Effect of bipolar pulsed radiofrequency on refractory chronic cervical radicular pain: A report of two cases

Deep Learning Algorithm Trained on Oblique Cervical Radiographs to Predict Outcomes of Transforaminal Epidural Steroid Injection for Pain from Cervical Foraminal Stenosis

INTRODUCTION

We developed a convolutional neural network (CNN) model to predict treatment outcomes of transforaminal epidural steroid injection (TFESI) for controlling cervical radicular pain due to cervical foraminal stenosis.

METHODS

We retrospectively recruited 293 patients with cervical TFESI due to cervical radicular pain caused by cervical foraminal stenosis. We obtained a single oblique cervical radiograph from each patient. We cut each oblique cervical radiograph image into a square shape, including the foramen that was targeted for TFESI, the intervertebral disc, the facet joint of the corresponding level with the targeted foramen, and the pedicles of the vertebral bodies just above and below the targeted foramen. Therefore, images including the targeted foramen and structures around the targeted foramen were used as input data. A favorable outcome was defined as a ≥ 50% reduction in the numeric rating scale (NRS) score at 2 months post TFESI compared to the pretreatment NRS score. A poor outcome was defined as a < 50% reduction in the NRS score at 2 months post TFESI vs. the pretreatment score.

RESULTS

The area under the curve of our developed model for predicting the treatment outcome of cervical TFESI in patients with cervical foraminal stenosis was 0.823.

CONCLUSION

A CNN model trained using oblique cervical radiographs can be helpful in predicting treatment outcomes after cervical TFESI in patients with cervical foraminal stenosis. If the predictive accuracy is increased, we believe that the deep learning model using cervical radiographs as input data can be easily and widely used in clinics or hospitals.

Comparison between ultrasound-guided monopolar and bipolar pulsed radiofrequency treatment for refractory chronic cervical radicular pain: A randomized trial

BACKGROUND

Many patients complain of chronic cervical radicular pain, and pulsed radiofrequency (PRF) is known to have a positive effect for alleviating neuropathic pain.

OBJECTIVES

In the present study, we used ultrasound (US) guidance and compared the effects of monopolar PRF with those of bipolar PRF in patients with chronic cervical radicular pain refractory to repeated transforaminal epidural steroid injections.

METHODS

Sixty-six patients with chronic cervical radicular pain were included in this study. Patients were randomly assigned to one of the two groups: monopolar or bipolar PRF group (n= 33 per group). Pain intensity was evaluated using a numeric rating scale (NRS) at pretreatment, and at 1 and 3 months after the treatment. Target stimulation site was the extraforaminal nerve root.

RESULTS

Compared to the pretreatment NRS scores, patients in both groups showed a significant decrease in NRS scores at 1 and 3 months after the treatment. Reductions in the NRS scores over time were significantly larger in the bipolar PRF group. Three months after the treatment, 18 patients (54.5%) in the monopolar PRF group and 27 (81.8%) in the bipolar PRF group reported successful pain relief (pain relief of ⩾50%).

CONCLUSIONS

US-guided PRF can be an effective interventional technique for the management of chronic refractory cervical radiculopathy. Moreover, bipolar PRF has better treatment outcome than monopolar PRF.

Efficacy and Safety of Pulsed Radiofrequency as a Method of Dorsal Root Ganglia Stimulation in Patients with Neuropathic Pain: A Systematic Review

OBJECTIVE

Pulsed radiofrequency (PRF) is a nonablative pain treatment that uses radiofrequency current in short high-voltage bursts, resulting in interruption of nociceptive afferent pathways. We conducted a systematic review with the aim to create a synthesis of evidence about the efficacy and safety of PRF applied to the dorsal root ganglion (DRG) for the treatment of neuropathic pain.

METHODS

We searched MEDLINE, CINAHL, Embase, and PsycINFO through January 8, 2019, as well as ClinicalTrials.gov and the clinical trial register of the World Health Organization. All study designs were eligible. We assessed risk of bias using the Cochrane tool for randomized controlled trials and the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I). We assessed level of evidence using the Oxford tool and quality of evidence with GRADE.

RESULTS

We included 28 studies with participants suffering from lumbosacral, cervical, or thoracic radicular pain, post-herpetic neuralgia, neuropathicbone pain in cancer patients, or carpal tunnel syndrome. Only five studies were randomized controlled trials (RCTs), while others were of nonrandomized designs, predominantly before and after comparisons. A total of 991 participants were included, with a median number (range) of 31 (1-101) participants. Only 204 participants were included in the RCTs, with a median number (range) of 38 (23-62) participants. The overall quality of evidence was low, as the majority of the included studies were rated as evidence level 4 or 5. The quality of evidence was very low.

CONCLUSIONS

Evidence about the efficacy and safety of PRF of the DRG for the treatment of neuropathic pain is based mainly on results from very small studies with low evidence quality. Current research results about the benefits of PRF of the DRG for the treatment of neuropathic pain should be considered preliminary and confirmed in high-quality RCTs with sufficient numbers of participants.

Pulsed Radiofrequency Neuromodulation Contributes to Activation of Platelet-Rich Plasma in In Vitro Conditions

OBJECTIVES

Recent years have brought new developments in interventional chronic pain management, namely regenerative orthopedics utilizing platelet-rich plasma (PRP) as well as further evolution of pulsed radiofrequency neuromodulation (PRF). Both methods have been used separately. Here, we investigated whether PRF may potentiate the activation of platelets in PRP samples when both these techniques are combined together in in vitro conditions.

MATERIALS AND METHODS

Studies were performed on concentrated PRP samples (PRPs) obtained from acid citrate dextrose-treated blood taken from 11 healthy volunteers. PRPs were divided into four groups: 1) nonactivated PRP; 2) thrombin-activated PRP as a positive control for maximal platelets activation; 3) PRF-treated PRP exposed for 20 min to PRF energy generated by neurotherm radio frequency generator at 500 kHz, with a voltage of 40 V and maximal temperature of 42°C; and 4) a combination of groups 2 and 3.

RESULTS

PRF-induced platelet activation measured by platelet factor 4 (PF4) and ATP release from PRPs was significantly higher compared to nonactivated PRPs, and similar to PF4 and ATP release from thrombin-activated PRPs. Thrombin activation did not potentiate PF4 release in PRF samples and even reduced ATP level. Additionally, PRF neither induced any platelet membrane damage measured by lactic dehydrogenase release from PRP nor modified any platelets viability or metabolism measured by MTT.

CONCLUSIONS

We confirmed that PRF may activate PRP without additional platelet activators. So, a combination of both methods PRF and PRP application may provide a more effective opportunity for tissue regeneration in dentistry, surgery, dermatology, or in orthopedics.

Management of refractory chronic migraine using ultrasound-guided pulsed radiofrequency of greater occipital nerve: Two case reports

RATIONALE

Although various oral medications and procedures are applied for managing migraine, their efficacy remains limited. To control migraine that does not respond to conventional treatments, we conducted pulsed radiofrequency (PRF) stimulation to the greater occipital nerve (GON) in 2 patients.

PATIENT CONCERNS

Patients 1 and 2 complained of chronic throbbing, pulsating, and tight headaches. Their headache intensities scored 8 and 7 on a numeric rating scale (NRS), respectively. Patient 1 experienced the headache bilaterally in the frontal, retro-orbital, parietal, and occipital regions. The initial onset of the symptoms was more than 15 years ago. Patient 2 complained of headaches in the left frontal, retro-orbital, parietal, and occipital regions, which occurred first more than 14 years ago.

DIAGNOSES

According to the International Classification of Headache Disorder-3 beta criteria, the patients were diagnosed with chronic migraine.

INTERVENTIONS

Oral medications, GON block with bupivacaine and dexamethasone, and botulinum toxin injections did not alleviate the patients' migraine.The PRF stimulation on GON was performed under the guidance of ultrasound, at 5 Hz and 5-millisecond pulsed width for 360 seconds at 45 V. The electrode tip temperature was maintained at or below 42°C.

OUTCOMES

Two weeks after applying PRF, the pain was reduced to NRS 3 in both patients, who also reported that the headache became bearable after PRF. The effectiveness of PRF on GON lasted for at least 3 months in both patients, and no adverse effects were observed.

LESSONS

Our findings suggested that the application of PRF on GON can be a useful option for treating refractory chronic migraine.

Effectiveness of pulsed radiofrequency treatment on cervical radicular pain: A meta-analysis

BACKGROUND

Cervical radicular pain is a challenging medical problem in terms of therapeutic management. Recently, pulsed radiofrequency (PRF) stimulation on the dorsal root ganglion (DRG) has been used to control several types of chronic pain. However, its effect on cervical radicular pain is still not well studied. To conduct a meta-analysis of available clinical studies on PRF treatment in patients with cervical radicular pain induced by cervical spine disease that was not responsive to other conservative treatments.

METHODS

A comprehensive database search was conducted on PubMed, Embase, Cochrane Library, and SCOPUS. We included studies published up to August 31, 2017, that fulfilled our inclusion and exclusion criteria. The pain degrees measured using visual analog scale (VAS) at pretreatment and after PRF on the DRG were collected for the meta-analysis. The Cochrane Collaboration's Handbook and Newcastle-Ottawa scale were used for the methodological quality assessments of included studies. The meta-analysis was performed using the Comprehensive Meta-analysis Version 2.

RESULTS

A total of 67 patients from one RCT study, 2 prospective observational studies, and one retrospective study were included in this meta-analysis. The pooled data of the 4 included studies showed that overall VAS after the PRF treatment was significantly reduced (P ≤ .001). In the subgroup analysis according to follow-up evaluation time points, the pain was significantly reduced at 2 weeks, 1 month, 3 months, and 6 months after the procedure (2 weeks: P = .02; 1, 3, and 6 months: P < .001).

CONCLUSION

According to the results of the meta-analysis, the use of PRF on the DRG is effective for alleviating cervical radicular pain, which was unresponsive to oral medications, physical therapy, or epidural steroid injection.

Effect of intradiscal pulsed radiofrequency on refractory chronic discogenic neck pain: A case report

RATIONALE

Despite medication, exercise, and medical intervention, many patients complain of persistent discogenic neck pain. To manage discogenic neck pain, we performed intradiscal pulsed radiofrequency (PRF) stimulation in a patient with chronic discogenic neck pain refractory to oral medication and epidural steroid injection.

PATIENT CONCERNS

A 26-year-old man presented with a numeric rating scale (NRS) score of 7 for chronic neck pain. His pain was worse when the neck was held in one position for a prolonged period. There was no pain in the upper extremities.

DIAGNOSES

Discography was positive at C4-5. Based on the pain characteristics, and the result of discography, we diagnosed him as having discogenic neck pain originating from C4-5.

INTERVENTIONS

Intradiscal PRF on the C4-5 intervertebral disc was performed under C-arm fluoroscopy. The PRF treatment was administered at 2 Hz and a 20-ms pulsed width for 20 minutes at 60 V with the constraint that the electrode tip temperature should not exceed 42°C.

OUTCOMES

At the 2-week, and 1-month follow-up visits, the patient's pain was completely relieved. At 2, and 3 months after intradiscal PRF, the pain was scored as NRS 2. No adverse effects of intradiscal PRF stimulation were observed.

LESSONS

Application of intradiscal PRF appears to be an effective and safe technique for treating chronic discogenic neck pain.