The Effect of Sensory Stimulation Threshold on the Efficacy of Pulsed Radiofrequency Applied to the Dorsal Root Ganglion in Patients with Chronic Lumbar Radicular Pain

NCT ID: NCT06756893

Last Updated: 2025-01-03

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Total Enrollment: 150 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2025-01-01
• Study Completion Date: 2025-10-01

Brief Summary

Lomber dorsal root ganglion pRF is an interventional treatment options in the treatment of lumbar radicular pain. The goal of this study is to investigate the effect of sensory threshold outcomes on pain severity during dorsal root ganglion pulsed radiofrequency (DRG-pRF). It will also learn effects about disability due to chronic LRP. The main questions it aims to answer are:

Does lower sensory threshold result in lower pain scores and chronic LRP related disability?

Participants will:

Take DRG-pRF procedure for 4 minutes. Visit the clinic at 1. and 3. month for questionnaries.

Detailed Description

Lumbar radicular pain is characterized by sharp, stabbing, or throbbing pain radiating to one or more dermatomes. It is a common and challenging condition for clinicians to manage in pain practice. Conservative treatments such as physical therapy, non-steroidal anti-inflammatory drugs, rest, and exercise may fail, leading to chronic pain. In such cases, minimally invasive methods such as epidural steroid injection (ESI) or pulsed radiofrequency (pRF) of the dorsal root ganglion (DRG) may be preferred.

Unlike conventional radiofrequency, pRF does not cause ablation. Due to the intermittent delivery of energy generated by the electric current, the target tissue temperature does not exceed 42°C. This creates a magnetic field that modulates pain without causing neuronal damage.

The DRG, highly sensitive to mechanical compression, is a critical target in radicular pain. There is evidence supporting the efficacy of DRG pRF in chronic lumbar radicular pain. Studies comparing pRF alone or in combination with ESI versus ESI alone have found it effective in providing long-term pain relief. However, despite the increasing body of evidence, studies are lacking on the impact of the proximity of pRF to the target neuronal tissue on clinical outcomes.

The primary aim of this study is to investigate the relationship between the sensory stimulation threshold, indicating the proximity to the target tissue during DRG pRF, and the reduction in Numeric Rating Scale (NRS) scores at the 3-month follow-up. Secondary objectives include examining the relationship between Oswestry Disability Index (ODI) and NRS scores at various assessment time points.

The DRG, highly sensitive to mechanical compression, is a critical target in radicular pain (5,6). There is evidence supporting the efficacy of DRG pRF in chronic lumbar radicular pain. Studies comparing pRF alone or in combination with ESI versus ESI alone have found it effective in providing long-term pain relief (7). However, despite the increasing body of evidence, studies are lacking on the impact of the proximity of pRF to the target neuronal tissue on clinical outcomes.

The primary aim of this study is to investigate the relationship between the sensory stimulation threshold, indicating the proximity to the target tissue during DRG pRF, and the reduction in Numeric Rating Scale (NRS) scores at the 3-month follow-up. Secondary objectives include examining the relationship between Oswestry Disability Index (ODI) and NRS scores at various assessment time points.

Conditions

Dorsal Root Ganglion; Pulsed Radiofrequency; Chronic Pain; Lumbar Radiculopathy; Lumbar Spinal Stenosis

Study Design

• Observational Model Type: CASE_ONLY
• Study Time Perspective: PROSPECTIVE

Study Groups

Dorsal Root Ganglion Pulsed Radiofrequency

Dorsal Root Ganglion Pulsed Radiofrequency

Intervention Type: PROCEDURE

Using C-arm fluoroscopy, a 22G, 10 cm RF needle with a 5 mm active tip will be directed from lateral to medial towards the vertebral foramen. Once the needle reaches the lateral edge of the pedicle shadow, the C-arm will be adjusted to a lateral view to confirm that the needle is located at the craniodorsal portion of the intervertebral foramen. Sensory stimulation will be delivered through the RF generator at 50 Hz, and paresthesia will be sought in the corresponding dermatome at values between 0.4-0.8 mA.

After achieving paresthesia, motor stimulation at 2 Hz will be applied, and the location near the DRG will be confirmed if motor stimulation is not elicited at values less than 1.5 times the sensory threshold. Pulsed RF will then be applied for 4 minutes at a setting of 45 V, 20 ms pulse width, and 2 Hz frequency. Following the application, needle will be directed slightly anterior and after appropriate contrast flow, dexamethasone will be injected.

Interventions

Dorsal Root Ganglion Pulsed Radiofrequency

Using C-arm fluoroscopy, a 22G, 10 cm RF needle with a 5 mm active tip will be directed from lateral to medial towards the vertebral foramen. Once the needle reaches the lateral edge of the pedicle shadow, the C-arm will be adjusted to a lateral view to confirm that the needle is located at the craniodorsal portion of the intervertebral foramen. Sensory stimulation will be delivered through the RF generator at 50 Hz, and paresthesia will be sought in the corresponding dermatome at values between 0.4-0.8 mA.

After achieving paresthesia, motor stimulation at 2 Hz will be applied, and the location near the DRG will be confirmed if motor stimulation is not elicited at values less than 1.5 times the sensory threshold. Pulsed RF will then be applied for 4 minutes at a setting of 45 V, 20 ms pulse width, and 2 Hz frequency. Following the application, needle will be directed slightly anterior and after appropriate contrast flow, dexamethasone will be injected.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

Pain lasting ≥3 months NRS score ≥4 Unilateral pain Diagnosis of spinal stenosis or lumbar disc herniation causing root compression, confirmed by magnetic resonance imaging (MRI) according to appropriate diagnostic criteria and classification Failure of conservative treatment

Exclusion Criteria

Unwillingness to participate in the study Epidural steroid injection within the past month Uncontrolled psychiatric disorders despite medical treatment Systemic or localized infection signs at the procedure site Severe spinal stenosis Allergy to steroids or contrast agents History of cancer Coagulopathy

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Ankara University

OTHER

Sponsor Role: lead

Responsible Party

Hanzade Aybuke Unal

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Güngör Enver Özgencil, MD

Role: STUDY_DIRECTOR

Ankara University Medicine Faculty Anesthesiology and Reanimation Department

Central Contacts

Hanzade Aybuke Unal, MD

Role: CONTACT

hanzadeunal@windowslive.com

+905057179039

Ersin Sönmez, MD

Role: CONTACT

ersins@outlook.com

+905370257858

References

Cohen SP, Strassels SA, Kurihara C, Lesnick IK, Hanling SR, Griffith SR, Buckenmaier CC 3rd, Nguyen C. Does sensory stimulation threshold affect lumbar facet radiofrequency denervation outcomes? A prospective clinical correlational study. Anesth Analg. 2011 Nov;113(5):1233-41. doi: 10.1213/ANE.0b013e31822dd379. Epub 2011 Sep 14.

Reference Type: BACKGROUND

PMID: 21918166 (View on PubMed)

Park S, Park JH, Jang JN, Choi SI, Song Y, Kim YU, Park S. Pulsed radiofrequency of lumbar dorsal root ganglion for lumbar radicular pain: A systematic review and meta-analysis. Pain Pract. 2024 Jun;24(5):772-785. doi: 10.1111/papr.13351. Epub 2024 Jan 31.

Reference Type: BACKGROUND

PMID: 38294072 (View on PubMed)

Other Identifiers

2024/766

Identifier Type: -

Identifier Source: org_study_id