Pulsed radiofrequency of cervical medial branches for treatment of whiplash-related cervical zygapophysial joint pain

Intramuscular Pulsed Radiofrequency Upregulates BNDF-TrKB Expression in the Spinal Cord in Rats as an Alternative Treatment for Complicated Pain

Two cases of complicated pain exist: posterior screw fixation and myofascial pain. Intramuscular pulsed radiofrequency (PRF) may be an alternative treatment for such patients. This is a two-stage animal study. In the first stage, two muscle groups and two nerve groups were subdivided into a high-temperature group with PRF at 58 °C and a regular temperature with PRF at 42 °C in rats. In the second stage, two nerve injury groups were subdivided into nerve injury with PRF 42 °C on the sciatic nerve and muscle. Blood and spinal cord samples were collected. In the first stage, the immunohistochemical analysis showed that PRF upregulated brain-derived neurotrophic factor (BDNF) in the spinal cord in both groups of rats. In the second stage, the immunohistochemical analysis showed significant BDNF and tropomyosin receptor kinase B (TrkB) expression within the spinal cord after PRF in muscles and nerves after nerve injury. The blood biomarkers showed a significant increase in BDNF levels. PRF in the muscle in rats could upregulate BDNF-TrkB in the spinal cord, similar to PRF on the sciatica nerve for pain relief in rats. PRF could be considered clinically for patients with complicated pain and this study also demonstrated the role of BDNF in pain modulation. The optimal temperature for PRF was 42 °C.

Effectiveness of pulsed radiofrequency on the medial cervical branches for cervical facet joint pain

BACKGROUND

Cervical facet joint pain (CFP) is one of the most common causes of neck pain and headache. Persistent CFP deteriorates the quality of life of patients and reduces their productivity at work.

AIM

To investigate the effectiveness of pulsed radiofrequency (PRF) stimulation of cervical medial branches in patients with chronic CFP.

METHODS

We retrospectively included 21 consecutive patients (age = 50.9 ± 15.3 years, range 26-79 years; male: female = 8:13; pain duration = 7.7 ± 5.0 mo) with chronic CFP, defined as ≥ 4 on the numeric rating scale (NRS). We performed PRF stimulation on the cervical medial branches. The outcomes of the PRF procedure were evaluated by comparing the NRS scores for CFP before treatment and 1 and 3 mo after treatment. Successful pain relief was defined as a ≥ 50% reduction in the NRS score at 3 mo when compared with the pretreatment NRS score.

RESULTS

No patient had immediate or late adverse effects following PRF. The average NRS score for CFP decreased from 5.3 ± 1.1 at pre-treatment to 2.4 ± 0.6 at the 1 mo follow-up, and 3.1 ± 1.1 at the 3 mo follow-up. Compared to the NRS scores before PRF stimulation, those at 1 and 3 mo after PRF stimulation had significantly decreased. Eleven of the 21 patients (52.4%) reported successful pain relief 3 mo after the PRF procedure. PRF stimulation on cervical medial branches may be a useful therapeutic option to control chronic CFP.

CONCLUSION

PRF stimulation of the cervical medial branches may be used as an alternative treatment method in patients with CFP. PRF can effectively alleviate CFP, and is safe to perform.

The Effectiveness of Pulsed Radiofrequency on Joint Pain: A Narrative Review

BACKGROUND

Pulsed radiofrequency (PRF) stimulation has been safely and effectively applied for controlling various types of pain.

PURPOSE

We reviewed the literature on the efficacy of PRF for controlling pain in joint disorders.

METHODS

We searched PubMed for papers published prior to September 7, 2019, that used PRF to treat pain due to joint disorders. The key search phrases for identifying potentially relevant articles were (PRF AND joint) OR (PRF AND arthritis) OR (PRF AND arthropathy). The following inclusion criteria were applied for the selection of articles: (1) patients' pain was caused by joint disorders; (2) PRF stimulation was applied to manage joint-origin pain; and (3) after PRF stimulation, follow-up evaluation was performed to assess the reduction in pain intensity. Moreover, joints with more than 3 reported PRF studies were included in our review.

RESULTS

The primary literature search yielded 141 relevant papers. After reading their titles and abstracts and assessing their eligibility based on the full-text articles, we finally included 34 publications in this review. Based on the positive therapeutic outcomes of previous studies, PRF stimulation seems to be an effective treatment for cervical and lumbar facet, sacroiliac, knee, and glenohumeral joint pain. PRF appears to be beneficial. For confirmation of the effectiveness of PRF on joint pain, more high-quality studies are needed.

CONCLUSIONS

Our review provides insights on the degree of evidence according to pain in each joint, which will help clinicians make informed decisions for using PRF stimulation in various joint pain conditions.

Effects of whole spine alignment patterns on neck responses in rear end impact

OBJECTIVE

The aim of this study was to investigate the whole spine alignment in automotive seated postures for both genders and the effects of the spinal alignment patterns on cervical vertebral motion in rear impact using a human finite element (FE) model.

METHODS

Image data for 8 female and 7 male subjects in a seated posture acquired by an upright open magnetic resonance imaging (MRI) system were utilized. Spinal alignment was determined from the centers of the vertebrae and average spinal alignment patterns for both genders were estimated by multidimensional scaling (MDS). An occupant FE model of female average size (162 cm, 62 kg; the AF 50 size model) was developed by scaling THUMS AF 05. The average spinal alignment pattern for females was implemented in the model, and model validation was made with respect to female volunteer sled test data from rear end impacts. Thereafter, the average spinal alignment pattern for males and representative spinal alignments for all subjects were implemented in the validated female model, and additional FE simulations of the sled test were conducted to investigate effects of spinal alignment patterns on cervical vertebral motion.

RESULTS

The estimated average spinal alignment pattern was slight kyphotic, or almost straight cervical and less-kyphotic thoracic spine for the females and lordotic cervical and more pronounced kyphotic thoracic spine for the males. The AF 50 size model with the female average spinal alignment exhibited spine straightening from upper thoracic vertebra level and showed larger intervertebral angular displacements in the cervical spine than the one with the male average spinal alignment.

CONCLUSIONS

The cervical spine alignment is continuous with the thoracic spine, and a trend of the relationship between cervical spine and thoracic spinal alignment was shown in this study. Simulation results suggested that variations in thoracic spinal alignment had a potential impact on cervical spine motion as well as cervical spinal alignment in rear end impact condition.

Application of pulsed radiofrequency currents to rat dorsal root ganglia modulates nerve injury-induced tactile allodynia

BACKGROUND

Application of pulsed radiofrequency (PRF) currents to the dorsal root ganglia (DRG) has been reported to produce relief from certain pain states without causing thermal ablation. In this study, we examined the direct correlation between PRF application to DRG associated with spinal nerve injury and reversal of injury-induced behavioral hypersensitivity in a rat neuropathic pain model.

METHODS

Neuropathic lesioning was performed via left L5 spinal nerve ligation on male adult Sprague-Dawley rats. Once the injured rats had developed tactile allodynia, one group was then assigned to PRF treatment of the L5 DRG and another group was assigned to the sham treatment to the DRG. Behavioral testing was performed on both the control and treated paws using the von Frey filament test before the surgery and at indicated days. The resulting data were analyzed using a linear mixed model to assess the overall difference between the treatment groups and the overall difference among the study days. Cohen's d statistic was computed from paired difference-from-baseline scores for each of the 14 study days after treatment and these measures of effect size were then used to descriptively compare the recovery patterns over time for each study group.

RESULTS

Spinal nerve injury resulted in the development of behavioral hypersensitivity to von Frey filament stimulation (allodynia) in the hindpaw of the left (injury) side. Mixed linear modeling showed a significant difference between the treatment groups (P = 0.0079) and a significant change of paw withdrawal threshold means over time (P = 0.0006) for all 12 animals. Evaluation of Cohen's d (effect size) revealed that the PRF-treated animals exhibited better recovery and recorded larger effect sizes than the sham-treated animals on 10 of the 14 post-PRF treatment days and exhibited moderate-to-strong effects posttreatment at days 8 to 10 and at and beyond day 32.

CONCLUSIONS

Findings from this study support that PRF of the DRG causes reversal of nerve injury (spinal nerve ligation)-induced tactile allodynia in rats. This allodynia reversal indicates that nonablative PRF acting via modulation of the DRG can speed recovery in nerve injury-induced pain.

A research synthesis of therapeutic interventions for whiplash-associated disorder (WAD): part 5 - surgical and injection-based interventions for chronic WAD

Whiplash-associated disorder (WAD) represents a significant public health problem, resulting in substantial social and economic costs throughout the industrialized world. While many treatments have been advocated for patients with WAD, scientific support regarding their effectiveness is often lacking. A systematic review was conducted to evaluate the strength of evidence associated with various WAD therapies. Multiple databases (including Web of Science, EMBASE and PubMed) were searched to identify all studies published from January 1980 through March 2009 that evaluated the effectiveness of any well-defined treatment for acute (less than two weeks), subacute (two to 12 weeks) or chronic (more than 12 weeks) WAD. The present article, the fifth in a five-part series, evaluates the evidence for surgical and injection-based interventions initiated during the chronic phase of WAD. Twenty-five studies were identified that met the inclusion criteria, six of which were randomized controlled trials with 'good' overall methodological quality (median Physiotherapy Evidence Database score of 7.5). For the treatment of chronic WAD, there was moderate evidence supporting radiofrequency neurotomy as an effective treatment for whiplash-related pain, although relief is not permanent. Sterile water injections have been demonstrated to be superior to saline injections; however, it is not clear whether this treatment is actually beneficial. There was evidence supporting a wide range of other interventions (eg, carpal tunnel decompression) with each of these evaluated by a single nonrandomized controlled trial. There is contradictory evidence regarding the effectiveness of botulinum toxin injections, and cervical discectomy and fusion. The evidence is not yet strong enough to establish the effectiveness of any of these treatments; of all the invasive interventions for chronic WAD, radiofrequency neurotomy appears to be supported by the strongest evidence. Further research is required to determine the efficacy and the role of invasive interventions in the treatment of chronic WAD.

9. Painful shoulder complaints

Painful shoulder complaints have a high incidence and prevalence. The etiology is not always clear. Clinical history and the active and passive motion examination of the shoulder are the cornerstones of the diagnostic process. Three shoulder tests are important for the examination of shoulder complaints: shoulder abduction, shoulder external rotation, and horizontal shoulder adduction. These tests can guide the examiner to the correct diagnosis. Based on this diagnosis, in most cases, primarily a conservative treatment with nonsteroidal anti-inflammatory drugs possibly in combination with manual and/or exercise therapy can be started. When conservative treatment fails, injection with local anesthetics and corticosteroids can be considered. In the case of frozen shoulder, a continuous cervical epidural infusion of local anesthetic and small doses of opioids or a pulsed radiofrequency treatment of the nervus suprascapularis can be considered.

Ultrastructural changes in axons following exposure to pulsed radiofrequency fields

Pulsed radiofrequency (PRF) fields applied by an electrode to neural structures, such as the peripheral sensory nociceptor axons and dorsal root ganglion, are clinically effective in reducing pain and other neuropathic syndromes. However, a full understanding of the underlying mechanisms by which this occurs has not yet been clarified. In this study, PRF is applied to the afferent axons of the sciatic nerves of rats. A standard radiofrequency (RF) electrode and RF generator is used to apply the RF signal output to the sciatic nerve using standard PRF parameters that have been successfully used in clinical practice. The ultrastructure of the treated axons is observed after 10 days by electron microscopy. A control, sham application is simultaneously applied to the contralateral sciatic nerve to provide a statistical differential comparison. It is found that the internal ultrastructural components of the axons show microscopic damage after PRF exposure, including: abnormal membranes and morphology of mitochondria, and disruption and disorganization of microfilaments and microtubules. The damage appears to be more pronounced for C-fibers than for A-delta and A-beta fibers. The results are discussed in terms of internal electric field strengths and thermodynamic parameters.