Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation of C2 Dorsal Root Ganglion for the Treatment of Refractory Atypical Facial Pain: A Technical Report and Case Series.

BACKGROUND: Chronic craniofacial pain can be difficult to manage clinically. This technical report documents the peripheral nerve stimulation of the C2 dorsal root ganglion as an effective modality to treat refractory atypical facial pain. MATERIALS AND METHODS: In this case series, three patients with chronic refractory atypical facial pain and p >50% pain relief following diagnostic C2 dorsal root ganglion blockade underwent ultrasound-guided percutaneous placement of a peripheral nerve stimulator adjacent to the C2 dorsal root ganglion. Patients were then observed clinically and monitored for improvement in symptoms and adverse events. RESULTS: Three patients underwent peripheral nerve stimulator placement. At follow-up, there were no reported adverse events, and all patients reported satisfactory improvement in pain. CONCLUSION: The neuromodulation of C2 dorsal root ganglion via ultrasound-guided percutaneously implanted peripheral nerve stimulator is a novel and potentially effective approach for the management of chronic refractory craniofacial pain.

Neuromodulation for the management of chronic pelvic pain syndromes: A systematic review.

BACKGROUND: Chronic pelvic pain is a burdensome condition that involves multiple medical sub-specialties and is often difficult to treat. Sacral stimulation for functional bladder disease has been well established, but little large-scale evidence exists regarding utilization of other neuromodulation techniques to treat chronic pelvic pain. Emerging evidence does suggest that neuromodulation is a promising treatment, and we aim to characterize the use and efficacy of such techniques for treating chronic pelvic pain syndromes. MATERIALS AND METHODS: A systematic review of the literature demonstrating the treatment of chronic pelvic pain syndromes with neuromodulation. Abstracts were reviewed and selected for inclusion, including case series, prospective studies, and randomized controlled trials (RCTs). Case studies and publications in abstract only were not included. The reporting for this systematic review follows Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The literature search was performed using MEDLINE, Embase, Cochrane Library, PubMed, CINAHL, and Scopus. RESULTS: A total of 50 studies were included in this review, three of which were randomized controlled trials, and the remaining were prospective and retrospective case series. The range of pelvic pain conditions treated included interstitial cystitis, peripheral neuralgia, pudendal neuralgia, gastrointestinal pain, urogenital pain, sacroiliac joint pain, and visceral chronic pelvic pain. We reported on outcomes involving pain, functionality, psychosocial improvement, and medication reduction. CONCLUSIONS: Neuromodulation is a growing treatment for various chronic pain syndromes. Peripheral nerve stimulation was the least studied form of stimulation. Posterior tibial nerve stimulation appears to offer short-term benefit, but long-term results are challenging. Sacral nerve stimulation is established for use in functional bladder syndromes and appears to offer pain improvement in these patients as well. Dorsal root ganglion stimulation and spinal cord stimulation have been used for a variety of conditions with promising results. Further studies of homogeneous patient populations are necessary before strong recommendations can be made at this time, although pooled analysis may also be impactful.

Use of Temporary Percutaneous Peripheral Nerve Stimulation in an Oncologic Population: A Retrospective Review.

OBJECTIVES: Patients with an underlying cancer diagnosis may experience pain from many sources. Temporary, percutaneous peripheral nerve stimulation (PNS) is a minimally invasive procedure that can control pain in those who have failed conservative management. The purpose of this retrospective review is to show the use of PNS in managing pain in the oncologic setting. MATERIALS AND METHODS: Temporary, percutaneous PNS was placed under fluoroscopic or ultrasound guidance for 15 patients at a cancer pain facility. Cases were grouped by subtypes of cancer pain (ie, tumor-related, treatment-related, cancer-associated conditions, and cancer-independent). Before PNS, patients were refractory to medical management or previous interventional treatments. Patients were observed with routine clinic visits to monitor pain levels via visual analog scale (VAS) and quality-of-life measures. PNS was removed after the indicated 60-day treatment period. RESULTS: This retrospective review presents ten successful cases of oncologic-related pain treated with PNS. Patients with subtypes of pain that were tumor related, from cancer-associated conditions, and cancer independent all experienced a similar degree of pain relief. However, patients with cancer-treatment-related pain experienced the least analgesia from PNS. We also present six cases in which PNS did not provide adequate pain relief. CONCLUSION: PNS is an emerging technology in neuromodulation that may be useful in managing pain, especially in the oncologic population. Patients with cancer-related and non-cancer-related pain localized to a specific nerve distribution should be considered appropriate candidates for PNS. Further research is needed to optimize patient selection and indications for PNS in the population with cancer.

Peripheral Nerve Stimulation With a High-Frequency Electromagnetic Coupled Powered Implanted Receiver at the Posterior Tibial Nerve for the Treatment of Chronic Pain in the Foot.

INTRODUCTION: Peripheral neuropathy has several causes, with diabetes being the most common. Conservative management may fail to control pain. Our study aimed at evaluating the use of peripheral nerve stimulation of the posterior tibial nerve for treating peripheral neuropathy. MATERIALS AND METHODS: This was an observational study of 15 patients who received peripheral nerve stimulation at the posterior tibial nerve to treat peripheral neuropathy. Outcomes measured were improvement of pain scores and Patient Global Impression of Change (PGIC) at 12 months compared with before the implant. RESULTS: Mean pain scores with the verbal rating scale were 3 ± 1.8 at >12 months compared with 8.6 ± 1.2 at baseline, a reduction of 65% (p < 0.001). Median satisfaction with the PGIC at >12 months was 7 of 7, with most subjects reporting a 6 (better) or a 7 (a great deal better). CONCLUSION: Peripheral nerve stimulation of the posterior tibial nerve can be a safe and effective modality for treating chronic pain symptoms related to peripheral neuropathy of the foot.

Peripheral Nervous System Pain Modulation.

The percutaneous technique of electrode insertion in the vicinity of the greater occipital nerves to treat occipital neuralgia was first described in the 1990s by Weiner and Reed. This subsequently stimulated awareness of peripheral nerve stimulation (PNS). The more recent advent emergence of a minimally invasive percutaneous approach by way of using ultrasound has further increased the interest in PNS as a viable alternative to more invasive techniques. PNS has become more popular recently and is increasingly used to treat various pain conditions. Its foundation is fundamentally based on the gate control theory, although the precise mechanism underlying its analgesic effect is still indefinite. Studies have demonstrated the peripheral and central analgesic mechanisms of PNS by modulating the inflammatory pathways, the autonomic nervous system, the endogenous pain inhibition pathways, and the involvement of the cortical and subcortical areas. Peripheral nerve stimulation exhibits its neuromodulatory effect both peripherally and centrally. Further understanding of the modulation of PNS mechanisms can help guide stimulation approaches and parameters to optimize the use of PNS. his chapter aims to review the background and mechanisms of PNS modulation. PNS is becoming one of the most diverse therapies in neuromodulation due to rapid evolution and expansion. It is an attractive option for clinicians due to the simplicity and versatility of procedures that can be combined with other neuromodulation treatments or used alone. It has a distinct role in the modulation of functional conditions.

Adenosine A2A receptors in the rostral ventrolateral medulla participate in blood pressure decrease with electroacupuncture in hypertensive rats.

Acupuncture is increasingly used to manage high blood pressure (BP) as a complementary therapy. However, the mechanisms underlying its hypotensive effects remain unclear. Our previous studies have shown that electroacupuncture (EA) at the ST36-37 acupoints, overlying the deep peroneal nerve, attenuates pressor responses through adenosine A2A receptors (A2AR) in the rostral ventrolateral medulla (rVLM). However, it is uncertain whether rVLM A2AR contributes to EA's BP-lowering effect in sustained hypertension. We hypothesized that a course of EA treatment lowers BP, in part, through the activation of adenosine A2AR in the rVLM in hypertensive rats. To mimic essential hypertension in the clinic, we performed EA in conscious Dahl salt-sensitive hypertensive rats (DSHRs). EA (0.1-0.4 mA, 2 Hz) was applied at ST36-37 for 30 min twice weekly for four weeks, while sham-EA was conducted in a similar manner but without electrical input. In hypertensive rats, BP was reduced by EA (n = 14) but neither by sham-EA (n = 14) nor in the absence of needling (n = 8). Following four weeks of eight treatments and then under anesthesia, EA's modulatory effect on elevated BP was reversed by unilateral rVLM microinjection of SCH 58261 (1 mM in 50 nl; an A2AR antagonist; n = 7; P < 0.05) but not the vehicle (n = 5) in EA-treated DSHRs. Activation of rVLM A2AR in DSHRs treated with sham-EA by an A2AR agonist, CGS-21680 (0.4 mM in 50 nl; n = 8), decreased BP. Unilateral administration of SCH 58261 or CGS-21680 into the rVLM did not alter basal BP in Dahl salt-sensitive rats fed a regular diet with normal BP. The A2AR level in the rVLM after EA was increased compared to the sham-EA and untreated DSHRs (n = 5 in each group; all P < 0.05). These data suggest that a 4-week twice weekly EA treatment reduced BP in salt-sensitive hypertensive rats likely through adenosine-mediated A2AR in the rVLM.

Current Neurostimulation Therapies for Chronic Pain Conditions.

PURPOSE OF REVIEW: Neurostimulation treatment options have become more commonly used for chronic pain conditions refractory to these options. In this review, we characterize current neurostimulation therapies for chronic pain conditions and provide an analysis of their effectiveness and clinical adoption. This manuscript will inform clinicians of treatment options for chronic pain. RECENT FINDINGS: Non-invasive neurostimulation includes transcranial direct current stimulation and repetitive transcranial magnetic stimulation, while more invasive options include spinal cord stimulation (SCS), peripheral nerve stimulation (PNS), dorsal root ganglion stimulation, motor cortex stimulation, and deep brain stimulation. Developments in transcranial direct current stimulation, repetitive transcranial magnetic stimulation, spinal cord stimulation, and peripheral nerve stimulation render these modalities most promising for the alleviating chronic pain. Neurostimulation for chronic pain involves non-invasive and invasive modalities with varying efficacy. Well-designed randomized controlled trials are required to delineate the outcomes of neurostimulatory modalities more precisely.

The Emerging Role of Peripheral Nerve Stimulation in Postoperative Analgesia.

PURPOSE OF REVIEW: Though peripheral nerve stimulation has long been utilized in the field of chronic pain management, its use in acute pain management in the postoperative period is relatively novel and warrants further consideration. RECENT FINDINGS: In the postsurgical period, peripheral nerve stimulation may offer an additional low-risk, opioid-sparing analgesic option, which is particularly pertinent in the setting of the ongoing opioid epidemic, as inadequate postsurgical analgesia has been shown to increase the risk of developing persistent or chronic postsurgical pain. In this review, we discuss the current literature that illustrate the emerging role of peripheral nerve stimulation as an effective treatment modality in the postoperative period for the management of acute pain, as various studies have recently been conducted evaluating the feasibility of utilizing percutaneous peripheral nerve stimulation as an adjunct in postsurgical analgesia. Nonetheless, future studies are necessary to continue to elucidate the short- and long-term impacts of peripheral nerve stimulation use in acute postsurgical analgesia.

Peripheral Nerve Stimulation for Pain Management: A Review.

PURPOSE OF REVIEW: Peripheral nerve stimulation has seen a recent upsurge in utilization for various chronic pain conditions, specifically from a neuropathic etiology, where a single peripheral nerve can be pinpointed as a culprit for pain. RECENT FINDINGS: There is conflicting evidence about the efficacy and long-term outcomes of peripheral nerve stimulation for chronic pain, with most studies being small sized. The focus of this article is to review available evidence for the utilization of peripheral nerve stimulation for chronic pain syndromes as well as upcoming evidence in the immediate postoperative realm. The indications for the use of PNS have expanded from neuropathic pain such as occipital neuralgia and post-amputation pain, to more widespread disease processes such as chronic low back pain. Percutaneous PNS delivered over a 60-day period may provide significant carry-over effects including pain relief, potentially avoiding the need for a permanently implanted system while enabling improved function in patients with chronic pain.

A Retrospective Review of Real-world Outcomes Following 60-day Peripheral Nerve Stimulation for the Treatment of Chronic Pain.

BACKGROUND: Real-world data can provide important insights into treatment effectiveness in routine clinical practice. Studies have demonstrated that in multiple different pain indications temporary (60-day) percutaneous peripheral nerve stimulation (PNS) treatment can produce significant relief, but few real-world studies have been published. The present study is the first real-world, retrospective review of a large database depicting outcomes at the end of a 60-day PNS treatment period. OBJECTIVES: Evaluate outcomes during a 60-day PNS treatment in routine clinical practice. STUDY DESIGN: Secondary retrospective review. METHODS: Anonymized records of 6,160 patients who were implanted with a SPRINT PNS System from August 2019 through August 2022 were retrospectively reviewed from a national real-world database. The percentage of patients with ? 50% pain relief and/or improvement in quality of life was evaluated and stratified by nerve target. Additional outcomes included average and worst pain score, patient-reported percentage of pain relief, and patient global impression of change. RESULTS: Overall, 71% of patients (4,348/6,160) were responders with >= 50% pain relief and/or improvement in quality of life; pain relief among responders averaged 63%. The responder rate was largely consistent across nerve targets throughout the back and trunk, upper and lower extremities, and posterior head and neck. LIMITATIONS: This study was limited by its retrospective nature and reliance on a device manufacturer's database. Additionally, detailed demographic information and measures for pain medication usage and physical function were not assessed. CONCLUSIONS: This retrospective analysis supports recent prospective studies demonstrating that 60-day percutaneous PNS can provide significant relief across a wide range of nerve targets. These data serve an important role in complementing the findings of published prospective clinical trials.

The role of peripheral nerve stimulation in refractory non-operative chronic knee osteoarthritis.

Aim: This case series aimed to analyze the efficacy of a temporary peripheral nerve stimulation (PNS) device implanted for 60 days at 60 days post-explant for patients with non-surgical osteoarthritic knee pain. Patients & methods: 19 patients were selected for treatment with temporary PNS at an outpatient pain management clinic. Results: Patients demonstrated improvement in their knee pain from baseline post-temporary PNS explant (p = 0.973). Conclusion: Temporary PNS serves as a promising therapy for patients with limited options for therapy, necessitating further high-quality studies.

Temporary peripheral nerve stimulation (PNS) is a treatment for patients with knee swelling and pain who can't get surgery. The authors studied temporary PNS to see if the patient's knee pain improved. 19 patients were treated with temporary PNS. The study found the patients' knee pain improved after completing the treatment. More research is needed in the future to temporary PNS in knee pain patients.

Peripheral nerve stimulation enables somatosensory feedback while suppressing phantom limb pain in transradial amputees.

To simultaneously treat phantom limb pain (PLP) and restore somatic sensations using peripheral nerve stimulation (PNS), two bilateral transradial amputees were implanted with stimulating electrodes in the proximity of the medial, ulnar and radial nerves. Application of PNS evoked tactile and proprioceptive sensations in the phantom hand. Both patients learned to determine the shape of invisible objects by scanning a computer tablet with a stylus while receiving feedback based on PNS or transcutaneous electrical nerve stimulation (TENS). Оne patient learned to use PNS as feedback from the prosthetic hand that grasped objects of different sizes. PNS abolished PLP completely in one patient and reduced it by 40-70% in the other. We suggest incorporating PNS and/or TENS in active tasks to reduce PLP and restore sensations in amputees.

Peripheral Nerve Stimulation for Low Back Pain: A Systematic Review.

PURPOSE OF REVIEW: Low back pain (LBP) is a prevalent condition that is associated with diminished physical function, poor mental health outcomes, and reduced quality of life. Peripheral nerve stimulation (PNS) is an emerging modality that has been utilized to treat LBP. The primary objective of this systematic review is to appraise the level of evidence on the efficacy of PNS for treatment of LBP. RECENT FINDINGS: Twenty-nine articles were included in this systematic review, consisting of 828 total participants utilizing PNS as the primary modality for LBP and 173 participants using PNS as salvage or adjunctive therapy for LBP after SCS placement. Different modalities of PNS therapy were reported across studies, including conventional PNS systems stimulating the lumbar medial branch nerves, peripheral nerve field stimulation (PNFS), and restorative neuromuscular stimulation of the multifidus muscles. All studies consistently reported positive modest to moderate improvement in pain intensity with PNS therapy when comparing baseline pain intensity to each study's respective primary follow-up period. There was a very low GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) quality of evidence supporting this finding. Inconsistency was present in some comparative studies that demonstrated no difference between PNS therapy versus control cohorts (sham or SCS therapy alone), which therefore highlighted the potential for placebo effect. This systematic review highlights that PNS, PNFS, and neuromuscular stimulation may provide modest to moderate pain relief in patients with LBP, although evidence is currently limited due to risk of bias, clinical and methodological heterogeneity, and inconsistency in data.

Mechanism of Action of Peripheral Nerve Stimulation for Chronic Pain: A Narrative Review.

The use of stimulation of peripheral nerves to test or treat various medical disorders has been prevalent for a long time. Over the last few years, there has been growing evidence for the use of peripheral nerve stimulation (PNS) for treating a myriad of chronic pain conditions such as limb mononeuropathies, nerve entrapments, peripheral nerve injuries, phantom limb pain, complex regional pain syndrome, back pain, and even fibromyalgia. The ease of placement of a minimally invasive electrode via percutaneous approach in the close vicinity of the nerve and the ability to target various nerves have led to its widespread use and compliance. While most of the mechanism behind its role in neuromodulation is largely unknown, the gate control theory proposed by Melzack and Wall in the 1960s has been the mainstay for understanding its mechanism of action. In this review article, the authors performed a literature review to discuss the mechanism of action of PNS and discuss its safety and usefulness in treating chronic pain. The authors also discuss current PNS devices available in the market today.

Wireless Peripheral Nerve Stimulation for The Upper Limb: A Case Report.

Peripheral neuro-stimulation (PNS) has been proved to be effective for the treatment of neuropathic pain as well as other painful conditions. We discuss two approaches to PNS placement in the upper extremity. The first case describes a neuropathic syndrome after the traumatic amputation of the distal phalanx of the fifth digit secondary to a work accident with lack of responsiveness to a triple conservative therapy. An upper arm region approach for the PNS was chosen. The procedure had a favorable outcome; in fact, after one month the pain symptoms were absent (VAS 0) and the pharmacological therapy was suspended. The second case presented a patient affected by progressive CRPS type II in the sensory regions of the ulnar and median nerve in the hand, unresponsive to drug therapy. For this procedure, the PNS device was implanted in the forearm. Unfortunately, in this second case the migration of the catheter affected the effectiveness of the treatment. After examining the two cases in this paper, we changed our practice and suggest the implantation of PNS for radial, median and/or ulnar nerve stimulation in the upper arm region, which has significant advantages over the forearm region.

Paired associative stimulation on the soleus H-Reflex using motor point and peripheral nerve stimulation.

Paired associative stimulation (PAS) has been shown to modulate the corticospinal excitability via spike timing dependent plasticity (STDP). In this study, we aimed to suppress the spinal H-Reflex using PAS. We paired two stimulation modalities, i.e., peripheral nerve stimulation (PNS) and motor point stimulation (MPS). We used PNS to dominantly activate the Ia sensory axon, and we used MPS to dominantly activate the α-motoneuron cell body antidromically. Thus, we applied both PNS and MPS such that the α-motoneuron cell body was activated 5 ms before the activation of the Ia sensory axon ending at the Ia-α motoneuron synapse. If the spinal reflexes can be modulated by STDP, and a combination of MPS and PNS is timed appropriately, then the H-Reflex amplitude will decrease while no change in H-Reflex amplitude is expected for MPS or PNS only. To test this hypothesis, six young healthy participants (5M/1F: 26.8 ± 4.1 yrs) received one of the three following conditions on days separated by at least 24 hr: 1) PAS, 2) MPS only or 3) PNS only. The H-Reflex and M-wave recruitment curves of the soleus were measured immediately prior to, immediately after, 30 min and 60 min after the intervention. The normalized H-Reflex amplitudes were then compared across conditions and times using a two-way ANOVA (3 conditions × 4 times). No main effects of condition or time, or interaction effect were found. These results suggest that relying solely on STDP may be insufficient to inhibit the soleus H-Reflex.

Peripheral Nerve Stimulation on the Brachial Plexus With Ultrasound-guided Percutaneous Technique: A Case Series.

INTRODUCTION: The aim of this case series was to assess the safety and effectiveness of peripheral nerve stimulation (PNS) of the brachial plexus performed using a low invasive percutaneous approach with ultrasound guide. MATERIALS AND METHODS: Patients affected by neuropathic pain with a documented brachial plexus partial avulsion were included in this observational study. A totally implantable PNS system specifically designed for peripheral placement (Neurimpulse, Padua, Italy) was implanted and followed for 18 months, recording the level of pain (Numeric Rating Scale [NRS]), therapy satisfaction (Patient Global Impression of Improvement), quality of life (Short Form Health Survey questionnaire), and change in drug consumption and work status. Descriptive statistic (mean and SD) was used to compare pre- and postimplantation differences. RESULTS: A total of 18 patients were included in the observational study; 16 of them proceeded with the permanent implantation. System infection (N = 1) and lead migrations (N = 2) were recorded during a follow-up mean of 14.8 ± 5.4 months. The average NRS reduction at 18 months was 41%. Average quality-of-life physical and mental indexes increased by 14% and 32%, respectively. Drug intake was stopped in 22% and reduced in 56% of the patients. CONCLUSIONS: PNS systems of the brachial plexus implanted with percutaneous approach appear to be safe and effective in a follow-up period of 18 months. Longer and larger studies are needed to confirm and extend these outcomes.

Steering Toward Normative Wide-Dynamic-Range Neuron Activity in Nerve-Injured Rats With Closed-Loop Peripheral Nerve Stimulation.

OBJECTIVES: Chronic pain is primarily treated with pharmaceuticals, but the effects remain unsatisfactory. A promising alternative therapy is peripheral nerve stimulation (PNS), but it has been associated with suboptimal efficacy because its modulation mechanisms are not clear and the current therapies are primarily open loop (ie, manually adjusting the stimulation parameters). In this study, we developed a proof-of-concept computational modeling as the first step toward implementing closed-loop PNS in future biological studies. When developing new pain therapies, a useful pain biomarker is the wide-dynamic-range (WDR) neuron activity in the dorsal horn. In healthy animals, the WDR neuron activity occurs in a stereotyped manner; however, this response profile can vary widely after nerve injury to create a chronic pain condition. We hypothesized that if injury-induced changes of neuronal response can be normalized to resemble those of a healthy condition, the pathological aspects of pain may be treated while maintaining protective physiological nociception. MATERIALS AND METHODS: Using an in vivo electrophysiology data set of WDR neuron recordings obtained in nerve-injured rats and naïve rats, we constructed sets of linear phenomenologic models of WDR firing rate during windup stimulation for both conditions. Then, we applied robust control systems techniques to identify a closed-loop PNS controller, which can drive the dynamics of WDR neuron response in neuropathic pain model into ranges associated with normal physiological pain. RESULTS: The sets of identified linear models can accurately predict, in silico, nonlinear neural responses to electrical stimulation of the peripheral nerve. In addition, we showed that continuous closed-loop control of PNS can be used to normalize WDR neuron firing responses in three injured cases. CONCLUSIONS: In this proof-of-concept study, we show how tractable, linear mathematical models of pain-related neurotransmission can be used to inform the development of closed-loop PNS. This new application of robust control to neurotechnology may also be expanded and applied across other neuromodulation applications.

Multidisciplinary chronic pain management strategies in patients with Ehlers-Danlos syndromes.

Ehlers-Danlos syndromes (EDS) are a group of disorders characterized by abnormal connective tissue affecting several organ systems. Patients with the hypermobile type of EDS (hEDS) commonly experience chronic pain which can present as musculoskeletal pain, fibromyalgia, neuropathic pain or abdominal pain. The effective management of chronic pain in hEDS patients is a challenge. This study reviews two cases of chronic pain in hEDS patients and the multimodal treatment regimen used along with peripheral nerve stimulation for shoulder and knee pains, never before reported in hEDS patients. Since hEDS associated chronic pain is multifactorial in origin, treatment requires a multidisciplinary approach which includes physical therapy, psychotherapy, pharmacotherapy and interventional pain procedures such as trigger point injections, peripheral nerve block, radiofrequency ablation and peripheral nerve stimulation.

Ehlers­Danlos Syndromes (EDS) are a group of disorders that affects the connective tissues that supports skin, muscles and organs. Patients with the hypermobile subtype of EDS (hEDS) often experience chronic pain of multiple locations including the muscles, joints, nerves, abdomen, head or generalized pain. Treating chronic pain in patients with hEDS is challenging. In this study, we review the treatment of chronic pain in two patients with hEDS using multiple therapies including the novel use of peripheral nerve stimulation in this patient population. Chronic pain in hEDS patients is caused by multiple different mechanisms and therefore, the treatment of this pain requires multiple different therapeutic interventions such as medications, physical therapy, psychotherapy and minimally invasive procedures such as peripheral nerve stimulation.

Genitofemoral peripheral nerve stimulator implantation for refractory groin pain: a case report.

PURPOSE: Genitofemoral neuralgia (GFN) is a chronic pain condition that may be refractory to commonly employed treatment modalities. Implantation of a peripheral nerve stimulator (PNS) may provide significant pain relief; however, few reports have described placement of and response to a GFN PNS implant. CLINICAL FEATURES: We implanted a StimRouter® PNS in a 42-yr-old male with severe GFN that did not respond to pharmacologic and interventional pain management modalities and impaired all aspects of his function and quality of life. The often-challenging sonographic visualization of the genitofemoral nerve was aided by intraprocedural sensory mapping using a stimulating probe. Preoperatively, the patient's average pain was rated as 7 on a 0 to 10 numeric rating scale. Following the procedure, the patient experienced over 90% pain relief after one week. At one and five months post implantation, the patient's average pain scores were 1 and 0.5, respectively. The patient also reported substantial improvement in the physical component scores on the 12-Item Short Form Survey (SF-12), which remained similar at the five-month follow-up (from 26.1 preop to 57.2 at one month and 49.7 at five months). CONCLUSIONS: Peripheral nerve stimulator implantation may be a promising intervention when other analgesic modalities fail to manage refractory GFN. Further research to verify the effectiveness of this intervention and evaluate for appropriate integration in patient care is required.

RéSUMé: OBJECTIF: La névralgie génito-crurale (NGC) est une douleur chronique pouvant être réfractaire aux modalités de traitement couramment utilisées. L'implantation d'un stimulateur nerveux périphérique (SNP) peut apporter un soulagement significatif de la douleur. Cependant, peu de présentations de cas ont décrit la mise en place et la réponse à l'implantation d'un SNP pour soulager une névralgie génito-crurale. CARACTéRISTIQUES CLINIQUES: Nous avons implanté un SNP StimRouter® chez un homme de 42 ans atteint d'une NGC grave qui ne répondait pas aux modalités pharmacologiques et interventionnelles de prise en charge de la douleur et entravait tous les aspects fonctionnels et de qualité de vie. La visualisation échographique souvent difficile du nerf génito-crural a été facilitée grâce à une cartographie sensorielle intraprocédurale, réalisée à l'aide d'une sonde de stimulation. Avant la procédure, la douleur moyenne du patient a été évaluée à 7 sur une échelle d'évaluation numérique de 0 à 10. Suite à l'intervention, le patient a ressenti un soulagement de la douleur de plus de 90 % après une semaine. À un et à cinq mois suivant l'implantation, les scores moyens de douleur du patient étaient de 1 et 0,5, respectivement. Le patient a également rapporté une amélioration substantielle des scores de la composante physique du questionnaire SF-12, scores qui sont restés similaires au suivi à cinq mois (de 26,1 avant l'intervention à 57,2 à un mois et 49,7 à cinq mois). CONCLUSION: L'implantation d'un stimulateur nerveux périphérique pourrait être une intervention prometteuse lorsque d'autres modalités analgésiques ne parviennent pas à prendre en charge une névralgie génito-crurale réfractaire. D'autres recherches sont nécessaires pour vérifier l'efficacité de cette intervention et évaluer son intégration appropriée dans les soins aux patients.