Nerve Root Injections Research Articles

1:50 17. Efficacy of Nerve Root Injection for Degenerative Lumbar Disorders—Who is a Good Responder?

1:50 17. Efficacy of Nerve Root Injection for Degenerative Lumbar Disorders—Who is a Good Responder?

Magnetic resonance imaging of the lumbar spine after epidural and nerve root injection therapy: evaluation of soft tissue changes

Magnetic resonance imaging (MRI) was performed to evaluate soft tissue changes after nerve root and epidural injections in lumbar spine in patients with radiculopathy. Patients underwent a multiple-shot injection protocol to nerve root/epidural space. The MRI protocol included T1-weighted, T2-weighted, STIR, and contrast-enhanced, fat-saturated T1-weighted sequences before and after treatment. In all treated patients, a diffuse wedge-shaped edema in paravertebral tissues with a slight contrast enhancement was seen. Two small hematomas in the paravertebral muscle were noted. No changes in the epidural space, the abscess, or a lipodystrophy in epidural/nerve root space occurred. Normal tissue changes after injection therapy of lumbar radiculopathy include wedge-shaped tissue edema at the injection level. In a minority of patients, small hematomas may occur.

Nerve Root Blocks in the Treatment of Lumbar Radicular Pain

In a previous prospective, randomized, controlled, double-blinded study on the effect of nerve root blocks on the need for operative treatment of lumbar radicular pain, we found that injections of corticosteroids were more effective than bupivacaine for up to thirteen to twenty-eight months. We performed a minimum five-year followup of those patients who had avoided surgery. All of the patients were considered to be operative candidates by the treating surgeon, and all had initially requested operative intervention. They had then been randomized to be treated with a selective nerve-root block with either bupivacaine or bupivacaine and betamethasone. Both the treating physician and the patient were blinded to the type of medication. Of fifty-five randomized patients, twenty-nine avoided an operation in the original study. Twenty-one of those twenty-nine patients were reevaluated with a follow-up questionnaire at a minimum of five years after the initial block. Seventeen of the twenty-one patients still had not had operative intervention. There was no difference between the group treated with bupivacaine alone and the group treated with bupivacaine and betamethasone with regard to the avoidance of surgery for five years. At the five-year follow-up evaluation, all of the patients who had avoided operative treatment had significant decreases in neurological symptoms and back pain compared with the baseline values. The majority of patients with lumbar radicular pain who avoid an operation for at least one year after receiving a nerve root injection with bupivacaine alone or in combination with betamethasone will continue to avoid operative intervention for a minimum of five years.

NERVE ROOT BLOCKS IN THE TREATMENT OF LUMBAR RADICULAR PAIN

Background: In a previous prospective, randomized, controlled, double-blinded study on the effect of nerve root blocks on the need for operative treatment of lumbar radicular pain, we found that injections of corticosteroids were more effective than bupivacaine for up to thirteen to twenty-eight months. We performed a minimum five-year followup of those patients who had avoided surgery. Methods: All of the patients were considered to be operative candidates by the treating surgeon, and all had initially requested operative intervention. They had then been randomized to be treated with a selective nerve-root block with either bupivacaine or bupivacaine and betamethasone. Both the treating physician and the patient were blinded to the type of medication. Of fifty-five randomized patients, twenty-nine avoided an operation in the original study. Twenty-one of those twenty-nine patients were reevaluated with a follow-up questionnaire at a minimum of five years after the initial block. Results: Seventeen of the twenty-one patients still had not had operative intervention. There was no difference between the group treated with bupivacaine alone and the group treated with bupivacaine and betamethasone with regard to the avoidance of surgery for five years. At the five-year follow-up evaluation, all of the patients who had avoided operative treatment had significant decreases in neurological symptoms and back pain compared with the baseline values. Conclusions: The majority of patients with lumbar radicular pain who avoid an operation for at least one year after receiving a nerve root injection with bupivacaine alone or in combination with betamethasone will continue to avoid operative intervention for a minimum of five years. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Failure of conservative treatment for lumbar spinal stenosis in elderly patients

Spinal stenosis syndrome affects mainly patients at their 5th–6th decades of life. There is a strong debate in the literature whether patients with spinal stenosis should be operated or treated conservatively. Our aim was to evaluate patients with lumbar spinal stenosis who were treated conservatively. All patients over 65 years of age who were handled conservatively in the private clinic of the senior author due to spinal stenosis syndrome were evaluated. There were 21 males and 15 females aged between 65 and 88 years. Intermittent claudication was the dominant clinical presentation. The radiological examination showed a frequent narrowing at the level L4-L5. All patients had a severe stenosis of less than 10 mm diameter of the spinal canal. All patients underwent a conservative therapy which included physical therapy with ultrasound waves, short waves, and flexion exercises. All patients were offered to undergo an epidural or nerve root injection. Twenty-four patients agreed also to have one of these procedures to relieve their symptoms. All patients were followed between 6 and 10 months after the initial diagnosis. We used the Oswestry index category for evaluation. In all parameters the conservative treatment failed to improve the symptoms in the vast majority of patients. None of the patients was very satisfied with the results of conservative treatment while 33 patients (92%) were not so satisfied or unsatisfied with the results. We conclude that conservative treatment for lumbar spinal stenosis is not a success for elderly patients. These patients should be convinced to undergo operative treatment.

Selective Nerve Root Injections Can Predict Surgical Outcome For Lumbar and Cervical Radiculopathy

Diagnostic selective nerve root injection (SNI) results were analyzed in 101 patients who underwent lumbar or cervical decompression for radiculopathy and compared to surgical outcome 1 year postoperatively. A comparison of surgical outcomes was also examined between magnetic resonance imaging (MRI) and SNI results. Of the 101 patients, 91 (90%) had positive and 10 had negative SNI results at the level operated. Ninety-one percent of the patients with a positive SNI had good surgical outcomes, whereas 60% of the patients with a negative SNI had good outcomes. Of the patients with a positive MRI result, 87% had good surgical outcomes, whereas a similar percentage of the patients with a negative MRI (85%) had good surgical outcomes. When findings between SNI and MRI differed (n = 20), surgery at a level consistent with the SNI was more strongly associated with a good surgical outcome. Of the patients with a poor surgical outcome, surgery was most often performed at a level inconsistent with the SNI finding. Our study found that a diagnostic SNI can safely and accurately discern the presence or absence of cervical or lumbar radiculopathy. The diagnostic SNI can persuade surgeons from operating on an initially suspicious, but incorrect, level of radiculopathy. In cases where MRI findings are equivocal, multilevel, and/or do not agree with the patient's symptoms, the result of a negative diagnostic SNI (ie, lack of presence of radiculopathy) becomes superior in predicting the absence of an offending lesion.

Coronal oblique turbo STIR imaging of the sacrum and sacroiliac joints at routine MR imaging of the lumbar spine

The objective of the study was to evaluate the clinical impact of coronal oblique imaging of the lumbrosacral junction and the sacrum at initial presentation for MR imaging of the lumbar spine in patients presenting with low back pain or sciatic pain. Two hundred and sixty consecutive patients attending for MRI of the lumbar spine underwent simultaneous coronal oblique turbo short tau inversion recovery (STIR; TR 2500, TE 40, TI 150, echo train length 7, number of scan acquisitions 2) imaging of the sacrum and the sacroiliac joints with a field of view of 30-cm and 3-mm slices (acquisition time 3 min and 20 s). Images were reviewed by two experienced radiologists to determine the cause of back pain, with and without images of the sacrum and sacroiliac joints. The added value of the additional sequence was assessed. Correlation was made with surgery, response to nerve root injection or clinical follow-up at 3 months. Subgroup analysis was performed to determine if patient stratification according to sex or symptoms would be useful. In total, in 19 of 260 patients (7.3%), abnormalities were identified at coronal STIR imaging. In 7 of 260 patients (2.7%), pathology was identified in the sacrum thought to account for back pain, altering the diagnosis made on the standard sequences. These diagnoses were sacroiliitis (n=2), sacral stress fracture (n=1), degenerative sacroiliac joints (n=1), degenerative accessory articulation between the lumbar spine and the sacrum (n=1), Tarlov cyst of nerve root (n=1) and retroverted uterus causing sciatic pain (n=1). Patient stratification according to sex or the presence or absence of sciatic symptoms was not useful in predicting the added benefit of the additional sequence. Routine coronal STIR imaging of the sacrum as part of lumbar spine MRI improves assessment of patients presenting with low back pain or sciatica in only a small number of patients.

Cost-effectiveness and safety of epidural steroids in the management of sciatica

To investigate the clinical effectiveness of epidural steroid injections (ESIs) in the treatment of sciatica with an adequately powered study and to identify potential predictors of response to ESIs. Also, to investigate the safety and cost-effectiveness of lumbar ESIs in patients with sciatica. A pragmatic, prospective, multicentre, double-blind, randomised, placebo-controlled trial with 12-month follow-up was performed. Patients were stratified according to acute (<4 months since onset) versus chronic (4-18 months) presentation. All analyses were performed on an intention-to-treat basis with last observation carried forward used to impute missing data. Rheumatology, orthopaedic and pain clinics in four participating centres: three district hospitals and one teaching hospital in the south of England. Total of 228 patients listed for ESI with clinically diagnosed unilateral sciatica, aged between 18 and 70 years, who had a duration of symptoms between 4 weeks and 18 months. Patients received up to three injections of epidural steroid and local anaesthetic (active), or an injection of normal saline into the interspinous ligament (placebo). The primary outcome measure was the Oswestry Disability Questionnaire (ODQ); measures of pain relief and psychological and physical function were collected. Health economic data on return to work, analgesia use and other interventions were also measured. Quality-adjusted life-years (QALYs) were calculated using the SF-6D, calculated from the Short Form (SF-36). Costs per patient were derived from figures supplied by the centres' finance departments and a costings exercise performed as part of the study. A cost-utility analysis was performed using the SF-36 to calculate costs per QALY. ESI led to a transient benefit in ODQ and pain relief, compared with placebo at 3 weeks (p = 0.017, number needed to treat = 11.4). There was no benefit over placebo between weeks 6 and 52. Using incremental QALYs, this equates to and additional 2.2 days of full health. Acute sciatica seemed to respond no differently to chronic sciatica. There were no significant differences in any other indices, including objective tests of function, return to work or need for surgery at any time-points. There were no clinical predictors of response, although the trial lacked sufficient power to be confident of this. Adverse events were uncommon, with no difference between groups. Costs per QALY to providers under the trial protocol were 44,701 pounds sterling. Costs to the purchaser per QALY were 354,171 pounds sterling. If only one ESI was provided then costs per QALY fell to 25,745 pounds sterling to the provider and 167,145 pounds sterling to the purchaser. ESIs thus failed the QALY threshold recommended by the National Institute for Health and Clinical Excellence (NICE). Although ESIs appear relatively safe, it was found that they confer only transient benefit in symptoms and self-reported function in a small group of patients with sciatica at substantial costs. ESIs do not provide good value for money if NICE recommendations are followed. Additional research is suggested into the epidemiology of radicular pain, producing a register of all ESIs, possible subgroups who may benefit from ESIs, the use of radiological imaging, optimal early interventions, analgesic agents and nerve root injections, the use of cognitive behavioural therapy in rehabilitation, improved methods of assessment, a comparative cost-utility analysis between various treatment strategies, and methods to reduce the effect of scarring and inflammation.

Transverse myelitis after lumbar steroid injection in a patient with Behcet's disease

Case report. We describe a patient who developed transverse myelitis (TM) following a nerve root injection of steroids and anesthetic at L2 for radicular pain. Baltimore, MD, USA. A 42-year-old woman developed progressive lower extremity weakness and paresthesias, a T12 sensory level and urinary urgency 8 h following the injection of Marcaine and Celestone into the left L2 nerve root. Magnetic resonance imaging showed T2 signal abnormality with gadolinium enhancement from T12 to the conus medullaris and there was no evidence of traumatic injury to the spinal cord. The patient had undiagnosed Behcet's disease (BD) and had experienced multiple episodes of pathergy: hyper-responsiveness of the skin to local trauma, resulting in inflammation and edema. Intravenous steroids were initiated and the patient experienced a near total clinical resolution and a complete radiologic resolution. Since the spinal cord inflammation developed after and immediately adjacent to local spinal trauma, we suggest that the TM in this patient was related to BD and was a pathergy response in the spinal cord.

Pre-, Intra-, and Postprocedure Nursing Care and Assessment of Patients Undergoing Diagnostic Neuroradiological Procedures

Many patients with back pain are referred to the radiology department for invasive diagnostic testing before spinal surgery. The most common of these procedures are epidural injection, selective nerve root injection, facet joint injection, and provocative discography. With the exception of discography, these procedures are therapeutic as well as diagnostic, providing symptomatic relief for up to 6 months. This article discusses the purpose and method of these procedures, as well as the relative pre-, intra-, and postprocedure care and assessments.

Spinal Cord Infarction Following Therapeutic Computed Tomography-Guided Left L2 Nerve Root Injection

Case report. To report a rare case of spinal cord infarction following therapeutic computed tomography-guided nerve root injection. Diagnostic and therapeutic image-guided nerve root injection is commonly performed in the management of low back pain and sciatica. The severe complication of spinal cord infarction has been reported in only 3 cases previously. Retrospective review of case records and imaging. A 71-year-old woman presented with symptoms and signs of left L2 nerve root compression. She was managed with computed tomography-guided left L2 nerve root injection using bupivacaine and triamcinolone and developed immediate bilateral sensory loss and paraplegia. Magnetic resonance imaging demonstrated diffuse hyperintensity within the distal thoracic cord and conus on T2-weighted images, consistent with spinal cord infarction. We report the fourth case of spinal cord infarction following nerve root injection. The severity of this complication warrants that it should be considered during patient consent for this procedure.

Complications and side effects of cervical and lumbosacral selective nerve root injections

Huston CW, Slipman CW, Garvin C. Complications and side effects of cervical and lumbosacral selective nerve root injections. Objective To determine the incidence of complications and side effects of cervical and lumbosacral selective nerve root injections (SNRIs). Design Prospective, nonrandomized controlled trial of consecutive patients with independent interviews for immediate, 1-week, and 3-month follow-ups. Setting Tertiary, academic spine center. Participants Of 160 patients eligible for SNRI, 151 underwent 306 SNRIs (study group). Sixty patients who had not undergone any intervention served as the control group. Interventions Diagnostic and therapeutic fluoroscopically guided cervical and lumbosacral SNRIs. Lidocaine (Xylocaine) was used in the diagnostic injections and a mixture of lidocaine and betamethasone was used in the therapeutic injections. Main outcome measures Complications and side effects experienced during the procedure were recorded by the interventionalist. Side effects and complications experienced immediately, 1 week, and 3 months after injection were determined through independent interviews using a questionnaire format. The control group was independently interviewed using the same questionnaire. Results There were no major complications, such as death, paralysis, spinal nerve injury, infection, or allergic reaction, during the study. Ninety-one percent of subjects had no side effects during the procedure. A positive response on interview was reported by 39.4% of the study subjects immediately after the procedure. Lumbosacral SNRI side effects were as follows: increased pain at the injection site (17.1%); increased radicular pain (8.8%); lightheadedness (6.5%); increased spine pain (5.1%); nausea (3.7%); nonspecific headache (1.4%); and vomiting (0.5%). Immediate side effects from cervical SNRI were as follows: increased pain at injection site (22.7%); increased radicular pain (18.2%); lightheadedness (13.6%); increased spine pain (9.1%); nonspecific headache (4.5%); and nausea (3.4%). At the 1-week interview, comparison of the study and control groups showed statistical significance for the following: pain at injection site, cervical ( P=.001) and lumbar ( P=.005); nonspecific headache, cervical ( P=.019); and nonspinal headache, cervical ( P=.002). At 3 months, 2 subjects complained of increased neck pain and 1 reported heartburn and fluid retention. Two lumbar SNRI subjects were lost to follow-up. Conclusions There were no major complications with cervical and lumbosacral SNRIs, although various minor side effects occurred.

Preganglionic approach to transforaminal epidural steroid injections.

Several studies have demonstrated the efficacy of transforaminal epidural steroid injections (TFESI) for the treatment of lumbosacral radicular pain. 1–4 Using standard TFESI technique, the spinal needle is positioned within the “safe triangle” (bordering the pedicle, the exiting nerve root, and the posterolateral border of the vertebral body), with the bevel below the inferior aspect of the pedicle. In a selective nerve root block, the injectate typically bathes the epidural space around the dorsal root ganglion and descends along the distal aspect of the nerve root (Fig. 1, bottom arrow). Ideally, if there is no stenosis, and the needle tip is appropriately positioned, the injectate may spread rostrally to the epidural portion of the preganglionic nerve root as well (Fig. 1, top arrow).Figure 1:: Fluoroscopic image (anteroposterior view) of transforaminal selective nerve root and epidural steroid injection of the left L4 nerve root. Bottom arrow, distal aspect of the nerve root; top arrow, epidural portion of the preganglionic nerve root.In most cases of lumbosacral radiculopathy secondary to stenosis or a herniated disc, the site of impingement usually lies at the level of the supra-adjacent intervertebral disc, which is rostral to the conventional lumbar TFESI bevel position. However, one cannot always guarantee a rostral spread of injectate to bathe the epidural/preganglionic portion of the nerve root. As an example, in treating a right S1 radiculopathy with TFESI at the exiting nerve root location (S1 foramen), the injectate failed to ascend to the L5-S1 disc level (Fig. 2, bottom arrow). In situations like this, one may wish to consider a supplementary preganglionic TFESI approach. The fluoroscopic landmarks utilized for needle positioning are similar to those used for intradiscal procedures (lateral to the superior articular process and parallel to the superior endplate of the vertebral body). The final needle position is at the inferior aspect of the supra-adjacent neural foramen, with the bevel immediately dorsal to the annulus/posterior longitudinal ligament. Injection at this position places the aliquot at the epidural preganglionic site of neural impingement, where the traversing nerve root is in closest proximity to the disc. The injectate may also descend to the intraforaminal and epidural portion of the exiting nerve root (Fig. 2, top arrow).Figure 2:: Fluoroscopic image (anteroposterior view) of epidural steroid injection of the right S1 root. Bottom arrow, L5-S1 disc level; top arrow, intraforaminal and epidural portion of the exiting nerve root.Theoretical advantages of the preganglionic TFESI technique include placing of the injectate closer to the site of neural impingement and providing a more effective washout of inflammatory disc material. Perhaps this methodology may be useful as a supplementary injection technique to the conventional TFESI, especially in patients who demonstrate poor rostral spread of injectate toward the epidural/preganglionic portion of the nerve root. A prospective, randomized, controlled trial may be needed to verify its clinical efficacy and further define its utility.

Far-Lateral disk herniation: case report, review of the literature, and a description of nonsurgical management

Objective To review the history and examination of a far-lateral lumbar intervertebral disk herniation (FLLIDH), as well as the treatment and outcomes of a nonsurgical approach. Clinical features A 60-year-old healthy male subject had a 3-week history of right buttock and calf pain. He initially had a left lateral list and asymmetrical pelvic landmarks. Range of motion (ROM) of the lumbar spine revealed full and pain-free lumbar flexion, right-sided pain with lumbar extension and left side bending, and painful and restricted left side bending. Neurologic examination was unremarkable. Intervention and outcome The patient was treated with a lumbar epidural and nerve root injection, as well as manipulation. Physical therapy consisted of deweighting treadmill, autotraction, and strengthening exercises. Outcomes were measured by using the Modified Oswestry Questionnaire, as well as a numerical pain rating scale. His initial Oswestry was 73%, pain 9/10 at presentation. Upon discharge, the Oswestry was 0% and pain was rated as 0/10. Conclusion A significant decrease was noted in both the Oswestry Questionnaire, as well as the pain rate. The patient returned to running on alternate days for a minimum of 30 minutes, which was his primary goal. This case demonstrated a positive outcome using a multidisciplinary approach in a patient diagnosed with a FLLIDH. He obtained his goals and his function was fully restored.

Comment with regard to: Outcomes of a prospective cohort study on peri-radicular infiltration for radicular pain in patients with lumbar disc herniation and spinal stenosis (L. Ng et al.)

In a patient presenting with clear-cut radicular pain, it is tempting to pursue non-surgical therapies directed towards the affected nerve. This would seem to be logical, especially in view of the increasing evidence that the genesis of such pain is not just nerve compression [1]. Amongst the techniques favoured in radicular pain syndromes is the injection of local anaesthetic and steroid around the nerve root, variously called peri-radicular infiltration, paravertebral block or nerve root block, a technique performed by anaesthetists as well as spinal surgeons. Whilst many practitioners can provide anecdotal evidence of efficacy, the literature is of little help: there are no controlled studies of reasonable quality. The study of Ng et al. in this issue is of interest because it does include carefully collected outcome data not only of pain and general function (Oswestry and Low Back Outcome Score), but also of the Dram score (Zung Depression Inventory and Modified Somatic Perceptions Questionnaire), in two cohorts of patients undergoing peri-radicular infiltrations for nerve root pain due either to lumbar disc herniation or spinal stenosis. The data provide details of the outcome that can be expected from the performance of a nerve root injection using a small volume of bupivacaine with 40 mg methyl prednisolone, on pain, distress and general function. Both groups get better, but this is much more marked in the disc herniation group. The improvement seen in the spinal stenosis group is minimal, with only a two-point reduction in ODI and 7 mm on VAS at 6 weeks with some further improvement (to 6 and 12, respectively), on the VAS at 12 weeks. Given that the patients started off with VAS scores of 77 a reduction to 70 after 7 weeks is not satisfactory pain management. It has been estimated that one needs a 13-point change to detect clinically relevant pain relief [3]. The disc herniation group fare somewhat better, with VAS changes of 11 at 6 weeks and 20 and 12 weeks, but this is a condition with a natural history of resolution, and the fundamental question of whether the injection aided this recovery is not answered due to lack of controls. Herewith, the major problem with the study: the lack of a control group ultimately limits its value. The authors refer to the literature on epidural steroids, which, although by no means categorical, is supportive of an effect in acute lumbar disc herniation. The authors added contrast medium to the injectate and only used a small volume. They do not report on epidural spread, but spread of injectate into the epidural space has been described during injections of this type [2] which raises the question as to the site of action of the drug. If one makes the charitable assumption that the authors injections do provide some benefit to patients with lumbar disc herniation, the question then arises as to whether this technique is easier to perform, cheaper, or more effective than epidural injection. One aspect that the literature on epidurals in acute disc prolapse does not adequately address is the short-term acute pain relief obtainable from such injections. The pain of an acute disc can be terrible and because of its neuropathic nature difficult to control even with strong analgesics. Effective relief of this pain is a rational end point of treatment even if the long-term outcome is unchanged. We thus do not need evidence of long-term benefit to justify a treatment if it can be shown to provide high-quality pain relief in the acute phase. Unfortunately, this study does not help in this respect. As always, there are more questions than answers: controlled studies are urgently needed.

P60. Selective nerve root injections can predict surgical outcome for cervical radiculopathy

P60. Selective nerve root injections can predict surgical outcome for cervical radiculopathy

Nerve-root injections for the relief of pain in patients with osteoporotic vertebral fractures

We have studied 58 patients with pain from osteoporotic vertebral fractures which did not respond to conservative treatment. These were 53 women and five men with a mean age of 72.5 years. They received a nerve-root injection with lidocaine, bupivicaine and DepoMedrol. The mean follow-up period was 13.5 months. The mean pain scores before treatment, at one and six months after treatment and at the final follow-up were 85, 24.9, 14.1, and 17.4, respectively. According to our modified criteria for grading results, six patients were considered to have an excellent result, 42 good and ten fair. A newly developed compression fracture was noted in three patients. There were no complications related to the injection. Our study suggests that nerve-root injections are effective in reducing pain in patients with osteoporotic vertebral fractures and that these patients should be considered for this treatment before percutaneous vertebroplasty or operative intervention is attempted.

Indocyanine green: evidence of neurotoxicity in spinal root axons.

The inadvertent intravascular injection of a local anesthetic during epidural anesthesia is an uncommon but potentially serious complication. Epinephrine, the most commonly used marker, does not provide sufficient sensitivity to exclude intravascular injection in all patient populations. The dye indocyanine green (ICG) has been proposed as an alternative marker. It has been demonstrated that ICG could be used to detect intravascular injections with a simple transcutaneous spectrophotometric technique. Although the safety of intravenous ICG is well documented, its neurotoxic potential requires careful study given the probability of inadvertent intrathecal injection during test injections used to verify epidural catheter placement. In this study, the authors investigated the neurophysiologic effects of clinically relevant concentrations of ICG (range, 28.6-286 microm) on single myelinated and unmyelinated dorsal root axons in rats by measuring effects on impulse generation and conduction. In contrast to the apparent absence of toxicity when injected intravenously, ICG applied to intact dorsal roots at concentrations likely to be encountered with an epidural test dose produced long-lasting conduction block (21 of 26 axons) or spontaneous bursting activity (7 of 26 axons) in myelinated and unmyelinated dorsal root axons. Given this apparent neurotoxicity, ICG should not be used when intrathecal or nerve root injection is possible.

Foraminal injection of a painful sacral nerve root using an epidural catheter: Case report

Background and Objectives: Nerve root pain has been treated with steroid injections since the 1970s. We will describe a novel method for nerve root injection using a directed epidural catheter. Case Report: A case is described where catheter placement accurately reproduced symptoms which were then relieved with local anesthetic and steroid. Conclusion: This is a novel approach to treatment of painful nerve roots with a catheter. Reg Anesth Pain Med 2002;27:214-216.

Selective nerve root injections can predict surgical outcome for lumbar and cervical radiculopathy: a retrospective review with comparison to magnetic resonance imaging

Selective nerve root injections can predict surgical outcome for lumbar and cervical radiculopathy: a retrospective review with comparison to magnetic resonance imaging