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

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.

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.

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