Ultrasound-guided cervical selective nerve root injections: a narrative review of literature

2. Cervical radicular pain

INTRODUCTION

Cervical radicular pain is pain perceived in the upper limb, caused by irritation or compression of a cervical spine nerve, the roots of the nerve, or both.

METHODS

The literature on the diagnosis and treatment of cervical radicular pain was retrieved and summarized.

RESULTS

The diagnosis is made by combining elements from the patient's history, physical examination, and supplementary tests. The Spurling and shoulder abduction tests are the two most common examinations used to identify cervical radicular pain. MRI without contrast, CT scanning, and in some cases plain radiography can all be appropriate imaging techniques for nontraumatic cervical radiculopathy. MRI is recommended prior to interventional treatments. Exercise with or without other treatments can be beneficial. There is scant evidence for the use of paracetamol, nonsteroidal anti-inflammatory drugs, and neuropathic pain medications such as gabapentin, pregabalin, tricyclic antidepressants, and anticonvulsants for the treatment of radicular pain. Acute and subacute cervical radicular pain may respond well to epidural corticosteroid administration, preferentially using an interlaminar approach. By contrast, for chronic cervical radicular pain, the efficacy of epidural corticosteroid administration is limited. In these patients, pulsed radiofrequency treatment adjacent to the dorsal root ganglion may be considered.

CONCLUSIONS

There is currently no gold standard for the diagnosis of cervical radicular pain. There is scant evidence for the use of medication. Epidural corticosteroid injection and pulsed radiofrequency adjacent to the dorsal root ganglion may be considered. [Correction added on 12 June 2023, after first online publication: The preceding sentence was corrected.].

Evaluating the Extent of Ultrasound-Guided Cervical Selective Nerve Root Block in the Lower Cervical Spine: Evidence Based on Computed Tomography Images

Objective

To verify the injectate dispersal patterns (IDP) and therapeutic outcome of ultrasound-guided cervical selective nerve root block (UG-SCNRB) in treating cervical radiculopathy (CR).

Methods

Overall, 18 CR patients were recruited to undergo UG-SCNRB in the CT room. Following placement of the puncture needle tip between the target nerve root and posterior tubercle, 3 mL of the drug was administered per root (0.33% lidocaine 0.5 mL + Compound betamethasone injection 0.5mL + methylcobalamin injection 1mL + iohexol 1mL). Subsequently, the IDP was assessed on postintervention CT scan images.

Results

In all, 18 participants were analyzed. We injected 21 target cervical nerve roots, namely, 1 C4 nerve, 9 C5 nerves, and 11 C6 nerves. Among the IDPs on postintervention CT scan images, two IDPs were most prevalent, namely, the contrast spread into the extraforaminal spaces (Zone I, the interscalene) in 100% (21/21) of cases, and the foraminal space spread (Zone II) in 61.90% (13/21) of cases. The injectate spread into the epidural spaces (Zone III) in only 2 out of 21 cases (9.52%). The pain relief was significantly improved two hours after surgery, compared to the preoperative VAS pain scores (2 hours, 1.39±0.50 vs VAS at baseline, P<0.01). The VAS pain scores during follow-up were significantly lower than preoperation (1 weeks, 1.94±0.54 vs VAS at baseline; 2 weeks, 2.61±0.70, P<0.01 vs VAS at baseline; 4 weeks, 2.67±0.59, P<0.01 vs VAS at baseline).

Conclusion

We verified, via CT imaging, that the UG-SCNRB drug diffusion was within safe range (the injectate mainly spread to the extraforaminal spaces), and without any serious complications, such as, intravascular drug injection, extensive diffusion of the epidural space, and general spinal anesthesia.

An open-label non-inferiority randomized trail comparing the effectiveness and safety of ultrasound-guided selective cervical nerve root block and fluoroscopy-guided cervical transforaminal epidural block for cervical radiculopathy

OBJECT

To compare therapeutic efficacy and safety of ultrasound (US)-guided selective nerve root block (SNRB) and fluoroscopy (FL)-guided transforaminal epidural steroid injection (TFESI) for cervical spine radiculopathy (CSR).

METHOD

156 patients with CSR randomly received US-guided SNRB verified by FL or FL-guided TFESI. We hypothesised that the accuracy rate of contrast dispersion into epidural or intervertebral foraminal space in the US group was not inferior to that in the FL group with a margin of clinical unimportance of -15%. Pain intensity assessed by Numeric Rating Scales (NRS) and functional disability estimated by neck disability index (NDI) were compared before treatment, at 1, 3 and 6 months after the intervention. Puncture time and complication frequencies were also reported.

RESULTS

88.7% and 90.3% accuracy ratings were respectively achieved in the US and FL groups with a treatment difference of -1.6% (95%CI: -9.7%, 6.6%) revealing that the lower limit was above the non-inferiority margin. Both NRS and NDI scores illustrated improvements at 1, 3 and 6 months after intervention with no statistically significant differences between the two groups (all p > .05). Additionally, shorter administration duration was observed in the US group (p < .001). No severe complications were observed in both group.

CONCLUSION

Compared with the FL group, the US group provided a non-inferior accuracy rate of epidural/foraminal contrast pattern. For the treatment of CSR, the US technique provided similar pain relief and functional improvements while facilitating distinguishing critical vessels adjacent to the foramen and requiring a shorter procedure duration without exposure to radiation. Therefore, it was an attractive alternative to the conventional FL method.Key messagesWe conducted a prospective, open-label, randomised and non-inferiority clinical trial to estimate a hypothesis that the precisely accurate delivery through ultrasound (US)-guided cervical selective nerve root block (SNRB) was non-inferior to that using FL-guided transforaminal epidural steroid injection. Additionally, US-guided SNRB was as effective as FL-guided TFESI in the treatment effect on pain relief and function improvements. Notably, the US technique might be an alternative to the conventional FL method due to the ability to prevent inadvertent vascular puncture (VP) and intravascular injection (IVI) with a shorter administration time and absence of radiation exposure.

Best practices for interventional pain procedures in the setting of an iodinated contrast media shortage: A multisociety practice advisory

Representatives from the Spine Intervention Society (SIS) and American Academy of Pain Medicine (AAPM) have developed the following best practice recommendations for the performance of interventional pain procedures in the setting of an iodinated contrast media shortage. The practice advisory has been endorsed by SIS, AAPM, American Academy of Physical Medicine and Rehabilitation (AAPMR), American Society of Neuroradiology (ASNR), American Society of Spine Radiology (ASSR), North American Neuromodulation Society (NANS), North American Spine Society (NASS), and Society of Interventional Radiology (SIR).

The Role of Diagnostic Injections in Spinal Disorders: A Narrative Review

Neck and back pain is increasingly prevalent, and has increased exponentially in recent years. As more resources are dedicated to the diagnosis of pain conditions, it is increasingly important that the diagnostic techniques used are as precise and accurate as possible. Traditional diagnostic methods rely heavily upon patient history and physical examination to determine the most appropriate treatments and/or imaging studies. Though traditional means of diagnosis remain a necessity, in many cases, correlation with positive or negative responses to injections may further enhance diagnostic specificity, and improve outcomes by preventing unnecessary treatments or surgeries. This narrative review aims to present the most recent literature describing the diagnostic validity of precision injections, as well as their impact on surgical planning and outcomes. Diagnostic injections are discussed in terms of facet arthropathy, lumbar radiculopathy, discogenic pain and discography, and sacroiliac joint dysfunction. There is a growing body of evidence supporting the use of diagnostic local anesthetic injections or nerve blocks to aid in diagnosis. Spinal injections add valuable objective information that can potentially improve diagnostic precision, guide treatment strategies, and aid in patient selection for invasive surgical interventions.

(4-Aminopyridine)-PLGA-PEG as a Novel Thermosensitive and Locally Injectable Treatment for Acute Peripheral Nerve Injury

Traumatic peripheral nerve injury (TPNI) represents a major medical problem that results in loss of motor and sensory function, and in severe cases, limb paralysis and amputation. To date, there are no effective treatments beyond surgery in selective cases. In repurposing studies, we found that daily systemic administration of the FDA-approved drug 4-aminopyridine (4-AP) enhanced functional recovery after acute peripheral nerve injury. This study was aimed at constructing a novel local delivery system of 4-AP using thermogelling polymers. We optimized a thermosensitive (4-AP)-poly(lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PLGA-PEG-PLGA) block copolymer formulation. (4-AP)-PLGA-PEG exhibited controlled release of 4-AP both in vitro and in vivo for approximately 3 weeks, with clinically relevant safe serum levels in animals. Rheological investigation showed that (4-AP)-PLGA-PEG underwent a solution to gel transition at 32 °C, a physiologically relevant temperature, allowing us to administer it to an injured limb while subsequently forming an in situ gel. A single local administration of (4-AP)-PLGA-PEG remarkably enhanced motor and sensory functional recovery on post-sciatic nerve crush injury days 1, 3, 7, 14, and 21. Moreover, immunohistochemical studies of injured nerves treated with (4-AP)-PLGA-PEG demonstrated an increased expression of neurofilament heavy chain (NF-H) and myelin protein zero (MPZ) proteins, two major markers of nerve regeneration. These findings demonstrate that (4-AP)-PLGA-PEG may be a promising long-acting local therapeutic agent in TPNI, for which no pharmacologic treatment exists.