Lumbar Radiofrequency Ablation Interfering With S1 Dorsal Root Ganglion Stimulation Systems: Experience From Two Cases

Abstract

Background Dorsal root ganglion stimulation (DRG‐S) has emerged as a treatment for complex regional pain syndrome (CRPS) of the lower extremities, and recent small studies are demonstrating its potential efficacy in pain syndromes that are traditionally considered nociceptive in nature, such as axial low back pain. While improvements in neuromodulation technology have been substantial over the past decade, with DRG‐S systems patients occasionally require additional interventional pain treatments for treatment of pain from other sources. Radiofrequency ablation (RFA) of medial branch nerves innervating the facet joints is an accepted therapy for pain arising from the facet joints. Methods We describe 2 cases from the same practice where we observed similar phenomena while performing a 2‐needle monopolar lumbar RFA in patients with a DRG‐S system implanted with leads positioned bilaterally at the S1 DRGs. Results Initiation of RFA resulted in motor activation and discomfort in an S1 distribution in the legs in both individual cases. Conclusions RFA can interfere with implanted DRG‐S systems, resulting in overstimulation with motor recruitment. Specific anatomical considerations and device settings that may prevent interference are discussed.

Best Practices for Dorsal Root Ganglion Stimulation for Chronic Pain: Guidelines from the American Society of Pain and Neuroscience

“…In addition to losing ability for device connection, there is a possibility that motor or painful stimulation may occur if the device remains in the "on mode". 231,232 The authors recommend ensuring patient and clinician awareness of various safety steps in protecting the patient and DRG-S device during MRI and radiofrequency energy exposure.…”

The American Society of Pain and Neuroscience (ASPN) Guidelines for Radiofrequency Ablative Procedures in Patients with Implanted Devices

“…Grade B, low level of certainty (Table 5). 15 Careful consideration should be used before using radiofrequency (RF) or microwave ablation in patients who have an implanted neurostimulation system since safety has not been established. Induced electrical currents may cause heating, especially at the lead electrode site, resulting in tissue damage Boston Scientific 38 -no RFA specific recommendation Electrocautery can transfer destructive current into the DBS Leads and/or Stimulator.…”

“…Spinal cord stimulators (SCS) have been used for chronic pain treatment since 1967. 15 , 16 The mechanism of action is explained mostly by Gate Control Theory, which proposes that non-painful stimuli “close” the gate, prevent transmission of painful afferent signals via wide-dynamic range neurons to the brain, and attenuate perception of pain. 16 Other subsequent theories proposed include dorsal horn GABAergic inhibitory interneurons, supraspinal involvement, and vasculature involvement in ischemic pain.…”

Magnetic resonance imaging scans in patients with dorsal root ganglion stimulation

“…10 Unlike SCS, which is the closest system to a DRG-S, the dorsal root ganglion (DRG) is characterized by a thin surrounding layer of cerebrospinal fluid and it can access small fiber nerves that are more susceptible to injury. 11 The RF energy can cause overstimulation or motor stimulation, 12 and it can interfere with RF wireless communication technologies, such as Bluetooth. The major concern with MRI and DRG-S is thermal injury to the DRG and the IPG malfunction.…”