Peripheral Nerve Stimulation for Painful Mononeuropathy Secondary to Leprosy: A 12-Month Follow-Up Study

Mononeuritis Multiplex Due to Hansen's Disease: A Look Through Ultrasound and Electrodiagnosis

Hansen's disease is caused by Mycobacterium leprae. This bacillus can invade the peripheral nerves asymmetrically, including the ulnar, median, and radial nerves, causing mononeuritis multiplex. We present the case of a 41-year-old man with a history of Hansen's disease with sensory and motor symptoms. Electrodiagnostic studies and ultrasound showed asymmetric lesions of the median, ulnar, and radial nerves. Because this is the main complication of this pathology, electrodiagnosis is clearly valuable for its diagnosis, demonstrating axonal and myelin involvement, as well as signs of denervation and reinnervation. Ultrasound is valuable in the detection, diagnosis, and assessment of the extent of mononeuritis multiplex due to Hansen's disease. It aids in identifying significant inflammatory deterioration, as indicated by increased blood flow in the nerves and enlargement of the nerves. This technique allows for the exploration of nerves such as the ulnar nerve and branches of the brachial plexus. In a complementary way, ultrasound provides information on the severity of the disease. Early diagnosis of this entity is essential because it can generate aesthetic and functional permanent affectation.

Implantable Peripheral Nerve Stimulation for Peripheral Neuropathic Pain: A Systematic Review of Prospective Studies

Peripheral nerve stimulation (PNS) has been utilized for over 50 years with accumulating evidence of efficacy in a variety of chronic pain conditions. The level and strength of evidence supporting the use of PNS for peripheral neuropathic pain remains unclear. The purpose of this review is to synthesize data from prospective studies on the efficacy of PNS for neuropathic pain as it pertains to pain intensity, neurological deficits/neuropathy (e.g., weakness, sensory deficits, gait/balance), and other secondary outcomes (quality of life, satisfaction, emotional functioning, and adverse events). In compliance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, this review identified articles from MEDLINE(R), EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus. Overall, per the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria, pooled results demonstrate very low quality or low quality of evidence supporting modest to substantial improvement in pain and neurological function after PNS implantation for treatment of peripheral neuropathic pain. PNS for phantom limb pain was the only indication that had moderate level evidence. Future prospective and well-powered studies are warranted to assess the efficacy of PNS for peripheral neuropathic pain.

Evidence-Based Clinical Guidelines from the American Society of Pain and Neuroscience for the Use of Implantable Peripheral Nerve Stimulation in the Treatment of Chronic Pain

The objective of this peripheral nerve stimulation consensus guideline is to add to the current family of consensus practice guidelines and incorporate a systematic review process. The published literature was searched from relevant electronic databases, including PubMed, Scopus, Cochrane Central Register of Controlled Trials, and Web of Science from database inception to March 29, 2021. Inclusion criteria encompassed studies that described peripheral nerve stimulation in patients in terms of clinical outcomes for various pain conditions, physiological mechanism of action, surgical technique, technique of placement, and adverse events. Twenty randomized controlled trials and 33 prospective observational studies were included in the systematic review process. There is Level I evidence supporting the efficacy of PNS for treatment of chronic migraine headaches via occipital nerve stimulation; chronic hemiplegic shoulder pain via stimulation of nerves innervating the trapezius, supraspinatus, and deltoid muscles; failed back surgery syndrome via subcutaneous peripheral field stimulation; and lower extremity neuropathic and lower extremity post-amputation pain. Evidence from current Level I studies combined with newer technologies facilitating less invasive and easier electrode placement make peripheral nerve stimulation an attractive alternative for managing patients with complex pain disorders. Peripheral nerve stimulation should be used judiciously as an adjunct for chronic and acute postoperative pain following adequate patient screening and positive diagnostic nerve block or stimulation trial.

Overcoming clinical challenges of refractory neuropathic pain

INTRODUCTION

: Refractory neuropathic pain (ReNP), and its definition, is widely disputed amongst clinicians due in part to unclear categorical diagnosing guidelines, overall time duration of neuropathic pain, and the exhaustiveness of treatment options. Usually ReNP is defined as chronic, intractable, and unresponsive neuropathic pain that have otherwise been untreatable.

AREAS COVERED

: In this narrative review, we discuss and summarize the effectiveness of prospective ReNP research conducted over the past 10 years. This research looks at pharmacological and interventional therapies in clinical trial settings. The pharmacological therapies discussed include the use of adjuvant treatments to improve the safety and efficacy of conventional approaches. Different modalities of administration, such as injection therapy and intrathecal drug delivery systems, provide targeted drug delivery. Interventional therapies such as neuromodulation, pulse radiofrequency, and nerve lesioning are more invasive, however, they are increasingly utilized in the field, as reflected in ongoing clinical trials.

EXPERT OPINION

: Based on the current data from RCTs and systematic reviews, it is clear that single drug therapy cannot be effective and has significant limitations. Transitioning to interventional modalities that showed more promising results sooner rather than later may be even more cost-efficient than attempting different conservative treatments with a high failure rate.

Peripheral Nerve Stimulation for Chronic Pain: A Systematic Review of Effectiveness and Safety

Peripheral nerve stimulation (PNS) was the first application of neuromodulation. Widespread application of PNS was limited by technical concerns. Recent advances now allow the percutaneous placement of leads with ultrasound or fluoroscopic guidance, while the transcutaneous powering of these leads removes the need for leads to cross major joints. This systematic review was written to assess the current status of high-quality evidence supporting the use of PNS for pain conditions treated by interventional pain physicians. The available literature on PNS, limited to conditions treated by interventional pain physicians, was reviewed and the quality assessed. Literature from 1966 to June 2021 was reviewed. The outcome measures were pain relief and functional improvement. One hundred and two studies were identified. Five randomized controlled trials (RCT) and four observational studies, all case series, met the inclusion criteria. One RCT was of high quality and four were of moderate quality; all four case series were of moderate quality. Three of the RCTs and all four case series evaluated peripheral nerve neuropathic pain. Based upon these studies, there is level II evidence supporting the use of PNS to treat refractory peripheral nerve injury. One moderate-quality RCT evaluated tibial nerve stimulation for pelvic pain, providing level III evidence for this indication. One moderate-quality RCT evaluated surgically placed cylindrical leads for cluster headaches, providing level III evidence for this indication. The evidence suggests that approximately two-thirds of patients with peripheral neuropathic pain will have at least 50% sustained pain relief. Adverse events from PNS are generally minor. A major advantage of PNS over spinal cord stimulation is the absence of any risk of central cord injury. The study was limited by the paucity of literature for some indications. No studies dealt with joint-related osteoarthritic pain.

Peripheral Nerve Stimulation of the Brachial Plexus for Chronic Refractory CRPS Pain of the Upper Limb: Description of a New Technique and Case Series

OBJECTIVE

Upper limb complex regional pain syndrome is an important cause of chronic pain, and its treatment is challenging. In this pilot case series, we preliminarily evaluated the feasibility, effectiveness, and safety of a new technique for brachial plexus neuromodulation in the treatment of this disease in patients refractory to conservative treatment.

METHODS

Between 2017 and 2018, 14 patients considered to be refractory to optimized conservative treatment were recruited to this study. In the first stage, patients were trialed for seven days with a new technique of implant of the brachial plexus. Patients with ≥50% pain relief in visual analog scale (VAS) score received a definitive implantation in the second stage. Follow-ups were conducted at pre-implant and 12 months using the Neuropathic Pain Scale, SF-32, and the visual analogic scale for pain.

RESULTS

After the initial trial, 10 patients had a pain reduction of ≥50% and received a permanent implant. At 12-month follow-up, VAS, Neuropathic Pain Scale, SF-12 physical and mental scores improved by 57.4% +/- 10% (P = 0.005), 60.2% +/- 12.9% (P = 0.006), and 21.9% +/- 5.9% (P = 0.015), respectively.

CONCLUSIONS

Our data suggest that this new technique of brachial plexus stimulation may have long-term utility in the treatment of painful upper limb complex regional pain syndrome. New more detailed comprehensive studies should be carried out to confirm our findings in a larger population and to further refine the clinical implementation of this technique.