Selective Spinal Nerve Research Articles

A clinical study of C arm-guided selective spinal nerve block combined with low-temperature plasma radiofrequency ablation of dorsal root ganglion in the treatment of zoster-related neuralgia.

This study evaluated the analgesic efficacy and psychological response of low-temperature plasma ablation of dorsal root ganglion (DRG) combined with selective spinal nerve block in patients with acute or subacute zoster-related neuralgia (ZRN). Totally 90 ZRN patients were randomly and evenly divided into three groups. Treatment was given to Group A using C arm-guided selective spinal nerve block (C-SSVB), Group B using C-SSVB and pulsed radiofrequency (PRF), and Group C using C-SSVB and low-temperature plasma ablation of the DRG. The outcomes were examined using the Visual Analog Scale (VAS). Anxiety and depression of patients were evaluated using the Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS). Quality of life was assessed using the Pittsburgh Sleep Quality Index (PSQI) and postoperative Satisfaction scale. In addition, data on adverse events and medication usage rates were collected. The 90 patients were eligible for this study. The three treatments reduced VAS scores with no significant difference between groups A and B at the same time points; however, group B tended to have numerically lower VAS scores. Comparatively, group C had significantly reduced VAS scores on day 1 and 1 month after treatment compared with the other two groups. In terms of the decreasing SAS, SDS and PSQI scores, all the three treatments improved the anxiety, depression and sleep quality of the patients. In addition, significant alleviation in anxiety was found in group C compared with group A at all- time points. However, there was no statistically significant difference among the three groups in treatment-related adverse events that mainly focused on puncture pain at the surgical-site, skin numbness and medication usage rates. C-SSVB and LTPRA of DRG will be considered as a promising treatment option for ZRN patients if those results can be confirmed after further validation.

Selective Spinal Nerve Root Block as an efficacious modality of treatment in lower backache with radiculopathy in cases of single level prolapsed intervertebral disc

Background: Back pain affects everybody at some point in their life and is one of the most common complaints evaluated by a spine surgeon. Lower limb radiculopathy is commonly associated with conditions like disc herniation, facet or ligamentous hypertrophy, and spondylolisthesis. The present study was conducted to assess the prognosis after a single dose of Selective Spinal Nerve Root Block in patients with lower backache with radiculopathy with a single level disc prolapse. Methods:Forty patients with complaints of lower backache with lower limb radiculopathy with a single level Prolapse Intervertebral disc[Magnetic Resonance Imaging (MRI) diagnosed] were assessed on the basis of Visual Analogue Scale score and Roland Morris Questionnaire score at different time intervals pre and post single level spinal nerve root block to assess the reduction in pain. Results:Pain recurrence was noted in four (10%) patients at 3-month post block and total five patients at six months post block. Five (12.5%) patients underwent a surgical procedure after six months of a block. A significant (p<0.0001) reduction in the Roland Morris Questionnaire scores (Mean 19.53) and Visual Analogue Scale score for back pain (Mean 4.48) and leg pain (Mean 7.5) were observed during the follow-ups of Roland Morris Questionnaire scores at three months (Mean 2.55) and six months (Mean 3.55); with Visual Analogue Scale score at three months for back pain (Mean 1.60), leg pain (Mean 1.45) and six months for back pain (Mean 1.07) and leg pain (Mean 2.2) in 35 (87.5%) study subjects after block. Conclusion: The study recorded a pain-free period averaging six months with positive outcomes in almost all patients, indicating selective nerve root block efficacy among patients with lower back pain with radiculopathy with a single level prolapsed intervertebral disc, especially in younger patients and those with a short duration of symptoms.

Outcome analysis of fluoroscopically guided selective spinal nerve root block for lumbar radicular pain in tertiary care centre

Introduction: Lumbar radiculopathy is a common complaint of patients presenting to spine clinic. A variety of conditions can lead to compression of the nerve roots, the most common cause is disc herniation. Selective Nerve Root block (SNRB) injections have been used in everyday clinical practice.Methods: Fifty patients with lumbar radicular pain were enrolled in the study as per the inclusion criteria. Patients were assessed clinically, neurologic evaluation done and pain quantified by Visual analogue scale (VAS) and the Oswestry Disability Index (ODI). They were reassessed after SNRB immediately, at 3 weeks and 6 weeks using the same outcome measures.Results: Majority of patients (40 out of 49) demonstrated improvement after SNRB).The degree of improvement in the VAS was significantly greater and statistically significant (P

Diagnostic Role of Selective Spinal Nerve Block in Treatment of Lumbar Spine Diseases by Percutaneous Endoscopic Technique.

To assess the role of our modified selective spinal nerve block (SSNB) procedure to predict the results of the subsequent Percutaneous endoscopic transforaminal lumbar surgeries (PETLS). We retrospectively analyzed data of patients who underwent our modified SSNBs before PETLS from February 2013 to March 2018 Clinical outcome data were collected 3 days after PETLS and at follow-up visits. A total of 120 modified SSNB procedures (transforaminal-78 paravertebral-24, and interlaminar-18) in 92 patients presented positive response. The median follow-up period was 30.6 months. Based on Macnab criteria, the overall success rate (excellent and good results) was 83.7%. Fair and poor outcomes were observed in 10 and 5 patients, respectively. Patients with atypical extraforaminal herniations, and patients with two-level or multiple-level lumbar disc herniations or stenosis achieved desirable results after PETLS. There was significant improvement in the average VAS score for the leg three days after surgery (7.38±0.97 vs. 1.96 ±1.17, p < 0.05) and on follow-up visits (1.21 ± 0.83, p < 0.05). ODI was also significantly improved three days after surgery (37.20 ± 2.36 vs. 10.95 ± 2.25, p < 0.05 and at follow-up visits (8.90 ± 1.72, p < 0.05) CONCLUSION: The needle tip should be located closely near the intended compressed nerve via suitable approach combined with slowly injecting 1 ml lidocaine (1%) when performing our modified SSNB technique. It presents an alternative diagnostic procedure to identify the origin of pain of complicated lumbar diseases and to predict PETLS outcomes.

Selective Spinal Nerve Block in Ilioinguinal, Iliohypogastric and Genitofemoral Neuralgia.

To seek the efficacy of selective spinal nerve blocks in the treatment of groin pain that are irresponsive to peripheral nerve blocks. This retrospective study comprised 17 patients with ilioinguinal, iliohypogastric, and genitofemoral neuralgias treated between 2017 and 2018. All patients received diagnostic peripheral nerve blocks and/or TAP blocks with blind or ultrasound-guided techniques. Four patients had ineffectual peripheral nerve blocks, after which they underwent T12 and L1 selective spinal nerve blocks. All four patients had satisfactory results. If distal peripheral nerve blocks are ineffective, an upper level nerve lesion, a lesion in the lumbar plexus or an L1 radiculopathy should be considered in ilioinguinal, iliohypogastric, and genitofemoral neuralgias. Upper level nerve blocks should be performed before deciding on surgery.

Factors That Affect the Efficacy of Fluoroscopically Guided Selective Spinal Nerve Root Block in the Treatment of Radicular Pain: A Prospective Cohort Study

AimThe fluoroscopically guided selective nerve root block (SNRB) is being used increasingly as a therapy for radicular pain as well as a diagnostic tool. However, studies and the literature reviews have yet to reach a definite conclusion on the efficacy in this setting. Our aim was to prospectively investigate factors that may affect the success of this procedure. Materials and MethodsA total of 301 treatment episodes with 283 patients were assessed over 25 months by patient questionnaire over a 7-day period. Changes in analgesic benefit over time, by operating consultant, referring specialty, spinal level, and the presence of periprocedural symptom provocation were evaluated. Statistical analysis was performed by using the χ2 test, Wilcoxon test, and Kruskal-Wallis rank sum test, and the asymptotic marginal-homogeneity test. P < .05 was considered significant. ResultsThere was a statistically significant increase in pain relief over the 7 days after the procedure. Pain provocation during the procedure did not improve analgesic success. Cervical, lumbar, and sacral level procedures were equally efficacious. The specialist who referred the patient and the use of contrast to verify needle position during the procedure also did not affect the analgesic outcome. Overall, 69.1% of patients experienced some pain relief by day 7. ConclusionAnalgesic success rates of selective nerve root blocks did not vary with spinal level, or use of contrast or periprocedural replication of symptoms, when using fluoroscopic guidance. Patients may expect a continued significant improvement in their symptoms for at least a week after the procedure.

Full-length membrane-bound tumor necrosis factor-α acts through tumor necrosis factor receptor 2 to modify phenotype of sensory neurons

Neuropathic pain resulting from spinal hemisection or selective spinal nerve ligation is characterized by an increase in membrane-bound tumor necrosis factor-alpha (mTNFα) in spinal microglia without detectable release of soluble TNFα (sTNFα). In tissue culture, we showed that a full-length transmembrane cleavage-resistant TNFα (CRTNFα) construct can act through cell–cell contact to activate neighboring microglia. We undertook the current study to test the hypothesis that mTNFα expressed in microglia might also affect the phenotype of primary sensory afferents, by determining the effect of CRTNFα expressed from COS-7 cells on gene expression in primary dorsal root ganglia (DRG) neurons. Co-culture of DRG neurons with CRTNFα-expressing COS-7 cells resulted in a significant increase in the expression of voltage-gated sodium channel isoforms NaV1.7 and NaV1.8, and voltage-gated calcium channel subunit CaV3.2 at both mRNA and protein levels, and enhanced CCL2 expression and release from the DRG neurons. Exposure to sTNFα produced an increase only in CCL2 expression and release. Treatment of the cells with an siRNA against tumor necrosis factor receptor 2 (TNFR2) significantly reduced CRTNFα-induced gene expression changes in DRG neurons, whereas administration of CCR2 inhibitor had no significant effect on CRTNFα-induced increase in gene expression and CCL2 release in DRG neurons. Taken together, the results of this study suggest that mTNFα expressed in spinal microglia can facilitate pain signaling by up-regulating the expression of cation channels and CCL2 in DRG neurons in a TNFR2-dependent manner.

Spinal Nerve Root Electroacupuncture for Symptomatic Treatment of Lumbar Spinal Canal Stenosis Unresponsive to Standard Acupuncture: A Prospective Case Series

To study the effectiveness of electroacupuncture of the spinal nerve root using a selective spinal nerve block technique for the treatment of lumbar and lower limb symptoms in patients with lumbar spinal canal stenosis. Subjects were 17 patients with spinal canal stenosis who did not respond to 2 months of general conservative treatment and conventional acupuncture. Under x-ray fluoroscopy, two acupuncture needles were inserted as close as possible to the relevant nerve root, as determined by subjective symptoms and x-ray and MRI findings, and low-frequency electroacupuncture stimulation was performed (10 Hz, 10 min). Patients received 3-5 once-weekly treatments, and were evaluated immediately before and after each treatment and 3 months after completion of treatment. After the first nerve root electroacupuncture stimulation, scores for lumbar and lower limb symptoms improved significantly (low back pain, p<0.05; lower limb pain, p<0.05; lower limb dysaesthesia, p<0.01) with some improvement in continuous walking distance. Symptom scores and continuous walking distance showed further improvement before the final treatment (p<0.01), and a significant sustained improvement was observed 3 months after completion of treatment (p<0.01). Lumbar and lower limb symptoms, for which conventional acupuncture and general conservative treatment had been ineffective, improved significantly during a course of electroacupuncture to the spinal nerve root, showing sustained improvement even 3 months after completion of treatment. The mechanisms of these effects may involve activation of the pain inhibition system and improvement of nerve blood flow.

Magnetic Resonance Imaging–Guided Spine Injections

Magnetic resonance (MR)-guided spine injections describe techniques for selective spine injection procedures, in which MR imaging is used to visualize spinal targets and needle placement, monitor the injected drugs, and detect spread to potentially confounding nearby structures. The introduction of clinical high-field wide-bore MR imaging systems has increased the practicability and availability of MR-guided spine injections. The use of 1.5-T field strength, modern coils, and parallel imaging technology increases the MR signal, which can be utilized for faster temporal image acquisition, higher image resolution, better image contrast, or combinations thereof. Magnetic resonance imaging guidance provides excellent osseous and soft-tissue detail of spinal structures and is well suited to avoid radiation exposure. In this article, we discuss the technical background of interventional MR imaging, review the literature, and illustrate interventional MR imaging techniques of commonly performed spinal injection procedures, including sacroiliac joint injections, lumbar facet joint injections, selective spinal nerve root infiltration, and percutaneous drug delivery to the lumbar sympathetic nerves.

Lidocaine Injection into the Rat Dorsal Root Ganglion Causes Neuroinflammation

Injury of a spinal nerve or dorsal root ganglion (DRG) during selective spinal nerve blocks is a potentially serious complication that has not been adequately investigated. Our hypothesis was that local anesthetic injection into these structures may result in an inflammatory response and hyperalgesia. We evaluated inflammatory and behavioral responses after injection of 4 microL lidocaine or saline into the L5 spinal nerve or DRG of rats after partial laminectomy. Behavioral testing was performed before and after surgery to examine hyperalgesia in response to nociceptive mechanical stimulation of the foot. DRGs were harvested and stained, and rings of immunoreactive glial cells around neurons were counted. Animals demonstrated hyperalgesia on the ipsilateral paw up to 4 days after lidocaine injection into the DRG but not after injection into the spinal nerve. The number of glial fibrillary acid protein immunopositive glial cell rings, which represent activation of satellite cells, significantly increased in DRGs after injection of lidocaine into either the DRG or the spinal nerve. The number of glial fibrillary acid protein-positive cells in the lidocaine-injected group was significantly larger than in the saline-injected group. Sporadic OX-42 immunopositive cells, which represent activated microglia, were also seen in lidocaine-injected DRGs. Testing for Pan-T expression, which labels activated T lymphocytes, showed no positive cells. Lidocaine injection into the DRG may produce hyperalgesia, possibly due to activation of resident satellite glial cells. In a clinical setting, local anesthetic injection into the DRG should be avoided during selective spinal nerve blocks.

Minocycline treatment inhibits microglial activation and alters spinal levels of endocannabinoids in a rat model of neuropathic pain.

Activation of spinal microglia contributes to aberrant pain responses associated with neuropathic pain states. Endocannabinoids (ECs) are present in the spinal cord, and inhibit nociceptive processing; levels of ECs may be altered by microglia which modulate the turnover of endocannabinoids in vitro. Here, we investigate the effect of minocycline, an inhibitor of activated microglia, on levels of the endocannabinoids anandamide and 2-arachidonoylglycerol (2-AG), and the related compound N-palmitoylethanolamine (PEA), in neuropathic spinal cord. Selective spinal nerve ligation (SNL) in rats resulted in mechanical allodynia and the presence of activated microglia in the ipsilateral spinal cord. Chronic daily treatment with minocycline (30 mg/kg, ip for 14 days) significantly reduced the development of mechanical allodynia at days 5, 10 and 14 post-SNL surgery, compared to vehicle-treated SNL rats (P < 0.001). Minocycline treatment also significantly attenuated OX-42 immunoreactivity, a marker of activated microglia, in the ipsilateral (P < 0.001) and contralateral (P < 0.01) spinal cord of SNL rats, compared to vehicle controls. Minocycline treatment significantly (P < 0.01) decreased levels of 2-AG and significantly (P < 0.01) increased levels of PEA in the ipsilateral spinal cord of SNL rats, compared to the contralateral spinal cord. Thus, activation of microglia affects spinal levels of endocannabinoids and related compounds in neuropathic pain states.

Identification of discrete sites of action of chronic treatment with desipramine in a model of neuropathic pain

Tricyclic antidepressants (TCAs) are an important analgesic treatment for neuropathic pain, though the neural substrates mediating these effects are poorly understood. We have used an integrative approach combining behavioural pharmacology with functional magnetic resonance imaging (fMRI) to investigate the effects of chronic treatment with the TCA desipramine, on touch-evoked pain (mechanical allodynia) and brain regional activity in the selective spinal nerve ligation (SNL) model of neuropathic pain. SNL and sham-operated rats received once daily i.p. administration of 10 mg/kg DMI, or saline, for 14 days. Withdrawal responses to the application of a normally non-noxious (10 g) stimulus were recorded in SNL and sham-operated rats over this period. On the final day of the study, SNL and sham-operated rats received a final challenge dose of DMI (10 mg/kg i.p.) during fMRI scanning. Chronic administration of desipramine (DMI) significantly attenuated mechancial allodynia in SNL rats. DMI challenge in chronic DMI-treated neuropathic rats produced significantly greater activation of the deep mesencephalic nucleus, primary somatosensory cortex, insular cortex, medial globus pallidus, inferior colliculus, perirhinal cortex and cerebellum compared to sham-operated rats and saline controls. By contrast, the spatial pattern of brain regional activation by chronic DMI treatment in sham controls encompassed a number of other areas including those associated with learning and memory processes. These novel findings identify key brain regions implicated in the analgesic and mood altering effects associated with chronic treatment with DMI.

Effects of selective spinal nerve ligation on acetic acid-induced nociceptive responses and ASIC3 immunoreactivity in the rat dorsal root ganglion

We investigated changes in pain behavior after injection of acetic acid in the hindpaws of rats with L5 spinal nerve ligation (SNL)-induced neuropathy. We also examined immunoreactivity for acid-sensing ion channel 3 (ASIC3) in the dorsal root ganglion (DRG) of rats with L5 SNL. Two weeks after SNL, the withdrawal threshold to a mechanical stimulus was significantly lower in the SNL group than in the sham-operated group ( n = 9 per group, P < 0.01). After acetic acid injection, spontaneous pain responses in the SNL group were significantly increased compared to those in the sham-operated group ( n = 5, P < 0.05). L5 SNL significantly increased the proportion of total ASIC3-immunoreactive (ir) neurons in the ipsilateral L4 DRG compared to that in sham-operated rats ( n = 4, P < 0.01). Analysis of cell size showed that the proportion of large (> 1200 mm 2) ASIC3-ir neurons in the ipsilateral L4 DRG significantly increased after L5 SNL ( P < 0.05). In the ipsilateral L5 DRG, the proportion of ASIC3-ir neurons was not significantly affected by treatment. However, L5 SNL significantly increased ( P < 0.01) the proportion of small (< 1200 mm 2) ASIC3-ir neurons and significantly decreased ( P < 0.01) the proportion of large ASIC3-ir neurons compared to proportions in sham-operated animals. These findings suggest that ASIC3 is associated with hyperalgesia in response to a chemical stimulus in the L5 SNL rat model.

Peripheral Nerve Injury–Induced Changes in Spinal α2-Adrenoceptor–Mediated Modulation of Mechanically Evoked Dorsal Horn Neuronal Responses

Peripheral nerve injury has been associated with changes in the modulatory action of noradrenergic pathways on nociceptive traffic through the spinal cord. Thus, the purpose of this study was to assess whether endogenous noradrenergic descending inhibition, acting via spinal alpha(2)-receptors, is altered after peripheral nerve damage. We investigated the effects of spinal administration of a selective alpha(2)-adrenoceptor antagonist, atipamezole, on the evoked activity of deep dorsal horn neurons in animals with selective spinal nerve ligation (SNL) compared with a sham-operated group. Intrathecal administration of atipamezole (1, 10, and 100 microg) did not produce any significant effects on the electrically evoked neuronal responses in either animal group, with the exception of a small but significant enhancement of the postdischarge in the sham control group only. Similarly, no significant effects were observed with the heat-evoked neuronal responses in either group. Interestingly, atipamezole significantly increased the evoked responses of neurons to low-intensity mechanical stimuli in the sham control group but was without effect in the SNL group. Thus, our findings suggest that peripheral nerve injury can result in the suppression of noradrenergic spinal alpha(2)-adrenoceptor-mediated inhibition of spinal dorsal horn neuronal activity evoked by low-intensity mechanical stimuli. These results suggest that a tonically active noradrenergic inhibition of mechanically evoked spinal dorsal horn neuronal responses is lost after nerve injury. This shift in the balance of noradrenergic controls may be one of the many underlying mechanisms by which behavioral symptoms of hypersensitivity develop after nerve damage.

Activation of Extracellular Signal-Regulated Protein Kinase in Sensory Neurons After Noxious Gastric Distention and Its Involvement in Acute Visceral Pain in Rats

Changes in the properties of visceral sensory neurons contribute to the development of gastrointestinal pain. However, little is known about the molecules involved in mechanosensation from the gastrointestinal tract. We investigated the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), a member of the mitogen-activated protein kinase cascade, in dorsal root ganglion (DRG) and nodose ganglion (NG) neurons by noxious gastric distention (GD) and its involvement in acute visceral pain in rats. Electromyographic responses to gastric balloon distention through gastrostomy were recorded from the acromiotrapezius muscle in rats after splanchnic nerve resection or vagotomy and in control rats. We then examined the phosphorylated-ERK1/2 (p-ERK1/2) labeling in the DRG and NG after GD using immunohistochemistry. Gastric distention induced p-ERK1/2 in DRG and NG neurons with a peak at 2 minutes after stimulation. We found a stimulus intensity-dependent increase in the number of activated neurons, and this activation corresponded well with the incidence of the visceromotor response. Most of these p-ERK1/2-labeled neurons were small- and medium-sized neurons that coexpressed transient receptor potential vanilloid 1 ion channel and acid-sensing ion channel 3. Splanchnic nerve resection, but not vagotomy, affected the visceromotor response, and attenuated the ERK1/2 activation in DRG neurons produced by GD. Furthermore, intrathecal administration of the mitogen-activated protein kinase kinase 1/2 inhibitor, U0126, altered the response to noxious GD. The activation of ERK1/2 pathways in DRG neurons by noxious GD may be correlated with functional activity, and may be involved in acute visceral pain.

An Unusual Cause of S1 Radicular Pain Presenting as Early Phantom Pain in a Transfemoral Amputee: A Case Report

Smuck M, Christensen S, Lee SS, Sagher O. An unusual cause of S1 radicular pain presenting as early phantom pain in a transfemoral amputee: a case report.Recent epidemiologic studies have shown back pain to be a significant cause of pain in lower-limb amputees, but only a handful of cases have reported sciatica in amputees. The symptoms are usually described as a phantom pain or neuropathic pain in the residual limb that is often refractory to conventional treatments. These symptoms typically occur with back pain and are distinct from the patient’s usual symptoms. Interestingly, back pain is not a universal finding. We present a patient with presumed phantom limb pain subsequently discovered to be caused by an S1 radiculopathy. This patient’s supposed phantom pain persisted despite multiple medication trials. Initial work-up revealed a sciatic neuroma at the stump. Treatments targeting this neuroma were unsuccessful. Further evaluation found that a sacroiliac joint screw placed to stabilize a pelvic fracture had intruded into the S1 neuroforamen. A diagnostic S1 nerve block temporarily relieved the patient’s pain, and the screw was removed. Pain persisted and a spinal cord stimulator was placed resulting in improvement of his pain. Because conventional diagnostic tests are limited, including physical exam and electromyography, a fluoroscopically guided selective spinal nerve block proved to be a useful diagnostic tool in this patient.

Expression changes of multiple brain-derived neurotrophic factor transcripts in selective spinal nerve ligation model and complete Freund's adjuvant model

Brain-derived neurotrophic factor (BDNF) expression changes in the dorsal root ganglion (DRG) and spinal cord in some pain models. Recently, rat BDNF transcripts containing novel 5′ untranslated exons were identified and characterized, and a new numbering system for rat BDNF exons was introduced. We examined the expression profiles of these novel BDNF transcripts in bilateral L4/5 DRGs in an L5-selective spinal nerve ligation (SSNL) model and bilateral L5 DRGs in a complete Freund's adjuvant (CFA) model of rats. L5SSNL increased significantly ( P < 0.05) the expression of total BDNF mRNA and exon I, IIA, IIB, IIC, III, IV, VI, and IXA transcripts in ipsilateral L4 DRG. Although expression of total BDNF mRNA remained unchanged in ipsilateral L5 DRG in the L5SSNL model, expression of exon I transcript increased significantly ( P < 0.05) and that of exon IV transcript decreased significantly ( P < 0.05). The expression profiles of the variant exons in ipsilateral L4 DRG of the L5SSNL model were quite similar to those in ipsilateral DRG of the CFA model, and exon I transcript was the most common BDNF mRNA in these DRGs. Although L5SSNL increased significantly ( P < 0.05) the expression of total BDNF mRNA and exon IIC and IXA transcripts in the contralateral L4/5 DRGs, CFA treatment did not alter the expression of total BDNF mRNA or specific transcripts in the contralateral DRGs. These findings suggest that exon I plays an important role in the increase in BDNF expression in ipsilateral DRGs regardless of condition.

Electroacupuncture Direct to Spinal Nerves as an Alternative to Selective Spinal Nerve Block in Patients with Radicular Sciatica – a Cohort Study

We applied electroacupuncture to the spinal nerve root by inserting needles under x ray imaging in three cases with radicular sciatica, as a non-pharmacological substitute for lumbar spinal nerve block. In all three cases, symptoms were markedly reduced immediately after electroacupuncture to the spinal nerve root. The sustained effect was noticeably longer than that of spinal nerve blocks previously performed, in two out of the three cases. We suggest that descending inhibitory control, inhibitory control at the spinal level, inhibition of potential activity by hyperpolarisation of nerve endings, or changes in nerve blood flow may be involved in the mechanism of the effect of electroacupuncture to the spinal nerve root. These results suggest that electroacupuncture to the spinal nerve root may be superior to lumbar spinal nerve block when it is applied appropriately in certain cases of radicular sciatica, taking into consideration patient age, severity of symptoms and duration of the disorder.

Selective Spinal Nerve Block for the Treatment of Lumbar Spinal Stenosis that indicated Operation

Purpose: This study evaluated the effectiveness of a selective nerve root block (SNRB) for a lumbar spinal stenosis (LSS) that indicated surgery. Materials and Methods: Twenty-one LSS patients, who were indicated for surgery but could not be operated on due to a high anesthetic risk, were evaluated retrospectively an evaluated on average of 19.5 months (range, 12 to 60 months) following the SNRB from April 1998 to October 2002. There were 9 males and 12 females with a mean age of 66.4 years (range, 59 to 78 years). The medical records and radiologic studies were reviewed, and a telephone interview was carried out where needed. The anesthetic risk was evaluated by the American Society of Anesthesiologists (ASA) physical status classification. The Kirkaldy-Willis criteria (at 9 months after SNRB and last FU) and the recurrence of symptoms (at 2 weeks, 1 month, 3 months, 5 months, 9 months after the SNRB, and the last FU) were analyzed. Results: Among the 21 patients, 8 patients were in the ASA class 3, 13 in class 4. The major physical conditions that indicated a high anesthetic risk was cardiac problems in 17 patients, renal problems in 2, and endocrine problem in 2. The interval between the onset of symptom and the SNRB ranged from one month to 30 years (average, 41.6 months). All but 3 patients had a recurrence of their symptoms at an average 1.9 months (range, 1 day to 9 months) after the SNRB. According to the Kirkardy-Wills criteria, 9 months after SNRB, the results were good in 1 patient, fair in 2, and poor in 18. At the last follow-up, all but 4 patients did not show a chang in their status according to the Kirkardy-Wills criteria, and 4 patients improved (poor to good in 2, poor to fair in 2) without treatment. Conclusion: The symptoms of LSS improved for a very short period (average, 1.9 month) by SNRB. These results suggest that SNRB suitable for the LSS patients who require need surgery.

Pharmacological evaluation of the selective spinal nerve ligation model of neuropathic pain in the rat

Rodent models of neuropathic pain are used to investigate the underlying mechanisms of pain associated with damage to peripheral nerves and to evaluate the efficacy of novel compounds. However, few models have been adequately characterized and the validity of many models remains unclear. The present experiment examined the activity of known anti-allodynic compounds in the L5 spinal nerve ligation (SNL) model of peripheral mononeuropathy in the rat, a modified version of the L5/L6 SNL model [S.H. Kim, J.M. Chung, An experimental model for peripheral neuropathy produced by segmental spinal nerve ligation in the rat, Pain 50 (1992) 355–363]. Tactile sensitivity was measured 7–21 days post-surgery using von Frey monofilaments before and following treatment with gabapentin (30, 60 and 120 mg/kg), morphine (1, 3 and 6 mg/kg), amitriptyline (1.5, 3 and 10 mg/kg), fluoxetine (3, 10 and 30 mg/kg), WIN55,212-2 (0.5, 1 and 2.5 mg/kg), indomethacin (1 and 5 mg/kg) or U-50,488H (3 and 6 mg/kg). Compared to sham-operated control animals, L5 SNL animals displayed significant tactile allodynia in the ipsilateral hindpaw that was completely reversed by treatment with gabapentin, morphine, and WIN55,212-2, partially reversed by amitriptyline and fluoxetine, and unaffected by U-50,488H or indomethacin. The robust effects of the non-selective cannabinoid receptor agonist WIN55,212-2 and morphine support reports in the literature that systemic cannabinoid receptor agonists and opioids are active in neuropathic pain. These results suggest that the L5 SNL model can be utilized to determine the anti-allodynic activity of novel compounds.