Clinical Identification of the Vertebral Level at Which the Lumbar Sympathetic Ganglia Aggregate

Surgical versus nonsurgical management of lumbar degenerative spondylolisthesis based on spinal canal cross-sectional area

Disability and pain associated with lumbar degenerative spondylolisthesis (LDS) result in a significant burden on both the healthcare costs and patients' quality of life. Currently, there exists controversy regarding employment of either nonsurgical management (NSM) or surgical management (SM) in a clinical setting. Spinal canal cross-sectional area (SCA) has been an important morphological parameter for the analysis of LDS. However, there is lack of research about the comparative value of NSM and SM according to SCA. Moreover, previous research have not yet evaluated the clinical most suitable cutoff values of SCA. The objective of this research was to evaluate the effective of NSM and SM for LDS using SCA as an objective morphological parameter. The axial T2 magnetic resonance imaging images were obtained from each patient. We collected SCA samples from 149 patients with LDS. 72 patients underwent SM and the rest did NSM. We measured SCA at the L4/5 LDS on magnetic resonance imaging using a picture archiving and communications system. We measured SCA at the intervertebral disk posterior border, turning down to reach the facet joint side on the opposite edge at the L4/5 level. The average SCA value was 114.34 ± 48.11 mm2 in the NSM group and 69.88 ± 27.87 mm2 in the SM group. Therefore, the SM group had considerably lower SCA (P < .001). In view of the effectiveness of SCA as a prediction factor of surgical option, Receiver Operating Characteristic curve analysis show the optimal cutoff value for SCA as 83.21 mm2, with 70.8% sensitivity, 71.4% specificity, and an area under the curve of 0.80 (95% CI, 0.73-0.87). The narrower the SCA, the higher the probability of SM. Thus, it is proposed that to evaluate surgical decision making, the pain physician should carefully inspect the SCA.

Characterization of Fragile X Mental Retardation Protein expression in human nociceptors and their axonal projections to the spinal dorsal horn

Fragile X Mental Retardation Protein (FMRP) regulates activity-dependent RNA localization and local translation to modulate synaptic plasticity throughout the central nervous system. Mutations in the FMR1 gene that hinder or ablate FMRP function cause Fragile X Syndrome (FXS), a disorder associated with sensory processing dysfunction. FXS premutations are associated with increased FMRP expression and neurological impairments including sex dimorphic presentations of chronic pain. In mice, FMRP ablation causes dysregulated dorsal root ganglion (DRG) neuron excitability and synaptic vesicle exocytosis, spinal circuit activity, and decreased translation-dependent nociceptive sensitization. Activity-dependent, local translation is a key mechanism for enhancing primary nociceptor excitability that promotes pain in animals and humans. These works indicate that FMRP likely regulates nociception and pain at the level of the primary nociceptor or spinal cord. Therefore, we sought to better understand FMRP expression in the human DRG and spinal cord using immunostaining in organ donor tissues. We find that FMRP is highly expressed in DRG and spinal neuron subsets with substantia gelatinosa exhibiting the most abundant immunoreactivity in spinal synaptic fields. Here, it is expressed in nociceptor axons. FMRP puncta colocalized with Nav1.7 and TRPV1 receptor signals suggesting a pool of axoplasmic FMRP localizes to plasma membrane-associated loci in these branches. Interestingly, FMRP puncta exhibited notable colocalization with calcitonin gene-related peptide (CGRP) immunoreactivity selectively in female spinal cord. Our results support a regulatory role for FMRP in human nociceptor axons of the dorsal horn and implicate it in the sex dimorphic actions of CGRP signaling in nociceptive sensitization and chronic pain.

Human lumbar sympathetic blockade: An anatomical study to address potential block failure

The lumbar sympathetic block is often used to treat complex regional pain syndrome, but it seems to have a high failure rate. This study seeks anatomical explanations for this apparent failure in order to refine our block procedure. Two simulated sympathetic trunk blocks were carried out on four fresh, cryopreserved unembalmed human cadavers under fluoroscopic control at the L2 vertebral body level, followed by two further simulated blocks at the L4 vertebral body level on the other side. Dye was injected, and the areas were dissected following a specific protocol. We then describe the anatomy and the spread of the dye compared to the spread of the contrast medium on fluoroscopy. The ganglia were differently located at different vertebral levels, and differed among the cadavers. Following this anatomical clarification, we now prefer to perform lumbar sympathetic blocks at the fourth lumbar vertebra level, using an extraforaminal approach at the caudal end of ​​the vertebra, avoiding the anterolateral margin of the vertebral body at the midpoint.

Application of machine learning algorithms in thermal images for an automatic classification of lumbar sympathetic blocks

PURPOSE

There are no previous studies developing machine learning algorithms in the classification of lumbar sympathetic blocks (LSBs) performance using infrared thermography data. The objective was to assess the performance of different machine learning algorithms to classify LSBs carried out in patients diagnosed with lower limbs Complex Regional Pain Syndrome as successful or failed based on the evaluation of thermal predictors.

METHODS

66 LSBs previously performed and classified by the medical team were evaluated in 24 patients. 11 regions of interest on each plantar foot were selected within the thermal images acquired in the clinical setting. From every region of interest, different thermal predictors were extracted and analysed in three different moments (minutes 4, 5, and 6) along with the baseline time (just after the injection of a local anaesthetic around the sympathetic ganglia). Among them, the thermal variation of the ipsilateral foot and the thermal asymmetry variation between feet at each minute assessed and the starting time for each region of interest, were fed into 4 different machine learning classifiers: an Artificial Neuronal Network, K-Nearest Neighbours, Random Forest, and a Support Vector Machine.

RESULTS

All classifiers presented an accuracy and specificity higher than 70%, sensitivity higher than 67%, and AUC higher than 0.73, and the Artificial Neuronal Network classifier performed the best with a maximum accuracy of 88%, sensitivity of 100%, specificity of 84% and AUC of 0.92, using 3 predictors.

CONCLUSION

These results suggest thermal data retrieved from plantar feet combined with a machine learning-based methodology can be an effective tool to automatically classify LSBs performance.

Efficacy of the lumbar sympathetic ganglion block in lower limb pain and its application prospects during the perioperative period

The sympathetic nervous system is involved in the physiological pathogenesis of many different types of chronic pain. Sympathetic blocks can interrupt the reflex control system by intercepting the noxious afferent fibers accompanying autonomic nerves, resulting in changes in peripheral or central sensory processing. A lumbar sympathetic ganglion block (LSGB), as a treatment method, refers to the injection of nerve blockers into the corresponding lumbar sympathetic nerve segments, usually requiring imaging assistance (CT, X-ray, ultrasound) to guide. At present, LSGB has been widely used in the clinical treatment of lower limb pain, such as neuropathic pain, lower limb ischemic pain, and so on. Its mechanism of action may be through inhibiting sympathetic nerve activity and dilating blood vessels, thereby alleviating pain and inhibiting stress response. However, there are few reports of LSGB during the perioperative period, especially in postoperative pain and gastrointestinal function. Therefore, by studying the literature about LSGB-related studies, this article reviews the anatomy of the lumbar sympathetic nerve (LSN), with its clinical application and possible mechanism. We reviewed the analgesic effect of LSGB in patients with lower limb pain and postoperative pain and the potential application prospects in the recovery of gastrointestinal function, finally providing a reference for its clinical application.

To Assess Technical Feasibility of Ultrasound Lumbar Sympathetic Block with Electrical Stimulation Needle in Out of Plane Needle Orientation: A Prospective Interventional Study

OBJECTIVE

We describe technical feasibility of a new technique of ultrasound lumbar sympathectomy (ULS) validated by fluoroscopy.

DESIGN

Prospective interventional study.

SETTING

Pain block area.

SUBJECTS

Thirty patients of peripheral arterial disease (PAD) with rest pain numerical rating score (NRS) ≥ 3 were recruited.

METHODS

In lateral position, curved probe (FUJIFILM SonoSite Edge, 2-5 MHz) was placed transversely at iliac crest. An electrical stimulation needle was inserted out-plane, below lower pole of kidneys directed anterior to the vertebral body below. When needle tip was not visualized, current of 2.0 A was applied. Patients quadriceps contractions, ultrasound psoas contractions and bone contact guided needle placement and confirmed on fluoroscopy. Other parameters noted were: number of needle insertions, vertebral level, Pain NRS at baseline and at 4 hrs, 24 hrs, one week and two weeks post block, temperature rise and any other complications.

RESULTS

In all patients, needle tip was correctly placed in one to three attempts. In 73% patients, needle tip was at L3. Baseline Pain NRS was 8 (IQR 7-8) which decreased to 2 (IQR 2-3) at one week post-procedure and maintained at this range till 2 weeks later. Temperature rise of > 20C was noted in all patients.

CONCLUSION

ULS can safely be performed in patients of PAD by out-plane approach in lateral patient position with electrical stimulation needle. Before injection of drug, aspiration of blood should be ruled out in view of possibility of aortocaval injection.

Quantitative Analysis of Real-Time Infrared Thermography for the Assessment of Lumbar Sympathetic Blocks: A Preliminary Study

Lumbar sympathetic blocks (LSBs) are commonly performed to treat pain ailments in the lower limbs. LSBs involve injecting local anesthetic around the nerves. The injection is guided by fluoroscopy which is sometimes considered to be insufficiently accurate. The main aim was to analyze the plantar foot skin temperature data acquired while performing LSBs in patients with complex regional pain syndrome (CRPS) affecting the lower limbs. Forty-four LSBs for treating lower limb CRPS in 13 patients were assessed. Pain medicine physicians visualized the infrared thermography (IRT) video in real time and classified the performance depending on the observed thermal changes within the first 4 min. Thirty-two percent of the cases did not register temperature variations after lidocaine was injected, requiring the needle to be relocated. Differences between moments are indicated using the 95% confidence intervals of the differences (CI 95%), the Cohen effect size (ES) and the significance (p value). In successful cases, after injecting lidocaine, increases at minute 7 for the mean (CI 95% (1.4, 2.1 °C), p < 0.001 and ES = 0.5), at minute 5 for maximum temperature (CI 95% (2.3, 3.3 °C), p < 0.001 and ES = 0.6) and at minute 6 for SD (CI 95% (0.2, 0.3 °C), p < 0.001 and ES = 0.5) were observed. The results of our preliminary study showed that the measurement of skin temperature in real time by infrared thermography is valuable for assessing the success of lumbar sympathetic blocks.

Continuous Lumbar Sympathetic Blockade Enhances the Effect of Lumbar Sympatholysis on Refractory Diabetic Neuropathy: A Randomized Controlled Trial

INTRODUCTION

There are a number of options for the symptomatic treatment of peripheral neuropathy, but the overall treatment outcomes remain unsatisfactory.

METHODS

A total of 60 patients with refractory diabetic neuropathy were randomly assigned to two groups. Patients in Group A were treated with computed tomography (CT)-guided sympathetic neurolysis with alcohol, and patients in Group B were treated with a combined therapy of CT-guided catheterization to achieve continuous lumbar block for 4 weeks followed by neurolysis with alcohol administered via the catheter. The outcomes of these two treatment strategies were then analyzed in terms of pain relief, blood flow in the lower limb microcirculation, plasma levels of inflammatory mediators, and complications.

RESULTS

The visual analog scale (VAS) pain scores of all patients after treatment decreased significantly at the different evaluation time points compared with pre-treatment values, with the intergroup analysis revealing that the VAS scores were lower in Group B patients than in Group A patients at all post-treatment time points. Skin temperature, capillary filling time, and blood oxygen saturation level were significantly improved in all patients at the 1- and 7-day post-treatment assessment compared to pre-treatment values, but patients in Group B showed a greater improvement. The plasma levels of inflammatory mediators were lower in all patients at the 7-day post-treatment assessment compared to pre-treatment values, with those of patients in Group B being statistically significantly lower than those of patients in Group A.

CONCLUSION

Combined treatment with continuous lumbar sympathetic block followed by neurolysis with alcohol provided more benefit in all assessed outcomes than sympathetic alcohol neurolysis alone. The results show that the procedures were associated with satisfactory safety outcomes and sustained analgesic effects, thereby providing clinical evidence supporting the use of this novel treatment for patients with painful diabetic neuropathy.

Correlation between paravertebral spread of injectate and clinical efficacy in lumbar transforaminal block

The potential paravertebral space includes spinal nerves, dorsal rami, rami communicants, and sympathetic chains. This study evaluated correlations between paravertebral spread of injectate and clinical efficacy in lumbar transforaminal block. We retrospectively analysed the data of 88 patients who received transforaminal blocks for lumbar radicular pain. We categorized patients into two groups: patients with ≥ 50% pain reduction on a numeric rating scale at 30 min following a block (responder group), and patients with < 50% pain reduction (non-responder group). Paravertebral spread of injectate was graded as limited to the anterior, middle, and posterior 1/3 of the anterolateral aspect of vertebral bodies; spread between the posterolateral margins of bodies and the posterior epidural space was considered no spread. Clinical and fluoroscopic data, perfusion index, temperature, and cold sensation were compared between the groups. Among 54 patients analysed, 26 (48.1%) experienced ≥ 50% and 28 (51.9%) < 50% pain reduction. Paravertebral spread occurred in 33 (61.1%) patients; 19 (57.6%) responders and 14 (42.4%) non-responders. On analysis, paravertebral spread, epidural spread patterns, perfusion index change ratios, temperature changes, and cold sensation changes showed no differences between responder and non-responder groups. Paravertebral spread occurred in 61.1%, with no correlation with the clinical efficacy of lumbar transforaminal block.

[Effect of bilateral superior cervical sympathetic ganglion occlusion on pathological process of aortic dissection and its mechanism]

OBJECTIVE

To investigate the effect of bilateral superior cervical sympathetic ganglion occlusion (SCG) on aortic dissection and its possible mechanism.

METHODS

Forty-five SD rats were randomly divided into three groups with 15 in each:blank control group, sham operation group and SCG group. β-aminopropione (666 mg·kg-1·d-1) was given by subcutaneous injection for 4 weeks to establish the aortic dissection model. Rats in SCG group were given SCG before the injection of β-aminopropione. Blood pressure and heart rate of the rats were monitored using noninvasive tail artery blood pressure measuring instrument; sympathetic activity was monitored using drug block method; the structure of aortic wall was observed using HE staining; collagen fibers in aortic wall was observed using Sirius red staining; protein expression of Apelin was detected by immunohistochemistry; and the protein expression of matrix metalloproteinase (MMP)-2, 9 was detected by Western blotting.

RESULTS

During the experiment, the body mass of the sham operation group and SCG group was smaller than that of the blank control group (all P<0.05), and the body mass of the SCG group was larger than that of the sham operation group (all P<0.05). The heart rate and sympathetic activity of the sham operation group were higher than those of the blank control group (all P<0.05), while the SCG group were lower (all P<0.05). Compared with the blank control group, the aortic wall in the sham operation group was thickening, while that in the SCG group was improved. A large number of collagen-1 in the aortic wall of the blank control group was stained brown by Sirius red, which was lighter in SCG group, and the staining in the sham operation group was the lightest. Compared with the blank control group, the expression of Apelin, MMP-2 and MMP-9 protein in the sham operation group increased (all P<0.05), while those in the SCG group decreased (all P<0.05).

CONCLUSIONS

SCG can effectively reduce the incidence and mortality of aortic dissection in rats, which may be related to the inhibition of sympathetic activity and the decrease of collagen-1, Apelin, MMP-2 and MMP-9 expression.

Superior articular process cross-sectional area is a new sensitive parameter for the diagnosis of lumbar central canal spinal stenosis

Purpose

Previous studies reported that hypertrophied superior articular process (SAP) was associated with an increased risk of lumbar foraminal stenosis. However, no study investigated the effect of SAP hypertrophy in lumbar central canal spinal stenosis (LCCSS). We hypothesized that the SAP cross-sectional area (SAPCSA) is the main morphologic feature in the diagnosis of LCCSS.

Patients and methods

Data regarding the SAPCSA were collected from 109 patients with LCCSS. All patients were enrolled after the LCCSS diagnosis was confirmed by an experienced, board-certified neuroradiologist. All patients had clinical manifestations compatible with LCCSS. A total of 120 subjects in the control group underwent lumbar spine MRI as part of non-symptomatic medical examination. T2-weighted axial images were obtained from the 2 groups. Using a picture archiving and communications system, we analyzed the CSA of the bone margin of SAP at the level of L4–L5 facet joint on MRI.

Results

The average SAPCSA was 96.63±13.37 mm² in the control group, and 123.59±14.18 mm² in the LCCSS. The LCCSS group showed significantly higher levels of the SAPCSA (P<0.001) compared with the control one. Receiver operator characteristic (ROC) curve analysis was performed to determine the validity of the SAPCSA as a predictor of LCCSS. In the LCCSS group, the optimal cut-off-point was 110.71 mm², with 83.5% sensitivity, 83.3% specificity, and area under the curve of 0.92 (95% CI: 0.88–0.95).

Conclusion

Higher SAPCSA values were associated with a higher possibility of LCCSS. These results are important in the evaluation of patients with LCCSS.

Optimal cut-off points of lumbar pedicle thickness as a morphological parameter to predict lumbar spinal stenosis syndrome: a retrospective study

Purpose

Lumbar spinal stenosis syndrome (LSSS) is induced by factors such as ligamentum flavum hypertrophy, facet joint hypertrophy and disc degeneration. However, the role of lumbar pedicle (LP) in LSSS has yet to be evaluated. We devised a new morphological parameter called the lumbar pedicle thickness (LPT) to evaluate the connection between LSSS and the LP. We hypothesized that the LPT is a major morphological parameter in the diagnosis of LSSS.

Patients and methods

The LPT data were collected from 136 patients diagnosed with LSSS. A total of 99 control subjects underwent lumbar spine magnetic resonance imaging (MRI) as part of a detailed medical assessment. Axial T2-weighted magnetic resonance (MR) images were acquired from all the participants. Using our picture archiving and communication system, we analyzed the thickness of the LP at the level of L5 vertebra on MRI.

Results

The average LPT was 9.46±1.81 mm in the control group and 13.26±1.98 mm in the LSSS group. LSSS patients showed a significantly greater LPT (P<0.001) than the control group. The receiver operating characteristic (ROC) curve analysis showed an optimal cutoff point of 11.33 mm for the LPT, with 83.8% sensitivity, 83.8% specificity and area under the curve of 0.92 (95% confidence interval [CI], 0.89-0.96).

Conclusion

A higher LPT was associated with a higher possibility of LSSS, suggesting its importance in the evaluation of patients with LSSS.

Does Temperature Increase by Sympathetic Neurolysis Improve Pain in Complex Regional Pain Syndrome? A Retrospective Cohort Study

BACKGROUND

Lumbar sympathetic neurolysis (LSN) is a treatment option for complex regional pain syndrome (CRPS). We examined whether LSN-related temperature changes are associated with clinical outcome and investigated relationships between the outcome of LSN and clinical variables in patients with CRPS-I.

METHODS

We included 95 patients with CRPS-I affecting a single lower extremity, by the Budapest criteria, and who underwent LSN after successful lumbar sympathetic blocks, in this retrospective study. Fluoroscopy-guided LSN was conducted with 1.5 mL of 99% alcohol at L2 and L3 vertebral levels. Positive outcome was defined as a reduction of ≥50% on a numeric rating scale pain score at 6 months after LSN. The relationship between successful outcome and clinical variables was analyzed.

RESULTS

Positive LSN outcome occurred in 49.5% of patients, and it was suggested that Sympathetically maintained pain may accompany CRPS-I in 28% of patients. The overall temperature in the affected limb was increased after LSN, without contralateral limb temperature changes, but did not differ significantly between the positive and negative outcome groups (P = 0.590). Temperature after LSN in warm-type CRPS was reduced in the affected limb, without contralateral limb temperature changes. The absolute temperature change was significantly greater in cold-type than in warm-type CRPS (P = 0.026). In multivariate analysis, a short duration of pain and concurrent cold intolerance were significant factors predicting a positive outcome after LSN.

CONCLUSIONS

LSN may be effective in some patients with CRPS, irrespective of temperature changes and temperature asymmetry pattern. A short duration of pain and concurrent cold intolerance significantly predict successful LSN.