Ultrasound-guided percutaneous peripheral nerve stimulation for chronic refractory neuropathic pain: a unique series.

During the last two decades, with the advent of recent technology, peripheral nerve stimulation has become an appealing modality at the forefront of pain management. In this case series, we document the clinical rationale and technical considerations on three of the most challenging cases, refractory to previous interventions, that were treated by our team with an ultrasound-guided percutaneous peripheral nerve stimulator targeting the musculocutaneous, bilateral greater occipital and subcostal nerves. At the 6-month follow-up, all patients experienced greater than 50% relief of baseline pain, with a near-complete resolution of pain exacerbations. Furthermore, to our knowledge, this is the first report of an ultrasound-guided percutaneous technique of a peripheral nerve stimulator targeting the musculocutaneous and subcostal nerves.

Peripheral nerve stimulation is a new tool used in the treatment of peripheral nerve pain. In this study, we share our experience using this technology in three unusual, difficult-to-treat chronic nerve pain presentations, targeting the musculocutaneous, bilateral greater occipital and subcostal nerves. All patients were asked about how pain levels had changed since the peripheral nerve stimulation device had been implanted. In every case, patients reported a decline in their pain level from day one. After 6 months of peripheral nerve stimulator use, all patients reported a greater than 50% pain relief.

Real-world evidence of sustained improvement following 60-day peripheral nerve stimulation treatment for pain: a cross-sectional follow-up survey.

Objective: This study presents real-world data from a cross-sectional follow-up survey of patients who previously received 60-day peripheral nerve stimulation (PNS) treatment for pain. Materials & methods: A survey including validated pain and other related outcome measures was distributed to patients who previously underwent implantation of temporary PNS leads for 60-day PNS treatment. Results: Among survey respondents who were at least 3 months from the start of treatment, most reported sustained clinically significant improvements in pain and/or quality of life, with the length of follow-up at the time of survey completion ranging from 3 to 30 months. Conclusion: These real-world data support recent prospective studies indicating that 60-day percutaneous PNS provides significant and sustained relief across a wide range of pain conditions.

This study presents the findings from a survey that was sent to patients who previously received a 60-day peripheral nerve stimulation (PNS) treatment for their chronic pain. Patients were asked about their current pain levels, how their quality of life and physical function have changed since their PNS treatment, and whether they had changed their usage of pain medications. The survey showed that most patients who were at least 3 months from the start of the PNS treatment continued to have meaningful pain relief and/or improvement in their quality of life. This information is consistent with clinical studies that were previously published and supports that the 60-day PNS treatment can provide patients with long-term relief of chronic pain.

Ultrasound-guided transversus abdominis plane block vs trigger point injections for chronic abdominal wall pain: a randomized clinical trial.

ABSTRACT: The primary aim of this randomized clinical trial is to investigate the effects of ultrasound-guided transversus abdominis plane (TAP) vs ultrasound-guided trigger point injections (TPIs) on numerical rating scale pain scores at month 3 follow-up in patients with a chronic abdominal wall pain. The primary outcome measure was the difference in mean numeric rating scale pain scores between the TAP and TPI groups at month 3 in an intent-to-treat (ITT) analysis. A total of 60 patients were randomized 1:1 to receive an ultrasound-guided TAP block (n = 30) or an ultrasound-guided TPI (n = 30). No significant group differences in baseline demographic or clinical characteristics were observed. The mean baseline pain score for the TAP and TPI groups was 5.5 and 4.7, respectively. In the ITT analysis at month 3, the between-group difference in pain scores was 1.7 (95% confidence interval, 0.3-3.0) favoring the TPI group. In a secondary per-protocol analysis, the between-group difference in pain scores was 1.8 (95% confidence interval, 0.4-3.2) favoring the TPI group. For the ITT and per-protocol analyses, the group differences in pain scores were consistent with a medium effect size. The main finding of this randomized clinical trial is that adults with chronic abdominal wall pain who received a TPI reported significantly lower pain scores at month 3 follow-up compared with patients who received a TAP block.

Peripheral Nerve Stimulation and Clinical Outcomes: A Retrospective Case Series.

PURPOSE: Peripheral nerve stimulation (PNS) is a rapidly expanding field within neuromodulation; however, there is limited data on therapeutic efficacy. This study describes the indications and clinical outcomes for patients undergoing PNS for chronic pain states. PATIENTS AND METHODS: This is a retrospective case series of adults undergoing PNS implantation from 2004 to 2017 at an academic medical center. The primary outcomes were changes in numeric rating scale (NRS) pain scores, opioid utilization in oral morphine milligram equivalent (MME), and self-reported patient functioning at 6 months postoperatively. Infectious and device-related complications were also assessed. RESULTS: A total of 72 patients underwent PNS implantation, including 59 patients that received a preceding PNS trial (59/78; 76% progression rate) and 13 that did not receive a PNS trial. The most common indication for stimulation was occipital neuralgia (47%) followed by lower-extremity neuropathies (17%). PNS implantation was associated with 6-month reductions in pain scores (7 [6, 8] baseline vs. 4 [2, 5] 6 months; P < 0.001) and opioid utilization (eg, median 60 [31, 104] vs. 18 [0, 52] MME among those with baseline opioid use; P < 0.001). Median functional improvement was 73% (50%, 88%). Seven patients (10%) suffered a postoperative surgical site infection at a median of 50 (30, 124) days, of which five devices were removed. CONCLUSION: Peripheral nerve stimulation was associated with reduced pain scores, lower opioid utilization, and improved patient function at 6 months. These data support PNS as a potentially effective nonopioid analgesic modality in chronic pain, though prospective multicenter evaluation is warranted to evaluate longer-term outcomes.

Immediate Adverse Events in Interventional Pain Procedures: A Multi-Institutional Study.

SETTING: Interventional procedures directed toward sources of pain in the axial and appendicular musculoskeletal system are performed with increasing frequency. Despite the presence of evidence-based guidelines for such procedures, there are wide variations in practice. Case reports of serious complications such as spinal cord infarction or infection from spine injections lack appropriate context and create a misleading view of the risks of appropriately performed interventional pain procedures. OBJECTIVE: To evaluate adverse event rate for interventional spine procedures performed at three academic interventional spine practices. METHODS: Quality assurance databases at three academic interventional pain management practices that utilize evidence-based guidelines [1] were interrogated for immediate complications from interventional pain procedures. Review of the electronic medical record verified or refuted the occurrence of a complication. Same-day emergency department transfers or visits were also identified by a records search. RESULTS: Immediate complication data were available for 26,061 consecutive procedures. A radiology practice performed 19,170 epidural steroid (primarily transforaminal), facet, sacroiliac, and trigger point injections (2006-2013). A physiatry practice performed 6,190 spine interventions (2004-2009). A second physiatry practice performed 701 spine procedures (2009-2010). There were no major complications (permanent neurologic deficit or clinically significant bleeding [e.g., epidural hematoma]) with any procedure. Overall complication rate was 1.9% (493/26,061). Vasovagal reactions were the most frequent event (1.1%). Nineteen patients (<0.1%) were transferred to emergency departments for: allergic reactions, chest pain, symptomatic hypertension, and a vasovagal reaction. CONCLUSION: This study demonstrates that interventional pain procedures are safely performed with extremely low immediate adverse event rates when evidence-based guidelines are observed.

Occipital Neuromodulation: A Surgical Technique with Reduced Complications.

BACKGROUND: Occipital neuromodulation is a promising treatment modality for refractory headache, but lead migration remains a frequent surgical complication. OBJECTIVES: The primary objective was to identify surgical techniques that may minimize adverse events, particularly lead migration. We hypothesized that a surgical technique employing 2-point anchoring of stimulator leads designed to provide a tension-relief loop and the use of ultrasound for lead placement would decrease the complication rate. STUDY DESIGN AND SETTING: A retrospective analysis was performed through electronic medical record chart review in a tertiary referral center. METHODS: Institutional Review Board (IRB) approval was obtained. Eighteen patients had a trial and subsequent permanent occipital nerve stimulator (ONS) implantation between 2004 and 2011 and were included. Adverse events were recorded and efficacy outcome variables analyzed for significance. RESULTS: The cohort was a median (IQR) 45 (37 - 58) in age and 9 (50%) were women. Tension-relief loops placed via a 2-point anchoring technique and ultrasound use for occipital lead placement were evident in 16 (89%) and 13 (72%), respectively. There was one (6%) clinically insignificant lead position change, not definitively a lead migration, which could have been an artifact of fluoroscope positioning. Adverse events included one (6%) battery malfunction, one (6%) lead malfunction, and 2 (12%) post-implantation infections. Following ONS, there were significant reductions in numeric rating scale (NRS) pain scores from a median (IQR) of 9.5 (8.25 - 10) to 2.5 (1 - 4.75) (P < 0.0001), headache days per week from 7 (7 - 7) to 1.5 (0.375 - 1.75) (P = 0.0005), and the number of daily headache medication from 3 (2.25 - 4) to 2.5 (2 - 3.75) (P = 0.0112). LIMITATIONS: Limitations include retrospective study design, investigator bias, and non-standardized intervals of headache burden assessment. CONCLUSIONS: In ONS, utilization of a 2-point anchoring technique with a tension-relief loop may significantly minimize the risk of lead migration, based on the absence of definitive lead migration in our series. Ultrasound use may improve the anatomic accuracy of lead placement with the possibility of improved efficacy. ONS was associated with significantly decreased headache pain, frequency, and medication use. KEY WORDS: Occipital neuromodulation, occipital nerve stimulation, surgical technique, lead migration, tension-relief loop.

Occipital neuromodulation: ultrasound guidance for peripheral nerve stimulator implantation.

We report a case of chronic left-sided occipital neuralgia in a 21-year old female patient. The patient in question suffered from chronic greater occipital neuralgia for a duration of many years, which had been refractory to other conservative medical management strategies. Blockade of the greater occipital nerve with local anesthetic was consistently useful in attenuating the patient's pain, though the effects were always short lived. Consequently, a successful trial of greater occipital nerve stimulation was undertaken. Compared with spinal cord stimulation, peripheral nerve stimulation devices are often more difficult to precisely place given limited ability to visualize soft tissues with traditional fluoroscopic guidance. Additionally, there are anatomic subtleties relevant to the greater occipital nerve that potentially complicate stimulator lead placement, both from the standpoint of optimal neuromodulation efficacy and maximum safety. Ultrasound technology is a maturing imaging modality that allows soft tissue visualization and is consequently useful in addressing each of these aforementioned concerns. The specific use of high-frequency ultrasound guidance for this procedure simplified the initial device placement and allowed proper visualization of soft tissue structures, which facilitates precise device deployment. Additionally, the ability to identify relevant vascular structures may further increase the safety of stimulator lead placement. The potential advantages of ultrasound-augmented procedural techniques, specifically as they pertain to occipital stimulator lead placement, are discussed with particular emphasis on potentially decreasing intraoperative and postoperative complications while optimizing stimulation efficacy.