active and simulated lumbar paravertebral injection

STUDY DESIGN

Multicenter randomized, double-blind, simulated therapy-controlled trial in a cohort of patients with acute low back pain (LBP) due to lumbar disc herniation (LDH).

OBJECTIVE

To assess the benefit of intramuscular-paravertebral injections of an oxygen-ozone (O2O3) mixture.

SUMMARY OF BACKGROUND DATA

Recent findings have shown that O2O3 therapy can be used to treat LDH that fails to respond to conservative management. However, these findings are based on intradiscal/intraforaminal O2O3 injection, whereas intramuscular-paravertebral injection is the technique used most in clinical practice in Italy and other Western countries.

METHODS

Sixty patients suffering from acute LBP caused by LDH was randomized to an intramuscular O2O3 or control group. Patients were observed up to assess pain intensity, LBP-related disability, and drug intake (15 [V2] and 30 [V3] days after treatment started, and 2 weeks [V4], and 3 [V5] and 6 [V6] months after treatment ended).

RESULTS

A significant difference between the 2 groups in the percentage of cases who had become pain-free (61% vs. 33%, P < 0.05) was observed at V6. Patients who received O2O3 had a lower mean pain score than patients who received simulated therapy throughout the observation period. A significant improvement was observed in LBP-related disability in the study group patients when compared with the control group patients. Active O2O3 therapy was followed by a significantly lower number of days on nonsteroidal anti-inflammatory drugs at V2 and V3 and by a lower number of days at V4. No adverse events were reported.

CONCLUSION

Treatment of LBP and sciatica is a major concern. Although the natural history of acute LBP is often self-limiting, conservative therapies are not always effective; in such cases, O2O3 intramuscular lumbar paravertebral injections, which are minimally invasive, seem to safely and effectively relieve pain, as well as reduce both disability and the intake of analgesic drugs.

Vasomotion of intraradicular microvessels in rat

STUDY DESIGN

This study is to investigate the changes of vasomotion of intraradicular microvessels in vivo.

OBJECTIVE

We have observed microvascular corrosion casts of the lumbar nerve root by scanning electron microscopy and used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerve in blood vessels of the nerve root.

SUMMARY OF BACKGROUND DATA

It is generally considered that the genesis of radiculopathy associated with the degenerative conditions of the spine may result from both mechanical compression and circulatory disturbance. However, the neurogenic control of intraradicular blood flow has received little attention in the past.

METHODS

For three-dimensional observation of intraradicular vessels, we used scanning electron microscopic examination of microvascular corrosion casts in ten Wister rats. To investigate the mechanism of vasomotion of the nerve root, we used immunohistochemical methods. The sections were incubated overnight with antisera to tyrosine hydroxylase, choline acetyl transferase, substance P, calcitonin-gene-related peptide, vasoactive intestinal peptide, somatostatin, neuropeptide Y, leucine-enkephalin, cholecystokinin octapeptide, brain-nitric oxide synthase, and endothelium-nitric oxide synthase. Abidin-biotin complex method was used as the immunohistochemical procedure and the sections were observed under the light microscope.

RESULTS

The general view of whole vascular casts of the lumbar spinal cord and nerve roots showed a high density of vessels. Bifurcation or anastomoses of capillaries approximately took place at right angles in a T-shaped pattern and capillaries showed a lot of ring-like compressions. This ring-like compression on the cast may represent a vascular sphincter in the microvessels. This study also reveals the existence of perivascular adrenergic, cholinergic, peptidergic, and nitroxydergic innervation with a possible role in neurogenic regulation of nerve root circulation.

CONCLUSION

Perivascular nerve plexuses around intraradicular microvessels suggest that the autonomic nerves play an important role in intraradicular circulation.

Ultrastructural analysis on lumbar disc herniation using surgical specimens: role of neovascularization and macrophages in hernias

STUDY DESIGN

The mechanisms responsible for the spontaneous regression of lumbar disc herniation (LDH) were studied by examining herniated tissue collected at operation from patients with LDH.

OBJECTIVE

The aim of the present study was to investigate the role of neovascularization and macrophages in hernias when spontaneous regression of LDH occurred.

SUMMARY OF BACKGROUND DATA

Spontaneous regression of LDHs has already been demonstrated by diagnostic imaging with tools such as magnetic resonance imaging. However, there have been few studies on the mechanisms of spontaneous regression based on pathologic examination of herniated tissue. In particular, there has been no detailed work on the role of macrophages, which are thought to be closely associated with spontaneous regression.

METHODS

The magnetic resonance imaging and operative findings of 73 patients who underwent surgery were investigated, and specimens collected during surgery were examined by light and transmission electron microscopy.

RESULTS

Capillaries that invade the hernia and macrophages derived from monocytes migrating out of these capillaries are considered to be important factors in the regression of the herniated disc. Macrophages contain lysosomes filled with collagen-degrading enzymes that break down substances after phagocytosis, whereas primary lysosomes are secreted by these cells and break down intercellular substances such as collagen. Both of these mechanisms are closely involved in the regression of herniation.

CONCLUSION

The inflammatory response that occurs around hernia tissue in the epidural space is believed to play an important role in herniated disc resorption, although it may also have a harmful effect on the adjacent nerve root. Therefore, control of the inflammatory reaction is an important challenge when treating patients with disc herniation.

Herniated and spondylotic intervertebral discs of the human cervical spine: histological and immunohistological findings in 500 en bloc surgical samples. Laboratory investigation

OBJECT

In this paper the authors' goal was to identify histological and immunohistochemical differences between cervical disc hemrniation and spondylosis.

METHODS

A total of 500 cervical intervertebral discs were excised from 364 patients: 198 patients with disc herniation and 166 patients with spondylosis. We examined en bloc samples of endplate-ligament-disc complexes. Types of herniation and graded degrees of disc degeneration on MR images were examined histologically and immunohistochemically.

RESULTS

The herniated discs showed granulation tissue, newly developed blood vessels, and massive infiltration of CD68-positive macrophages, which surrounded the herniated tissue mainly in the ruptured outer layer of the anulus fibrosus. The vascular invasion was most significant in uncontained (extruded)-type herniated discs. Chondrocytes positive for matrix metalloproteinase (MMP)-3, tumor necrosis factor (TNF)-alpha, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were abundant in both herniated and spondylotic discs. Free nerve fibers, positive for nerve growth factor (NGF), neurofilament 68, growth-associated protein (GAP)-43, and substance P, were strongly apparent in and around the outer layer of uncontained (extruded)-type herniated discs, with enhanced expression of NGF. The authors observed that herniated discs showed more advanced degeneration in the outer layer of the anulus fibrosus around the granulation tissue than spondylotic discs. On the other hand, spondylotic discs showed more advanced degeneration in the cartilaginous endplate and inner layer of the anulus fibrosus than herniated discs. Spondylotic discs also had thicker bony endplates and expressed TNFalpha and MMP-3 more diffusely than herniated discs, especially in the inner layer of the anulus fibrosus.

CONCLUSIONS

The authors' results indicate that herniated and spondylotic intervertebral discs undergo different degenerative processes. It is likely that TNFa, MMP-3, bFGF, and VEGF expression is upregulated via the herniated mass in the herniated intervertebral discs, but by nutritional impairment in the spondylotic discs. Macrophage accumulation around newly formed blood vessels in the herniated disc tissues seemed to be regulated by MMP-3 and TNFalpha expression, and both herniated and spondylotic discs exhibited marked neoangiogenesis associated with increased bFGF and VEGF expression. Nerve fibers were associated with NGF overexpression in the outer layer of the anulus fibrosus as well as in endothelial cells of the small blood vessels.

Effects of arterial ischemia and venous congestion on the lumbar nerve root in dogs

The development of radiculopathy in patients with lumbar canal stenosis is thought to be closely related to intraradicular edema resulting from compression. However, there is little agreement as to question which is more essential for intermittent claudication: ischemia or congestion. The aim of the present experimental investigation was to examine the effect of ischemia and congestion on the nerve root using dogs. The aorta was clamped as an ischemia model of the nerve root and the inferior vena cava was clamped as a congestion model at the sixth costal level for 30 min using forceps transpleurally. Measurements of blood flow, partial oxygen pressure, and conduction velocity in the nerve root were repeated over a period of 1 h after release of clamping. Finally, we examined the status of intraradicular blood-nerve barrier under fluorescence and transmission electron microscope. Immediately after clamping of the inferior vena cava, the central venous pressure increased by about four times and marked extravasation of protein tracers was induced in the lumbar nerve root. Blood flow, partial oxygen pressure, and conduction velocity of the nerve root were more severely affected by aorta clamp, but this ischemia model did not show any intraradicular edema. The blood-nerve barrier in the nerve root was more easily broken by venous congestion than by arterial ishemia. In conclusion, venous congestion may be an essential factor precipitating circulatory disturbance in compressed nerve roots and inducing neurogenic intermittent claudication.

Sciatica: review of epidemiological studies and prevalence estimates

STUDY DESIGN

Review of studies on sciatica prevalence and synthesis of available evidence.

OBJECTIVE

To assess the studies on sciatica prevalence, discuss reasons for variation in estimates, provide suggestions for improving accuracy of recording sciatica in epidemiological and outcome studies so as to enable better evaluation of natural history and treatment effect in the presence of low back pain related sciatica.

SUMMARY OF BACKGROUND DATA

Sciatica is a common cause of pain and disability. It is more persistent and severe than low back pain, has a less favorable outcome and consumes more health resources. However, sciatica prevalence rates reported in different studies and reviews vary considerably and provide no clear picture about sciatica prevalence.

METHODS

A literature search of all English language peer reviewed publications was conducted using Medline, EMBASE, and CINAHL for the years 1980-2006. Two reviewers extracted data on sciatica prevalence and definitions from the identified articles.

RESULTS

Of the papers retrieved, 23 were included in the review. Only 2 studies out of the 23 used clinical assessment for assessing sciatic symptoms, and definitions of sciatica varied widely. Sciatica prevalence from different studies ranged from 1.2% to 43%.

CONCLUSION

Sciatica prevalence estimates vary considerably between studies. This may be due to differences in definitions, methods of data collection and perhaps populations studied. Suggestions are made on how to improve accuracy of capturing sciatica in epidemiological studies.