Median Nerve Stimulation in a Patient with Complex Regional Pain Syndrome Type II

A 54-year-old man experienced injury to the second finger of his left hand due to damage from a paintball gun shot 8 years prior, and the metacarpo-phalangeal joint was amputated. He gradually developed mechanical allodynia and burning pain, and there were trophic changes of the thenar muscle and he reported coldness on his left hand and forearm. A neuroma was found on the left second common digital nerve and was removed, but his symptoms continued despite various conservative treatments including a morphine infusion pump on his left arm. We therefore attempted median nerve stimulation to treat the chronic pain. The procedure was performed in two stages. The first procedure involved exposure of the median nerve on the mid-humerus level and placing of the electrode. The trial stimulation lasted for 7 days and the patient''s symptoms improved. The second procedure involved implantation of a pulse generator on the left subclavian area. The mechanical allodynia and pain relief score, based on the visual analogue scale, decreased from 9 before surgery to 4 after surgery. The patient''s activity improved markedly, but trophic changes and vasomotor symptom recovered only moderately. In conclusion, median nerve stimulation can improve chronic pain from complex regional pain syndrome type II.     

Peripheral Nerve Stimulation: A Treatment for Chronic Low Back Pain and Failed Back Surgery Syndrome?

Objective. This study aims to evaluate the usefulness of peripheral nerve stimulation as a treatment option for patients with chronic low back pain. Materials and Methods. More than 12 months, we collected data on consecutive patients who had successful trials and were subsequently implanted with octrode percutaneous leads placed subcutaneously within the major area of pain. Eleven patients met diagnostic criteria for failed back surgery syndrome. A questionnaire assessed outcomes including: pain, analgesic use, and patient satisfaction. The response rate was 93% (13/14): average follow‐up time was seven months. Results. There was a significant decrease in pain levels: an average reduction of 3.77 visual analog scale points. Eleven patients (85%) reported successful outcomes and an average pain reduction of 4.18 points but two reported a poor response. Pain relief was highly correlated with reduced analgesia and patient satisfaction. No complications were reported. Conclusion. This study demonstrates a treatment option that is safe, nonpharmacologic, reversible, and effective for patients with chronic low back pain that have exhausted other treatment options.     

Efficacy of Peripheral Nerve Field Stimulation for the Management of Chronic Low Back Pain and Persistent Spinal Pain Syndrome: A Narrative Review

ObjectivesVarious approaches have been developed with a view to treating the back pain component in patients with chronic low back pain (CLBP) and persistent spinal pain syndrome (PSPS). Emerging evidence shows that peripheral nerve field stimulation (PNFS) may be an efficacious therapeutic modality against axial low back pain. Hence, the aim of the review was to evaluate the analgesic efficacy and safety of PNFS, when used alone or as an adjunct to spinal cord stimulation (SCS), for managing CLBP and PSPS.Materials and MethodsA comprehensive search for clinical studies on PNFS and PNFS + SCS used for the management of CLBP and/or PSPS was performed using PubMed, EMBASE, MEDLINE via Proquest, and Web of Science.ResultsA total of 15 studies were included, of which four were randomized controlled trials (RCTs), nine were observational studies, and two were case series. For patients receiving PNFS, a significant decrease in back pain intensity and analgesic consumption, together with a significant improvement in physical functioning, was observed upon implant of the permanent system. Meanwhile, the addition of PNFS to SCS in refractory cases was associated with a significant reduction in back and leg pain, respectively.ConclusionsThis review suggests that PNFS, when used alone or in combination with SCS, appears to be effective in managing back pain. However, high-quality evidence that supports the long-term analgesic efficacy and safety is still lacking. Hence, RCTs with a larger patient population and of a longer follow-up duration are warranted.     

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.     

Subcutaneous Peripheral Nerve Stimulation Treatment for Chronic Pelvic Pain

Two cases of chronic pelvic pain of unknown etiology with symptoms referable to the low abdominal wall are presented. These patients are often difficult to manage because of multiple causes and multiple pathways for pain transmission from the pelvis. In these cases, the patients’ complaints were refractory to medication management, as well as diagnostic and therapeutic nerve blockade. After careful evaluation, a successful trial of peripheral nerve stimulation was followed by permanent implantation of low abdominal subcutaneous leads and a pulse generator device. The patients reported excellent relief of their chronic pelvic pain. The use of neuromodulation via peripheral stimulation deserves further investigation as an alternative to spinal cord stimulation for chronic pelvic pain.     

Spinal Cord Stimulation for Complex Regional Pain Syndrome I [RSD]: a Retrospective Multicenter Experience from 1995 to 1998 of 101 Patients

Objective. To evaluate effectiveness of spinal cord stimulation (SCS) applied to complex regional pain syndrome I (CRPS I). To analyze trends to focus the design of a multicenter prospective study. Design. Retrospective multicenter series, 3 years. Outcome measures. We collected visual analog scales for pain and patient satisfaction data on n= 101 patients. Patients were divided into two groups: Group I had single-lead quadrapolar systems, Group II had dual-lead octapolar systems. Results. Mean pain scores decreased in both groups with a significantly greater decrease in Group II (p < 0.0001). 74.6% of Group II patients preferred multiple programming arrays with 15.5% requiring frequencies > 250Hz.; overall satisfaction scores were 70% in Group I and 91% in Group II (p < 0.05). Conclusions. SCS is an effective treatment of pain in CRPS I. Frequencies > 250Hz were necessary in some patients to maintain or re-establish pain control. Bilateral multielectrode leads appear superior with application of multiple arrays, permitting paresthesia steering without need for surgical revision. A multicenter, prospective design is needed applying dual-lead multichannel systems with high frequency capabilities in the treatment of CRPS I.     

A Review of Neuromodulation for Treatment of Complex Regional Pain Syndrome in Pediatric Patients and Novel Use of Dorsal Root Ganglion Stimulation in an Adolescent Patient With 30-Month Follow-Up

ObjectivesComplex regional pain syndrome (CRPS) is a disorder in which pain and discomfort are out of proportion to the amount of tissue damage. While prevalence is 20.57 per 100,000 adults, it has not been studied in the U.S. pediatric population. Conservative treatment options include pharmacologic, behavioral, and psychological treatment. If these fail, invasive therapies such as sympathetic blocks and neuromodulation may be performed. The ACCURATE study demonstrated efficacy of dorsal root ganglion (DRG) stimulation for the treatment of refractory CRPS, but did not include pediatric patients and there are no reported cases of its use in the pediatric population. We review the use of neuromodulation for CRPS in pediatric patients and present a novel case using DRG stimulation in an adolescent patient.Materials and MethodsA literature search was performed for any studies of neuromodulation as treatment of pediatric CRPS. The literature is reviewed and the case of a 17-year-old female with CRPS treated with DRG stimulation is presented.ResultsA 15-year-old female developed CRPS type I of the left ankle after a sports injury. She was unable to wear a shoe or venture outside the home due to pain, swelling, and allodynia. Conservative therapies, including medications, physical therapy, and lumbosacral sympathetic plexus blocks, failed. At age 17, she underwent DRG stimulator lead placement targeting the left L4 and L5 nerve roots. Her therapy provided 100% relief of pain within four days of placement and was sustained at 30-month follow-up.ConclusionsDRG stimulation has been shown to significantly alter the symptomatology in patients with CRPS. This case suggests that DRG stimulation may be as effective for the treatment of refractory CRPS in pediatric patients as in adults.     

A Case Report of Subcutaneous Peripheral Nerve Stimulation for the Treatment of Axial Back Pain Associated With Postlaminectomy Syndrome

Objective. This article aims to present a case of the use of an alternative form of neuromodulation for the treatment of axial back pain associated with postlaminectomy syndrome. Materials and Methods. An elderly patient with long‐standing axial back pain in the setting of a prior decompressive laminectomy presented for evaluation and treatment. After failing to obtain significant benefit from more conservative measures, a trial of peripheral nerve stimulation (PNS) was performed. Results. The patient reported > 75% relief of his pain during the seven‐day trial period, and accordingly a permanent PNS system was implanted. The permanent system consisted of four Medtronic Quad Plus leads, two on each side of midline oriented horizontally over the L4–5 paraspinous muscles. Our patient was ultimately weaned off of all narcotic medications and, at one year follow‐up, continues to report > 90% reduction of pain.     

Selective Nerve Root Stimulation (SNRS) in the Treatment of End‐Stage,Diabetic, Peripheral Neuropathy: A Case Report

Spinal cord stimulation (SCS) for the treatment of painful peripheral neuropathy (PN) has been met with mixed results. It has been suggested that early‐stage symptoms that are sympathetically maintained (SMP) are more likely to respond to SCS, while progressive sympathetically independent symptoms (SIP) will not. Peripheral nerve stimulation (PNS), however, has successfully treated certain SIP presentations. With the advent of new selective nerve root stimulation (SNRS) strategies, the possibility of utilizing epidural, peripheral neurostimulation was investigated in a patient with endstage, diabetic, “dying back” peripheral SIP.