Cervical Nerve Root Blocks: Indications and Role of MR Imaging

Long-term effectiveness of transforaminal anterolateral approach CT-guided cervical epidural steroid injections for cervical radiculopathy treatment

AIM

To evaluate the long-term clinical effectiveness of computed tomography (CT)-guided transforaminal cervical epidural steroid injection using an anterolateral approach for the treatment of cervical radiculopathy (CR) using well-established robust clinical scoring systems for neck pain and neck disability. Despite its widespread use, evidence to support the long-term benefit of routine cervical epidural steroid injection is currently very limited.

MATERIALS AND METHODS

This study included 113 patients with magnetic resonance imaging (MRI)-confirmed CR who underwent a steroid injection at a single cervical level via a unilateral transforaminal anterolateral approach. Pain was assessed quantitatively at pre-injection, 15 minutes post-injection, 1 month, 3 months, and at 1 year. Neck disability was assessed using the Oswestry Neck Disability Index (NDI) at pre-injection, 1 month, 3 months, and 1 year time points.

RESULTS

Eighty patients completed the study. Sixty per cent reported reduced neck pain (mean pain reduction, 55%), which was clinically significant in 45% cases. Furthermore, 66% reported an improvement in neck disability (mean improvement, 51%), which was clinically significant for 56% patients. Clinically significant good outcomes in both neck pain and neck disability were evident from as early as 1-month, and importantly, were independent both of pre-treatment CR characteristics (including severity of pre-injection neck pain or disability) and of findings on pre-injection MRI imaging.

CONCLUSION

Transforaminal anterolateral approach CT-guided epidural steroid injection resulted in a clinically significant long-term improvement in both neck pain and disability for half of the present cohort of patients with unilateral single-level CR. This improvement was independent of the severity of the initial symptoms and pre-injection MRI findings.

Ultrasound-guided cervical selective nerve block: A case series

BACKGROUND

Cervical radiculopathy is characterized by pain, numbness, tingling, and weakness, mostly in an affected extremity, reflecting compression of a nerve in the neck is compressed or irritated where it emerges from the spinal cord. Diagnosis requires a detailed anamnesis, physical examination, and imaging. Physical therapy, exercise, medical therapy, and injections are the preferred treatments, but injections into the cervical region are only indicated if conservative treatment is ineffective.

OBJECTIVE

This study explored the utility of selective cervical nerve root blocks (SNRBs) performed at various levels under ultrasound guidance (USG).

METHODS

We evaluated patients diagnosed with cervical radiculopathy via physical examination and magnetic resonance imaging from November 2019 to March 2020. We included those who did not respond to conservative treatment and therefore received SNRBs at various levels. Sixty-three patients were evaluated over 6 months in terms of pain, functional status, and complications.

RESULTS

We retrospectively evaluated patients with cervical herniated discs who received SNRBs at various levels between C4-7 under USG. Pain and functional status improved in month 1 and was maintained until at least month 6.

CONCLUSION

SNRB injections performed under USG effectively treated pain and poor functional status in selected patients. The procedure is safe (especially) for patients who do not respond to conservative treatment.

One-year results from a randomized comparative trial of targeted steroid injection via epidural catheter versus standard transforaminal epidural injection for the treatment of unilateral cervical radicular pain

OBJECTIVES

The objective of this study was to evaluate the long-term effectiveness of catheter-directed cervical interlaminar epidural steroid injection with triamcinolone compared with cervical transforaminal steroid injection with dexamethasone for the treatment of refractory unilateral radicular pain.

DESIGN

Prospective, randomized, comparative trial.

METHODS

The primary outcome was the proportion of participants with ≥50% Numeric Rating Scale 'dominant pain' (the greater of arm vs neck) reduction from baseline. Secondary outcomes included ≥30% Neck Disability Index reduction and Patient Global Impression of Change response indicating 'much improved' or 'very much improved'.

RESULTS

Data from 117 participants (55.6% women; 52.3±12.5 years of age; body mass index, 28.2±6.5 kg/m²) were analyzed. The proportion of participants who experienced ≥50% pain reduction at 1 month, 3 months, and 6 months has been previously reported. At 1 year, 61.2% (95% CI, 46.9% to 73.9%) of the catheter group compared with 51.9% (95% CI, 38.4% to 65.2%) of the transforaminal group reported ≥50% 'dominant' pain reduction (p=0.35). The proportion of participants who experienced ≥30% improvement in Neck Disability Index score was 60.4% (95% CI, 45.9% to 73.3%) and 47.1% (95% CI, 33.7% to 60.8%) in the catheter and transforaminal groups (p=0.18). Patient Global Impression of Change improvement was similar in both groups: 60.5% (95% CI, 44.2% to 74.8%) and 57.5% (95% CI, 41.7% to 71.9%) of the catheter and transforaminal groups reported being 'much improved' or 'very much improved', respectively (p=0.79).

CONCLUSION

Both cervical catheter-directed interlaminar epidural injection and cervical transforaminal steroid injection were effective in reducing pain and disability in the majority of participants with refractory unilateral cervical radiculopathy for up to 1 year.

Paravertebral Collateral Arteries in Patients with Carotid Stenosis: Is There a Safe Space for Transforaminal Cervical Nerve Root Injections?

AIM

Image-guided cervical nerve root injections can cause serious complications including spinal cord infarction. This risk may be increased in patients with carotid stenosis who develop collateral arteries. The aim of this study is to describe the prevalence, and anatomical location, of arterial collateral vessels in relation to the optimal needle tip position in cervical nerve root injections.

MATERIALS AND METHODS

This retrospective study included 25 patients who had > 70% stenosis on a carotid CT angiogram. For each foramen the position of collateral arteries and the most anterior point of the facet joint were recorded, as Cartesian coordinates, by two independent observers. Descriptive statistics were used to analyse and present the results.

RESULTS

14 patients had unilateral and 11 had bilateral stenoses. A total of 85 collaterals were identified at all levels, the most common being C2/3. The median distance from collateral to optimal needle tip placement was 9.6 mm (95% CI median: 6.7-12.4, IQR: 5.6-15.6). The minimum distance was 2.9 mm. Inter-observer reliability was "substantial" (ICC 0.78, 95% CI 0.71-0.83).

CONCLUSION

Collateral arteries were common in our cohort of patients with carotid artery stenosis and half lay within 10 mm of the optimal position for transforaminal cervical nerve root injection.

The value of short-term pain relief in predicting the long-term outcome of 'indirect' cervical epidural steroid injections

BACKGROUND

The predictive value of short-term arm pain relief after 'indirect' cervical epidural steroid injection (ESI) for the 1-month treatment response has been previously demonstrated. It remained to be answered whether the long-term response could be estimated by the early post-interventional pain course as well.

METHODS

Prospective observational study, following a cohort of n = 45 patients for a period of 24 months after 'indirect' ESI for radiculopathy secondary to a single-level cervical disk herniation (CDH). Arm and neck pain on the visual analog scale (VAS), health-related quality of life with the Short Form-12 (SF-12), and functional outcome with the Neck Pain and Disability (NPAD) Scale were assessed. Any additional invasive treatment after a single injection (second injection or surgery) defined treatment outcome as 'non-response'.

RESULTS

At 24 months, n = 30 (66.7%) patients were responders and n = 15 (33.3%) were non-responders. Non-responders exited the follow-up at 1 month (n = 10), at 3 months (n = 4), and at 6 months (n = 1). No patients were injected again or operated on between the 6- and 24-month follow-up. Patients with favorable treatment response at 24 months had significantly lower VAS arm pain (p < 0.05) than non-responders at days 6, 8-11, and at the 3-month follow-up. The previously defined cut-off of > 50% short term pain reduction was not a reliable predictor of the 24-month responder status. SF-12 and NPAD scores were better among treatment responders in the long term.

CONCLUSIONS

Patients who require a second injection or surgery after 'indirect' cervical ESI for a symptomatic CDH do so within the first 6 months. Short-term pain relief cannot reliably predict the long-term outcome.

Post Procedural Complication following Cervical Epidural Local Anesthetic Injection: A Case Report

Introduction

Cervical radiculopathy is a common condition affecting many people each year. The efficacy of cervical epidural steroid injection for patients that have not responded to conservative treatment has been demonstrated. Even with confirmatory radiocontrast dispersion indicating correct presence in the epidural space, there still may be rostral spread of steroid and local anesthetic resulting in an unusual presentation of symptoms and potentially life threatening complications.

Case Presentation

We present the case of a 52-year-old male presenting for a right sided C6-C7 epidural steroid injection. The epidural space was identified and a Tuohy needle was advanced using loss of resistance technique. Isovue contrast was used for needle localization and after confirmation of the presence of the contrast in the epidural space, dexamethasone and lidocaine were injected to the area without any complications. Five minutes after arrival to the PACU, the patient developed a constellation of symptoms including inability to swallow, vertigo, and horizontal nystagmus which required reassurance and vigilant monitoring.

Conclusions

Interventional pain physicians must be cognizant that even with confirmatory epidural radiocontrast dispersion, there still may be inadvertent uptake of steroid and local anesthetic rostrally resulting in an unusual presentation of symptoms and potentially life threatening complications. Potential reasons for the rostral spread include inadvertent subdural or intrathecal injection.

The value of short-term pain relief in predicting the 1-month outcome of 'indirect' cervical epidural steroid injections

BACKGROUND

Clinical management after epidural steroid injections (ESI) of patients with radiculopathy secondary to a cervical disc herniation (CDH) is uncertain. This study aims to determine whether short-term arm pain alleviation following computed tomography-guided 'indirect' cervical ESI can predict the 1-month outcome.

METHODS

We conducted a prospective observation of 45 consecutive patients at a tertiary radiological department. Study components were visual analog scale arm and neck pain at baseline, 15, 30, and 45 min, 1, 2, and 4 h, on days 1-14, 1 month, and at 1 year. Health-related quality of life and functional impairment were assessed using the short form-12 and Neck Pain and Disability Scale. Patients who reported ≥80 % persisting arm pain, as well as patients who underwent a second injection or an operation within 1 month were defined as 'non-responders'. Logistic regression was used to analyze the effect size of the relationship between >50 % pain relief at any given study visit and responder status.

RESULTS

Patients experiencing a >50 % pain reduction 4 h after the injection were four times as likely to be responders as those experiencing ≤50 % pain reduction (OR 4.04, 95 % CI 1.10-14.87). The effect was strongest on days 5-6 (OR 18.37, 95 % CI 3.39-99.64) and remained significant until day 14.

CONCLUSIONS

The results of this study can guide physicians in managing patients with CDH: a ≤50 % arm pain relief within 1 week after an 'indirect' cervical ESI predicts an unfavorable 1-month outcome and suggests that other treatment options may be considered at an earlier point in time.

[Periradicular infiltration therapy : Clinical indications, technique and results]

BACKGROUND

Minimally invasive procedures have played an emerging role in pain management during recent years.

OBJECTIVES

Evaluation of the different types of periradicular infiltration as fundamental procedures in the progressive stepwise concept of pain management. Comparison of the different therapeutic substances.

RESULTS

In the mid-term and long-term periradicular infiltration is effective in 60-80 % of patients regarding analgesic and functional aspects. Compliance with the guidelines should help to minimize potentially fatal complications.

CONCLUSION

Periradicular infiltration is of significant importance concerning the treatment of spinal nerve root irritation. Periradicular infiltration is regarded as a safe procedure, especially when supported by computed tomography (CT) scans.

Perineural Injection for Treatment of Root-Signature Signs Associated with Lateralized Disk Material in Five Dogs (2009-2013)

Intervertebral disk disease (IVDD) is common in dogs; cervical IVDD accounts for 13–25% of all cases. Ventral slot decompression provides access to ventral and centrally extruded or protruded disk material. However, procedures to remove dorsally or laterally displaced material are more difficult. This case series describes the use of perineural injection as a potential treatment option for dogs experiencing root-signature signs associated with lateralized disk material in the cervical spine. Five dogs underwent fluoroscopically guided perineural injection of methylprednisolone ± bupivacaine. Most patients experienced improvement in root-signature signs and remained pain free without the assistance of oral pain medication. These findings suggest the perineural injection of methylprednisolone ± bupivacaine represents a viable option for dogs with cervical lateralized disk material causing root-signature signs.

Correlation of Foraminal Area and Response to Cervical Nerve Root Injections

Introduction: Patients with age-related degenerative changes in the cervical spine leading to cervical spondylosis may be symptomatic or asymptomatic. Older patients with radicular pain tend to have a better response to epidural steroid injections, but it is often difficult to predict which patients will have a positive response to selective nerve root block (SNRB). We analyzed whether the cervical neuroforaminal area measured on MRI predicts immediate therapeutic responses to SNRB in patients who have cervical radiculopathy.

Methods: We retrospectively reviewed all patients who had cervical SNRBs treated at a single tertiary referral center. We recorded patient demographics, the neuroforaminal area of the symptomatic and contralateral sides, Visual Analog Scale (VAS) score pre- and post-injection, history of previous cervical surgery, comorbidities, and history of tobacco use.

Results: Sixty-four patients with symptoms of cervical radiculopathy treated with neuroforaminal nerve root injections had appropriate imaging and VAS scores recorded. The average foraminal area of the symptomatic side before treatment was significantly smaller than the contralateral asymptomatic neuroforamen (p<0.0001). Those patients with the smallest neuroforamen had a positive response to SNRB. Diabetes and tobacco use did not influence patient response to treatment.

Conclusions: Measurement of neuroforaminal areas on MRI may represent a useful pre-procedural technique to predict which patients with symptoms of cervical radiculopathy secondary to foraminal stenosis are likely to respond to selective nerve root injections. The predictive ability appears to be limited to those patients with severe stenosis and was less useful in those patients with moderate or mild stenosis.

The short- and medium-term effectiveness of CT-guided selective cervical nerve root injection for pain and disability

INTRODUCTION

CT-guided cervical nerve root injection with corticosteroid and/or local anesthetic is a recognized technique in the evaluation and treatment of cervical radiculopathy. There are few prospective studies on the efficacy of the various techniques employed in cervical nerve root injection. We present our results from a 1-year prospective series using a CT-guided anterolateral transforaminal approach for cervical nerve root injection of bupivacaine and dexamethasone.

METHODS

Pain using a numeric rating scale was assessed at pre-injection, 15 min post-injection, 1 month, and 3 months. Disability was assessed using the Oswestry Neck Disability Index (NDI) questionnaire at pre-injection, 1 month post-injection, and 3 months.

RESULTS

In total, 50 patients were followed for 3 months. The mean reductions in pain were: 15 min (77 %), 1 month (39 %), and 3 months (33 %). The mean reductions in NDI were: 1 month (26 %) and 3 months (also 26 %). Results were statistically significant.

CONCLUSIONS

CT-guided selective cervical nerve root injection in the treatment of cervical radicular pain and related disability produces statistically significant reductions in pain and disability to at least 3 months post-procedure.

Inadvertent Subdural Injection during Cervical Transforaminal Epidural Steroid Injection

Serious complications following cervical epidural steroid injection are rare. Subdural injection of local anesthetic and steroid represents a rare but potentially life threatening complication. A patient presented with left sided cervical pain radiating into the left upper extremity with motor deficit. MRI showed absent lordosis with a broad left paramedian disc-osteophyte complex impinging the spinal cord at C5-6. During C5-6 transforaminal epidural steroid injection contrast in AP fluoroscopic view demonstrated a subdural contrast pattern. The needle was withdrawn slightly and repositioned. Normal lateral epidural and nerve root contrast pattern was subsequently obtained and injection followed with immediate improvement in radicular symptoms. There were no postoperative complications on subsequent clinic follow-up. The subdural space is a potential space between the arachnoid and dura mater. As the subdural space is larger in the cervical region, there may be an elevated potential for inadvertent subdural injection. Needle placement in the cervical subdural space during transforaminal injection is uncommon. Failure to identify aberrant needle entry within the cervical subdural space may result in life threatening complications. We recommend initial injection of a limited volume of contrast agent to detect inadvertent subdural space placement.

Three-dimensional kinematic stress magnetic resonance image analysis shows promise for detecting altered anatomical relationships of tissues in the cervical spine associated with painful radiculopathy

For some patients with radiculopathy a source of nerve root compression cannot be identified despite positive electromyography (EMG) evidence. This discrepancy hampers the effective clinical management for these individuals. Although it has been well-established that tissues in the cervical spine move in a three-dimensional (3D) manner, the 3D motions of the neural elements and their relationship to the bones surrounding them are largely unknown even for asymptomatic normal subjects. We hypothesize that abnormal mechanical loading of cervical nerve roots during pain-provoking head positioning may be responsible for radicular pain in those cases in which there is no evidence of nerve root compression on conventional cervical magnetic resonance imaging (MRI) with the neck in the neutral position. This biomechanical imaging proof-of-concept study focused on quantitatively defining the architectural relationships between the neural and bony structures in the cervical spine using measurements derived from 3D MR images acquired in neutral and pain-provoking neck positions for subjects: (1) with radicular symptoms and evidence of root compression by conventional MRI and positive EMG, (2) with radicular symptoms and no evidence of root compression by MRI but positive EMG, and (3) asymptomatic age-matched controls. Function and pain scores were measured, along with neck range of motion, for all subjects. MR imaging was performed in both a neutral position and a pain-provoking position. Anatomical architectural data derived from analysis of the 3D MR images were compared between symptomatic and asymptomatic groups, and the symptomatic groups with and without imaging evidence of root compression. Several differences in the architectural relationships between the bone and neural tissues were identified between the asymptomatic and symptomatic groups. In addition, changes in architectural relationships were also detected between the symptomatic groups with and without imaging evidence of nerve root compression. As demonstrated in the data and a case study the 3D stress MR imaging approach provides utility to identify biomechanical relationships between hard and soft tissues that are otherwise undetected by standard clinical imaging methods. This technique offers a promising approach to detect the source of radiculopathy to inform clinical management for this pathology.

Must we discontinue selective cervical nerve root blocks? Report of two cases and review of the literature

We report two detrimental neurologic complications after technically correct selected cervical nerve root blocks. Based on these cases and a thorough review of the literature, the indication for cervical nerve root blocks was reconsidered and limited. Similarly, we modified our technique to further reduce the likelihood for the occurrence of such severe complications.

Safety and efficacy of CT-guided transforaminal cervical epidural steroid injections using a posterior approach

BACKGROUND AND PURPOSE

Image-guided cervical transforaminal epidural injections play an important role in the management of cervical radicular pain syndromes. The safety and efficacy of these injections via an anterolateral approach has been well-studied. The goal of this retrospective review was to determine the safety and efficacy of CT-guided transforaminal epidural injections by using a posterior approach.

MATERIALS AND METHODS

Retrospective review of patient records was used to define VNPS and RMDI of patients undergoing CT-guided transforaminal cervical epidural injections between 2006 and 2010. Pain scores were recorded preprocedure, immediately postprocedure, at 2 weeks, and at 2 months. The RMDI was recorded preprocedure, at 2 weeks, and at 2 months. Data analysis of 247 patients was completed. Differences in VNPS scores and the RMDI were then compared on the basis of a CT-guided approach (anterolateral versus posterior).

RESULTS

There was no statistical difference in the degree of pain relief and improvement in the RMDI between the CT-guided transforaminal anterolateral approach and the posterior approach at 2 weeks and at 2 months. Both groups demonstrated a statistically significant improvement in pain scores and the RMDI. Approximately 35% of patients in both groups demonstrated >50% pain relief at 2 months. There were no serious complications in either group.

CONCLUSIONS

CT-guided transforaminal cervical epidural injections by using a posterior approach are safe and effective.

CT-guided cervical nerve root injections: comparing the immediate post-injection anesthetic-related effects of the transforaminal injection with a new indirect technique

OBJECTIVE

To describe an "indirect" cervical nerve root injection technique with a dorsal approach that should carry less inherent risk than the "direct" cervical transforaminal injection approach, and to compare the immediate post-injection results of the two procedures.

MATERIALS AND METHODS

The indirect and direct cervical nerve root injection procedures are described in detail. Fifty-three consecutive patients receiving the indirect nerve root injections during 2009-2010 were age- and gender-matched to 53 patients who underwent direct transforaminal nerve root injections performed in 2006. Pain level data were collected immediately before and 20-30 min after each procedure. The percentages of pain change in the two groups were compared using the unpaired Student's t test.

RESULTS

Fifty-two men (mean age 49) and 54 women (mean age 55) were included. The mean percentage of pain reduction for patients receiving indirect nerve root injections was 38.4% and for those undergoing the direct nerve root injections approach it was 43.2%. This was not significantly different (P = 0.455). No immediate or late adverse effects were reported after either injection procedure.

CONCLUSIONS

The indirect cervical nerve root injection procedure is a potentially safer alternative to direct cervical transforaminal nerve root injections. The short-term pain reduction is similar using the two injection methods.

Ultrasound-guided cervical nerve root block: spread of solution and clinical effect

OBJECTIVES

We investigated the clinical effects and accuracy of ultrasound-guided cervical nerve root block. Additionally, spinal level and spread of injected solution were confirmed by anatomic dissection of fresh cadavers. DESIGN SETTING, PATIENTS, AND INTERVENTIONS: Twelve patients diagnosed with mono-radiculopathy between C5-7 underwent ultrasound-guided nerve root block. An insulated needle was advanced with an in-plane approach using nerve stimulation and 2 mL of 0.375% ropivacaine with 4 mg of dexamethasone was injected using nerve stimulation. Ultrasound-guided C5-7 nerve root block was also performed in ten fresh cadavers. Blue dye (2 mL) was injected onto each nerve root and anatomic dissection was performed to confirm the exact spinal level and spread pattern of the dye.

RESULTS

  Pain score before the procedure (65 [46-80], median [interquartile range]) was decreased to 25 [3-31] at 24 hours (P = 0.003) and 40 [28-66] at 30 days (P = 0.02) after the root block. Obvious side effects were not seen. All target nerve roots in patients and cadavers were correctly identified by ultrasound imaging. The needle tip did not reach the pedicle of the vertebral arch in the anteroposterior view of fluoroscopy, and spread pattern of contrast medium was extraforaminal and extraneural.

CONCLUSIONS

This study suggests that injected solution by ultrasound-guided cervical nerve root block mainly spreads to the extraforaminal direction compared with conventional fluoroscopic technique. Therefore, present clinical study involves possibility of safer selective nerve root block with sufficient analgesic effects by ultrasound guidance, despite the absence of intraforaminal epidural spread of solution.

Comparison of clinical effectiveness of cervical transforaminal steroid injection according to different radiological guidances (C-arm fluoroscopy vs. computed tomography fluoroscopy)

BACKGROUND CONTEXT

Transforaminal steroid injection using C-arm fluoroscopy has been regarded as a useful method of treatment for cervical herniated disc. But C-arm fluoroscopy cannot identify soft tissue; so there is controversy about its safety and efficacy. Computed tomography (CT) fluoroscopy permits precise anatomical resolution and has the potential to offer a safer technique compared with C-arm fluoroscopy.

PURPOSE

This study was to identify the clinical effectiveness of CT fluoroscopy guidance in cervical transforaminal steroid injection compared with C-arm fluoroscopy guidance.

STUDY DESIGN/SETTING

Prospective randomized controlled study/spine hospital. PATIENTS SAMPLE: Patients with neck pain and radiating upper limb pain resulting from cervical disc herniation participated in the study. They were allocated into either the CT (CT group, N=51) or C-arm (C group, N=65) fluoroscopy guidance group.

OUTCOME MEASURE

Numeric Rating Scale (NRS) pain score and Neck Disability Index (NDI) values were measured at pretreatment and 8 weeks after treatment. Successful pain relief and functional improvement were defined as a 50% or more reduction in NRS and at least 40% reduction in NDI compared with pretreatment one. Numeric Rating Scale and NDI efficiency were also calculated by the difference between pre and 8 weeks after treatment to validate the degree of change in pain reduction and functional improvement.

RESULTS

After 8 weeks, both groups showed pain reduction and functional improvement. The CT group showed significantly the better outcomes in reduction of NRS for arm pain score and improvement of NDI. Whereas the CT group had no cases of side effects, the C group had 10 cases.

CONCLUSIONS

The CT group, without any side effects, showed the better effectiveness than the C-arm group in the improvement of radiating pain and functional status in patients with cervical disc herniation. Therefore, CT fluoroscopy can be a substitute for C-arm fluoroscopy in transforaminal steroid injection when treating patients with cervical disc herniation.

CT-guided cervical selective nerve root block with a dorsal approach

BACKGROUND AND PURPOSE

Cervical transforaminal blocks are frequently performed to treat cervical radicular pain. These blocks are performed mostly under fluoroscopy, but a CT-guided technique has also been described. The aim of this study was to review the results of CT-guided CSNRB by using a dorsal approach, to describe the contrast patterns achieved with this injection technique, and to estimate the degree of specificity and sensitivity.

MATERIALS AND METHODS

We used a CT-guided technique with a dorsal approach leading to a more extra-than transforaminal but a selective nerve root block as well. Of 53 blocks, we performed 38 for diagnostic and 15 for therapeutic indications. Pain relief was measured hourly on a VAS. The distribution of contrast and the angle of the trajectory of the injection needle were analyzed as well as the degree of pain relief.

RESULTS

Contrast was found in the intraforaminal region in 8 (15%) blocks, extraforaminally in 40 (78%) blocks, and intraspinally in 3 (6%) blocks. The mean angle between the needle and the sagittal plane was 26.6° (range, from 1° to 50°). The mean distance between needle tip and nerve root was 4.43 mm (range, 0-20 mm). Twenty-six (68.4%) of the 38 diagnostic blocks led to a decrease in the pain rating of >50%. There were no complications or unintended side effects, apart from occasional local puncture pain.

CONCLUSIONS

We conclude that CT-guided CSNRBs using a dorsal approach are feasible and that they are sensitive and specific.

A patient-mount navigated intervention system for spinal diseases and its clinical trial on percutaneous pulsed radiofrequency stimulation of dorsal root ganglion

STUDY DESIGN

Development of a patient-mount navigated intervention (PaMNI) system for spinal diseases. An in vivo clinical human trial was conducted to validate this system.

OBJECTIVE

To verify the feasibility of the PaMNI system with the clinical trial on percutaneous pulsed radiofrequency stimulation of dorsal root ganglion (PRF-DRG).

SUMMARY OF BACKGROUND DATA

Two major image guiding techniques, i.e., computed tomography (CT)-guided and fluoro-guided, were used for spinal intervention. The CT-guided technique provides high spatial resolution, and is claimed to be more accurate than the fluoro-guided technique. Nevertheless, the CT-guided intervention usually reaches higher radiograph exposure than the fluoro-guided counterpart. Some navigated intervention systems were developed to reduce the radiation of CT-guided intervention. Nevertheless, these systems were not popularly used due to the longer operation time, a new protocol for surgeons, and the availability of such a system.

METHODS

The PaMNI system includes 3 components, i.e., a patient-mount miniature tracking unit, an auto-registered reference frame unit, and a user-friendly image processing unit. The PRF-DRG treatment was conducted to find the clinical feasibility of this system.

RESULTS

The in vivo clinical trial showed that the accuracy, visual analog scale evaluation after surgery, and radiograph exposure of the PaMNI-guided technique are comparable to the one of conventional fluoro-guided technique, while the operation time is increased by 5 minutes.

CONCLUSION

Combining the virtues of fluoroscopy and CT-guided techniques, our navigation system is operated like a virtual fluoroscopy with augmented CT images. This system elevates the performance of CT-guided intervention and reduces surgeons' radiation exposure risk to a minimum, while keeping low radiation dose to patients like its fluoro-guided counterpart. The clinical trial of PRF-DRG treatment showed the clinical feasibility and efficacy of this system.

A Whitacre-type spinal needle does not prevent intravascular injection during cervical nerve root injections

We present a case of intravascular injection in a 41-year-old female during cervical selective nerve root injection using a 22-gauge 3.5-inch Whitacre-type pencil-point subarachnoid needle with a curve placed at the distal tip positioned using continual live fluoroscopic guidance. After negative aspiration for blood and cerebrospinal fluid and no elicited paresthesias during the procedure, 1 mL of contrast was injected. Initial imaging at C6 captured the outline of the nerve root along with a significant amount of transient vascular runoff. This case report demonstrates that Whitacre-type spinal needles do not prevent vascular injection, and that aspiration of the needle is not a reliable sign of intravascular injection.

Cervical nerve injection: computed tomography guidance with intravenous contrast and extraforaminal needle placement. Series of seven consecutive case reports

BACKGROUND CONTEXT

Image-guided cervical nerve injections are being performed with increasing frequency. Severe complications are being reported.

PURPOSE

The purpose of this study is to introduce a technique for cervical nerve injection that may decrease the possibility for severe complications.

STUDY DESIGN/SETTING

This is a series of case reports describing the technique and clinical follow-up.

PATIENT SAMPLE

The sample comprises seven consecutive cases of unilateral neck and arm pain referred for cervical nerve injection.

OUTCOME MEASURES

Retrospective evaluation of pain relief before and after the injection and at follow-up is reported as case studies.

METHODS

The technique for computed tomography guided cervical nerve injection is described with case reports of seven consecutive patients.

RESULTS

The results are case reports of each of the seven patients after unilateral cervical nerve injection.

CONCLUSION

A technique for cervical nerve injection is described with the results of the injection. This technique may allow some standardization in the procedure, decrease the learning curve for training physicians, and minimize the potential complications.

Evidence-based radiology (part 1): Is there sufficient research to support the use of therapeutic injections for the spine and sacroiliac joints?

INTRODUCTION

This review article addresses the best evidence currently available for therapeutic injection therapy for conditions targeting the spine and sacroiliac joints. The article is presented by spinal region. Controversies and areas of interest for further studies are identified.

DISCUSSION

There is conclusive evidence supporting the effectiveness of the caudal approach for the administration of epidural steroid injections for patients with low back pain from a variety of causes. In general, there is moderate-to-strong evidence supporting the use of transforaminal therapeutic epidural injections for lumbar nerve-root compression and facet injections for joint pain arising from these joints in the cervical, thoracic and lumbar spine, but further subgroup analysis is needed to help predict which specific patients may receive the most benefit from these procedures.

CONCLUSION

No randomized controlled trials, meta-analyses or systematic reviews addressing the effectiveness of therapeutic sacroiliac joint injections have been found. For some injections, corticosteroids may not provide better outcomes compared to local anesthetic injections alone.

Complications of transforaminal cervical epidural steroid injections

STUDY DESIGN

A comprehensive literature review.

OBJECTIVES

To review and critically evaluate the past literature focusing on incidence and clinical presentation of complications associated with transforaminal cervical epidural steroid injection (TFCESI) and techniques employed to avoid them. The overall goal is to guide the direction of future research and improve clinical care by increasing awareness of complications and measures that may be undertaken to increase safety.

SUMMARY OF BACKGROUND DATA

TFCESI is a component in the diagnosis and management of cervical radicular syndromes in patients who have failed conservative management. There has been much discussion and also controversy in the recent literature. Considerable attention has been paid to reports of catastrophic complications and proposed measures to avoid them.

METHODS

Medical databases were searched for studies of TFCESI. The bibliographies of these articles were then searched as well. Thoracic and lumbar articles were discarded as were any non-transforaminal cervical procedures or those that did not involve injection into the epidural space. Particular attention was paid to serious neurologic sequelae after TFCESI and its mechanism, as well as techniques being employed to avoid complications.

RESULTS

There are a limited number of studies looking at complications of TFCESI. One retrospective study reported an overall rate of complications of 1.64%. There are reports of serious neurologic sequelae in the literature including brain and spinal cord infarction due to embolic phenomenon of particulate steroids. Cadaveric dissection revealed ascending and deep cervical arterial branches entering the external opening of the posterior intervertebral foramen, the classic target site for TFCESI. Measures to avoid complications mentioned in the literature include the use of nonparticulate steroids, test dose of local anesthetic before injection of steroids, live fluoroscopy, digital subtraction, no to light sedation, use of true lateral view to supplement frontal and oblique views in fluoroscopy, use of blunt needles, and computed tomography guidance.

CONCLUSION

The literature reveals a number of rare, potentially catastrophic neurologic sequelae including brain and spinal cord infarction. Most of these are thought to be due to intravascular uptake of particulate steroids. The true overall incidence remains obscure due to the lack of blinded controlled studies. Injectionists, referring physicians, and patients should be aware of the nature and potential consequences of these complications. Additionally, it is imperative for injectionists to standardize techniques to minimize complications, especially by using a test dose of local anesthetic before injection of preferably nonparticulate corticosteroid.

Spinal injection procedures: a review of concepts, controversies, and complications

The field of spinal injection procedures is growing at a tremendous rate. Many disciplines are involved, including radiology, anesthesiology, orthopedics, physiatry and rehabilitation medicine, as well as other specialties. However, there remains tremendous variability in the assessment of patients receiving these therapies, methods for evaluation of outcome, and in the understanding of where these procedures belong in the triaging of those who require surgery. In this article, we attempt to highlight the biologic concepts on which these therapies are based, controversies that have arisen with their increasing use, and a description of complications that have been reported.

Efficacy and durability of fluoroscopically guided cervical nerve root block

The objective of the study was to assess the long-term efficacy of fluoroscopically-guided cervical nerve root block as a non-surgical treatment for cervical radicular pain. This was a retrospective study of 19 consecutive patients who had undergone cervical nerve root blocks over a period of 18 months, at a regional neurosurgery referral centre in the UK. Two of these patients underwent a second procedure; therefore, the number of total nerve root blocks was 21. Data regarding age, sex and diagnosis were obtained from medical records. MR reports formed the basis for imaging findings. Patients were contacted by telephone and post in order to obtain information about their 'pain relief. This was measured by using a 100-point Visual Analogue Scale (VAS). Four points in time were chosen in order to determine the time course of pain relief, i.e. before procedure, at 2 weeks, at 2 months and at 6 months following the procedure. Mean VAS scores at 6 month follow-up were broken up into 3 categories to indicate the level of pain relief. These categories were: VAS decrease of less than 20 points indicating no relief (12 procedures, 57.1%); VAS decrease 20 - 40 points, i.e. moderate relief (three procedures, 14.3%); VAS decrease of greater than 40 points, i.e. significant relief (six procedures, 28.6%). CNRB has limited efficacy for definitive treatment of nerve root pain, but may lead to significant short term relief, in a subgroup of such patients.

Selective cervical nerve root blockade: experience with a safe and reliable technique using an anterolateral approach for needle placement

BACKGROUND AND PURPOSE

[corrected] Our aim was to evaluate the safety and clinical utility of a fluoroscopically guided anterolateral oblique approach technique for outpatient diagnostic and therapeutic selective cervical nerve root blockade (SCNRB).

MATERIALS AND METHODS

During a 13-year period (1994 through February 2007), 4612 patients underwent fluoroscopically guided diagnostic and/or therapeutic extraforaminal SCNRB by using an anterior oblique approach at affiliated outpatient imaging centers. Each procedure was performed by 1 of 6 procedural radiologists, all highly experienced in and actively performing spinal injections on a full-time basis in clinical practice. All of the proceduralists were thoroughly experienced with lumbar injections before endeavoring to perform SCNRBs. Nonionic contrast was injected in nearly all patients (except isolated patients with contrast allergy), and a minimum of 2 projection filming procedures were performed to document the accuracy of needle placement and contrast dispersal before the injection of therapeutic substances. All clinically significant complications beyond skin discoloration and temporary exacerbation of symptoms were recorded.

RESULTS

There were no serious neurologic complications, such as stroke, spinal cord insult, or permanent nerve root deficit. One life-threatening anaphylactic reaction occurred and was attributed to the injected materials and not the specific procedure itself. Another patient had a 3- to 4-minute grand mal seizure, from which he fully recovered within 30 minutes. There were no infections.

CONCLUSION

The technique we describe for fluoroscopically guided SCNRB is a useful and safe outpatient procedure when performed by skilled and experienced proceduralists.

Infiltrations, blocs et neurolyses en pathologie ostéo-articulaire

Computed Tomography fluoroscopy for blocks and neurolysis provides a minimally-invasive, accurate and rapid alternative to surgery. Spinal and peri-spinal ultrasound-guided procedures, excluding peripheral procedures, will be discussed as well. The imaging-guided procedures discussed are performed using small needles. These percutaneous procedures must be performed with maximum patient comfort and cause as little complications as possible. These procedures should be performed by an experienced radiologist after discussion with the treating clinician.

Cervical transforaminal epidural steroid injections: more dangerous than we think?

STUDY DESIGN

Survey/case series.

OBJECTIVE

To survey pain physicians about neurologic infarctions following cervical transforaminal epidural steroid injections (TF-ESIs).

SUMMARY OF BACKGROUND DATA

Cervical TF-ESIs are commonly performed in patients with cervical radiculopathy, although there are no randomized controlled studies supporting their efficacy. Eight case reports of brain and spinal cord infarction have been published. In addition, one of the investigators (M.S.W.) has reviewed 4 cases of major cerebellum/brainstem infarction following cervical TF-ESIs with methylprednisolone.

METHODS

To better characterize these complications, anonymous surveys were sent to all U.S. physician members of the American Pain Society. Respondents were asked about awareness of complications, year of occurrence, practice setting and specialty of the treating physician, use of fluoroscopy/contrast/local anesthetic/corticosteroid, doses administered, and CT/MRI/autopsy findings.

RESULTS

Overall response rate was 21.4% (287 of 1340). In all, 78 complications were reported, including 16 vertebrobasilar brain infarcts, 12 cervical spinal cord infarcts, and 2 combined brain/spinal cord infarcts. Brain infarcts invariably involved the cerebellum, brainstem, or posterior cerebral artery territory. Thirteen cases resulted in a fatal outcome: 5 with brain infarcts, 1 with combined brain/spinal cord infarcts, 1 following high spinal anesthesia, 1 associated with a seizure, and 5 with unspecified etiology. All 4 cases with corticosteroid alone involved methylprednisolone, resulting in 3 cerebellar infarcts and 1 posterior cerebral territory infarct. Of these, 3 had fatal outcomes and 2 autopsies revealed no vertebral artery trauma.

CONCLUSIONS

This study demonstrates a significant risk of serious neurologic injury after cervical TF-ESIs. A growing body of evidence supports an embolic mechanism, whereby inadvertent intra-arterial injection of particulate corticosteroid causes a distal infarct. Embolism to the distal basilar artery region can cause midbrain, pons, cerebellum, thalamus, temporal and occipital lobe infarctions. Other potential mechanisms of infarction include vertebral artery perforation causing dissection/thrombosis and needle-induced vasospasm.

Cerebellar and brainstem infarction as a complication of CT-guided transforaminal cervical nerve root block

A 60-year-old man with a 4-year history of intractable neck pain and radicular pain in the C5 nerve root distribution presented to our department for a CT-guided transforaminal left C5 nerve root block. He had had a similar procedure on the right 2 months previously, and had significant improvement of his symptoms with considerable pain relief. On this occasion he was again accepted for the procedure after the risks and potential complications had been explained. Under CT guidance, a 25G spinal needle was introduced and after confirmation of the position of the needle, steroid was injected. Immediately the patient became unresponsive, and later developed a MR-proven infarct affecting the left vertebral artery (VA) territory. This is the first report of a major complication of a cervical root injection under CT guidance reported in the literature. We present this case report and the literature review of the potential complications of this procedure.

Transforaminal steroid injections for the treatment of cervical radiculopathy: a prospective and randomised study

Steroid injections are often employed as an alternative treatment for radicular pain in patients with degenerative spinal disorders. Prospective randomised studies of the lumbar spine reveal contradictory results and non-randomised and most often retrospective studies of the cervical spine indicate pain reduction from steroid injections. No prospective randomised study on transforaminal steroid injections for the treatment of radicular pain in the cervical spine focusing on short-term results has been performed. Forty consecutive patients were employed for the study. The inclusion criteria were one-sided cervical radiculopathy with radicular distribution of arm pain distal to the elbow and corresponding significant degenerative pathology of the cervical spine at one or two levels on the same side as the radicular pain and visualised by MRI. A transforaminal technique was used for all injections. A positive response to a diagnostic selective nerve root block at one or two nerve roots was mandatory for all patients. The patients were randomised for treatment with steroids/local anaesthetics or saline/local anaesthetic. Only the neuroradiologist performing the blocks was aware of the content of the injection; all other persons involved in the study were blinded. Follow up was made 3 weeks after the randomised treatment by a clinical investigation and with a questionnaire focusing on the subjective effects from the injections. At follow up, there were no differences in treatment results in the two patient groups. Statistical analysis of the results confirmed the lack of difference in treatment effect. Further studies have to be performed before excluding steroids in such treatment and for evaluating the influence of local anaesthetics on radiculopathy in transforaminal injections.

Injection studies in spinal disorders

Spinal injections have an important role in many centers in the diagnostic assessment and treatment of patient with various spinal disorders. In the literature, many studies describe the application, techniques, and potential benefit of spinal infections. It is well accepted morphologic alterations and pain correlate weakly because many imaging findings in patients with spinal symptoms can be found in asymptomatic individuals. Accordingly, one rationale for spinal injections is to provoke or eliminate pain presumably caused by the target spinal structure; this ostensibly allows a physician to make a better assessment of whether a particular morphologic alteration does or does not cause symptoms. Another rationale is to use spinal injections to support conservative treatment in patients who have from nerve root compromise, spinal stenosis, or facet joint osteoarthritis. Despite the widespread use of these spinal injections, their application is based widely on anecdotal experience and evidence that is not evidence based. We highlight the need for prospective randomized trials on the clinical efficiency of spinal injections and stress the importance for future considerations of cost effectiveness to justify their further application.

LEVEL OF EVIDENCE

Level V (expert opinion). See the Guidelines for Authors for a complete description of the levels of evidence.

Distribution patterns of transforaminal injections in the cervical spine evaluated by multi-slice computed tomography

Transforaminal injections are sometimes used for the diagnosis and treatment of painful conditions in the lumbar and to a lesser degree in the cervical spine. The technique is most often used when investigating/treating radiculopathy caused by degenerative disease. But how selective are the nerve root blocks? What possible structures other than the intended nerve root are affected from such injections? This study was undertaken in order to try to answer these questions, as no study focusing on the possible spread from the transforaminal selective nerve root blocks in the cervical spine has been performed earlier. In three groups of patients, each group including three patients, we injected three different volumes (0.6, 1.1 and 1.7 ml) with a transforaminal technique in the cervical spine. In all the injections, a small amount of contrast media was added. The spread of the injections were then investigated using multi-slice computed tomography with reconstructions. The imaging revealed a possible effect on other nerve roots than the intended ones when a larger volume was used for the root blocks. The spread was related to the injected volume as well as to local anatomy (size of foraminal area). In this study, only 0.6-ml injections could be accepted for being selective enough for diagnostic investigations.

Relationship between Northwick Park neck pain questionnaire and cervical spine MR imaging findings

The study was aimed at determining the association between the self-report of pain and disability by means of Northwick neck pain questionnaire (NPQ) and cervical spine MR imaging findings. A random sample of 251 patients, 132 men and 119 women aged 43+/-13 years, submitted with neck pain were investigated. Patients with previous discitis, surgery, neoplasm or hospitalized for cervical spine trauma were excluded. All patients completed the NPQ and were studied with sagittal gradient-echo T1 and turbo spin-echo T2, axial gradient-echo T2* and heavily T2 weighted MR myelographic weighted images. MR images of the two most affected disc levels were read, offering an MR imaging score from 0 to 30. There was no statistically significant correlation between NPQ and MR imaging scores. From the NPQ items, only difficulty in sleeping and numbness were related to the MR imaging score. Disc extrusion was the only MR finding almost significantly associated with NPQ (P=0.054). Neck injury did not increase NPQ scores. In patients with neck pain, NPQ scores do not correlate with MR imaging findings. NPQ and cervical spine MR imaging show different facets of the multidimensional complex of neck pain.