Pulsed Radiofrequency Increases Nestin and Matrix Metalloproteinase-2 Expression in Porcine Lumbar Dorsal Root Ganglion.

Background: Pulsed radiofrequency (PRF) has been used for the treatment of chronic lumbar radicular pain and other chronic pain states. The dorsal root ganglion (DRG) consists of primary afferent somatic and visceral nerve cell bodies that transduce sensory signals from the periphery to the central part of the nervous system. It is a very important part of acute nociception, as well as the development and maintenance of chronic pain. Methods: A total of seven domestic pigs were investigated. All pigs underwent a PRF procedure while under general anesthesia and with X-ray imaging. Four lumbar DRGs were randomly treated. We used the opposite side of the DRGs as controls. The lumbar region of the spine was placed in 10% formaldehyde for one month. After this fixation, DRG samples were prepared for slide analysis. Results: Nestin (Nes, code-Nr. AB 5968, dilution 1:250, rabbit, Abcam, United Kingdom) and matrix metallopeptidase 2 (MMP-2, code-Nr. DUB 03, dilution 1:100, goat) expressions were detected by immunohistochemical staining. The cell numbers with Nes (28.4 ± 3.3 vs. 16.1 ± 3.4; P < 0.05) and MMP-2 (26.2 ± 3.2 vs. 14.1 ± 2.3; P < 0.05) expressions were larger on the PRF side compared to the control side. The glial cells in the spinal ganglia on both sides showed immunoreactivity. Conclusions: The increase of MMP-2-containing gangliocytes one month after PRF procedures highlights active neural cell proliferation. Increased Nes factor expression in spinal gangliocytes of the lumbar region indicates neural remodeling and regeneration.

The response to radiofrequency neurotomy of medial branches including a bipolar system for thoracic facet joints.

Background and aims The evidence for interventional treatment of thoracic facet joint pain remains limited. This is partly due to inconsistency of the path of thoracic medial branches and a lower incidence of thoracic facet pain among spine pain patients. The purpose of this study is to evaluate the efficacy of bipolar radiofrequency (RF) neurotomy of medial branches for treating chronic thoracic facet joint pain. Methods This is a retrospective record review of all patients diagnosed to have thoracic facet pain with diagnostic block and subsequently treated with bipolar RF neurotomy of medial branch between January 2012 and December 2015. The outcome measures were mean changes in Numeral Rating Scale (NRS) and Pain Disability Index (PDI). Results There were 71 patients with complete data available for analysis. The mean age of the patients was 57.9±11.2 years. The mean duration of pain was 23±10.5 months. The majority of patients (82%) had pain reduction of more than 50% at 12 months after bipolar RF neurotomy. The NRS decreased significantly from baseline of 7.75±1.25 to 2.86±1.53 at 3 months and 2.82±1.29 at 12 months post-procedure (p<0.001. p<0.001, respectively). The PDI improved significantly from 40.92±12.22 to 24.15±9.79, p<0.05). There were no serious adverse effects or complications of the procedure reported in this study. Conclusions Bipolar RF neurotomy of thoracic medial branch is associated with a significant reduction in thoracic facet joint pain. The promising findings from this case series merit further assessment with prospective, randomized controlled trial which will produce a more reliable and accurate finding for its clinical applications.

Caudal Epidural of Pulsed Radiofrequency in Post Herpetic Neuralgia (PHN); Report of Three Cases.

INTRODUCTION: Postherpetic neuralgia (PHN) is a frequently occurring neuropathic pain, its pathophysiology is not fully understood. There are only few evidence based therapeutic options; sympathetic nerve block can be considered for patients with PHN refractory to conservative treatment, but long-term effects are poor. Application of pulsed radiofrequency was effective to treat a variety of pain syndromes without neurological complications or other sequelae. CASE PRESENTATION: We observed a remarkable long-lasting pain relief in patients with post herpetic neuralgia (PHN) treated with caudal epidural PRF. We described the technique of caudal epidural PRF and three case reports. CONCLUSIONS: The mode of action of PRF is far from being completely elucidated. The high frequency current induces an electric field that in turn seems to influence the immunity, the inflammation and other pain conducting mechanisms. Our findings suggest an effect distal from the application of the current. It reaches targets that are difficultly attainable by any other means of current application. The observations of pain relief in the difficult to treat patients with PHN justifies further investigation.

Intradiscal pulsed radiofrequency for chronic lumbar discogenic low back pain: a one year prospective outcome study using discoblock for diagnosis.

BACKGROUND: Discogenic pain is an important cause of low back pain (LBP). We have developed a pulsed radiofrequency (PRF) technique, using Diskit II needles (NeuroTherm, Middleton, MA, USA) placed centrally in the disk, for applying radiofrequency current in the disc (Intradiscal PRF method). OBJECTIVE: The purpose of this study was to investigate the effect of this intradiscal pulsed radiofrequency method in patients with chronic discogenic LBP diagnosed by discoblock, in terms of pain relief and reduction of disability. STUDY DESIGN: Prospective case series clinical outcome study. METHODS: The participants consisted of 23 patients with a mean age of 35.3 ± 9.86 years with chronic discogenic LBP that was not responsive to aggressive nonoperative care. A Diskit II needle (15-cm length, 20G needle with a 20-mm active tip) was placed centrally in the disc. PRF was applied for 15 minutes at a setting 5x5 ms/s and 60 V. Outcome measures included the pain intensity score on a 0-10 numeric rating scale (NRS) and the Roland-Morris Disability Questionnaire (RMDQ) at pre-treatment, one, 3, 6, and 12 months post-treatment. RESULTS: The mean pain severity scores (NRS) improved significantly from 7.47 ± 0.85 pre-treatment to 3.13 ± 2.58 at the 12 month follow-up (P < 0.01). The RMDQ showed significant (P < 0.01) improvement from 11.4 ± 1.57 pre-treatment to 2.90 ± 2.97 at the 12 month follow-up (P < 0.01). Nineteen of 23 (82.6%) of the patients demonstrated NRS improvements of greater than 2, and 15 of 23 (65.2%) had > 50% pain reduction, 12 months after treatment. LIMITATIONS: The number of patients was relatively low and secondary outcomes such as medication requirement or psychological effects were not addressed. CONCLUSIONS: This intradiscal PRF method with consecutive PRF 5/5/60V, 15 min (with Diskit needle) appears to be a safe, minimally invasive treatment option for patients with chronic discogenic LBP.

Results of intradiscal pulsed radiofrequency for lumbar discogenic pain: comparison with intradiscal electrothermal therapy.

BACKGROUND: We have developed an intradiscal pulsed radiofrequency (Disc PRF) technique, using Diskit II® needles (NeuroTherm, Wilmington, MA, USA), as a minimally invasive treatment option for chronic discogenic low back pain (LBP). The purpose of this study was to compare the representative outcomes of Disc PRF and Intradiscal Electrothermal Therapy (IDET) in terms of pain relief and reduction of disability. METHODS: Thirty-one patients with chronic discogenic LBP who underwent either Disc PRF (n = 15) or IDET (n = 16) were enrolled in the study. A Diskit II® needle (15-cm length, 20-gauge needle with a 20-mm active tip) was placed centrally in the disc. PRF was applied for 15 min at a setting of 5 × 50 ms/s and 60 V. The pain intensity score on a 0-10 numeric rating scale (NRS) and the Roland-Morris Disability Questionnaire (RMDQ) were assessed pretreatment and at 1, 3, and 6 months post-treatment. RESULTS: The mean NRS was significantly improved from 7.2 ± 0.6 pretreatment to 2.5 ± 0.9 in the Disc PRF group, and from 7.5 ± 1.0 to 1.7 ± 1.5 in the IDET group, at the 6-month follow-up. The mean RMDQ also showed significant improvement in both the Disc PRF group and the IDET group at the 6-month follow-up. There were no significant differences in the pretreatment NRS and RMDQ scores between the groups. CONCLUSIONS: Disc PRF appears to be an alternative to IDET as a safe, minimally invasive treatment option for patients with chronic discogenic LBP.

Results of pulsed radiofrequency technique with two laterally placed electrodes in the annulus in patients with chronic lumbar discogenic pain.

Discogenic pain is an important cause of low back pain (LBP). We have developed a pulsed radiofrequency (P-RF) technique, using two electrodes placed bilaterally in the annulus, for applying radiofrequency current in the disc (bi-annular P-RF disc method). The purpose of this study was to investigate the effect of the bi-annular P-RF disc method, using Diskit needles (Neurotherm, Middleton, MA, USA) in patients with discogenic LBP. The subjects were 15 patients with a mean age of 37.3 ± 8.63 years with chronic discogenic lower back pain that was not responsive to aggressive nonoperative care. Two Diskit II needles (15-cm length, 20G needles with a 20-mm active tip) were placed bilaterally in the annulus in the disc. Pulsed radiofrequency was applied for 12 min at a setting of 5 × 50 ms/s and 60 V. The pain intensity scores on a 0-10 numeric rating scale (NRS) and the Roland-Morris Disability Questionnaire (RMDQ) were measured pretreatment, and at 1 week and 1, 3, and 6 months post-treatment. The mean pain severity score (NRS) improved from 7.27 ± 0.58 pretreatment to 2.5 ± 0.94 at the 6-month follow-up (p < 0.01). The RMDQ showed significant (p < 0.01) improvement, from 10.70 ± 2.35 pretreatment to 2.10 ± 1.85 at the 6-month follow up (p < 0.01). The bi-annular P-RF disc method with consecutive P-RF 5/5/60 V, 12-min (with Diskit needle), appears to be a safe, minimally invasive treatment option for patients with chronic discogenic LBP.

Intradiscal pulsed radiofrequency application following provocative discography for the management of degenerative disc disease and concordant pain: a pilot study.

The development of diagnostic criteria and the use of provocative discography allow identifying the degenerative disc as causative structure for chronic low-back pain. Unfortunately, none of the available interventional treatment options have been demonstrated to be effective over a prolonged period of time for a considerable number of patients. Pathophysiological studies indicate sprouting of sensory nerves and inflammatory processes as underlying pain mechanisms. Pulsed radiofrequency (PRF) treatment in small and larger joints was described to reduce pain and improve healing by stimulating the immunology. Earlier findings of PRF applied in the disc annulus were promising. It is assumed that PRF applied in the nucleus would change the conductivity of nerve endings and provide a clinically relevant pain reduction. The application of the electric field of PRF in the disc may also activate the immune system, thus reducing the inflammation process of chronic pain. Pulsed radiofrequency in the nucleus was studied in 76 patients with discogenic pain confirmed by magnetic resonance imaging and provocative discography. At 3-month follow-up, 38% of the patients had > 50% pain reduction, at 12 month the effect is maintained in 29%. In patients with unsatisfactory pain relief 3 months after the intervention, secondary pain sources may have been revealed. The latter were treated accordingly. Of all patients, 56% had > 50% pain reduction 1 year after first treatment. Our findings suggest that PRF in the nucleus may be considered for patients with proven discogenic pain. A randomized controlled trial to confirm our findings is justified.▪

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.