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Cervical CT-Guided, Selective Nerve Root Blocks: Improved Safety by Dorsal Approach
Abstract
Cervical transforaminal blocks are frequently performed as a treatment of cervical radicular pain. These blocks are performed mostly under fluoroscopy, but a CT-guided technique also has been described. We describe a modification that leads to a more extraforaminal than transforaminal and equally selective nerve root block.
... Another alternative to the traditional direct approach for cervical transforaminal CT-guided nerve root injections is a "modified direct" approach, the so-called dorsal approach as described by Wolter et al. [23,24]. With this method the patient lies prone on the table and the needle is inserted posterolateral to the nerve root foramen so that the tip of the needle can be placed directly between the extra-foraminal portion of the nerve root and the facet joint. ...
... With this method the patient lies prone on the table and the needle is inserted posterolateral to the nerve root foramen so that the tip of the needle can be placed directly between the extra-foraminal portion of the nerve root and the facet joint. This dorsal approach, based on extraforaminal rather than transforaminal blocks, is suspected to be less prone to serious adverse effects because puncturing the nerve root artery, the vertebral artery but also the carotid and jugular vessels is less likely compared with the transforaminal nerve root injections for anatomical reasons [23,24]. The technique used in our study is markedly different from the so-called dorsal approach described above because the tip of the needle is not placed in an extra-foraminal position, but rather dorsal to the facet joint and the therapeutic effect originates from drugs that disperse to the extra-foraminal or intra-foraminal portion of the nerve root either initially or a few hours after the injection. ...
... The vertebral artery has also been implicated as the source of needle penetration and hence spinal cord or brain infarction [16][17][18]. Based on the anatomy of the neck, puncture of the nerve root artery, the vertebral artery or the carotid and jugular vessels is extremely unlikely with our indirect cervical nerve root injection approach and we therefore expect this procedure to be safer than the cervical transforaminal approach and the risk of serious adverse effects to still be lower than with the dorsal approach used by Wolter et al. [23,24]. ...
PURPOSE
We describe an ‘indirect’ cervical nerve root block technique that should have less inherent risk than the ‘direct’ transforaminal injection approach. The short-term patient outcomes from a pilot study are reported.
METHOD AND MATERIALS
Institutional board approval and informed consent were obtained. The new 'indirect' cervical nerve root block is based on a strictly dorsal approach similar to cervical facet joint injections. Fifty three patients receiving the ‘indirect’ nerve root block injections were age and gender matched to 53 patients having ‘direct’ transforaminal nerve root blocks. Numerical pain scale data was collected immediately before and 20 – 30 minutes after each procedure. The percentage of pain change was calculated and compared between the two groups using the unpaired Student’s t-test.
RESULTS
The mean percentage of pain reduction for patients receiving ‘indirect’ nerve root block injections was 38.4% and for those having the ‘direct’ nerve root block approach it was 43.2%. This was not significantly different (P = .455). No immediate or late adverse effects were reported after the indirect or direct nerve root blocks in our study.
CONCLUSION
The CT-guided ‘indirect’ cervical nerve root block is technically feasible. Short-term pain reduction is similar between the ‘indirect’ and traditional transforaminal injection method.
CLINICAL RELEVANCE/APPLICATION
The ‘indirect’ cervical nerve root block is potentially safer than the ‘direct’ transforaminal cervical nerve root block while featuring a similar short-term pain reduction.
... Another alternative to the traditional direct approach for cervical transforaminal CT-guided nerve root injections is a "modified direct" approach, the so-called dorsal approach as described by Wolter et al. [23,24]. With this method the patient lies prone on the table and the needle is inserted posterolateral to the nerve root foramen so that the tip of the needle can be placed directly between the extra-foraminal portion of the nerve root and the facet joint. ...
... With this method the patient lies prone on the table and the needle is inserted posterolateral to the nerve root foramen so that the tip of the needle can be placed directly between the extra-foraminal portion of the nerve root and the facet joint. This dorsal approach, based on extraforaminal rather than transforaminal blocks, is suspected to be less prone to serious adverse effects because puncturing the nerve root artery, the vertebral artery but also the carotid and jugular vessels is less likely compared with the transforaminal nerve root injections for anatomical reasons [23,24]. The technique used in our study is markedly different from the so-called dorsal approach described above because the tip of the needle is not placed in an extra-foraminal position, but rather dorsal to the facet joint and the therapeutic effect originates from drugs that disperse to the extra-foraminal or intra-foraminal portion of the nerve root either initially or a few hours after the injection. ...
... The vertebral artery has also been implicated as the source of needle penetration and hence spinal cord or brain infarction [16][17][18]. Based on the anatomy of the neck, puncture of the nerve root artery, the vertebral artery or the carotid and jugular vessels is extremely unlikely with our indirect cervical nerve root injection approach and we therefore expect this procedure to be safer than the cervical transforaminal approach and the risk of serious adverse effects to still be lower than with the dorsal approach used by Wolter et al. [23,24]. ...
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.
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.
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.
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.
... We believe it critical to point out that, the FDA has missed significant and valuable literature and a multitude of techniques with alternate approaches and other preventive modalities instead of focusing on only limited aspects (49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)66,67). ...
... www.painphysicianjournal.com also anatomic considerations, technical considerations, alternate approaches, and limited effectiveness of cervical transforaminal epidural injections in the diagnosis and therapy of cervical radicular pain syndromes (16,(36)(37)(38)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62)(63)(64)(65)66,71,70,72,76,95,(121)(122)(123)(124)(125)(126)(133)(134)(135)(136)(137)139,(141)(142)(143)(144)(145)(147)(148)(149)152,(154)(155)(156)(157)(158)162,163,(167)(168)(169)(170)(171)(173)(174)(175)(180)(181)(182)(183)(184)187,188,190) Mechanisms of brain injury and spinal cord infarction that have been suggested to account for the brain and spinal cord infarctions include the leading hypothesis that inadvertent intraarterial injection of particulate corticosteroid creates an embolus, causing a distal infarct (18,22,66,71,72,84,92,191). In addition to infarction, a variety of other complications were reported which include vasospasm, ischemic events, cortical blindness, high spinal anesthesia, and seizures. ...
On April 23, 2014, the Food and Drug Administration (FDA) issued a letter of warning that injection of corticosteroids into the epidural space of the spine may result in rare, but serious adverse events, including "loss of vision, stroke, paralysis, and death." The advisory also advocated that patients should discuss the benefits and risks of epidural corticosteroid injections with their health care professionals, along with the benefits and risks associated with other possible treatments. In addition, the FDA stated that the effectiveness and safety of the corticosteroids for epidural use have not been established, and the FDA has not approved corticosteroids for such use. To raise awareness of the risks of epidural corticosteroid injections in the medical community, the FDA's Safe Use Initiative convened a panel of experts including pain management experts to help define the techniques for such injections with the aim of reducing preventable harm. The panel was unable to reach an agreement on 20 proposed items related to technical aspects of performing epidural injections. Subsequently, the FDA issued the above referenced warning and a notice that a panel will be convened in November 2014. This review assesses the inaccuracies of the warning and critically analyzes the available literature. The literature has been assessed in reference to alternate techniques and an understanding of the risk factors when performing transforaminal epidural injections in the cervical, thoracic, and lumbar regions, ultimately resulting in improved safety. The results of this review show the efficacy of epidural injections, with or without steroids, in a multitude of spinal ailments utilizing caudal, cervical, thoracic, and lumbar interlaminar approaches as well as lumbar transforaminal epidural injections . The evidence also shows the superiority of steroids in managing lumbar disc herniation utilizing caudal and lumbar interlaminar approaches without any significant difference as compared to transforaminal approaches, either with local anesthetic alone or local anesthetic and steroids combined. In conclusion, the authors request that the FDA modify the warning based on the evidence.
... 8 CT guidance offers the advantage of enhanced anatomic resolution with a more precise needle-tip positioning. 9 It is, however, seen as more time-consuming and likely to involve more radiation exposure. In both fluoroscopic and CT-guided CSNRBs, the aim is to block the root in the foramen. ...
... Recently, the technique has been described in a technical note, but no information was supplied regarding the patterns of contrast distribution, the angle of the trajectory, the distance between the needle tip and the nerve root, and pain relief after the block. 9 In the present study, the angle of the needle toward the sagittal plane correlated with the distance between the needle tip and the foramen and the distance between the needle tip and the nerve root but not with the distribution of contrast. The pattern of contrast distribution did not correlate with either a positive or negative response to the nerve block. ...
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.
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.
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.
We conclude that CT-guided CSNRBs using a dorsal approach are feasible and that they are sensitive and specific.
... In 2009, Wolter et al. [29] first reported on the dorsal approach (Fig. 5A). A year later, they used the same approach to perform dorsal cervical SNRB in 53 patients [30]. ...
Cervical spondylotic radiculopathy (CSR) is one of the most common degenerative diseases of the spine that is commonly treated with surgery. The primary goal of surgery is to relieve symptoms through decompression or relieving pressure on compressed cervical nerves. Nevertheless, cutaneous pain distribution is not always predictable, making accurate diagnosis challenging and increasing the likelihood of inadequate surgical outcomes. With the widespread application of minimally invasive surgical techniques, the requirement for precise preoperative localization of the affected segments has become critical, especially when treating patients with multi-segmental CSR. Recently, the preoperative use of a selective nerve root block (SNRB) to localize the specific nerve roots involved in CSR has increased. However, few reviews discuss the currently used block approaches, risk factors, and other aspects of concern voiced by surgeons carrying out SNRB. This review summarized the main cervical SNRB approaches currently used clinically and the relevant technical details. Methods that can be used to decrease risk during cervical SNRB procedures, including choice of steroids, vessel avoidance, guidance with radiographs or ultra-sound, contrast agent usage, and other concerns, also are discussed. We concluded that a comprehensive understanding of the current techniques used for cervical SNRB would allow surgeons to perform cervical SNRB more safely.
... Cho describes a method that utilizes an extraforaminal technique with CT guidance (Cho, 2010). Wolter et al. discuss positioning the patient prone versus supine allowing them to place the needle extraforaminally from a dorsal approach (Wolter, Mohadjer, Berlis, et al., 2009). Finally, Wagner and Cyteval et al. describe an approach where the needle is located at the outer edge of the posterior foramen (Cyteval, Thomas, Decoux, et al., 2004;Wagner, 2005). ...
Computed Tomography-guided procedures for epidural injections
... Steroids also work by reducing the activity of the immune system to react to inflammation associated with nerve or tissue damage [7]. Imaging-guided techniques with fluoroscopy or computed tomography increase the precision of the injection procedures and help confirm needle placement [8]. ...
Aim of the work: To assess the efficacy of CT-guided transforaminal epidural steroid injection (CT-TFESI) as compared to vertebral axial decompression (VAX-D), the combined effect of both and medical treatment in the management of acute lumbar disc herniation.
Patients and methods: Forty-eight patients complaining of low back pain (LBP) with radicular symptoms due to lumbar disc herniation (
... The 2004 Spine Intervention Society practice guidelines for cervical NRB recommended intraforaminal positioning of the needle tip as deep as the midpoint of articular pillars but never deeper than a vertical line connecting the uncinate processes (117). After reports of catastrophic neurologic injuries from cervical NRBs, some investigators recommended protocol modifications (55,75,92,(118)(119)(120). Potentially safer techniques include extraforaminal needle placement, a lateral or posterior approach, digital At S1, the needle (N4) crosses the posterior S1 foramen and enters the epidural space inferior to the S1 pedicle. ...
Image-guided spinal injection is commonly performed in symptomatic patients to decrease pain severity, confirm the pain generator, and delay or avoid surgery. This article focuses on the radiologist as spine interventionist and addresses the following four topics relevant to the radiologist who performs corticosteroid injections for pain management: (a) the rationale behind corticosteroid injection, (b) the interaction with patients, (c) the role of imaging in procedural selection and planning, and (d) the pearls and pitfalls of fluoroscopically guided injections. Factors that contribute to the success of a pain management service include communication skills and risk mitigation. A critical factor is the correlation of clinical symptoms with magnetic resonance (MR) imaging findings. Radiologists can leverage their training in MR image interpretation to distinguish active pain generators in the spine from incidental abnormalities. Knowledge of fluoroscopic anatomy and patterns of contrast material flow guide the planning and execution of safe and effective needle placement.
... Some assume that a relatively deep position, with the needle tip within the outer neural foramen and immediately adjacent to the targeted nerve root, is required for proper analgesic and steroid efficacy, 3,10,18 while others advocate a more cautious, extraforaminal needle tip position to minimize the risk of complications. 8,19,20 Junctional and foraminal needle tip positions have been previously shown to have higher rates of foram- inal contrast flow compared with the extraforaminal needle position, 10 though contrast dispersal pattern was shown not to correlate with pain relief in 1 study. 21 To our knowledge, we are the first to observe, on CT-guided TFESI, contrast appearing within vessels during steroid/analgesic cocktail injection, a finding we believe depicts intravascular injection of steroid and analgesic. ...
Background and purpose:
Cervical transforaminal epidural steroid injections are commonly performed for temporary pain relief or diagnostic presurgical planning in patients with cervical radiculopathy. Intravascular injection of steroids during the procedure can potentially result in cord infarct, stroke, and even death. CT-fluoroscopy allows excellent anatomic resolution and precise needle positioning. This study sought to determine the safest needle tip position during CT-guided cervical transforaminal epidural steroid injection as determined by the incidence of intravascular injection.
Materials and methods:
We retrospectively evaluated procedural imaging for consecutive single-site CT-fluoroscopic cervical transforaminal epidural steroid injection performed during a 13-month period. Intravascular injections were identified and classified by volume, procedure phase, vessel type, and needle tip position relative to the targeted neural foramen. ANOVA, Wilcoxon, or Pearson χ(2) testing was used to assess differences among groups as appropriate.
Results:
Intravascular injections occurred in 49/201 (24%) procedures. Of the intravascular injections, 13/49 (27%) were large, 10/49 (20%) were small, and 26/49 (53%) were trace volume. Sixteen of 49 (33%) intravascular injections occurred with a trial contrast dose; 27/49 (55%), with a steroid/analgesic cocktail; and 6/49 (12%), with both. Twenty-seven of 49 (55%) intravascular injections were likely venous, 22/49 (45%) were indeterminate, and none were likely arterial. The intravascular injection rate was significantly lower (P < .001) for the extraforaminal needle position (8/82, 10%) compared with junctional (27/88, 31%) and foraminal (14/31, 45%) needle tip positions.
Conclusions:
An extraforaminal needle position for CT-guided cervical transforaminal epidural steroid injection decreases the risk of intravascular injection and therefore may be safer than other needle tip positions.
... Different technique including Fluoroscopy, CT and US guidance have been in use for cervical nerve root blocks. [21][22][23][24] In our study, all the cases were performed under fluoroscopic guidance. ...
Objective: It is often difficult to pinpoint the affected nerve root/roots from clinical symptoms and Magnetic Resonance Imaging (MRI) alone in patients with chronic cervical radiculopathy and multilevel degenerative changes. MRI often shows degenerative changes at more than one level. Degenerative changes can occur in patients without symptoms and clinical diagnosis. Analyses of referred pain distribution from cervical nerve roots have shown only 50% correlation to the classical sensory dermatome. Surgical treatment of patients with cervical radiculopathy attributed to degenerative disease is associated with moderate outcome results. Our aim was to assess the diagnostic value of cervical selective nerve root blocks (SNRB) in our Trust in surgical decision making. Methods: The data was collected retrospectively from electronic hospital records on CRIS, PACS and NOTIS on consecutive patients who underwent cervical nerve root blocks for diagnostic purpose between 1st Jan 2011 and 31st December 2011. Results: Total of 50 patients had cervical SNRB for diagnostic reasons. It influenced surgical decision making in 84% (42) of these patients and not in 2% cases. 10% did not have any follow up after cervical SNRB. Decision in favour of surgery was made in 71.5% of these 42 patients. Conclusions: In chronic cervical brachialgia, cervical SNRB is extremely influential in surgical decision making, in both whether to operate and which levels scenario.
... Various approaches have been described in the literature in order to minimize this inadvertent arterial puncture including an "indirect" cervical nerve root Fluoroscopically Guided Infiltration of the Cervical Nerve Root injection technique with a dorsal approach or modified dorsal direct approach (1,17,18). ...
PURPOSE
Purpose of our study is to assess safety and efficacy of percutaneous, fluoroscopy-guided transforaminal infiltrations in cases of cervical radiculopathy. Approach was performed indirectrly through the ipsilateral facet joint.
METHOD AND MATERIALS
During the last 2 years, 17 patients suffering from cervical radiculopathy underwent percutaneous, fluoroscopy-guided transforaminal infiltrations by means of an indirect approach through the ipsilateral facet joint. The intra-articular position of the needle (22 Gauge spinal needle) was fluoroscopically verified after injection of a small amount of contrast medium. Then a mixture of long acting glucocorticosteroid (cortivazol) diluted in normal saline (1.5/1 cc) was injected intraarticularly. A questionnaire with NVS scale helped assessing pain relief degree, life quality and mobility improvement.
RESULTS
A mean of 2.3 sessions was performed in the patients of our study. Comparing the pain scores prior (mean value 8.75±1.2 NVS units) and after (mean value 2.25±1.5 NVS units) there was a mean decrease of 6.5±1.6 NVS units [74.29% (p=0.000)] on terms of pain reduction, effect upon mobility and life quality. There were no clinically significant complications noted in our study.
CONCLUSION
Fluoroscopy-guided transforaminal infiltrations through the ipsilateral facet joint seems to be a feasible, efficacious and safe approach for the treatment of patients with cervical radiculopathy.
CLINICAL RELEVANCE/APPLICATION
Approach through the ipsilateral facet joint facilitates needle placement and minimizes risk of complications.
... Various approaches have been described in the literature in order to minimize this inadvertent arterial puncture including an "indirect" cervical nerve root Fluoroscopically Guided Infiltration of the Cervical Nerve Root injection technique with a dorsal approach or modified dorsal direct approach (1,17,18). ...
Transforaminal infiltrations in the cervical spine are governed by a higher rate of vascular puncture than in the lumbar spine. The purpose of our study is to assess the safety and efficacy of percutaneous, fluoroscopically guided nerve root infiltrations in cases of cervical radiculopathy. An indirect postero-lateral approach was performed through the ipsilateral facet joint. During the last 2 years, 25 patients experiencing cervical radiculopathy underwent percutaneous, fluoroscopically guided nerve root infiltrations by means of an indirect postero-lateral approach through the ipsilateral facet joint. The intra-articular position of the needle (22-gauge spinal needle) was fluoroscopically verified after injection of a small amount of contrast medium which also verified dispersion of the contrast medium periradicularly and in the epidural space. Then a mixture of long-acting glucocorticosteroid diluted in normal saline (1.5/1 mL) was injected intra-articularly. A questionnaire with a Numeric Visual Scale (NVS) scale helped assess pain relief, life quality, and mobility improvement. A mean of 2.3 sessions was performed in the patients of our study. In the vast majority of our patients 19/25 (76%), the second infiltration was performed within 7 - 10 days of the first one. Comparing the pain scores prior (mean value 8.80 ± 1.080 NVS units) and after (mean value 1.84 ± 1.405 NVS units), there was a mean decrease of 6.96 ± 1.695 NVS units [median value 7 NVS units (P < 0.001) in terms of pain reduction, effect upon mobility, and life quality. There were no clinically significant complications noted in our study. Fluoroscopically guided transforaminal infiltrations through the ipsilateral facet joint seem to be a feasible, efficacious, and safe approach for the treatment of patients with cervical radiculopathy. This approach facilitates needle placement and minimizes risk of complications.
... Both extraforaminal and transforaminal (intraforaminal) techniques have been described in the literature 2,5,20 . Final needle tip position typically depends upon trajectory options available given the location of the carotid artery and jugular vein. ...
Cervical transforaminal epidural injections (C-TfEI) are commonly performed in patients with cervical radiculopathy/pain. C-TfEIs are typically performed without incident but adverse events can occur. Using CT-fluoroscopy-guided C-TfEI, we commonly observe the vertebral artery in proximity to the target injection site. The purpose of this study was to assess the position of the vertebral artery relative to the typical C-TfEI injection point.
CT-fluoroscopy-guided C-TfEIs were performed at 70 levels in 68 patients with radiculopathy/neck pain (age range 19–83 yrs, mean 50.6 yrs). Degenerative neural foraminal narrowing at each level was characterized (normal-to-mild, moderate, severe). Vertebral artery position was categorized as: anterior (normal), partially covering neural foramen, complete/near-complete covering the neural foramen. Additional measured variables included angle of needle trajectory, foraminal angle, and whether or not needle trajectory intersected with the vertebral artery.
Foraminal vertebral artery covering correlated with severity of foraminal degenerative narrowing (p=0.003). Complete/near-complete covering was seen in: 65% severely narrowed foramina, 30% moderately narrowed foramina and 10% normal/mildly-narrowed foramina. Needle trajectory intersected with the vertebral artery in 30 of 70 injections (46%) by CT-fluoroscopy, frequently associated with shallow (lateral) approaches. Foraminal angle, approximating oblique fluoroscopic technique, suggests needle trajectory intersection with the vertebral artery in 27 of 70 foramina (39%).
Vertebral artery position is commonly displaced into the foramen in patients with advanced cervical degenerative disease. Operator awareness of altered vertebral artery position is important for determination of optimal needle trajectory and tip placement prior to injection in patients undergoing C-TfEI.
... Imaging may detect inadvertent intravascular injections. CT precisely demonstrates the needle tip in relation to the vertebral artery [22], but may not detect very small vessels and vessels running out of the imaging plane [3]. CT has not been proved to be less safe than fluoroscopy guidance. ...
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.
... Anesthesiologists have performed the procedure for many years using anatomical landmarks [19] but with an improve in imaging guidance, it is now increasingly within the spectrum of interventional radiologists and neuroradiologists. Besides ultrasoundguidance [15], nowadays these blocks are often performed under fluoroscopy or with CT-guided techniques [15,20,21,22]. Despite attractive features of CT-guided techniques compared to fluoroscopy and ultrasound-guidance, including direct visualization of soft-tissue planes, vital organs, neural and vascular structures and the precise anatomic localization with millimeter accuracy, all previously introduced approaches lack the possibility of detailed 3D puncture planning and 2D laser-guided needle control. ...
Cervical selective nerve root block (CSNRB) is a well-established, minimally invasive procedure to treat radicular cervical pain. However, the procedure is technically challenging and might lead to major complications. The objective of this study was to evaluate the feasibility of a three-dimensional puncture planning and two-dimensional laser-guidance system for CSNRB in an ex-vivo model.
Dyna-CT of the cervical spine of an ex-vivo lamb model was performed with the Artis Zee® Ceiling (Siemens Medical Solutions, Erlangen, Germany) to acquire multiplanar reconstruction images. 15 cervical nerve root punctures were planned and conducted with the syngo iGuide® laser-guidance system. Needle tip location and contrast dye distribution were analyzed by two independent investigators. Procedural, planning, and fluoroscopic time, tract length, and dose area product (DAP) were acquired for each puncture.
All 15 punctures were rated as successful with 12 punctures on the first attempt. Total procedural time was approximately 5 minutes. Mean planning time for the puncture was 2.03 (±0.39) min. Mean puncture time was 2.16 (±0.32) min, while mean fluoroscopy time was 0.17 (±0.06) min. Mean tract length was 2.68 (±0.23) cm. Mean total DAP was 397.45 (±15.63) µGy m(2).
CSNRB performed with Dyna-CT and the tested laser guidance system is feasible. 3D pre-puncture planning is easy and fast and the laser-guiding system ensures very accurate and intuitive puncture control.
... They vary in the description of patient position, needle technique, and use of contrast. [3][4][5][6][7] Our study is the largest one to evaluate CT-guided CTSI and the first to explore needle position, to our knowledge. We did not have any reported complications and found that junctional and foraminal zone needle locations provided similar high rates of intraforaminal distribution of con-trast, significantly higher than that for the extraforaminal needle position. ...
Background and purpose:
The aim of CT-guided CTSI is to inject medication into the foraminal region where the nerve root is inflamed. The optimal location for needle placement and therapeutic delivery, however, remain uncertain. The purpose of this study was to investigate how needle positioning and angle of approach impact the transforaminal distribution of injectate.
Materials and methods:
We retrospectively reviewed fluoroscopic images from 90 CT-guided CTSI procedures for needle-tip location, needle angle, and contrast distribution. Needle-tip position was categorized as either foraminal zone, junctional, or extraforaminal. Distribution of contrast injected immediately before steroid administration was categorized as central epidural, intraforaminal, or extraforaminal in location. Needle-tip location and angle were correlated with contrast distribution.
Results:
The needle tip was most commonly placed in the junctional position (36 cases, 40%), followed by foraminal (30 cases, 33%) and extraforaminal (24 cases, 27%) locations. Intraforaminal contrast distribution was highest when the needle location was foraminal (30/30, 100%) or junctional (35/36, 97%), compared with extraforaminal (7/24, 29%) (P value <.0001). There was no relationship between needle angle and contrast distribution.
Conclusions:
Needle-tip location at the outer edge of the neural foramen (junctional location) correlated well with intraforaminal distribution of contrast for CT-guided CTSI and compared favorably with injectate distribution following foraminal zone needle positioning. Junctional needle positioning may be preferred over the foraminal zone by some proceduralists. Extraforaminal needle positioning resulted in less favorable contrast distribution, which may significantly diminish the therapeutic efficacy of CTSI.
Epidural steroid injections (ESIs) are among the most commonly performed interventional pain management procedures to treat radiculopathy. Appropriate image guidance is required to avoid vulnerable vascular or neural structures during performance of ESIs. This is critical for appropriate needle placement, for monitoring injectate flow patterns and to ensure injectate is delivered to the correct target. Moreover, the use of image guidance has been shown to reduce the risk of complications. Fluoroscopy is utilized more commonly for ESIs. However, in certain conditions, CT-guided injections may be preferred over fluoroscopy due its advantage of better visualization of the bony and soft tissues such as the presence of deformities, severe degenerative changes, osteophytes, cysts, vascular structures, and pleura. In this chapter, we aim to overview CT-guided ESIs.
Radiculopathy and spinal pain are debilitating conditions affecting millions of people worldwide each year. While most cases can be managed conservatively with physiotherapy and nonsteroidal anti-inflammatory medications, minimally invasive corticosteroid injections are the mainstay intervention for those not responsive to conservative treatment. Historically, spinal injections were performed in the absence of imaging guidance; however, imaging modalities, in particular fluoroscopy and computer tomography (CT), have become the standard of care in performing most of these procedures. Under imaging guidance, operators can accurately confirm needle placement and safely target localised pathologies.
Background and purpose:
The conventional fluoroscopy-guided (CF) selective cervical nerve root block (SCNRB) is being used commonly as a treatment for cervical radicular pain as well as a diagnostic tool. This study aimed to identify any major complications and determine the safety and clinical utility of CF-SCNRB performed in a university hospital and associated outpatient clinics.
Materials and methods:
Two-hundred fifty-four conventional fluoroscopy-guided selective cervical nerve root blocks were retrospectively identified from 2011 to 2018 using a radiology report search tool. Each procedure was performed by an experienced neuroradiologist performing spinal injections on a full-time basis in clinical practice. A 10-point pain scale was used for pre- and postprocedural pain-level assessment. Successful conventional, fluoroscopy-guided, selective cervical nerve root block was defined as a patient-reported pain scale reduction of at least 50% and/or alleviation of numbness or paresthesia at ≥2 weeks postinjection. All clinically important immediate and delayed complications were also recorded.
Results:
Two-hundred fifty-four conventional fluoroscopy-guided selective cervical nerve root blocks were performed via an anterolateral approach with an average fluoroscopy time of 24.3 seconds for all cases. There were no aborted procedures and no major or permanent complications. There were 14 minor complications; 12 of these were periprocedural and resolved by the 2-week follow-up visit. One-hundred eighty-five patients (75.2%) reported pain improvement of >50% from baseline at 15 minutes postinjection. Overall, 172 patients (67.7%) reported >50% pain scale reduction or alleviation from paresthesia at least 2 weeks postinjection.
Conclusions:
Conventional fluoroscopy-guided selective cervical nerve root block is an efficacious, efficient, and safe outpatient procedure when performed by a skilled and experienced proceduralist.
Background:
Cervical selective nerve root blocks (C-SNRBs) maintain utility for presurgical planning in patients with cervical radiculopathy. Traditional fluoroscopic or stationary computed tomography (CT)-guided methods have been associated with complications, including catastrophic neurologic insults, while ultrasound guidance has been investigated based on its theoretical advantages. Maximizing patient safety by obtaining superior anatomic and procedural details promotes the exploration for better alternative guidance.
Methods:
We describe a novel approach of posterolateral (PL) extraforaminal (EF) C4 SNRB using cone beam-based CT (CBCT)/fluoroscopy, which was performed on 3 separate occasions for 1 patient with suspected right C4 radiculopathy for presurgical evaluation. CBCT/fluoroscopy uniquely provides the function of both CT and fluoroscopy using a C-arm machine. It allows precise 3-dimensional needle planning and sophisticated 2-dimensional needle guidance, while ensuring tight needle control and detailed monitoring of contrast spread.
Results:
A successful right C4 SNRB was repeatedly achieved, as evidenced by postprocedural paresthesias over the C4 dermatomal distribution and periradicular contrast spread. Additionally, the patient reported symptomatic relief (with regard to pain scores and neck range of motion), leading to cancelation of his surgical plan.
Conclusion:
We propose the PL-EF approach as the safest protocol for C-SNRBs. When compared with fluoroscopy or CT, CBCT/fluoroscopy is an advanced imaging system that provides superior anatomic neurovascular detail, while offering precise needle control, contrast media monitoring, and easy operation in an office setting. These advanced features support it as the ideal guidance method for maximizing both the safety and efficiency of the PL-EF C-SNRB approach. However, the claimed advantages cannot be concluded without increasing its accessibility to pain specialists and conducting a prospective study with a large sample size.
Introduction: Image guided interventions are increasingly being used for the management of chronic low back ache. It has inherent advantages of confirming needle placement and thus increasing precision of these procedures. Aim: To assess the efficacy of pain relief provided by CT guided perineural and CT guided facet joint steroid injections respectively in patients with chronic spinal pain. Materials and Methods: A prospective study was performed to analyse the effect of image guided procedures in providing adequate pain relief. Patients were asked to grade pain on a Visual Analog Scale (VAS) for pain before the procedure as well as on subsequent reviews at 3 days, 30 days and 90 days. The pain score was used to calculate percentage of pain relief since previous follow-up and classified accordingly. Results: A total of 67 perineural injections and 20 facetal injections were administered. In present study, out of 67 perineural injections at least 31.5% reported very good pain relief as early as 3 days post-injection, while 28.3% continued to have very good pain relief at the end of 30 days but this fell to 10.4% at the end of 90 days. Out of 20 facet joint injections, none of the patients reported good pain relief during the follow-up. Conclusion: CT-guided perineural steroid injections for management of chronic low back ache are safe and effective interventions that can be incorporated into any existing interventional radiology practice.
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.
Background:
Computed tomography (CT)-guided cervical nerve injections are broadly being used in the treatment of cervical radiculopathy; however, catastrophic complications have been reported. Herein, we aimed to evaluate the efficacy, feasibility, and safety of a novel CT-guided cervical injection technique.
Materials and methods:
We prospectively performed cervical injections in 28 patients with cervical radiculopathies using a novel CT-guided cervical transforaminal injection technique; lateral peri-isthmic approach in which the tip of the needle advanced to the lateral cortex of the isthmus instead of the foraminal area. Patients' pain reduction rates were evaluated using visual analog scores (VAS) at pre-treatment, immediately after treatment, at 3 weeks and 6 months after the treatment. Intra-vascular contrast medium injections and distribution of the contrast material into the foraminal, epidural or extraforaminal area during the procedure were noted.
Results:
Pre-treatment pain scores were reduced by 4.2 ± 1.4 (p < 0.001), 3.9 ± 1.37 (p < 0.001) and 3.25 ± 1.53 (p < 0.001) immediately after the treatment, 3 weeks and 6 months after the treatment respectively. The number of patients with >50% pain relief as measured by VAS were 21 (75%) immediately after the procedure, 19 (67.8%) at 3 weeks and 17 (60%) at 6 months after the procedure. The injected contrast material was dispersed into the neural foramen in 9 cases (32.1%), the foraminal and epidural area in 14 cases (50%) and the extraforaminal area in 5 cases (17.9%).
Conclusion:
The CT-guided lateral peri-isthmic approach seems to be a secure and feasible method for cervical injections with satisfactory pain reduction.
Over the past 20 years, the use of imaging guidance has progressively but very rapidly evolved to become a standard practice to date, with fluoroscopy and Ultrasound being the most popular imaging guiding tools. However, CT guidance is relatively underused in the field of Interventional pain management, mainly due to acces and availabilty issues for pain physicians. Therefore, the objective of this thesis are mulitple :*to evaluate the usefulness of CT scan guidance, in applying existing neurolytic techniques(block.infiltration and neurolysis) to innovative indications, allowed by the use of such animagingguiding tool.*to evaluate the clinical effectiveness of these novel indications*Finally, to emphasize on the importance of the clinical aspects of Interventional pain managementAfter after having reminded the definitions of the different existing techniques (neural blocks, infiltration, neurolysis) and detailed existing materials (Local anesthestics, Steroids, Chemical Neurolysis, Physical Neurolysis), a brief description of existing indication of Interventional Pain will be made. Emphasis will then be made on the assessment of innovative interventional CT Guided pain techniques in various refractory pain syndromes :- Evaluation of Alcohol percutaneous neurolysis of the sphenopalatine ganglion in the management of refractory cranio facial pain , in 42 patients : overall efficacy rate of alcohol SPN was 67.2% with a mean pain relief duration of 10,3 months. Analysis showed a higher efficacy rate in patients with Cluster Headaches (76.5%) andPersisting Facial Idiopathic Pain (85.7%)-Evaluation of the efficacy of a simplified CT guided greater occipital nerve (GON) infiltration approach inthe management of occipital neuralgia (ON) in 33 patients : Clinical success rate was 86%. In case of clinicalsuccess, mean pain relief duration following procedure was 9.16 months.-Evaluation of CT-guided Stellate Ganglion Blockade vs. Radiofrequency Neurolysis in the Managementof Refractory type I Complex Régional Pain Syndrome of the Upper Limb in 67 patients : analysis performed onthe blockade and RFN groups showed a significantly (P
Chronic neck pain and cervical radicular pain are relatively common in the adult population. Treatment for chronic radicular pain recalcitrant to conservative management includes surgical management as well as interventional techniques with epidural injections utilizing either an interlaminar approach or transforaminal approach. Although there have been multiple systematic reviews and randomized clinical trials of cervical interlaminar epidural injections, the literature is sparse in reference to cervical transforaminal epidural injections. Overall, there is good evidence for the effectiveness of cervical interlaminar epidural injections in managing cervical disc herniation and fair evidence in managing central spinal stenosis and postsurgery syndrome. The evidence is poor, however, for cervical transforaminal epidural injections. Complications with cervical interlaminar epidural injections are rare, but more commonly occur with transforaminal epidural injections and can be fatal. Emerging concepts in pain include further randomized trials; proper placebo design; focus on control design (either active control or placebo control); and appropriate methodologic quality assessment and evidence synthesis.
To evaluate the accuracy, safety, and efficacy of cervical nerve root injection therapy using magnetic resonance guidance in an open 1.0 T MRI system.
Between September 2009 and April 2012, a total of 21 patients (9 men, 12 women; mean age 47.1 ± 11.1 years) underwent MR-guided cervical periradicular injection for cervical radicular pain in an open 1.0 T system. An interactive proton density-weighted turbo spin echo (PDw TSE) sequence was used for real-time guidance of the MR-compatible 20-gauge injection needle. Clinical outcome was evaluated on a verbal numeric rating scale (VNRS) before injection therapy (baseline) and at 1 week and 1, 3, and 6 months during follow-up.
All procedures were technically successful and there were no major complications. The mean preinterventional VNRS score was 7.42 and exhibited a statistically significant decrease (P < 0.001) at all follow-up time points: 3.86 ± 1.53 at 1 week, 3.21 ± 2.19 at 1 month, 2.58 ± 2.54 at 3 months, and 2.76 ± 2.63 at 6 months. At 6 months, 14.3 % of the patients reported complete resolution of radicular pain and 38.1 % each had either significant (4-8 VNRS score points) or mild (1-3 VNRS score points) relief of pain; 9.5 % experienced no pain relief.
Magnetic resonance fluoroscopy-guided periradicular cervical spine injection is an accurate, safe, and efficacious treatment option for patients with cervical radicular pain. The technique may be a promising alternative to fluoroscopy- or CT-guided injections of the cervical spine, especially in young patients and in patients requiring repeat injections.
Development of a patient-mount navigated intervention (PaMNI) system for spinal diseases. An in vivo clinical human trial was conducted to validate this system.
To verify the feasibility of the PaMNI system with the clinical trial on percutaneous pulsed radiofrequency stimulation of dorsal root ganglion (PRF-DRG).
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.
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.
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.
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.
The labelled steroid hormones [3H]hydrocortisone and [14C]testosterone, being injected into the gray matter of the rat spinal cord L5-L6 segments, were shown to be transported at a high velocity along the ventral (anterograde) and dorsal (retrograde) root fibres. The maximum velocity of axonal transport along the ventral and dorsal roots in adult rats was, on average, 3006 +/- 101 and 3028 +/- 48 mm/day for [3H]hydrocortisone and 4594 +/- 186 and 5185 +/- 485 mm/day for [14C]testosterone, respectively. In old rats, axonal transport of steroid hormones was markedly slower. Its maximum velocity along the ventral and dorsal roots averaged to 756 +/- 64 and 738 +/- 48 mm/day for [3H]hydrocortisone and 624 +/- 54 and 608 +/- 80 mm/day for [14C]testosterone, respectively. In old rats the amount of labelled hydrocortisone incorporated into the ventral root fibres was sharply reduced (by more than an order of the value) as compared to that in adult animals. At the same time, the intensity of the labelled testosterone incorporation into the ventral root fibres did not demonstrate any significant age-related difference. The injection of low doses of steroid hormones (from less than one microgram to a few micrograms) into the lumbar spinal cord resulted in a significant hyperpolarization several hours later first of the gastrocnemius and then of deltoideus muscle fibres. In old rats, such a hyperpolarization occurred much later. It is suggested that axonal transport of steroid hormones is one of the mechanisms responsible for the effects of hormones on the tissues, which undergoes considerable changes with ageing.
Unlabelled:
Although epidural steroid injections (ESIs) are a common treatment for chronic pain conditions, it is not clear whether there is consensus on their technical aspects. The current literature suggests that variations in technical aspects may affect ESI outcomes. The goal of the survey was to help establish a standard frame of reference for the performance of ESIs. We analyzed survey results from 68 academic anesthesia programs and 28 private practices in the United States. The main finding in this survey is that there is no clear-cut consensus as to the ideal method to perform ESI. There is a wide variation among individual practices in almost every technical aspect of ESI. Private practices use significantly more fluoroscopy than academic centers. The large difference was found in the cervical region where 73% of private practices and only 39% of academic institutions polled perform the ESIs with fluoroscopic guidance (P = 0.005). A similar discrepancy was found in approaches to the epidural space after laminectomy where 61% of private practices, but only 15% of academic centers, use the transforaminal approach. The study results indicate that there is no consensus, and that there is a wide variation in current practices.
Implications:
A national survey of practices performing epidural steroid injections was conducted. The purpose was to establish whether consensus exists on technical aspects of this procedure. The study results indicate that there is no consensus, and that there is a wide variation in current practices.
Treatment for individuals suffering from migraines and pain due to an inflammation or impingement of a nerve range from noninvasive methods such as massage, physical therapy, and medications to invasive methods such as epidural steroid injections and surgery. Each method of treatment has an associated level of risk. While minor to moderate complications from such procedures do occur, deaths are very rare. We report the first cited case of a death associated with the pain management procedure called nerve root block, also referred to as a transforaminal epidural steroid injection. We present the medical history and autopsy findings of a 44-year-old white female who died of massive cerebral edema secondary to the dissection of the left vertebral artery and subsequent thrombosis due to the perforation of that artery by a 25-gauge spinal needle during a C-7 nerve root block.
To describe the effects of spinal cord block after injection of local anesthetic into a cervical radicular artery.
Case report.
Neurology practice specializing in spinal pain. Interventions. A patient underwent a C6-7 transforaminal injection. Contrast medium indicated correct and safe placement of the needle.
After the injection of local anesthetic, the patient developed quadriplegia. The injection was terminated. The neurologic impairment resolved after 20 minutes observation.
Despite correct placement of the needle for a cervical transforaminal injection, injectate may nevertheless enter a cervical radicular artery. Whereas local anesthetic, so injected, appears to have only a temporary effect on spinal cord function, particulate steroids may act as an embolus and cause permanent impairment.
While both fluoroscopic and CT-guidance during cervical nerve root blocks have been well documented in the literature, the use of CT fluoroscopy (CTF) has not. CTF is well suited to provide imaging guidance during these procedures due to its combination of excellent anatomic detail, relatively low radiation dose and the ability to perform an initial dynamic contrast injection, and is a viable alternative to fluoroscopic guidance. Details of the technique along with the initial experience at one institution are presented.
Interventional pain management has been growing by leaps and bounds with the introduction of an array of new CPT codes, the expansion of interventional techniques, and utilization. Interventional pain management dates back to the origin of neural blockade and regional analgesia, in 1884. Over the years, pain medicine and interventional pain management have taken many approaches, including biological, biopsychosocial, and psychosocial. In the late 1990s and early 2000s, a new philosophy of precision diagnosis and high-tech management has evolved. An interventional pain physician may be either a reductionist, a monotherapist or a combination of the two. Interventionalists have been criticized for excessive undisciplined application of needle procedures. Interventional techniques are performed by many primary specialists (anesthesiology, physiatry, neurology, etc.) and physicians designated by CMS in interventional pain management (-09) and pain management or pain medicine (-72) which went into effect in 2003 and 2002. Overall, the frequency of utilization of interventional procedures has increased substantially since 1998. It is estimated that among Medicare recipients, the frequency of interventional procedures, which includes epidural, spinal neurolysis, and adhesiolysis procedures; facet joint interventions and sacroiliac joint blocks; and other types of nerve blocks, excluding continuous epidurals, implantables, disc procedures, intraarticular injections, trigger point and ligament injections, had increased by 95% from 1998 to 2003. In the Medicare population, facet joint interventions and sacroiliac joint blocks have increased by 222% from 1998 to 2003. Overall, the utilization of various nerve blocks (excluding epidurals, disc injections, and facet joint blocks) in Medicare recipients from 1998 to 2003 were performed approximately 50% of the time by non-pain physicians. Interventional pain management is growing rapidly, under the watchful eye of the government, and third party payors. Establishing an algorithmic approach and following guidelines may improve compliance and quality of care without implications of abuse.
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.
Survey/case series.
To survey pain physicians about neurologic infarctions following cervical transforaminal epidural steroid injections (TF-ESIs).
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.
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.
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.
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.
Fig 1. CT scan of the contrast distribution after CSNRB of the right C5 nerve root
Fig 1. CT scan of the contrast distribution after CSNRB of the right C5 nerve root.
SPINE
TECHNICAL NOTE
AJNR Am J Neuroradiol 30:336 –37 Feb 2009 www.ajnr.org