Hagedorn, Jonathan M.

Epidural and dorsal root stimulation have emerged as promising therapies to restore function after spinal cord injury. However, how each modality uniquely or jointly engages spinal circuits remains unclear. To address this, we analyzed leg electromyography (EMG) responses to epidural stimulation (ES) and dorsal root ganglia stimulation (DRGS) delivered to the lumbosacral cord in the same individuals.

Introduction This case describes the application of spinal cord stimulation for the treatment of phantom limb pain in a patient with a left transhumeral amputation. Treatment of pain involving a high frequency spinal cord stimulator allowed the patient to utilize his myoelectric prosthesis and improve his overall function. Clinical findings Severe, phantom limb pain with associated involuntary muscle contractions prevented the patient from wearing a prosthesis for more than three hours per day. He also had difficulty using his myoelectric prosthesis to use his left upper extremity for functional tasks. Therapeutic intervention A high frequency spinal cord stimulator was placed at the level of the cervical spine. The patient had improvement in pain and overall function. He was also able to tolerate wearing his prosthesis longer each day. Conclusion High frequency spinal cord stimulation may be an effective treatment option for individuals with phantom limb pain. Treatment of phantom limb pain may decrease barriers to prosthesis use and improve overall function.

Background The efficacy of EVOKE therapy, a closed-loop spinal cord stimulation (SCS) system, has been demonstrated in a double-blinded randomized controlled trial (RCT). RCT evidence, however, may not be generalizable to clinical practice, while limitations of real-world evidence may affect its validity. The aim of this study was to evaluate the effectiveness of EVOKE therapy in routine clinical practice employing a rigorous data collection approach. Methods The ECAP study was a prospective, multicenter, single-arm, pragmatic study that enrolled SCS candidates with chronic, intractable trunk and/or limb pain in 22 US investigational sites. PROMIS-29 questionnaire and objective neurophysiological metrics were collected, and minimal clinically important differences (MCIDs) were used to characterize baseline dysfunction and response to EVOKE therapy both at trial end and maximal analgesic effect post-implant visit. Pre-specified subgroup analyses were conducted based on diagnosis. Results EVOKE therapy observed included a dose ratio of 1.3 and neural dose accuracy of 2.8 μV. Improvements of >1 MCID were observed for all domains and improvements of ≥2 MCIDs were observed for six of the seven domains. Improvements observed at trial end were maintained or improved at post-implant visit, with statistically significant improvement in holistic MCID (MD 0.2, 95% CI 0.1 to 0.4, p=0.004), and a significantly greater proportion of patients considered holistic MCID responders (p=0.047). Subgroup analysis by diagnosis showed similar outcomes. Conclusions EVOKE therapy was associated with clinically meaningful improvements in a real-world chronic pain population across different subgroups and disease pathologies, with effects observed at trial end reproduced at post-implant visit.

OBJECTIVE Hundreds of thousands of Americans undergo decompression for lumbar spinal stenosis annually. The mild (minimally invasive lumbar decompression) procedure was developed as a potentially less invasive alternative to open decompression; however, much of the evidence has been gathered from industry-sponsored studies. The present study sought to compare real-world clinical outcomes between the mild procedure and open decompression for lumbar spinal stenosis. METHODS All patients who underwent the mild procedure at a single-institution, multisite, tertiary care center from 2005 to October 2024 were included. One-to-one propensity score matching was used to identify patients who underwent open decompression at the same institution, with age, sex, smoking, and comorbidities as covariates. Primary outcomes were change in pain on the numeric rating scale (NRS), surgical reoperation, and perioperative complications. For pain, the minimal clinically important difference (MCID) was defined as a 30% improvement in NRS score. RESULTS A total of 175 patients who underwent the mild procedure (mean age 76.3 ± 8.7 years; 44.6% female) were matched to 175 patients treated with open decompression (mean age 75.4 ± 8.7 years; 44.0% female). Among patients with at least 60 days of follow-up, those treated with open decompression were more likely to achieve the MCID for pain (43.1% vs 22.2%, p < 0.001). Patients treated with mild were more likely to require reoperation (46.2% vs 29.3%, p = 0.008). Those who underwent the mild procedure experienced lower rates of durotomies (0% vs 2.9%, p = 0.024) but had higher rates of neurological deficits (6.3% vs 0.6%, p = 0.003). CONCLUSIONS For patients with symptomatic lumbar stenosis, those who underwent open decompression were more likely to achieve pain improvement and less likely to require reoperation compared with those who underwent the mild procedure.

Background: Spasticity is common in spinal cord injury (SCI) and multiple sclerosis (MS), and it can manifest as repeated, rhythmic muscle contractions called clonus. The spontaneous nature of clonus can disrupt independent performance of activities of daily living and negatively impact overall health and quality of life. Objectives: To quantify biomarkers of clonus and explore management of clonus in individuals with SCI or progressive MS using epidural spinal cord stimulation (ES) or dorsal root stimulation (DRS). Methods: Four male participants were included in this case series study: 3 with SCI and 1 with MS. All participants underwent temporary percutaneous ES lead placement over the dorsolateral thoracolumbar region of the spinal cord. Participants with SCI were also implanted with DRS leads at the L4 dorsal root. Clonus was elicited mechanically at the ankle while recording electromyography of the soleus muscle synchronized to direct spinal cord field potential recordings from ES and DRS percutaneous leads. Results: Clonus was evident as a prominent band (5-8 Hz) in recordings from ES leads, DRS leads, soleus muscle, and accelerometry. In 4 participants, percutaneous spinal stimulation reduced median clonus duration and cycle count. Clonus was immediately suppressed upon activation of spinal cord stimulation, and the suppression persisted even when clonus was reinitiated after turning off the stimulation. Conclusion: The use of objective biomarkers, including spinal cord potentials, to quantify clonus in real time combined with the immediate and reversible effects of stimulation highlight the potential of neuromodulation as a therapeutic tool for managing clonus. These data demonstrate preliminary efficacy of ES and DRS for clonus monitoring and treatment in 4 participants.

Abstract Objectives Lumbar spine surgery is a common procedure for treating disabling spine‐related pain. In recent decades, both the number and cost of spine surgeries have increased despite technological advances and modification in surgical technique. For those patients that have continued uncontrolled back and/or lower extremity pain following lumbar spine surgery, spinal cord stimulation (SCS) has emerged as a viable treatment option. However, the impact of lumbar spine surgical history remains largely unstudied. Specifically, the current study considers the impact of number of prior lumbar spine surgeries on pain relief outcomes following SCS implantation. Materials and Methods We queried the electronic medical record of five separate pain practices for all patients who have undergone a SCS implant between January 1, 2017, and March 1, 2020. Inclusion criteria consisted of any patients with an SCS implant who underwent a prior lumbar spine surgery. The primary outcome was the mean calculated percentage pain relief in patients based on number of prior lumbar spine surgeries. Results There was a total of 1974 total SCS implant cases identified across five separate pain clinics. There was no difference in mean calculated pain relief in patients with one prior spine surgery versus those with two or more prior spine surgeries (28.2% vs. 25.8%, adjusted β‐coefficient –3.1, 95% CI –8.9 to 2.7, p = 0.290). Similarly, when analyzing number of spine surgeries as a continuous variable, there was no association between number of spine surgeries and calculated pain relief (adjusted β‐coefficient –1.5, 95% CI –4.0 to 1.1, p = 0.257). Additionally, after patients were stratified based on waveform, there was no association between number of prior lumbar spine surgeries (analyzed both as a categorical and continuous variable) and calculated percentage pain relief. Conclusions This multicentered retrospective study found that there was no significant difference in pain scores in individuals who received SCS following one or more lumbar spine surgeries. Additionally, the waveform of the SCS device had no statistically significant impact on post‐operative pain scores following one or more lumbar spine surgeries.

AbstractBackgroundChronic 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 MethodsA 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.ResultsA 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.ConclusionsNeuromodulation 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.

AbstractObjectiveThis prospective longitudinal study compares outcomes between Medicare beneficiaries receiving percutaneous image‐guided lumbar decompression (PILD) using the mild® procedure and a control group of patients receiving interspinous spacers for the treatment of lumbar spinal stenosis (LSS) with neurogenic claudication (NC).MethodsPatients diagnosed with LSS with NC and treated with either the mild procedure or a spacer were identified in the Medicare claims database. The incidence of harms, the rate of subsequent interventions, and the overall combined rate of harms and subsequent interventions during 2‐year follow‐up after the index procedure were compared between the two groups and assessed for statistical significance with p = 0.05.ResultsThe study included 2229 patients in the mild group and 3401 patients who were implanted with interspinous spacers. The rate of harms for those treated with the mild procedure was less than half that of patients implanted with a spacer (5.6% vs. 12.1%, respectively; p < 0.0001) during 2‐year follow‐up. The rate of subsequent interventions was not significantly different between the two groups (24.9% and 26.1% for the mild and spacer groups, respectively; p = 0.7679). The total rate of harms and subsequent interventions for mild was found to be noninferior to spacers (p < 0.0001).ConclusionsThis comprehensive study of real‐world Medicare claims data demonstrated a significantly lower rate of harms for the mild procedure compared to interspinous spacers for patients diagnosed with LSS with NC, and a similar rate of subsequent interventions during 2‐year follow‐up.

Background/importance Patient selection for spinal cord stimulation (SCS) therapy is crucial and is traditionally performed with clinical selection followed by a screening trial. The factors influencing patient selection and the importance of trialing have not been systematically evaluated. Objective We report a narrative review conducted to synthesize evidence regarding patient selection and the role of SCS trials. Evidence review Medline, EMBASE and Cochrane databases were searched for reports (any design) of SCS in adult patients, from their inception until March 30, 2022. Study selection and data extraction were carried out using DistillerSR. Data were organized into tables and narrative summaries, categorized by study design. Importance of patient variables and trialing was considered by looking at their influence on the long-term therapy success. Findings Among 7321 citations, 201 reports consisting of 60 systematic reviews, 36 randomized controlled trials (RCTs), 41 observational studies (OSs), 51 registry-based reports, and 13 case reports on complications during trialing were included. Based on RCTs and OSs, the median trial success rate was 72% and 82%, and therapy success was 65% and 61% at 12 months, respectively. Although several psychological and non-psychological determinants have been investigated, studies do not report a consistent approach to patient selection. Among psychological factors, untreated depression was associated with poor long-term outcomes, but the effect of others was inconsistent. Most RCTs except for chronic angina involved trialing and only one RCT compared patient selection with or without trial. The median (range) trial duration was 10 (0–30) and 7 (0–56) days among RCTs and OSs, respectively. Conclusions Due to lack of a consistent approach to identify responders for SCS therapy, trialing complements patient selection to exclude patients who do not find the therapy helpful and/or intolerant of the SCS system. However, more rigorous and large studies are necessary to better evaluate its role.