Selective Radiofrequency Stimulation of the Dorsal Root Ganglion (DRG) as a Method for Predicting Targets for Neuromodulation in Patients With Post Amputation Pain: A Case Series

Intraoperative Neurophysiological Monitoring During Lead Placement for Dorsal Root Ganglion Stimulation: A Literature Review and Case Series

INTRODUCTION

Dorsal root ganglion stimulation (DRG-S) is a viable interventional option for intractable pain management. Although systematic data are lacking regarding the immediate neurologic complications of this procedure, intraoperative neurophysiological monitoring (IONM) can be a valuable tool to detect real-time neurologic changes and prompt intervention(s) during DRG-S performed under general anesthesia and deep sedation.

MATERIALS AND METHODS

In our single-center case series, we performed multimodal IONM, including peripheral nerve somatosensory evoked potentials (pnSSEPs) and dermatomal somatosensory evoked potentials (dSSEPs), spontaneous electromyography (EMG), transcranial motor evoked potentials (MEPs), and electroencephalogram (EEG) for some trials and all permanent DRG-S lead placement per surgeon preference. Alert criteria for each IONM modality were established before data acquisition and collection. An IONM alert was used to implement an immediate repositioning of the lead to reduce any possible postoperative neurologic deficits. We reviewed the literature and summarized the current IONM modalities commonly applied during DRG-S, including somatosensory evoked potentials and EMG. Because DRG-S targets the dorsal roots, we hypothesized that including dSSEP would allow more sensitivity as a proxy for potential sensory changes under generalized anesthesia than would including standard pnSSEPs.

RESULTS

From our case series of 22 consecutive procedures with 45 lead placements, one case had an alert immediately after DRG-S lead positioning. In this case, dSSEP attenuation was seen, indicating changes in the S1 dermatome, which occurred despite ipsilateral pnSSEP from the posterior tibial nerve remaining at baselines. The dSSEP alert prompted the surgeon to reposition the S1 lead, resulting in immediate recovery of the dSSEP to baseline status. The rate of IONM alerts reported intraoperatively was 4.55% per procedure and 2.22% per lead (n = 1). No neurologic deficits were reported after the procedure, resulting in no postoperative neurologic complications or deficits. No other IONM changes or alerts were observed from pnSSEP, spontaneous EMG, MEPs, or EEG modalities. Reviewing the literature, we noted challenges and potential deficiencies when using current IONM modalities for DRG-S procedures.

CONCLUSIONS

Our case series suggests dSSEPs offer greater reliability than do pnSSEPs in quickly detecting neurologic changes, and subsequent neural injury, during DRG-S cases. We encourage future studies to focus on adding dSSEP to standard pnSSEP to provide a comprehensive, real-time neurophysiological assessment during lead placement for DRG-S. More investigation, collaboration, and evidence are required to evaluate, compare, and standardize comprehensive IONM protocols for DRG-S.

Evolving techniques for reducing phantom limb pain

At least two million people in the United States of America live with lost limbs, and the number is expected to double by 2050, although the incidence of amputations is significantly greater in other parts of the world. Within days to weeks of the amputation, up to 90% of these individuals develop neuropathic pain, presenting as phantom limb pain (PLP). The pain level increases significantly within one year and remains chronic and severe for about 10%. Amputation-induced changes are considered to underlie the causation of PLP. Techniques applied to the central nervous system (CNS) and peripheral nervous system (PNS) are designed to reverse amputation-induced changes, thereby reducing/eliminating PLP. The primary treatment for PLP is the administration of pharmacological agents, some of which are considered but provide no more than short-term pain relief. Alternative techniques are also discussed, which provide only short-term pain relief. Changes induced by various cells and the factors they release are required to change neurons and their environment to reduce/eliminate PLP. It is concluded that novel techniques that utilize autologous platelet-rich plasma (PRP) may provide long-term PLP reduction/elimination.

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

With continued innovations in neuromodulation comes the need for evolving reviews of best practices. Dorsal root ganglion stimulation (DRG-S) has significantly improved the treatment of complex regional pain syndrome (CRPS), and it has broad applicability across a wide range of other conditions. Through funding and organizational leadership by the American Society for Pain and Neuroscience (ASPN), this best practices consensus document has been developed for the selection, implantation, and use of DRG stimulation for the treatment of chronic pain syndromes. This document is composed of a comprehensive narrative literature review that has been performed regarding the role of the DRG in chronic pain and the clinical evidence for DRG-S as a treatment for multiple pain etiologies. Best practice recommendations encompass safety management, implantation techniques, and mitigation of the potential complications reported in the literature. Looking to the future of neuromodulation, DRG-S holds promise as a robust intervention for otherwise intractable pain.

Consensus Guidelines on Interventional Therapies for Knee Pain (STEP Guidelines) from the American Society of Pain and Neuroscience

Knee pain is second only to the back as the most commonly reported area of pain in the human body. With an overall prevalence of 46.2%, its impact on disability, lost productivity, and cost on healthcare cannot be overlooked. Due to the pervasiveness of knee pain in the general population, there are no shortages of treatment options available for addressing the symptoms. Ranging from physical therapy and pharmacologic agents to interventional pain procedures to surgical options, practitioners have a wide array of options to choose from – unfortunately, there is no consensus on which treatments are “better” and when they should be offered in comparison to others. While it is generally accepted that less invasive treatments should be offered before more invasive ones, there is a lack of agreement on the order in which the less invasive are to be presented. In an effort to standardize the treatment of this extremely prevalent pathology, the authors present an all-encompassing set of guidelines on the treatment of knee pain based on an extensive literature search and data grading for each of the available alternative that will allow practitioners the ability to compare and contrast each option.

Dorsal Root Ganglion Stimulation for Lower Extremity Neuropathic Pain Syndromes: An Evidence-Based Literature Review

Dorsal root ganglion stimulation (DRG-S) is a form of selective neuromodulation therapy that targets the dorsal root ganglion. DRG-S offers analgesia in a variety of chronic pain conditions and is approved for treatment of complex regional pain syndrome (CRPS) by the US Food and Drug Administration (FDA). There has been increasing utilization of DRG-S to treat various neuropathic pain syndromes of the lower extremity, although evidence remains limited to one randomized controlled trial and 39 observational studies. In this review, we appraised the current evidence for DRG-S in the treatment of lower extremity neuropathic pain using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria. The primary outcome was change in pain intensity after DRG-S compared to baseline. We stratified presentation of results based of type of neuropathy (CRPS, painful diabetic neuropathy, mononeuropathy, polyneuropathy) as well as location of neuropathy (hip, knee, foot). Future powered randomized controlled trials with homogeneous participants are warranted.

Stimulation of the dorsal root ganglion using an Injectrode®

Objective. The goal of this work was to compare afferent fiber recruitment by dorsal root ganglion (DRG) stimulation using an injectable polymer electrode (Injectrode^®) and a more traditional cylindrical metal electrode.Approach. We exposed the L6 and L7 DRG in four cats via a partial laminectomy or burr hole. We stimulated the DRG using an Injectrode or a stainless steel (SS) electrode using biphasic pulses at three different pulse widths (80, 150, 300μs) and pulse amplitudes spanning the range used for clinical DRG stimulation. We recorded antidromic evoked compound action potentials (ECAPs) in the sciatic, tibial, and common peroneal nerves using nerve cuffs. We calculated the conduction velocity of the ECAPs and determined the charge-thresholds and recruitment rates for ECAPs from Aα, Aβ, and Aδfibers. We also performed electrochemical impedance spectroscopy measurements for both electrode types.Main results. The ECAP thresholds for the Injectrode did not differ from the SS electrode across all primary afferents (Aα, Aβ, Aδ) and pulse widths; charge-thresholds increased with wider pulse widths. Thresholds for generating ECAPs from Aβfibers were 100.0 ± 32.3 nC using the SS electrode, and 90.9 ± 42.9 nC using the Injectrode. The ECAP thresholds from the Injectrode were consistent over several hours of stimulation. The rate of recruitment was similar between the Injectrodes and SS electrode and decreased with wider pulse widths.Significance. The Injectrode can effectively excite primary afferents when used for DRG stimulation within the range of parameters used for clinical DRG stimulation. The Injectrode can be implanted through minimally invasive techniques while achieving similar neural activation to conventional electrodes, making it an excellent candidate for future DRG stimulation and neuroprosthetic applications.

The role of periradicular infiltration in dorsal root ganglion stimulation for chronic neuropathic pain

Background

Targeting the correct spinal level is essential in dorsal root ganglion (DRG) stimulation. Anatomical selection of the DRG alone is not ideal since the pain area is not necessarily confined to the borders of the dermatomes. This study aims to establish the role of periradicular infiltration therapy (PRT) in the preoperative assessment of the correct level for DRG stimulation performed under general anesthesia.

Method

We report a prospective study of 20 patients selected for DRG stimulation and submitted to a PRT for identification of the spinal level. Lead implantation for the stimulation trial occurred under general anesthesia: 19 patients experienced positive results and underwent implantation of the pulse generator. All patients suffered from chronic neuropathic pain unresponsive to best medical treatment. PRT levels were compared with the levels targeted with DRG leads. Patients were followed for up to 12 months; pain intensity and coverage of the painful area were assessed.

Results

In 12 patients, the trial leads were placed on the same level as previously tested positive by PRT. In 6 patients, leads were placed in the PRT target and additionally in adjacent spinal levels. In one case, the selected target for the trial diverged from the PRT target because of intense fibrosis in the chosen level. Coverage of the target area of at least 50% was achieved by two-thirds of the patients. For the six subjects with additional implanted leads as a consequence of the PRT results, 80% achieved a coverage of at least 50%. A total of 47.4% of the patients achieved sustained significant pain relief in the last follow-up. None of the patients needed a repeated surgery for implantation of additional leads.

Conclusions

PRT is a helpful tool to confirm the stimulation targets. A PRT preceding the stimulation trial is an additional opportunity to optimize the coverage of the target area with stimulation-induced paresthesia for patients operated under general anesthesia.

The Use of Peripheral Nerve Stimulation in Conjunction with TMR for Neuropathic Pain

Targeted muscle reinnervation and regenerative peripheral nerve interfaces are increasingly utilized strategies to mitigate phantom and residual limb pain in amputees. These interventions are successful, yet often imperfect in completely ameliorating neuropathic pain following amputation. Implantable peripheral nerve stimulators are another tool in the armamentarium for management of neuropathic pain. These devices have been utilized adjacent to the spinal cord and more recently in the extremities with good results, and there has been additional interest in their utility for nerve regeneration. In this case report, we present the first reported case in the readily available literature of combining contemporary peripheral nerve strategies with an implantable peripheral nerve stimulator for postamputation neuropathic pain. The patient is a 72-year-old man who presented with severe neuropathic pain following prior below knee amputation with an osseointegrated implant and regenerative peripheral nerve interfaces. The authors performed targeted muscle reinnervation with intra-operative placement of a peripheral nerve stimulator. He did well after the procedure, and his pain improved with activation of the device. The most symptomatic nerve is targeted with the nerve stimulator, and it is placed adjacent to the nerve transfer(s). Combining these contemporary techniques may lead to improved prosthetic use and quality of life for these patients.

Successful application of burst spinal cord stimulation for refractory upper limb pain: a case series

Spinal cord stimulation (SCS) has been used to treat sustained pain that is intractable despite various types of treatment. However, conventional tonic waveform SCS has not shown promising outcomes for spinal cord injury (SCI) or postamputation pain. The pain signal mechanisms of burst waveforms are different to those of conventional tonic waveforms, but few reports have presented the therapeutic potential of burst waveforms for the abovementioned indications. This current case report describes two patients with refractory upper limb pain after SCI and upper limb amputation that were treated with burst waveform SCS. While the patients could not obtain sufficient therapeutic effect with conventional tonic waveforms, the burst waveforms provided better pain reduction with less discomfort. However, further studies are necessary to better clarify the mechanisms and efficacy of burst waveform SCS in patients with intractable pain.

Diagnosis and Treatment of Sciatica in the Netherlands: A Survey among Neurologists and Anesthesiologists

BACKGROUND

This study aimed to assess how Dutch neurologists and anesthesiologists diagnose and treat people with sciatica in secondary care and to evaluate their adherence to the newest guidelines.

METHODS

We conducted a cross-sectional survey. Respondents were asked about their current clinical practice related to sciatica. Three authors rated the respondents' adherence to the guidelines on a three-point Likert scale.

RESULTS

Eighty neurologists and 44 anesthesiologists completed the questionnaire. Neurologists diagnose their sciatica patients primarily using a magnetic resonance imaging (89%). Selective diagnostic nerve blocks are considered useful by 81% of the neurologists. Neurologists primarily treat patients with pain medication, and 40% of them think epidural steroid injections are effective in 40-60% of injected patients. Twenty-nine percent of neurologists refer patients to a neurosurgeon after 4 months. Anesthesiologists consider a selective diagnostic nerve root block to have a higher diagnostic value than mapping. The most reported side effect of epidural injections is exacerbation of pain (82%). Pulse radiofrequency is applied in 9-11% of acute cases. The results also indicate that Dutch neurologists and anesthesiologists follow an evidence-based approach that is strictly or broadly in line with the guideline.

CONCLUSIONS

Neurologists treat sciatica patients initially with pain medication and physiotherapy, followed by epidural steroid injections and referral for surgery. Anesthesiologists treat sciatica patients with one or more steroid injections or may perform a selective nerve root block. Imaging, selective nerve root blocks, medication, physiotherapy, and pulse radiofrequency are topics of further research.

Dorsal Root Ganglion (DRG) and Chronic Pain

Context

Chronic neuropathic pain is a common condition, and up to 11.9% of the population have been reported to suffer from uncontrolled neuropathic pain. Chronic pain leads to significant morbidity, lowered quality of life, and loss of workdays, and thus carries a significant price tag in healthcare costs and lost productivity. dorsal root ganglia (DRG) stimulation has been recently increasingly reported and shows promising results in the alleviation of chronic pain. This paper reviews the background of DRG stimulation, anatomical, and clinical consideration and reviews the clinical evidence to support its use.

Evidence Acquisition

The DRG span the length of the spinal cord and house the neurons responsible for sensation from the periphery. They may become irritated by direct compression or local inflammation. Glial cells in the DRG respond to nerve injury, producing inflammatory markers and contribute to the development of chronic pain, even after the resolution of the original insult. While the underlying mechanism is still being explored, recent studies explored the efficacy of DRG stimulation and neuromodulation for chronic pain treatment.

Results

Several reported cases and a small number of randomized trials were published in recent years, describing different methods of DRG stimulation and neuromodulation with promising results. Though evidence quality is mostly low, these results provide evidence to support the utilization of this technique.

Conclusions

Chronic neuropathic pain is a common condition and carries significant morbidity and impact on the quality of life. Recent evidence supports the use of DRG neuromodulation as an effective technique to control chronic pain. Though studies are still emerging, the evidence appears to support this technique. Further studies, including large randomized trials evaluating DRG modulation versus other interventional and non-interventional techniques, are needed to further elucidate the efficacy of this method. These studies are also likely to inform the patient selection and the course of treatment.

Dorsal Root Ganglion Stimulation for the Treatment of Non-Complex Regional Pain Syndrome Related Chronic Pain Syndromes: A Systematic Review

BACKGROUND

While the majority of indications and approvals for dorsal root ganglion stimulation (DRGS) are for the refractory management of complex regional pain syndrome (CRPS), emerging evidence has suggested that DRGS may be favorably used for a plethora of other chronic pain phenomena. Consequently, we aimed to characterize the use and efficacy of DRGS for these non-CRPS-related chronic pain syndromes.

MATERIALS AND METHODS

A systematic review of clinical studies demonstrating the use of DRGS for non-CRPS-related chronic pain syndromes. The literature search was performed using PubMed, Cochrane Library, and CINAHL plus across August and September 2020.

RESULTS

A total of 28 reports comprising 354 total patients were included in the analysis. Of the chronic pain syndromes presented, axial low back pain, chronic pelvic and groin pain, other peripheral neuropathies, and studies with multiple concomitant pain syndromes, a majority demonstrated >50% mean pain reduction at the time of last follow-up following DRGS. Physical function, quality of life (QOL), and lesser pain medication usage also were repeatedly reported to be significantly improved.

CONCLUSIONS

DRGS continues to lack supportive evidence from well designed, high level studies and recommendations from consensus committee experts. However, we present repeated and consistent evidence from lower level studies showing success with the use of DRGS for various non-CRPS chronic pain syndromes in reducing pain along with increasing function and QOL from one week to three years. Due to such low-level, high bias evidence, we strongly encourage the continuation of high-level studies in order to provide a stronger foundation for the use of DRGS in non-CRPS chronic pain patients. However, it may be reasonable and appropriate to evaluate patients for DRGS candidacy on a case-by-case basis particularly if they manifest focal pain syndromes refractory to noninterventional measures and may not be ideal candidates for other forms of neuromodulation.

Dorsal Root Ganglion Stimulation for the Management of Intractable Painful Polyneuropathy: A Prospective Pilot Study

OBJECTIVES

Dorsal root ganglion stimulation (DRGS) is a promising neurostimulation modality in the treatment of painful polyneuropathy. The aim of this prospective pilot study was to investigate the effect of DRGS on pain intensity in patients with intractable painful polyneuropathy.

MATERIALS AND METHODS

Nine patients with chronic, intractable painful polyneuropathy in the lower limbs were recruited. In each subject, between two and four DRGS leads were placed at the level of the L5 and S1 dorsal root ganglion. If trial stimulation was successful, a definitive implantable pulse generator (IPG) was implanted. Pain intensity was scored using an 11-point numeric rating scale (NRS) and reported as median and interquartile range (IQR), and compared to baseline values using the Wilcoxon signed-rank test. Additionally, patients' global impression of change (PGIC), pain extent, presence of neuropathic pain, physical functioning, quality of life, and mood were assessed.

RESULTS

Eight out of nine patients had a successful trial phase, of which seven received an IPG. Daytime pain decreased from a median (IQR) NRS score of 7.0 (5.9-8.3) to 2.0 (1.0-3.5) and 3.0 (1.6-4.9) in the first week and at six months after implantation, respectively. Similar effects were observed for night time and peak pain scores.

CONCLUSIONS

The results of this study suggest that DRGS significantly reduces both pain intensity and PGIC in patients with intractable painful polyneuropathy in the lower extremities. Large-scale clinical trials are needed to prove the efficacy of DRGS in intractable painful polyneuropathy.

Pulsed radiofrequency as alternative method for phantom pain treatment. Case report

Pulse radiofrequency is a safe method of fighting phantom pain. It creates the possibility of treating cases that have exhausted other therapeutic options.

Neuromodulation of the Dorsal Root Ganglion for Chronic Postsurgical Pain

Objective

The objective of this study is to review the available evidence for dorsal root ganglion (DRG) stimulation for the treatment of complex regional pain syndrome type II (CRPS II; peripheral causalgia) associated with chronic neuropathic postsurgical pain (NPP).

Design

Available literature was identified through a search of the US National Library of Medicine’s Medline database, PubMed.gov. References from published articles also were reviewed for relevant citations.

Results

The data published to date support the use of DRG stimulation to treat chronic NPP of the groin, knee, and foot. NPP following procedures such as thoracotomy, hernia surgery, and knee replacement surgery were identified as some of the conditions for which DRG stimulation is likely to be effective.

Conclusion

DRG stimulation is known to be an effective treatment for focal neuropathic pain. Currently, NPP of the foot, groin, and knee all appear to be the conditions with the most clinical experience, backed by a limited but growing body of evidence. However, prospective studies lag behind real-world clinical experience and are needed to confirm these findings.

Unique Characteristics of the Dorsal Root Ganglion as a Target for Neuromodulation

Objective

The dorsal root ganglion (DRG) is a novel target for neuromodulation, and DRG stimulation is proving to be a viable option in the treatment of chronic intractable neuropathic pain. Although the overall principle of conventional spinal cord stimulation (SCS) and DRG stimulation—in which an electric field is applied to a neural target with the intent of affecting neural pathways to decrease pain perception—is similar, there are significant differences in the anatomy and physiology of the DRG that make it an ideal target for neuromodulation and may account for the superior outcomes observed in the treatment of certain chronic neuropathic pain states. This review highlights the anatomy of the DRG, its function in maintaining homeostasis and its role in neuropathic pain, and the unique value of DRG as a target in neuromodulation for pain.

Methods

A narrative literature review was performed.

Results

Overall, the DRG is a critical structure in sensory transduction and modulation, including pain transmission and the maintenance of persistent neuropathic pain states. Unique characteristics including selective somatic organization, specialized membrane characteristics, and accessible and consistent location make the DRG an ideal target for neuromodulation. Because DRG stimulation directly recruits the somata of primary sensory neurons and harnesses the filtering capacity of the pseudounipolar neural architecture, it is differentiated from SCS, peripheral nerve stimulation, and other neuromodulation options.

Conclusions

There are several advantages to targeting the DRG, including lower energy usage, more focused and posture-independent stimulation, reduced paresthesia, and improved clinical outcomes.

Neurostimulation for Intractable Chronic Pain

The field of neuromodulation has seen unprecedented growth over the course of the last decade with novel waveforms, hardware advancements, and novel chronic pain indications. We present here an updated review on spinal cord stimulation, dorsal root ganglion stimulation, and peripheral nerve stimulation. We focus on mechanisms of action, clinical indications, and future areas of research. We also present current drawbacks with current stimulation technology and suggest areas of future advancements. Given the current shortage of viable treatment options using a pharmacological based approach and conservative interventional therapies, neuromodulation presents an interesting area of growth and development for the interventional pain field and provides current and future practitioners a fresh outlook with regards to its place in the chronic pain treatment paradigm.

The Neuromodulation Appropriateness Consensus Committee on Best Practices for Dorsal Root Ganglion Stimulation

INTRODUCTION

The Neuromodulation Appropriateness Consensus Committee (NACC) is dedicated to improving the safety and efficacy of neuromodulation and thus improving the lives of patients undergoing neuromodulation therapies. With continued innovations in neuromodulation comes the need for evolving reviews of best practices. Dorsal root ganglion (DRG) stimulation has significantly improved the treatment of complex regional pain syndrome (CRPS), among other conditions. Through funding and organizational leadership by the International Neuromodulation Society (INS), the NACC reconvened to develop the best practices consensus document for the selection, implantation and use of DRG stimulation for the treatment of chronic pain syndromes.

METHODS

The NACC performed a comprehensive literature search of articles about DRG published from 1995 through June, 2017. A total of 2538 article abstracts were then reviewed, and selected articles graded for strength of evidence based on scoring criteria established by the US Preventive Services Task Force. Graded evidence was considered along with clinical experience to create the best practices consensus and recommendations.

RESULTS

The NACC achieved consensus based on peer-reviewed literature and experience to create consensus points to improve patient selection, guide surgical methods, improve post-operative care, and make recommendations for management of patients treated with DRG stimulation.

CONCLUSION

The NACC recommendations are intended to improve patient care in the use of this evolving therapy for chronic pain. Clinicians who choose to follow these recommendations may improve outcomes.

DRG FOCUS: A Multicenter Study Evaluating Dorsal Root Ganglion Stimulation and Predictors for Trial Success

INTRODUCTION

Dorsal root ganglion stimulation (DRGS) is a powerful tool in the treatment of chronic, neuropathic pain. The premise of DRGS is similar to that of conventional spinal cord stimulation (cSCS), however, there is more variability in how it can be utilized. While it is this variability that likely gives it its versatility, DRGS is not as straightforward to implement as cSCS. The purpose of this study was to assess the efficacy of DRGS on a broad number of diagnoses, determine which dorsal root ganglia were associated with better outcomes for particular body parts/diagnoses, and evaluate what factors/parameters were associated with higher rates of trial success.

METHODS

This is a physician initiated, multicenter retrospective registry of 217 patients trialed with DRGS. Data were collected via an online questionnaire that assessed specifics regarding the patient's pain, distribution, size, and response to treatment. The data were analyzed to see if there were certain diagnoses and/or parameters that were more or less associated with trial success.

RESULTS

DRGS was found to be an effective treatment in all diagnoses evaluated within this study, most of which had statistically significant improvements in pain. The most important predictor of trial success was the amount of painful area covered by paresthesias during the programing phase. The number of leads utilized had a direct and indirect impact on trial success. Pain in the distribution of a specific peripheral nerve responded best and there was no statistical difference based on what body part was being treated.

CONCLUSION

DRGS can be an effective treatment for a variety of neuropathic pain syndromes, in addition to CRPS. It is recommended that a minimum of 2 leads should be utilized per area being treated. In addition, this therapy was shown to be equally efficacious in any body part/region so long as the area being treated is focal and not widespread.

Dorsal Root Ganglion Stimulation for Chronic Pelvic Pain: A Case Series and Technical Report on a Novel Lead Configuration

INTRODUCTION

Chronic pelvic pain (CPP) is an elusive and complex neuropathic condition that is notoriously recalcitrant to treatment. The term "CPP" encompasses a number of treatment-resistant conditions like pudendal neuralgia, interstitial cystitis, coccygodynia, vulvodynia. CPP has been presented neuromodulators attempting to utilize conventional spinal cord stimulation (SCS), with constant frustration and high explant rates. Contrary to SCS, dorsal root ganglion stimulation (DRGS) delivers targeted target to focal areas, does not rely on paresthesias, and is able to reliably capture body parts like the pelvis making it an ideal modality for the treatment of CPP. We present seven patients with intractable CPP, resistant to conventional treatment methods, all successfully treated with DRGS.

METHODS

The case series includes seven patients with severe, CPP who failed to respond to a variety interventional treatments, and in some cases SCS. All seven patients were successfully trialed with DRGS utilizing leads placed over the bilateral L1 and S2 DRG's-to our knowledge, no publications describing either this particular lead configuration, or utilizing DRG stimulation on CPP, exist.

RESULTS

Following treatment, all seven patients experienced significant pain relief as well as reduction in opioid consumption and some cases improvement with sexual function and urination. Four of these patients have been implanted and continue to self-report sustained pain relief with high-satisfaction and functional improvement. To date no explants or instances of loss of efficacy have occurred (>1 year since implant).

CONCLUSION

Like most neuropathic pain states, CPP is resilient, difficult to manage, and typically unresponsive to the traditional therapeutics and SCS. Our case series demonstrates no only that DRGS is potentially effective, long-term treatment modality for CPP, but that the L1/S2 lead placement is the configuration of choice despite distinct differences in etiologies of pain and location.