Cost-effectiveness of Transforaminal epidural steroid injections for patients with ACUTE sciatica: a randomized controlled trial

BACKGROUND

Transforaminal epidural injections with steroids (TESI) are increasingly being used in patients sciatica. The STAR (steroids against radiculopathy)-trial aimed to evaluate the (cost-) effectiveness of TESI in patients with acute sciatica (< 8 weeks). This article contains the economic evaluation of the STAR-trial.

METHODS

Participants were randomized to one of three study arms: Usual Care (UC), that is oral pain medication with or without physiotherapy, n = 45); intervention group 1: UC and transforaminal epidural steroid injection (TESI) 1 ml of 0.5% Levobupivacaine and 1 ml of 40 mg/ml Methylprednisolone and intervention group 2: UC and transforaminal epidural injection (TEI) with 1 ml of 0,5% Levobupivacaine and 1 ml of 0.9% NaCl (n = 50). The primary effect measure was health-related quality of life. Secondary outcomes were pain, functioning, and recovery. Costs were measured from a societal perspective, meaning that all costs were included, irrespective of who paid or benefited. Missing data were imputed using multiple imputation, and bootstrapping was used to estimate statistical uncertainty.

RESULTS

None of the between-group differences in effects were statistically significant for any of the outcomes (QALY, back pain, leg pain, functioning, and global perceived effect) at the 26-weeks follow-up. The adjusted mean difference in total societal costs was €1718 (95% confidence interval [CI]: - 3020 to 6052) for comparison 1 (intervention group 1 versus usual care), €1640 (95%CI: - 3354 to 6106) for comparison 2 (intervention group 1 versus intervention group 2), and €770 (95%CI: - 3758 to 5702) for comparison 3 (intervention group 2 versus usual care). Except for the intervention costs, none of the aggregate and disaggregate cost differences were statistically significant. The maximum probability of all interventions being cost-effective compared to the control was low (< 0.7) for all effect measures.

CONCLUSION

These results suggest that adding TESI (or TEI) to usual care is not cost-effective compared to usual care in patients with acute sciatica (< 8 weeks) from a societal perspective in a Dutch healthcare setting.

TRIAL REGISTRATION

Dutch National trial register: NTR4457 (March, 6th, 2014).

Ultrasound-guided versus fluoroscopy-guided lumbar selective nerve root block: a retrospective comparative study

The purpose of this study is to compare the accuracy and effectiveness of ultrasound-guided and fluoroscopy-guided lumbar selective nerve root block (SNRB), and to explore the feasibility of ultrasound-guided methods. This retrospective study included patients with lumbar radicular pain who underwent ultrasound-guided and fluoroscopy-guided selective nerve root block at Honghui Hospital Affiliated to Xi'an Jiaotong University from August 2020 to August 2022. Patients were divided into U-SNRB group and F-SNRB group according to ultrasound-guided or fluoroscopy-guided selective nerve root block. There were 43 patients in U-SNRB group and 20 patients in F-SNRB group. The pain visual analogue scale (VAS) scores, Japanese Orthopaedic Association (JOA) scores, related indexes and complications were recorded and compared between the two groups before, 30 min, 1 month and 6 months after block. To evaluate the feasibility, accuracy and effectiveness of ultrasound-guided selective nerve root block. There were no complications in the process of selective nerve root block in both groups. The operating time and the times of closing needle angle adjustment in U-SNRB group were better than those in F-SNRB group, and the difference was statistically significant (P < 0.05). The VAS score and JOA score of patients in the two groups were significantly improved 30 min after block, 1 month and 6 months after block, and the difference was statistically significant (P < 0.05). There was no significant difference between the two groups (P > 0.05). The accuracy of ultrasound-guided selective nerve root block and the degree of pain relief of patients were similar to those of fluoroscopy guidance, but the operation time and needle angle adjustment times were significantly less than that of fluoroscopy, and could effectively reduce radiation exposure. Therefore, it can be used as a better way to guide for choice.

Isolated Deep Infiltrating Endometriosis of the Sciatic Nerve: A Case Report and Overview of the Literature

Isolated deep infiltrating endometriosis (DIE) of sacral nerve roots or major pelvic nerves, including the sciatic nerve, is considered to be extremely rare. Due to the overlap with sciatica symptoms, the diagnosis of sciatica DIE is difficult yet crucial, as it results in permanent neural damage if left untreated. We report a case of a 45-year-old woman who experienced a three-year-long and recently exacerbating pain in her right leg, accompanied by a tingling sensation and weakness in her right leg and foot, with difficulty walking. In between regular menstrual bleedings, when her aforementioned symptoms worsened, she had been experiencing mild 10-day extra-cyclical bleeding. Her neurologist's, orthopedist's, and gynecological examinations were unremarkable. Magnetic resonance imaging (MRI) showed an infiltrative lesion on the right sciatic nerve that was immunohistochemically confirmed to be endometriosis. The patient was treated with gonadotropin-releasing hormone analogues (GnRHa), which led to a significantly diminished size of the lesion on the control MRI, and endometriosis remission was obtained. For persistent mild, but cyclical, pain and muscle weakness, continuous progestagnes were administered, with advice for physical therapy provided for her neuro-muscle rehabilitation and a scheduled check-up in 6 months.

Predictors of neuropathic pain and related functional disability in sciatica patients: a cross-sectional study

PURPOSE

The aim of the present paper was to assess neuropathic pain and its predictors among patients with sciatica. In addition, we sought to investigate the predictors of functional disability in sciatica patients with neuropathic pain.

METHODS

A cross-sectional study was carried out on a sample of 100 sciatica patients aged 18 years and older with a radiating pain from the lower back down to the leg below the knee. Information about socio-demographic characteristics, duration of symptoms, being treated or not, type of treatment, side of sciatica, presence of back pain, leg pain occurrence, leg pain intensity, functional disability and pain catastrophizing were collected.

RESULTS

Of the total patients, 57% had neuropathic pain. Multivariable analysis showed that leg pain intensity was higher in the neuropathic pain group as compared to the non-neuropathic pain group. Also, patients with left sciatica were less likely to have neuropathic pain than patients with right sciatica. Patients with neuropathic pain having high levels of pain catastrophizing and being on bed rest for at least one week were at a higher risk of developing functional disability as compared to their counterparts.

CONCLUSION

Low levels of pain catastrophizing and less bed rest should be considered in interventions aimed at improving the functional ability for sciatica patients with neuropathic pain.

Recommendations for terminology and the identification of neuropathic pain in people with spine-related leg pain. Outcomes from the NeuPSIG working group

ABSTRACT

Pain radiating from the spine into the leg is commonly referred to as "sciatica," "Sciatica" may include various conditions such as radicular pain or painful radiculopathy. It may be associated with significant consequences for the person living with the condition, imposing a reduced quality of life and substantial direct and indirect costs. The main challenges associated with a diagnosis of "sciatica" include those related to the inconsistent use of terminology for the diagnostic labels and the identification of neuropathic pain. These challenges hinder collective clinical and scientific understanding regarding these conditions. In this position paper, we describe the outcome of a working group commissioned by the Neuropathic Pain Special Interest Group (NeuPSIG) of the International Association for the Study of Pain (IASP) which was tasked with the following objectives: (1) to revise the use of terminology for classifying spine-related leg pain and (2) to propose a way forward on the identification of neuropathic pain in the context of spine-related leg pain. The panel recommended discouraging the term "sciatica" for use in clinical practice and research without further specification of what it entails. The term "spine-related leg pain" is proposed as an umbrella term to include the case definitions of somatic referred pain and radicular pain with and without radiculopathy. The panel proposed an adaptation of the neuropathic pain grading system in the context of spine-related leg pain to facilitate the identification of neuropathic pain and initiation of specific management in this patient population.

Full endoscopic versus open discectomy for sciatica: randomised controlled non-inferiority trial

OBJECTIVE

To assess whether percutaneous transforaminal endoscopic discectomy (PTED) is non-inferior to conventional open microdiscectomy in reduction of leg pain caused by lumbar disc herniation.

DESIGN

Multicentre randomised controlled trial with non-inferiority design.

SETTING

Four hospitals in the Netherlands.

PARTICIPANTS

613 patients aged 18-70 years with at least six weeks of radiating leg pain caused by lumbar disc herniation. The trial included a predetermined set of 125 patients receiving PTED who were the learning curve cases performed by surgeons who did not do PTED before the trial.

INTERVENTIONS

PTED (n=179) compared with open microdiscectomy (n=309).

MAIN OUTCOME MEASURES

The primary outcome was self-reported leg pain measured by a 0-100 visual analogue scale at 12 months, assuming a non-inferiority margin of 5.0. Secondary outcomes included complications, reoperations, self-reported functional status as measured with the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery. Outcomes were measured until one year after surgery and were longitudinally analysed according to the intention-to-treat principle. Patients belonging to the PTED learning curve were omitted from the primary analyses.

RESULTS

At 12 months, patients who were randomised to PTED had a statistically significantly lower visual analogue scale score for leg pain (median 7.0, interquartile range 1.0-30.0) compared with patients randomised to open microdiscectomy (16.0, 2.0-53.5) (between group difference of 7.1, 95% confidence interval 2.8 to 11.3). Blood loss was less, length of hospital admission was shorter, and timing of postoperative mobilisation was earlier in the PTED group than in the open microdiscectomy group. Secondary patient reported outcomes such as the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery, were similarly in favour of PTED. Within one year, nine (5%) in the PTED group compared with 14 (6%) in the open microdiscectomy group had repeated surgery. Per protocol analysis and sensitivity analyses including the patients of the learning curve resulted in similar outcomes to the primary analysis.

CONCLUSIONS

PTED was non-inferior to open microdiscectomy in reduction of leg pain. PTED resulted in more favourable results for self-reported leg pain, back pain, functional status, quality of life, and recovery. These differences, however, were small and may not reach clinical relevance. PTED can be considered as an effective alternative to open microdiscectomy in treating sciatica.

TRIAL REGISTRATION

NCT02602093ClinicalTrials.gov NCT02602093.

Causal Associations of Obesity With the Intervertebral Degeneration, Low Back Pain, and Sciatica: A Two-Sample Mendelian Randomization Study

The role of obesity in the development of dorsopathies is still unclear. In this study, we assessed the associations between body mass index (BMI) and several dorsopathies including intervertebral disc degeneration (IVDD), low back pain (LBP), and sciatica by using the Mendelian randomization method. We also assessed the effect of several obesity-related traits on the same outcomes. Single-nucleotide polymorphisms associated with the exposures are extracted from summary-level datasets of previously published genome-wide association studies. Summary-level results of IVDD, LBP, and sciatica were from FinnGen. In our univariable Mendelian randomization analysis, BMI is significantly associated with increased risks of all dorsopathies including sciatica (OR = 1.33, 95% CI, 1.21-1.47, p = 5.19 × 10^-9), LBP (OR = 1.28, 95% CI, 1.18-1.39, p = 6.60 × 10^-9), and IVDD (OR = 1.23, 95% CI, 1.14-1.32, p = 2.48 × 10^-8). Waist circumference, hip circumference, whole-body fat mass, fat-free mass, and fat percentage, but not waist-hip ratio, were causally associated with increased risks of IVDD and sciatica. Higher hip circumference, whole-body fat mass, fat-free mass, and fat percentage increased the risk of LBP. However, only whole-body fat-free mass remained to have a significant association with the risk of IVDD after adjusting for BMI with an odds ratio of 1.57 (95% CI, 1.32-1.86, p = 2.47 × 10^-7). Proportions of BMI's effect on IVDD, sciatica, and LBP mediated by leisure sedentary behavior were 41.4% (95% CI, 21.8%, 64.8%), 33.8% (95% CI, 17.5%, 53.4%), and 49.7% (95% CI, 29.4%, 73.5%), respectively. This study provides evidence that high BMI has causal associations with risks of various dorsopathies. Weight control is a good measure to prevent the development of dorsopathies, especially in the obese population.

[Cruralgia heralding the rupture of an abdominal aneurysm - reminder through a clinical case]

Abdominal aneurysm is a common pathology that affects mainly men and for which there are many risk factors. This pathology predominantly stays asymptomatic until rupture and symptoms depend on location. We report the case of a 71-year-old patient. She is presenting herself to the emergency room for a nagging pain, typical of a left cruralgia as she is both febrile and shivering. The abdominal scanner is showing a ruptured infra renal aortic aneurysm. The patient is transferred to universities for an uncomplicated stent. Despite a cruralgia that seemed quite banal, both clinical and anamnestic arguments suggested an abdominal aortic rupture.

Predicting conservative treatment failure in patients with lumbar disc herniation. Single center, case-control study

OBJECTIVES

The aim of this study was to identify independent predictors of conservative treatment failure in patients presenting due to lumbar disc herniation-associated low back pain and sciatica.

PATIENTS AND METHODS

This is a single institution, case-control study including 240 patients that were selected for microsurgical or conservative treatment due to lumbar disc herniation in a 2,5-year period. Bivariate and multivariate analyses were performed in order to identify independent predictors among demographic, clinical and radiographic factors.

RESULTS

Statistically significant differences were observed between conservatively and surgically managed groups in bivariate analysis. Logistic regression models further revealed that leg paresthesia (p =  0,003; OR = 5,136) and percentage of spinal canal stenosis ratio (p < 0,001; OR = 1,055) had the strongest, independent correlation with conservative treatment failure in our cohort. Back-to-leg ratio did not reach statistical significance although it proved a strong correlation in bivariate analysis (p < 0,001, Cramér's V = 0,53).

CONCLUSION

Increasing % canal compromise ratio (cut-off value 23%) and co-occurrence of leg paresthesia were the most important risk factors for surgery in our series of patients.

Micronized Palmitoylethanolamide: A Post Hoc Analysis of a Controlled Study in Patients with Low Back Pain - Sciatica

BACKGROUND

Despite being widely prescribed, relatively few controlled trials have been conducted on the class of neurotrophic/antinociceptive nutraceuticals. While performing a search in the literature, we came across an old registration study on micronized palmitoylethanolamide in patients with low back pain - sciatica by Guida and colleagues.

METHODS

We contacted the authors of the article and obtained all the original material, which allowed us to reanalyze the study. We assessed its clinical relevance by calculating the numbers needed to treat for pain (visual analog scale) and function (Roland-Morris Questionnaire). After excluding patients for whom the information available was insufficient, we assigned each patient to one of the five categories of increasing probability of neuropathic pain: pure lumbago, lumbago with projecting pain to surrounding regions (e.g. gluteus or groin), lumbago with projecting pain to the thigh or leg, pure sciatica and radiculopathy, and investigated any correlations (Spearman) between the improvement in pain and function with these five classes.

RESULTS

Compared with placebo, palmitoylethanolamide 600 mg/die yielded a number needed to treat of 1.7 (95% confidence interval: 1.4-2) for pain, and 1.5 (95% confidence interval: 1.4-1.7) for function. The correlation between the five categories was highly significant for pain relief (P <0.0001), though not significant for reduced dysfunction.

CONCLUSION

Palmitoylethanolamide was extremely effective on pain and function in a large cohort of patients with low back pain - sciatica. Although, the multiple mechanisms of action of palmitoylethanolamide are ideal for mixed pain conditions such as low back pain - sciatica, the correlation between pain relief and the likelihood of neuropathic pain suggests that this drug exerts a predominant action on the neuropathic pain component.

Prenatal alcohol exposure is a risk factor for adult neuropathic pain via aberrant neuroimmune function

BACKGROUND

Clinical studies show that prenatal alcohol exposure (PAE) results in effects that persist into adulthood. Experimental animal models of moderate PAE demonstrate that young adults with PAE display potentiated sensitivity to light touch, clinically termed allodynia, following sciatic nerve chronic constriction injury (CCI) that coincides with heightened spinal glial, spinal macrophage, and peripheral immune responses. However, basal touch sensitivity and corresponding glial and leukocyte activation are unaltered. Therefore, the current study explored whether the enduring pathological consequences of moderate PAE on sensory processing are unmasked only following secondary neural insult.

METHODS

In middle-aged (1 year) Long Evans rats that underwent either prenatal saccharin exposure (control) or moderate PAE, we modified the well-characterized model of sciatic neuropathy, CCI, to study the effects of PAE on neuro-immune responses in adult offspring. Standard CCI manipulation required 4 chromic gut sutures, while a mild version applied a single suture loosely ligated around one sciatic nerve. Spinal glial immunoreactivity was examined using immunohistochemistry. The characterization and functional responses of leukocyte populations were studied using flow cytometry and cell stimulation assays followed by quantification of the proinflammatory cytokines interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α). Data were statistically analyzed by ANOVA and unpaired t tests.

RESULTS

The current report demonstrates that mild CCI generates robust allodynia only in PAE rats, while the pathological effects of PAE following the application of a standard CCI are revealed by enhanced allodynia and elevated spinal glial activation. Additionally, mild CCI increases spinal astrocyte activation but not microglia, suggesting astrocytes play a larger role in PAE-induced susceptibility to aberrant sensory processing. Leukocyte populations from PAE are altered under basal conditions (i.e., prior to secondary insult), as the distribution of leukocyte populations in lymphoid organs and other regions are different from those of controls. Lastly, following in vitro leukocyte stimulation, only PAE augments the immune response to antigen stimulation as assessed by heightened production of TNF-α and IL-1β.

CONCLUSIONS

These studies demonstrate PAE may prime spinal astrocytes and peripheral leukocytes that contribute to enduring susceptibility to adult-onset neuropathic pain that is not apparent until a secondary insult later in life.

MRI-detection rate and incidence of lumbar bleeding sources in 190 patients with non-aneurysmal SAH

BACKGROUND

Up to 15% of all spontaneous subarachnoid hemorrhages (SAH) have a non-aneurysmal SAH (NASAH). The evaluation of SAH patients with negative digital subtraction angiography (DSA) is sometimes a diagnostic challenge. Our goal in this study was to reassess the yield of standard MR-imaging of the complete spinal axis to rule out spinal bleeding sources in patients with NASAH.

METHODS

We retrospectively analyzed the spinal MRI findings in 190 patients with spontaneous NASAH, containing perimesencephalic (PM) and non-perimesencephalic (NPM) SAH, diagnosed by computer tomography (CT) and/or lumbar puncture (LP), and negative 2nd DSA.

RESULTS

190 NASAH patients were included in the study, divided into PM-SAH (n = 87; 46%) and NPM-SAH (n = 103; 54%). Overall, 23 (22%) patients had a CT negative SAH, diagnosed by positive LP. MR-imaging of the spinal axis detected two patients with lumbar ependymoma (n = 2; 1,05%). Both patients complained of radicular sciatic pain. The detection rate raised up to 25%, if only patients with radicular sciatic pain received an MRI.

CONCLUSION

Routine radiological investigation of the complete spinal axis in NASAH patients is expensive and can not be recommended for standard procedure. However, patients with clinical signs of low-back/sciatic pain should be worked up for a spinal pathology.

Prognostic Factors for Persistent Leg-Pain in Patients Hospitalized With Acute Sciatica

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

To identify potential prognostic factors for persistent leg-pain at 12 months among patients hospitalized with acute severe sciatica.

SUMMARY OF BACKGROUND DATA

The long-term outcome for patients admitted to hospital with sciatica is generally unfavorable. Results concerning prognostic factors for persistent sciatica are limited and conflicting.

METHODS

A total of 210 patients acutely admitted to hospital for either surgical or nonsurgical treatment of sciatica were consecutively recruited and received a thorough clinical and radiographic examination in addition to responding to a comprehensive questionnaire. Follow-up assessments were done at 6 weeks, 6 months, and 12 months. Potential prognostic factors were measured at baseline and at 6 weeks. The impact of these factors on leg-pain was analyzed by multiple linear regression modeling.

RESULTS

A total of 151 patients completed the entire study, 93 receiving nonrandomized surgical treatment. The final multivariate models showed that the following factors were significantly associated with leg-pain at 12 months: high psychosocial risk according to the Örebro Musculosceletal Pain Questionnaire (unstandardized beta coefficient 1.55, 95% confidence interval [CI] 0.72-2.38, P < 0.001), not receiving surgical treatment (1.11, 95% CI 0.29-1.93, P = 0.01), not actively employed upon admission (1.47, 95% CI 0.63-2.31, P < 0.01), and self-reported leg-pain recorded 6 weeks posthospital admission (0.49, 95% CI 0.34-0.63, P < 0.001). Interaction analysis showed that the Örebro Musculosceletal Pain Questionnaire had significant prognostic value only on the nonsurgically treated patients (3.26, 95% CI 1.89-4.63, P < 0.001).

CONCLUSION

The results suggest that a psychosocial screening tool and the implementation of a 6-week postadmission follow-up has prognostic value in the hospital management of severe sciatica.

LEVEL OF EVIDENCE

2.

Exacerbation of Charcot-Marie-Tooth type 2E neuropathy following traumatic nerve injury

Charcot-Marie-Tooth disease (CMT) is the most commonly inherited peripheral neuropathy. CMT disease signs include distal limb neuropathy, abnormal gait, sensory defects, and deafness. We generated a novel line of CMT2E mice expressing hNF-L(E397K), which displayed muscle atrophy of the lower limbs without denervation, proximal reduction in large caliber axons, and decreased nerve conduction velocity. In this study, we challenged wild type, hNF-L and hNF-L(E397K) mice with crush injury to the sciatic nerve. We analyzed functional recovery by measuring toe spread and analyzed gait using the Catwalk system. hNF-L(E397K) mice demonstrated reduced recovery from nerve injury consistent with increased susceptibility to neuropathy observed in CMT patients. In addition, hNF-L(E397K) developed a permanent reduction in their ability to weight bear, increased mechanical allodynia, and premature gait shift in the injured limb, which led to increasingly disrupted interlimb coordination in hNF-L(E397K). Exacerbation of neuropathy after injury and identification of gait alterations in combination with previously described pathology suggests that hNF-L(E397K) mice recapitulate many of clinical signs associated with CMT2. Therefore, hNF-L(E397K) mice provide a model for determining the efficacy of novel therapies.

Engagement of the GABA to KCC2 signaling pathway contributes to the analgesic effects of A3AR agonists in neuropathic pain

More than 1.5 billion people worldwide suffer from chronic pain, yet current treatment strategies often lack efficacy or have deleterious side effects in patients. Adenosine is an inhibitory neuromodulator that was previously thought to mediate antinociception through the A1 and A2A receptor subtypes. We have since demonstrated that A3AR agonists have potent analgesic actions in preclinical rodent models of neuropathic pain and that A3AR analgesia is independent of adenosine A1 or A2A unwanted effects. Herein, we explored the contribution of the GABA inhibitory system to A3AR-mediated analgesia using well-characterized mouse and rat models of chronic constriction injury (CCI)-induced neuropathic pain. The deregulation of GABA signaling in pathophysiological pain states is well established: GABA signaling can be hampered by a reduction in extracellular GABA synthesis by GAD65 and enhanced extracellular GABA reuptake via the GABA transporter, GAT-1. In neuropathic pain, GABAAR-mediated signaling can be further disrupted by the loss of the KCC2 chloride anion gradient. Here, we demonstrate that A3AR agonists (IB-MECA and MRS5698) reverse neuropathic pain via a spinal mechanism of action that modulates GABA activity. Spinal administration of the GABAA antagonist, bicuculline, disrupted A3AR-mediated analgesia. Furthermore, A3AR-mediated analgesia was associated with reductions in CCI-related GAD65 and GAT-1 serine dephosphorylation as well as an enhancement of KCC2 serine phosphorylation and activity. Our results suggest that A3AR-mediated reversal of neuropathic pain increases modulation of GABA inhibitory neurotransmission both directly and indirectly through protection of KCC2 function, underscoring the unique utility of A3AR agonists in chronic pain.

A randomized clinical trial comparing the effectiveness of ultrasound guidance versus nerve stimulation for lateral popliteal-sciatic nerve blocks in obese patients

OBJECTIVES

Ultrasound guidance may decrease the procedural time for many peripheral nerve blocks compared to nerve stimulation, but these studies have generally excluded obese patients. This single-blinded randomized clinical trial was designed to compare procedural times and related outcomes for ultrasound- versus nerve stimulation-guided lateral popliteal-sciatic nerve blockade specifically in obese patients.

METHODS

With Institutional Review Board approval and informed consent, patients with a body mass index greater than 30 kg/m(2) who were scheduled for foot/ankle surgery and desiring a peripheral nerve block were offered enrollment. Study patients were randomly assigned to receive a lateral popliteal-sciatic nerve block under either ultrasound or nerve stimulation guidance. The patient and assessor were blinded to group assignment. The primary outcome was procedural time in seconds. Secondary outcomes included number of needle redirections, procedure-related pain, patient satisfaction with the block, success rate, sensory and motor onset times, block duration, and complication rates.

RESULTS

Twenty-four patients were enrolled and completed the study. All patients had successful nerve blocks. The mean procedural times (SD) were 577 (57) seconds under nerve stimulation and 206 (40) seconds with ultrasound guidance (P< .001; 95% confidence interval for difference, 329-412 seconds). Patients in the ultrasound group had fewer needle redirections and less procedure-related pain, required less opioids, and were more satisfied with their block procedures. There were no statistically significant differences in other outcomes.

CONCLUSIONS

The results of this study show that, for obese patients undergoing lateral popliteal-sciatic nerve blocks, ultrasound guidance reduces the procedural time and procedure-related pain and increases patient satisfaction compared to nerve stimulation while providing similar block characteristics.

Influence of low back pain and prognostic value of MRI in sciatica patients in relation to back pain

BACKGROUND

Patients with sciatica frequently complain about associated back pain. It is not known whether there are prognostic relevant differences in Magnetic Resonance Imaging (MRI) findings between sciatica patients with and without disabling back pain.

METHODS

The study population contained patients with sciatica who underwent a baseline MRI to assess eligibility for a randomized trial designed to compare the efficacy of early surgery with prolonged conservative care for sciatica. Two neuroradiologists and one neurosurgeon independently evaluated all MR images. The MRI readers were blinded to symptom status. The MRI findings were compared between sciatica patients with and without disabling back pain. The presence of disabling back pain at baseline was correlated with perceived recovery at one year.

RESULTS

Of 379 included sciatica patients, 158 (42%) had disabling back pain. Of the patients with both sciatica and disabling back pain 68% did reveal a herniated disc with nerve root compression on MRI, compared to 88% of patients with predominantly sciatica (P<0.001). The existence of disabling back pain in sciatica at baseline was negatively associated with perceived recovery at one year (Odds ratio [OR] 0.32, 95% Confidence Interval 0.18-0.56, P<0.001). Sciatica patients with disabling back pain in absence of nerve root compression on MRI at baseline reported less perceived recovery at one year compared to those with predominantly sciatica and nerve root compression on MRI (50% vs 91%, P<0.001).

CONCLUSION

Sciatica patients with disabling low back pain reported an unfavorable outcome at one-year follow-up compared to those with predominantly sciatica. If additionally a clear herniated disc with nerve root compression on MRI was absent, the results were even worse.

Variations among primary care physicians in exercise advice, imaging, and analgesics for musculoskeletal pain: results from a factorial experiment

OBJECTIVE

To examine whether medical decisions regarding evaluation and management of musculoskeletal pain conditions varied systematically by characteristics of the patient or provider.

METHODS

We conducted a balanced factorial experiment among primary care physicians in the US. Physicians (n = 192) viewed 2 videos of different patients (actors) presenting with pain: undiagnosed sciatica symptoms or diagnosed knee osteoarthritis. Systematic variations in patient gender, socioeconomic status, and race and physician gender and experience (<20 versus ≥20 years in practice) permitted estimation of unconfounded effects. Analysis of variance was used to evaluate associations between patient or provider attributes and clinical decisions. Quality of decisions was defined based on the current recommendations of the American College of Rheumatology, American Pain Society, and clinical expert consensus.

RESULTS

Despite current recommendations, less than one-third of physicians would provide exercise advice (30.2% for osteoarthritis and 32.8% for sciatica). Physicians with fewer years in practice were more likely to provide advice on lifestyle changes, particularly exercise (P ≤ 0.01), and to prescribe nonsteroidal antiinflammatory drugs for pain relief, both of which were appropriate and consistent with current recommendations for care. Newer physicians ordered fewer tests, particularly basic laboratory investigations or urinalysis. Test ordering decreased as organizational emphasis on business or profits increased. Patient factors and physician gender had no consistent effects on pain evaluation or treatment.

CONCLUSION

Physician education on disease management recommendations regarding exercise and analgesics and implementation of quality measures may be useful, particularly for physicians with more years in practice.

Sigma-1 receptor-mediated increase in spinal p38 MAPK phosphorylation leads to the induction of mechanical allodynia in mice and neuropathic rats

The direct activation of the spinal sigma-1 receptor (Sig-1R) produces mechanical allodynia (MA) and thermal hyperalgesia (TH) in mice. In addition, the blockade of the spinal Sig-1R prevents the induction of MA, but not TH in chronic constriction injury (CCI)-induced neuropathic rats. The present study was designed to investigate whether the increase in spinal p38 MAPK phosphorylation (p-p38 MAPK) mediates Sig-1R-induced MA or TH in mice and the induction of MA in neuropathic rats. MA and TH were evaluated using von Frey filaments and a hot-plate apparatus, respectively. Neuropathic pain was produced by CCI of the right sciatic nerve in rats. Western blot assay and immunohistochemistry were performed to determine the changes of p-p38 MAPK expression in the spinal cord. Intrathecal (i.t.) injection of PRE084, a selective Sig-1R agonist, into naïve mice time-dependently increased the expression of p-p38 MAPK, which was blocked by pretreatment with BD1047, a Sig-1R antagonist. I.t. pretreatment with SB203580, a p38 MAPK inhibitor also dose-dependently inhibited PRE084-induced MA, whereas TH induction was not affected. In CCI rats, i.t. injection of BD1047 during the induction phase (postoperative days 0 to 5) reduced the CCI-induced increase in p-p38 MAPK. In addition, i.t. SB203580 treatment during the induction phase also suppressed the development of CCI-induced MA, but not TH. Conversely, i.t. SB203580 treatment during the maintenance phase (postoperative days 15 to 20) had no effect on CCI-induced MA or TH. These results demonstrate that the increase in spinal p-p38 MAPK is closely associated with the induction of Sig-1R mediated MA, but not TH. Sigma-1 receptor modulation of p-p38 MAPK also plays an important role in the induction, but not the maintenance, of MA in neuropathic pain.

Traction for low-back pain with or without sciatica

BACKGROUND

Traction has been used to treat low-back pain (LBP), often in combination with other treatments. We included both manual and machine-delivered traction in this review. This is an update of a Cochrane review first published in 1995, and previously updated in 2006.

OBJECTIVES

To assess the effects of traction compared to placebo, sham traction, reference treatments and no treatment in people with LBP.

SEARCH METHODS

We searched the Cochrane Back Review Group Specialized Register, the Cochrane Central Register of Controlled Trials (2012, Issue 8), MEDLINE (January 2006 to August 2012), EMBASE (January 2006 to August 2012), CINAHL (January 2006 to August 2012), and reference lists of articles and personal files. The review authors are not aware of any important new randomized controlled trial (RCTs) on this topic since the date of the last search.

SELECTION CRITERIA

RCTs involving traction to treat acute (less than four weeks' duration), subacute (four to 12 weeks' duration) or chronic (more than 12 weeks' duration) non-specific LBP with or without sciatica.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction. As there were insufficient data for statistical pooling, we performed a descriptive analysis. We did not find any case series that identified adverse effects, therefore we evaluated adverse effects that were reported in the included studies.

MAIN RESULTS

We included 32 RCTs involving 2762 participants in this review. We considered 16 trials, representing 57% of all participants, to have a low risk of bias based on the Cochrane Back Review Group's 'Risk of bias' tool.For people with mixed symptom patterns (acute, subacute and chronic LBP with and without sciatica), there was low- to moderate-quality evidence that traction may make little or no difference in pain intensity, functional status, global improvement or return to work when compared to placebo, sham traction or no treatment. Similarly, when comparing the combination of physiotherapy plus traction with physiotherapy alone or when comparing traction with other treatments, there was very-low- to moderate-quality evidence that traction may make little or no difference in pain intensity, functional status or global improvement.For people with LBP with sciatica and acute, subacute or chronic pain, there was low- to moderate-quality evidence that traction probably has no impact on pain intensity, functional status or global improvement. This was true when traction was compared with controls and other treatments, as well as when the combination of traction plus physiotherapy was compared with physiotherapy alone. No studies reported the effect of traction on return to work.For chronic LBP without sciatica, there was moderate-quality evidence that traction probably makes little or no difference in pain intensity when compared with sham treatment. No studies reported on the effect of traction on functional status, global improvement or return to work.Adverse effects were reported in seven of the 32 studies. These included increased pain, aggravation of neurological signs and subsequent surgery. Four studies reported that there were no adverse effects. The remaining studies did not mention adverse effects.

AUTHORS' CONCLUSIONS

These findings indicate that traction, either alone or in combination with other treatments, has little or no impact on pain intensity, functional status, global improvement and return to work among people with LBP. There is only limited-quality evidence from studies with small sample sizes and moderate to high risk of bias. The effects shown by these studies are small and are not clinically relevant. Implications for practice To date, the use of traction as treatment for non-specific LBP cannot be motivated by the best available evidence. These conclusions are applicable to both manual and mechanical traction. Implications for research Only new, large, high-quality studies may change the point estimate and its accuracy, but it should be noted that such change may not necessarily favour traction. Therefore, little priority should be given to new studies on the effect of traction treatment alone or as part of a package.

The clinical features of the piriformis syndrome: a systematic review

Piriformis syndrome, sciatica caused by compression of the sciatic nerve by the piriformis muscle, has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. The objectives of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical features in patients reported to have PS; second, to identify future research questions. A systematic review was conducted of any study type that reported extractable data relevant to diagnosis. The search included all studies up to 1 March 2008 in four databases: AMED, CINAHL, Embase and Medline. Screening, data extraction and analysis were all performed independently by two reviewers. A total of 55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The most common features found were: buttock pain, external tenderness over the greater sciatic notch, aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start with comparing the frequencies of these features in sciatica patients with and without disc herniation or spinal stenosis.

[When should a patient with low back pain/sciatica be referred to the emergency ward?]

Low back pain and sciatica are common causes of medical consultation. The medical history and the physical examination are essential in their management. The primary care physician initiates treatment and relies on his physical examination to identify "red flags" that require further investigations. Regarding sciatica, it is essential to identify 3 clinical entities that require prompt referral to the emergency department for prompt neurosurgical management. These include hyperalgic sciatica, sciatica with motor deficits and the cauda equina syndrome. Sciatica with sensory deficits do not require emergency department referral.

Periganglionic inflammation elicits a distally radiating pain hypersensitivity by promoting COX-2 induction in the dorsal root ganglion

We have developed a model in which inflammation contiguous to and within a dorsal root ganglion (DRG) was generated by local application of complete Freund's adjuvant (CFA) to the L4 lumbar spinal nerve as it exits from the intervertebral foramen. The periganglionic inflammation (PGI) elicited a marked reduction in withdrawal threshold to mechanical stimuli and an increase in heat pain sensitivity in the ipsilateral hindpaw in the absence of any hindpaw inflammation. The pain sensitivity appeared within hours and lasted for a week. The PGI also induced a prominent increase in IL-1beta and TNF-alpha levels in the DRG and of cyclooxygenase-2 (COX-2) expression in neurons and satellite cells. A selective COX-2 inhibitor reduced the PGI-induced hyperalgesia. We also show that IL-1beta induces COX-2 expression and prostaglandin release in DRG neurons in vitro in a MAP kinase-dependent fashion. The COX-2 induction was prevented by ERK and p38 inhibitors. We conclude that periganglionic inflammation increases cytokine levels, including IL-1beta, leading to the transcription of COX-2 and prostaglandin production in the affected DRG, and thereby to the development of a dermatomally distributed pain hypersensitivity.

[Backpain and haemophilia]

A literature research for back pain in hemophilia (1990-2007) revealed only five papers! They all had lumbar or sciatic pain due to hematoma. All symptoms responded to factor VIII replacement. A similar research for a normal population showed hundreds of papers with a lifetime prevalence of 80% for back pain. A survey of 49 patient with hemophilia showed similar results. 70% had experienced back pain before. The reported pain of 40 to 70 on a visual analog scale was significant. 40% reported that the back pain would be more limiting than the pain associated with hemophilia. The hemophilic patient has learned to cope! The treatment of back pain will be of growing importance for hemophilia centers while the typical complaints of hemophilic symptoms will decrease due to better treatment protocols.

Papilledema and tumours of the cauda equina: a case report

PURPOSE

Bilateral papilledema is a rare symptom of cauda equina tumours. The authors report a case of neurinoma of cauda equina, which had a bilateral papilledema among its initial symptoms.

CASE REPORT

A 28 years old man showed the presence of a bilateral papilledema; a cerebral MRI did not show any endocranial pathology. After three months the patient started suffering, especially at night, of right-leg-sciatica. A lumbar MRI showed a neurinoma of the cauda equina. The patient was operated and after surgery the papilledema slowly shrank.

CONCLUSIONS

The tumours of cauda equina could cause endocranial hypertension and consequently a papilledema because of hyperproteinorachia. If there is a bilateral papilledema and the cerebral MRI does not show any endocranial pathology, there is the need for the examination of any spinal disorders.

Extended Swimming Exercise Reduces Inflammatory and Peripheral Neuropathic Pain in Rodents

Physical exercise is often recommended to patients who have chronic pain. However, only a small number of studies report exercise-induced analgesia in the setting of inflammatory pain, and even fewer relate long-term exercise to reductions in neuropathic pain. To address these questions, we evaluated the effect of extended swimming exercise in animal models of inflammatory (intraplantar injection of dilute formalin) and neuropathic (partial peripheral nerve injury) pain. We found that 9 days of swimming exercise in 37 degrees C water for 90 min/d decreased licking and flinching responses to formalin, as compared with nonexercised control animals. In addition, 18 to 25 days of swimming decreased nerve injury-induced cold allodynia and thermal hyperalgesia in rats, and 7 days of swimming decreased nerve injury-induced thermal hyperalgesia in mice. Our data indicate that swimming exercise reduces behavioral hypersensitivity in formalin- and nerve injury-induced animal models of persistent pain.

PERSPECTIVE

Surprisingly, few animal studies have investigated the effects of extended exercise on chronic pain. Our results support the use of exercise as a nonpharmacological approach for the management of peripheral neuropathic pain.

Analysis of the antinociceptive effect of systemic administration of tramadol and dexmedetomidine combination on rat models of acute and neuropathic pain

The aim of the present study was to investigate the possible antinociceptive effect of systemic administration of tramadol and dexmedetomidine either alone or in combination on acute and neuropathic pain models in rats. The antinociceptive effects of intraperitoneal (i.p.) tramadol (5-20 mg/kg) and dexmedetomidine (5-20 microg/kg) and three different combinations of tramadol+dexmedetomidine (5+5, 5+10 and 10+5, mg/kg+microg/kg, respectively) were measured by tail-flick and hot-plate methods in acute pain. The effects on the sciatic nerve ligation-induced neuropathic pain was tested by i.p. administration of tramadol (5 mg/kg), dexmedetomidine (5 microg/kg) and tramadol+dexmedetomidine combination (5+5) using a thermal plantar test. Sedation/motor-incoordination was assessed on rotarod. Tramadol and dexmedetomidine produced dose-related antinociception in tail-flick and hot-plate tests. In both tests, combination of these drugs produced an antinociceptive effect that is greater than that produced by tramadol or dexmedetomidine alone at several time points. In hot-plate test, tramadol+dexmedetomidine combination (5+10) exerted the strongest antinociceptive effect, while tramadol+dexmedetomidine combination (10+5) was significantly most effective in tail-flick test. In the neuropathic pain, the antinociceptive effect exerted by tramadol+dexmedetomidine combination (5+5) was also significantly greater than their applications alone. In rotarod test, tramadol (30 and 40 mg/kg), dexmedetomidine (30 and 40 microg/kg), tramadol+dexmedetomidine combination (10+10, 20+20) produced sedation/motor-incoordination, whereas tramadol (5-20 mg/kg), dexmedetomidine (5-20 microg/kg) and tramadol+dexmedetomidine combination (5+5, 5+10 and 10+5) did not produce any effect on sedation/motor-incoordination. The combination of tramadol and dexmedetomidine was more effective in increasing the pain threshold in acute and neuropathic pain when compared with the administration of either of these drugs alone.

A case of lumbar sciatica in a patient with spondylolysis and spondylolysthesis and underlying misdiagnosed brucellar discitis

We report the case of a patient affected by vertebral pain refractory to conventional analgesic therapy with a diagnosis of spondylolysthesis and also the affects of a misdiagnosed brucellar spondylodiscitis. The absence of a positive response to conventional analgesics, a suggestive medical history (epidemiologic data still show a high incidence of Brucella infections for the Province of Catania), radiological findings and microbiological tests led to the correct diagnosis of algic syndrome in a patient affected by brucellar spondylodiscitis with the concomitant presence of retroperitoneal muscular abscess, and a previously diagnosed spondylolysthesis. All symptoms improved after correct antibrucellar antibiotic therapy and surgical drainage of the retroperitoneal abscess. Vertebral pain is a relatively frequent symptom observed in Pain Medicine Services; in a zone in which Brucella infections may be considered endemic, neurobrucellosis must be considered highly probable in the differential diagnosis of several clinical pictures, including vertebral pain that could result from vertebral localization of Brucella infection. The role of the Pain Medicine Specialist is not only to treat the symptoms, but also to research and confirm the etiopathogenetic mechanisms before starting a correct treatment.

Small interfering RNA-mediated selective knockdown of NaV1.8 tetrodotoxin-resistant sodium channel reverses mechanical allodynia in neuropathic rats

The biophysical properties of a tetrodotoxin resistant (TTXr) sodium channel, Na(V)1.8, and its restricted expression to the peripheral sensory neurons suggest that blocking this channel might have therapeutic potential in various pain states and may offer improved tolerability compared with existing sodium channel blockers. However, the role of Na(V)1.8 in nociception cannot be tested using a traditional pharmacological approach with small molecules because currently available sodium channel blockers do not distinguish between sodium channel subtypes. We sought to determine whether small interfering RNAs (siRNAs) might be capable of achieving the desired selectivity. Using Northern blot analysis and membrane potential measurement, several siRNAs were identified that were capable of a highly-selective attenuation of Na(V)1.8 message as well as functional expression in clonal ND7/23 cells which were stably transfected with the rat Na(V)1.8 gene. Functional knockdown of the channel was confirmed using whole-cell voltage-clamp electrophysiology. One of the siRNA probes showing a robust knockdown of Na(V)1.8 current was evaluated for in vivo efficacy in reversing an established tactile allodynia in the rat chronic constriction nerve-injury (CCI) model. The siRNA, which was delivered to lumbar dorsal root ganglia (DRG) via an indwelling epidural cannula, caused a significant reduction of Na(V)1.8 mRNA expression in lumbar 4 and 5 (L4-L5) DRG neurons and consequently reversed mechanical allodynia in CCI rats. We conclude that silencing of Na(V)1.8 channel using a siRNA approach is capable of producing pain relief in the CCI model and further support a role for Na(V)1.8 in pathological sensory dysfunction.

The absence of endogenous beta-endorphin selectively blocks phosphorylation and desensitization of mu opioid receptors following partial sciatic nerve ligation

Phosphorylation of specific sites in the second intracellular loop and in the C-terminal domain have previously been suggested to cause desensitization and internalization of the mu-opioid receptor (MOP-R). To assess sites of MOP-R phosphorylation in vivo, affinity-purified, phosphoselective antibodies were raised against either phosphothreonine-180 in the second intracellular loop (MOR-P1) or the C-terminal domain of MOP-R containing phosphothreonine-370 and phosphoserine-375 (MOR-P2). We found that MOR-P2-immunoreactivity (IR) was significantly increased within the striatum of wild-type C57BL/6 mice after injection of the agonist fentanyl. Pretreatment with the antagonist naloxone blocked the fentanyl-induced increase. Furthermore, mutant mice lacking MOP-R showed only non-specific nuclear MOR-P2-IR before or after fentanyl treatment, confirming the specificity of the MOR-P2 antibodies. To assess whether MOP-R phosphorylation occurs following endogenous opioid release, we induced chronic neuropathic pain by partial sciatic nerve ligation (pSNL), which caused a significant increase in MOR-P2-IR in the striatum. pSNL also induced signs of mu opioid receptor tolerance demonstrated by a rightward shift in the morphine dose response in the tail withdrawal assay and by a reduction in morphine conditioned place preference (CPP). Mutant mice selectively lacking all forms of the beta-endorphin peptides derived from the proopiomelanocortin (Pomc) gene did not show increased MOR-P2-IR, decreased morphine antinociception, or reduced morphine CPP following pSNL. In contrast gene deletion of either proenkephalin or prodynorphin opioids did not block the effects of pSNL. These results suggest that neuropathic pain caused by pSNL in wild-type mice activates the release of the endogenous opioid beta-endorphin, which subsequently induces MOP-R phosphorylation and opiate tolerance.

Traction for low-back pain with or without sciatica

BACKGROUND

Traction is used to treat low-back pain (LBP), often with other treatments.

OBJECTIVES

To determine traction's effectiveness, compared to reference treatments, placebo, sham traction or no treatment for LBP.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2006, issue 4), MEDLINE, EMBASE, and CINAHL to October 2006, references in relevant reviews and personal files.

SELECTION CRITERIA

Randomized controlled trials (RCTs) involving traction to treat acute (less than four weeks duration), sub-acute (four to 12 weeks) or chronic (more than 12 weeks) non-specific LBP with or without sciatica.

DATA COLLECTION AND ANALYSIS

Study selection, methodological quality assessment and data extraction were done independently by two authors. As there were insufficient data for statistical pooling, we performed a qualitative analysis.

MAIN RESULTS

We included 25 RCTs (2206 patients; 1045 receiving traction). Five trials were considered high quality. For patients with mixed symptom patterns (acute, sub-acute and chronic LBP with and without sciatica) there is: strong evidence of no statistically significant difference in outcomes between traction as a single treatment and placebo, sham or no treatment; moderate evidence that traction as a single treatment is no more effective than other treatments; limited evidence of no significant difference in outcomes between a standard physical therapy program with or without continuous traction. For LBP patients with sciatica (with acute, sub-acute or chronic pain), there is conflicting evidence in several comparisons: autotraction compared to placebo, sham or no treatment; other forms of traction compared to other treatments; different forms of traction. In other comparisons, there were no statistically significant differences; the evidence is moderate for continuous or intermittent traction compared to placebo, sham or no treatment, and limited for light versus normal force traction.

IMPLICATIONS FOR PRACTICE

The results of the available studies involving mixed groups of acute, sub-acute and chronic patients with LBP with and without sciatica were quite consistent, indicating that continuous or intermittent traction as a single treatment for LBP is not likely effective for this group. Traction for patients with sciatica cannot be judged effective at present either, due to inconsistent results and methodological problems in most studies. We conclude that traction as a single treatment for LBP is probably not effective.

IMPLICATIONS FOR RESEARCH

Any future research on traction for patients with LBP should distinguish between symptom pattern and duration, and should be carried out according to the highest methodological standards.

A role for G protein-coupled receptor kinase 2 in mechanical allodynia

Inflammation and nerve injury can both induce mechanical allodynia via mechanisms involving the production of pro-inflammatory cytokines and increased neuronal activity. Many neurotransmitters involved in pain signal via G protein-coupled receptors (GPCRs). GPCR kinase (GRK)2 is a member of the GRK family that regulates agonist-induced desensitization and signalling of GPCRs. Low intracellular GRK2 levels are associated with increased receptor signalling. The aim of this study was to investigate whether mechanical allodynia is associated with decreased spinal cord GRK2 expression and whether reduced GRK2 increases inflammation-induced mechanical allodynia. Mechanical allodynia was induced in rats by chronic constriction injury of the sciatic nerve. After 2 weeks, neuronal GRK2 expression was decreased bilaterally in the superficial layers of the lumbar spinal cord dorsal horn. Moreover, interleukin-1beta significantly reduced GRK2 expression ex vivo in spinal cord slices. To investigate whether reduced GRK2 potentiates inflammation-induced mechanical allodynia, we used GRK2(+/-) animals expressing decreased GRK2. At baseline, the threshold for mechanical stimulation did not differ between GRK2(+/-) and wild-type mice. However, GRK2(+/-) animals were more sensitive to mechanical stimulation than wild-type animals after intraplantar lambda-carrageenan injection. We propose cytokine-induced down-regulation of spinal cord neuronal GRK2 expression as a novel mechanism that contributes to increased neuronal signalling in mechanical allodynia.

A typical low-back pain caused by an atypical etiology

OBJECTIVE

Pain arising in the lumbar spine can have many etiologies, nearly 80% of which cannot be established with certainty. We present a very rare cause of back pain.

CASE REPORT

A 54-year-old woman presented with a 2-month history of low-back pain and right-sided sciatica. Conventional analgesics, physiotherapy, and epidural steroid application had failed to provide relief. She had tenderness of the right sacroiliac joint. Diagnostic fluoroscopic-guided sacroiliac-joint injection with lidocaine did not produce symptomatic relief. Pelvic ultrasonography and magnetic resonance imaging showed septated multilocular hydatic cysts along the sciatic nerve. Surgical exploration noted multicystic lesions along the sciatic nerve woven to the nerve. Her low-back pain disappeared completely after the operation. She received oral albendazole for 6 months to prevent any recurrence of the disease and remains asymptomatic.

CONCLUSION

Hydatid cyst can be included in the differential diagnosis of lumbar back pain, especially in the endemic areas.

Delays in the treatment of cauda equina syndrome due to its variable clinical features in patients presenting to the emergency department

OBJECTIVE

To identify reasons for delay in management of patients with cauda equina syndrome (CES) and to determine commonly presented features of CES.

METHODS

Retrospectively, the presenting features and management of patients treated for CES over a 4-year period were reviewed.

RESULTS

Reasons for delay in treatment were identified in over half of the patients.

DISCUSSION

Most patients do not present with all the characteristic features of CES. Sacral sensory loss is a sensitive and relatively specific sign for diagnosing CES.

Antinociception mediated by alpha(2)-adrenergic activation involves increasing tumor necrosis factor alpha (TNFalpha) expression and restoring TNFalpha and alpha(2)-adrenergic inhibition of norepinephrine release

The central component that establishes chronic pain from peripheral nerve injury is associated with increased tumor necrosis factor-alpha (TNFalpha) production in the brain. This study examined TNFalpha and its reciprocally permissive role with alpha(2)-adrenergic activation during peak and progressive decline of thermal hyperalgesia in sciatic nerve chronic constriction injury (CCI). Accumulation of TNFalpha mRNA (in situ hybridization) increases in the hippocampus and locus coeruleus during the onset of neuropathic pain and persists as hyperalgesia abates. Activation of alpha(2)-adrenergic receptors in control rats decreases TNFalpha mRNA accumulation in these brain regions. In contrast, during hyperalgesia, alpha(2)-adrenergic activation enhances TNFalpha mRNA accumulation. Whether this enhanced TNFalpha production is associated with changes in the regulation of norepinephrine (NE) release was tested. Hippocampal slices were electrically depolarized to evaluate alpha(2)-adrenergic and TNFalpha regulation of NE release. While inhibition of NE release by TNFalpha is maximal during peak hyperalgesia, it subsequently transforms to facilitate NE release. In addition, alpha(2)-adrenergic receptor activation with clonidine (0.2mg/kg, i.p.) in CCI rats experiencing hyperalgesia restores TNFalpha and alpha(2)-adrenergic inhibition of NE release. While TNFalpha directs the development of hyperalgesia, it also directs its resolution. Transformed sensitivity to alpha(2)-adrenergic agonists during hyperalgesia demonstrates a mechanism for therapy.

Cauda equina syndrome: factors affecting long-term functional and sphincteric outcome

STUDY DESIGN

Retrospective cohort study with prospective clinical follow-up.

OBJECTIVE

To determine the factors that influence outcome after surgery for cauda equina syndrome (CES).

SUMMARY OF BACKGROUND DATA

CES is a rare but serious consequence of lumbar disc prolapse and can have devastating long-lasting neurologic consequences. The timing of surgical decompression remains controversial.

METHODS

Fifty-six patients with evidence of a sphincteric disturbance who underwent urgent surgery were identified and invited to follow-up. The outcome measures comprised history and examination and several validated self-assessment questionnaires.

RESULTS

Forty-two patients (78%) attended with a mean follow-up of 60 months (range, 25-114 months). Mean age at onset was 41 years (range, 24-67 years) with 23 males and 19 females. Twenty-six patients were operated on within 48 hours of onset of sphincteric symptoms; 5 of these were within 24 hours. Acute onset of sphincteric symptoms and the time to operation did not influence the outcomes. Leg weakness at onset persisted in a significant number of patients at follow-up (P < 0.005). Urinary disturbance at presentation did not affect the outcomes. At follow-up, significantly more females had urinary incontinence (P < 0.005). Bowel dysfunction at presentation was associated with sexual problems at follow-up (P < 0.005). The 13 patients who failed their post operative trial without catheter had worse outcomes. The SF-36 scores at follow-up were reduced compared with age-matched controls in the population. The mean ODI was 29, Low Back Outcome Score 42, and VAS 4.5. The time elapsed from operation to follow-up was not found to influence the outcomes.

CONCLUSIONS

In our series, the symptom duration before operation and the speed of onset do not affect the outcome more than 2 years after surgery. Based on the SF-36, ODI, and Low Back Outcome Scores, patients who have had CES do not return to a normal status.

Anti-allodynic efficacy of botulinum neurotoxin A in a model of neuropathic pain

Neuropathic pain is typified by injuries to the peripheral and central nervous system and derives from such causes as cancer, diabetes, multiple sclerosis, post-herpetic neuralgia, physical trauma or surgery, and many others. Patients suffering neuropathic pain do not respond to conventional treatment with non-steroidal anti-inflammatory drugs and show a reduced sensitivity to opiates often associated with serious side effects. Recently, it has been demonstrated that botulinum neurotoxin serotype-A (BoNT/A) is able to induce analgesia in inflammatory pain conditions. The goal of this research was to test if BoNT/A was able to relieve also neuropathic pain symptoms. By using chronic constriction injury of the sciatic nerve, a mouse model of neuropathic pain, we observed that peripheral administration of BoNT/A strongly reduced the mechanical allodynia associated with this neuropathy. Remarkably, a single non-toxic dose of BoNT/A was sufficient to induce anti-allodynic effects, which lasted for at least 3 weeks. This result is particularly relevant since neuropathic pain is poorly treated by current drug therapies. This communication enlarges our knowledge on potentially new medical uses of BoNT/A in efforts to ameliorate human health conditions, with very important implications in the development of new pharmacotherapeutic approaches against neuropathic pain.

Association between sciatica and microbial infection: true infection or culture contamination?

STUDY DESIGN

Discs were cultured during discectomy from patients with back pain, sciatica, and radiologic evidence of disc herniation causing nerve root compression.

OBJECTIVE

To investigate the claim of culpability of bacteria in causing the local inflammatory process seen in patients with disc herniation and radiculopathy.

SUMMARY OF BACKGROUND DATA

Bacteria have been cultured from intervertebral discs of patients with sciatica. An infectious etiology for sciatica could have a dramatic effect on treatment options for this common problem.

METHODS

To minimize the risk of contamination, the surgeon performed processing and culturing procedures intraoperatively under stringent sterile conditions. Immediately following disc excision, the specimens were divided into 4 pieces, and cultured in various aerobic and anaerobic culture mediums that were incubated for 2 weeks.

RESULTS

The 120 specimens from 30 patients underwent bacterial culture growth: 116 were sterile, an 4 aerobic cultures (2 patients) grew coagulase-negative staphylococci, suggestive of contamination.

CONCLUSIONS

These results refute the hypothesis that microbial infection plays a role in the pathogenesis of sciatica. It is possible that bacterial growth from discs reported in previous studies was at least partly related to contamination, which we painstakingly avoided by application of rigorous aseptic techniques.

Dramatic etanercept-induced remission of relapsing febrile sciatic neuralgia related to p46l mutation of the tnfrsf1a gene

An adult patient experienced attacks of severe low back pain and sciatic neuralgia for several years, sometimes associated with myalgias, skin lesions, and high fever. Specific inflammatory laboratory tests were the major abnormalities. P46L mutation in the gene on chromosome 12p13 that encodes tumor necrosis factor receptor superfamily 1A (TNFRSF1A) was found. Management with anti-TNF agent was effective with a complete remission of bouts of pain and fever.

Natural course of disc morphology in patients with sciatica: an MRI study using a standardized qualitative classification system

STUDY DESIGN

A prospective observational study of patients with sciatica.

OBJECTIVES

To describe the 14-month development of disc-related MRI findings in patients with sciatica receiving active conservative treatment.

SUMMARY OF BACKGROUND DATA

Previous studies of disc changes over time have reported reduction of herniations in 35% to 100% of cases. This wide range may be explained by differences in patient populations and classifications used to describe disc herniations.

METHODS

Data were obtained from patients with radicular pain (n = 181) who were randomly allocated into one of two active conservative treatment regimens lasting 8 weeks. All patients were scanned at baseline and at 14 months of follow-up. Variables of interest in the present study were disc contour and nerve root compromise at the presumed symptomatic disc level. Disc contour was assessed using the recommendations from the Combined Task Forces of NASS, ASSR, and ASNR.

RESULTS

In all, 154 patients were included in this study (70 women and 84 men; range, 18-65 years; mean and median age, 45 years). It was possible to identify the symptomatic disc level in 90% of patients. Extrusions or sequestrations were more common in individuals younger than 45 years and in men. Men were also more likely to have nerve root compromise. Only 3% of bulges and 38% of focal protrusions improved, whereas 75% to 100% of broad-based protrusions, extrusions, and sequestrations improved (P < 0.0001). Nerve root compromise improved in 21% to 80% depending on the disc contour. Neither type of treatment nor age had any effect on the development of MRI findings over time. However, nerve root compromise was more likely to improve in men.

CONCLUSIONS

This classification system could be used to identify the majority of symptomatic disc levels. At 14 months, the MRI outcome was generally good for disc herniations and nerve root compromise. Nerve root compromise had the best MRI prognosis if the disc was extruded at baseline. There were significant differences between men and women in relation to baseline findings as well as in relation to development of MRI findings over time.

Traction for low back pain with or without sciatica: an updated systematic review within the framework of the Cochrane collaboration

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine if traction is more effective than reference treatments, placebo/sham traction, or no treatment for low back pain (LBP).

SUMMARY OF BACKGROUND DATA

Various types of traction are used in the treatment of LBP, often in conjunction with other treatments.

METHODS

We searched MEDLINE, EMBASE, and CINAHL to November 2004, and screened the latest issue of the Cochrane Library (2004, issue 4) and references in relevant reviews and our personal files. We selected randomized controlled trials (RCTs) involving any type of traction for the treatment of acute (less than 4 weeks duration), subacute (4-12 weeks), or chronic (more than 12 weeks) nonspecific LBP with or without sciatica. Sets of 2 reviewers independently performed study selection, methodological quality assessment, and data extraction. Because available studies did not provide sufficient data for statistical pooling, we performed a qualitative "levels of evidence" analysis, systematically estimating the strength of the cumulative evidence on the difference/lack of difference observed in trial outcomes.

RESULTS

A total of 24 RCTs (2177 patients) were included. There were 5 trials considered high quality. For mixed groups of patients with LBP with and without sciatica, we found: (1) strong evidence that there is no statistically significant difference in short or long-term outcomes between traction as a single treatment, (continuous or intermittent) and placebo, sham, or no treatment; (2) moderate evidence that traction as a single treatment is no more effective than other treatments; and (3) limited evidence that adding traction to a standard physiotherapy program does not result in significantly different outcomes. For LBP with sciatica, we found conflicting evidence in several of the comparisons: autotraction compared to placebo, sham, or no treatment; other forms of traction compared to other treatments; and different forms of traction. In the remaining comparisons, there were no statistically significant differences; level of evidence is moderate regarding continuous or intermittent traction compared to placebo, sham, or no treatment, and is limited regarding different forms of traction.

CONCLUSION

Based on the current evidence, intermittent or continuous traction as a single treatment for LBP cannot be recommended for mixed groups of patients with LBP with and without sciatica. Neither can traction be recommended for patients with sciatica because of inconsistent results and methodological problems in most of the studies involved. However, because high-quality studies within the field are scarce, because many are underpowered, and because traction often is supplied in combination with other treatment modalities, the literature allows no firm negative conclusion that traction, in a generalized sense, is not an effective treatment for patients with LBP.

A clinical genetic method to identify mechanisms by which pain causes depression and anxiety

Background

Pain patients are often depressed and anxious, and benefit less from psychotropic drugs than pain-free patients. We hypothesize that this partial resistance is due to the unique neurochemical contribution to mood by afferent pain projections through the spino-parabrachial-hypothalamic-amygdalar systems and their projections to other mood-mediating systems. New psychotropic drugs for pain patients might target molecules in such brain systems. We propose a method to prioritize molecular targets by studying polymorphic genes in cohorts of patients undergoing surgical procedures associated with a variable pain relief response. We seek molecules that show a significant statistical interaction between (1) the amount of surgical pain relief, and (2) the alleles of the gene, on depression and anxiety during the first postoperative year.

Results

We collected DNA from 280 patients with sciatica due to a lumbar disc herniation, 162 treated surgically and 118 non-surgically, who had been followed for 10 years in the Maine Lumbar Spine Study, a large, prospective, observational study. In patients whose pain was reduced >25% by surgery, symptoms of depression and anxiety, assessed with the SF-36 Mental Health Scale, improved briskly at the first postoperative measurement. In patients with little or no surgical pain reduction, mood scores stayed about the same on average. There was large inter-individual variability at each level of residual pain. Polymorphisms in three pre-specified pain-mood candidate genes, catechol-O-methyl transferase (COMT), serotonin transporter, and brain-derived neurotrophic factor (BDNF) were not associated with late postoperative mood or with a pain-gene interaction on mood. Although the sample size did not provide enough power to persuasively search through a larger number of genes, an exploratory survey of 25 other genes provides illustrations of pain-gene interactions on postoperative mood – the mu opioid receptor for short-term effects of acute sciatica on mood, and the galanin-2 receptor for effects of unrelieved post-discectomy pain on mood one year after surgery.

Conclusion

Genomic analysis of longitudinal studies of pain, depression, and anxiety in patients undergoing pain-relieving surgery may help to identify molecules through which pain alters mood. Detection of alleles with modest-sized effects will require larger cohorts.