Peripheral Nerve Field Stimulation Research Articles

Incidence and Management of Hardware-Related Wound Infections in Spinal Cord, Peripheral Nerve Field, and Deep Brain Stimulation Surgery: A Single-Center Study

Introduction: Neuromodulation using deep brain stimulation (DBS), spinal cord stimulation (SCS), and peripheral nerve field stimulation (PNFS) to treat neurological, psychiatric, and pain disorders is a rapidly growing field. Infections related to the implanted hardware are among the most common complications and result in health-related and economic burden. Unfortunately, conservative medical therapy is less likely to be successful. In this retrospective study, we aimed to identify characteristics of the infections and investigated surgical and antimicrobial treatments. Methods: A retrospective analysis was performed of patients with an infection related to DBS, SCS, and/or PNFS hardware over an 8-year period at our institution. Data were analyzed for type of neurostimulator, time of onset of infection following the neurosurgical procedure, location, and surgical treatment strategy. Surgical treatment of infections consisted of either a surgical wound revision without hardware removal or a surgical wound revision with partial or complete hardware removal. Data were further analyzed for the microorganisms involved, antimicrobial treatment and its duration, and clinical outcome. Results: Over an 8-year period, a total of 1,250 DBS, 1,835 SCS, and 731 PNFS surgeries were performed including de novo system implantations, implanted pulse generator (IPG) replacements, and revisions. We identified 82 patients with infections related to the neurostimulator hardware, representing an incidence of 3.09% of the procedures. Seventy-one percent of the patients had undergone multiple surgeries related to the neurostimulator prior to the infection. The infections occurred after a mean of 12.2 months after the initial surgery. The site of infection was most commonly around the IPG, especially in DBS and SCS. The majority (62.2%) was treated by surgical wound revision with simultaneous partial or complete removal of hardware. Microbiological specimens predominantly yielded Staphylococcus epidermidis (39.0%) and Staphylococcus aureus (35.4%). After surgery, antimicrobials were given for a mean of 3.4 weeks. The antimicrobial regime was significantly shorter in patients with hardware removal in comparison to those who only had undergone surgical wound revision. One intracranial abscess occurred. No cases of infection-related death, sepsis, bacteremia, or intraspinal abscesses were found. Conclusion: Our data did show the predominance of S. epidermidis and S. aureus as etiologic organisms in hardware-related infections. Infections associated with S. aureus most likely required (partial) hardware removal. Aggressive surgical treatment including hardware removal shortens the duration of antimicrobial treatment. Clear strategies should be developed to treat hardware-related infections to optimize patient management and reduce health- and economic-related burden.

ID: 199400 Pain-Relief Outcomes Using Peripheral Nerve/Field Stimulation (PNFS) Combined With Spinal Cord Stimulation: Multicenter European Evaluation

Peripheral Nerve Field Stimulation (PNFS) and Spinal Cord Stimulation (SCS) are treatment options for patients with chronic pain. Combining localized stimulation using PFNS along with SCS may have potential to treat areas of pain not previously covered with SCS alone. To address this question, we undertook an observational, multicenter study of patients using PNFS together with SCS implanted with a device that allows for precise customized programming of therapeutic neurostimulation parameters and settings.

Role of peripheral nerve stimulation in treating chronic neuropathic pain: an international focused survey of pain medicine experts

Interventional pain management (IPM) options for refractory neuropathic pain (NP) have recently increased with availability of peripheral nerve stimulation (PNS) equipment and expertise. Given a lack of high-quality evidence and...

Birds of a Feather Redux: Defining Ways to Stimulate the Peripheral Nervous System.

Peripheral nerve stimulation (PNS) has become an essential component in the pain management plan for individuals suffering from peripheral nerve-mediated pain. The recent surge in interest in PNS can be attributed to the advancements in imaging techniques and the availability of minimally invasive stimulation systems along with a deeper grasp of PNS physiology. These advancements have made PNS more accessible to clinicians and patients alike. However, it is important to note that PNS requires a different set of technical requirements and skills compared to other pain management procedures. The work, knowledge, and surgical and interventional skillset required for PNS are in a class of their own. This article aims to educate and clarify the differences between procedures that may have similar names but are vastly different in terms of technology, expertise, and skill sets necessary for their safe implementation. Some of the procedures that this article will cover include indirect peripheral nerve field stimulation (PNfS), indirect percutaneous electrical nerve stimulation (PENS), PENS-Field Stimulation (PENFS), and transcutaneous electrical nerve stimulation (TENS). By understanding the differences between these procedures, patients and health-care providers can make informed decisions about the best approach for managing pain.

Management of primary frozen shoulder (Avabahuka) through Agnikarma (peripheral nerve field stimulation) and adjuvant therapy: A case series

Management of primary frozen shoulder (Avabahuka) through Agnikarma (peripheral nerve field stimulation) and adjuvant therapy: A case series

Atypical Facial Pain Treatment With Peripheral Nerve Field Stimulation Using a Micro-Implantable and External Battery Impulse Generator

Atypical facial pain (AFP) is continuous, deep, poorly localized, often initiated by facial trauma or surgery and can involve multiple trigeminal nerve branches. Poor response to medical treatment is often found and ablative invasive procedures has been classically discouraged due to fear of worsening AFP symptoms. Peripheral nerve field stimulation (PNFS) is an emerging treatment for AFP but the optimal stimulation parameters are still being investigated. Pulse generator placement for craniofacial PNFS is usually in the infraclavicular region which can cause discomfort and is cosmetically disadvantageous.

Peripheral Field Stimulation for the Management of Facial Pain

Peripheral nerve field stimulation (PNFS) is a tool in the armamentarium of treatment options for trigeminal pain; however, the efficacy of this modality in mitigating trigeminal pain remains unclear. The aim of the present study was to examine the existing literature on PNFS and elucidate outcomes associated with its use in patients with trigeminal pain.

Clinical outcomes and complications of peripheral nerve field stimulation in the management of refractory trigeminal pain: a systematic review and meta-analysis.

Peripheral nerve field stimulation (PNFS) is a tool in the armamentarium of treatment options for trigeminal pain. The efficacy of this modality in mitigating trigeminal pain remains unclear. The aim of this study was to examine the existing literature on PNFS and elucidate pain score outcomes associated with its use in patients with trigeminal pain. A systematic review and meta-analysis was performed in accordance with the PRISMA framework. The PubMed, Web of Science, and Scopus databases were queried on June 10, 2020. Studies reporting pain outcomes in more than 5 adult patients treated with PNFS for facial pain were included. The primary outcome of the study was the mean difference in the visual analog scale (VAS) score from the last follow-up to baseline, and it was analyzed by an inverse-variance, random-effect model. The risk of bias was assessed using the Newcastle-Ottawa Scale and a funnel plot. Of the 4597 studies screened for inclusion, 46 relevant full-text articles were assessed for eligibility. Eleven observational cohort studies from the 46 articles were found to be eligible, and reported on a total of 109 patients. In 86% (94/109) of cases, trial stimulation was successful and followed by a permanent system implantation. VAS scores improved by 75% (mean difference 6.32/10 points, 95% CI 5.38-7.27 points) compared to baseline. Seventy-six percent (42/55) of patients became medication free or required lower doses of medications. The complication rate necessitating surgical revision was estimated at 32% per procedure. These findings support the belief that PNFS provides effective, long-term pain control for trigeminal pain. Statistical heterogeneity was considerable across all studies. Future work should be aimed at conducting double-blind randomized controlled trials to determine the utility of PNFS for treating various forms of trigeminal pain for which limited therapeutic options exist.

O136 / #587 PAIN RELIEF OUTCOMES USING PERIPHERAL NERVE/FIELD STIMULATION (PNFS) COMBINED WITH SPINAL CORD STIMULATION: A MULTICENTER EUROPEAN EVALUATION: TRACK 1: NEUROMODULATION FOR PAINFUL NEUROPATHIES / PERIPHERAL NERVE STIMULATION

Peripheral Nerve Field Stimulation (PNFS) and Spinal Cord Stimulation (SCS) are treatment options for patients with chronic pain. Combining localized stimulation using PFNS along with SCS may have potential to treat areas of pain not previously covered with SCS alone. To address this question, we undertook an observational, multicenter study of patients using PNFS together with SCS implanted with a device that allows for precise customized programming of therapeutic neurostimulation parameters and settings.

PO216 / #677 NEUROMODULATION OPTIONS IN ATYPICAL FACIAL NEUROPATHIC PAIN: E-POSTER VIEWING

Atypical facial pain and trigeminal neuropathy are notoriously difficult to treat. Technical advances have improved and opened new approaches in peripheral nerve field stimulation (PNFS) of the face, Ganglion Gasseri stimulation and Motor Cortex Stimulation (MCS).

PO166 / #706 PAIN RELIEF OUTCOMES USING NEUROMODULATION SYSTEMS WITH MULTIPLE WAVEFORM AND PROGRAMMING MODALITIES: AN AUSTRALIAN CASE-SERIES: E-POSTER VIEWING

Treatment of chronic pain is inherently challenging given the subjective nature of pain that uniquely manifests within each patient. The availability of different approaches such as spinal cord stimulation (SCS), peripheral nerve stimulation (PNS), peripheral nerve field stimulation (PNFS) and occipital nerve stimulation (ONS) may help address this variability.

The Modifying of Functional Connectivity Induced by Peripheral Nerve Field Stimulationusing Electroacupuncture for Migraine: A Prospective Clinical Study.

We examined the functional connectivity (FC) in patients with migraine compared with healthy subjects before and after C2 peripheral nerve field stimulation with electroacupuncture (EA-C2-PNfS) to evaluate the effect of EA-C2-PNfS and elucidate the mechanism of migraine. Twenty-six patients with migraine and 24 healthy controls were recruited. All patients underwent resting state functional magnetic resonance imaging before and after 3 months of EA-C2-PNfS. We evaluated a numerical rating scale, the Headache Impact Test, and the Self-Rating Depression Scale, which assesses depression. Healthy controls underwent magnetic resonance imaging twice at a 3-month interval without acupuncture. An analysis of FC in the region of interest in the pain matrix was performed. Twenty patients with migraine and 23 healthy controls (mean ± standard deviation: 44.9 ± 12.9 years of age) were included. Three patients had migraine with aura (55.0 ± 18.0 years of age), 11 patients had migraine without aura (MWoA) (45.6 ± 14.6 years of age), and six patients had chronic migraine (40.8 ± 13.9 years of age). The clinical assessments significantly improved after EA-C2-PNfS in the MWoA group only. In FC analysis, the MWoA group showed a significant decrease after EA-C2-PNfS in FC between the right hypothalamus and left insula. Right hypothalamus-related FC was lower before acupuncture in the chronic migraine group than in the MWoA group. After EA-C2-PNfS for MWoA, significant changes in FC were observed at the hypothalamus and insula. Our results indicate that EA-C2-PNfS could improve migraine headache by modifying pain-related FC.

Subcutaneous Stimulation as Add-on Therapy to Spinal Cord Stimulation in Patients With Persistent Spinal Pain Syndrome Significantly Increases the Total Electrical Charge per Second: Aspects on Stimulation Parameters and Energy Requirements of the Implanted Neurostimulators

ObjectiveIn our previous multicenter randomized controlled trial, we demonstrated the clinical effectiveness of peripheral nerve field stimulation (PNFS) as add-on therapy to spinal cord stimulation (SCS) for the treatment of chronic back pain in patients with persistent spinal pain syndrome (PSPS) or failed back surgery syndrome (FBSS). To our knowledge, no previous study has investigated the effect of PNFS as an add-on to SCS on the energy consumption of the implanted neurostimulators. Therefore, in this study, we compared the specific stimulation parameters and energy requirements of a previously unreported group of patients with only SCS with those of a group of patients with SCS and add-on PNFS. We also investigated differences that might explain the need for PNFS in the treatment of chronic low back pain. Materials and MethodsWe analyzed 75 patients with complete sets of stimulation parameters, with 21 patients in the SCS-only group and 54 patients in the SCS + PNFS group. Outcome measures were average visual analog scale score, SCS parameters (voltage, frequency, and pulse width), SCS charge per second, and total charge per second. We analyzed baseline characteristics and differences between and within groups over time. ResultsBoth groups had comparable patient characteristics at baseline and showed a significant decrease in back and leg pain. SCS charge per second did not significantly differ between the groups at baseline or at 12 months. The total charge per second was significantly higher in the active SCS + PNFS group than in the SCS-only group at baseline; in the SCS + PNFS group, this persisted for up to 12 months, and the SCS charge per second and total charge per second increased significantly over time. ConclusionsOur results show that add-on PNFS increases the total charge per second compared with SCS alone, as expected. However, further research is needed because our results do not directly explain why some patients require add-on PNFS to treat low back pain.

Spinal Cord Stimulation With Additional Peripheral Nerve/Field Stimulation Versus Spinal Cord Stimulation Alone on Back Pain and Quality of Life in Patients With Persistent Spinal Pain Syndrome

IntroductionPersistent spinal pain syndrome (PSPS) or failed back surgery syndrome (FBSS) refers to new or persistent pain following spinal surgery for back or leg pain in a subset of patients. Spinal cord stimulation (SCS) is a neuromodulation technique that can be considered in patients with predominant leg pain refractory to conservative treatment. Patients with predominant low back pain benefit less from SCS. Another neuromodulation technique for treatment of chronic low back pain is subcutaneous stimulation or peripheral nerve field stimulation (PNFS). We investigated the effect of SCS with additional PNFS on pain and quality of life of patients with PSPS compared with that of SCS alone after 12 months. Materials and MethodsThis is a comparative study of patients with PSPS who responded to treatment with either SCS + PNFS or SCS only following a multicenter randomized clinical trial protocol. In total, 75 patients completed the 12-month follow-up: 21 in the SCS-only group and 54 in the SCS + PNFS group. Outcome measures were pain (visual analog scale), quality of life (36-Item Short Form Survey [SF-36]), anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), overall health (EuroQol Five-Dimension [EQ-5D]), disability (Oswestry Disability Index [ODI]), and pain assessed by the McGill questionnaire. ResultsThere were no significant differences in baseline characteristics between the two groups. Both groups showed a significant reduction in back and leg pain at 12 months compared with baseline measurements. No significant differences were found between the groups in effect on both primary (pain) and secondary parameters (SF-36, HADS, EQ-5D, ODI, and McGill pain). ConclusionIn a subgroup of patients with chronic back and leg pain, SCS alone provided similar long-term pain relief and quality-of-life improvement as PNFS in addition to SCS. In patients with refractory low back pain not responding to SCS alone, adding PNFS should be recommended. Clinical Trial RegistrationThe Clinicaltrials.gov registration number for the study is NCT01776749.

Electrical neurostimulation for the treatment of chronic pruritus: A systematic review.

Approximately one fifth of the world population experiences continuous itch for 6 weeks or more during their life, that is chronic itch. It is diverse in its aetiologies, and it is notoriously hard to treat. Because itch and pain have largely overlapping pathophysiology and the demonstrated efficacy of neurostimulation in treatment of selected chronic pain conditions, we conducted a systematic review to investigate whether neurostimulation could be an effective treatment for chronic itch. We identified two randomized controlled trials and 17 open label studies or case reports investigating various neurostimulation modalities for the treatment of refractory itch of various aetiologies. Transcutaneous electrical nerve stimulation (TENS) was the most investigated modality (n = 17), and in the largest number of conditions. Other modalities were cutaneous field stimulation (n = 2), painscrambler (n = 1), transcranial direct current stimulation (n = 1) and peripheral nerve field stimulation (n = 1). Atopic dermatitis was the most studied condition (n = 5). Despite the large heterogeneity in used stimulation paradigms and outcome parameters, all studies reported a positive effect of at least one neurostimulation modality. Our review indicates that electrical neurostimulation could be considered for the treatment of refractory chronic itch of selected aetiologies, such as atopic dermatitis or burn pruritus. However, better understanding of the mechanisms of action of the neurostimulation modalities and regimens in various pruritic conditions is necessary.

The Added Value of Subcutaneous Peripheral Nerve Field Stimulation Combined with SCS, as Salvage Therapy, for Refractory Low Back Pain Component in Persistent Spinal Pain Syndrome Implanted Patients: A Randomized Controlled Study (CUMPNS Study) Based on 3D-Mapping Composite Pain Assessment.

While Spinal Cord Stimulation (SCS) provides satisfaction to almost 2/3 of Persistent Spinal Pain Syndrome-Type 2 (PSPS-T2) patients implanted for refractory chronic back and/or leg pain, when not adequately addressed the back pain component, leaves patients in a therapeutic cul-de-sac. Peripheral Nerve field Stimulation (PNfS) has shown interesting results addressing back pain in the same population. Far from placing these two techniques in opposition, we suggest that these approaches could be combined to better treat PSPS-T2 patients. We designed a RCT (CUMPNS), with a 12-month follow-up, to assess the potential added value of PNfS, as a salvage therapy, in PSPS-T2 patients experiencing a “Failed SCS Syndrome” in the back pain component. Fourteen patients were included in this study and randomized into 2 groups (“SCS + PNfS” group/n = 6 vs. “SCS only” group/n = 8). The primary objective of the study was to compare the percentage of back pain surface decrease after 3 months, using a computerized interface to obtain quantitative pain mappings, combined with multi-dimensional SCS outcomes. Back pain surface decreased significantly greater for the ”SCS + PNfS” group (80.2% ± 21.3%) compared to the “SCS only” group (13.2% ± 94.8%) (p = 0.012), highlighting the clinical interest of SCS + PNfS, in cases where SCS fails to address back pain.

The Predictive Value of Transcutaneous Electrical Nerve Stimulation for Patient Selection in Peripheral Nerve Field Stimulation for Chronic Low Back Pain: A Prospective Study

Peripheral nerve field stimulation (PNFS) is an effective alternative treatment for patients with chronic low back pain. Transcutaneous electrical nerve stimulation (TENS) is frequently used in pain therapy. Aim of this prospective study was to examine the predictive value of TENS for later PNFS treatment. Between 2014 and 2019, a prospective cohort study of 41 patients with chronic lumbar pain was conducted. Pain intensity (NRS) was assessed before and after TENS use, preoperatively/postoperatively and in the follow-up after three and sixmonths, SF12v2 questionnaires with physical (PCS) and mental component summary (MCS) scores, and Oswestry disability index (ODI) questionnaire at baseline as well as three and six months after PNFS implantation. Implantation of the PNFS-system with two percutaneous leads was performed after four to seven days of positive testing. Statistical analysis was performed using depending t-test, ANOVA, and Spearman correlation. The cohort consisted of 41 patients (19 females, 22 males) with a median age of 60.5 years (IQR25-75 52-67). Two patients were lost to follow-up. After positive PNFS testing a pulse generator (IPG) was implanted in 15 patients with positive TENS effect and 15 patients without TENS effect. Leads were explanted in nine patients after negative PNFS trial phase. TENS positive patients showed significant correlation to a positive effect in the PNFS trial phase in NRS reduction (p=0.042) indicating that TENS responders will also respond to PNFS (94% patients). After three and six months follow-up median NRS and SF12v2 (PCS) improved significantly in both cohorts, SF12v2 (MCS) and ODI only in the TENS positive cohort, respectively. TENS can be predictive for patient selection in PNFS, as TENS positive patients showed significant correlation with a positive PNFS trial period. Therefore, TENS positive patients might be justifiable to be directly implanted with leads and IPG. TENS positive patients further tend to show a better improvement in the follow-up.

Preoperative Elevated Levels for Depression, Anxiety, and Subjective Mental Stress Have No Influence on Outcome Measures of Peripheral Nerve Field Stimulation for Chronic Low Back Pain—A Prospective Study

Peripheral nerve field stimulation (PNFS) is an effective alternative treatment for patients with chronic low back pain. The treatment of low back pain strongly depends on psychological factors like anxiety, depression, and mental stress. The aim of this study was to evaluate the impact of such factors on outcome measures after lead- and implantable pulse generator-implantation. Between 2014 and 2019, a prospective cohort study of 39 patients with chronic lumbar pain was conducted. Hospital Anxiety and Depression Scale (HADS) score was assessed at baseline to measure symptoms of anxiety and depression. Symptom checklist-90 (SCL-90) was used to measure subjective psychopathology. Pain intensity (numeric pain rating scale [NRS]), SF12v2 with Physical Component Summary and Mental Component Summary (MCS) scores, and Oswestry Disability Index (ODI) were assessed pre- and postoperatively as well as three and six months after PNFS implantation. Outcome values were compared to baseline data. Statistical analysis was performed using depending t-test and analysis of variance (ANOVA). A pvalue <0.05 was considered significant. The cohort consisted of 39 patients (18 females, 21 males) with a median age of 61 years (IQR25-75 =52-67 years). NRS, ODI, and SF12v2 showed significant improvement in the whole follow-up period compared to baseline values (p < 0.05). Elevated HADS scores for anxiety were seen in 64.1%, for depression in 76.9% of the patients at baseline. SCL-90 was pathologic in 71.8% of the cases. A one-way ANOVA revealed no differences between elevated HADS- and SCL-90 values and all outcome measures after PNFS implantation in the whole follow-up period (p > 0.05). Chronic low back pain is often associated with psychological distress. Our study showed highly elevated levels for anxiety and depression as well as subjective mental stress in patients with chronic low back pain without negative impact on NRS, ODI, and SF12v2 in the whole follow-up after PNFS implantation.

Psychological measures and their influence on outcome parameters of peripheral nerve field stimulation in patients with chronic low back pain

Psychological measures and their influence on outcome parameters of peripheral nerve field stimulation in patients with chronic low back pain

Cost-Effectiveness Analysis of Peripheral Nerve Field Stimulation as Add-On Therapy to Spinal Cord Stimulation in the Treatment of Chronic Low Back Pain in Failed Back Surgery Syndrome Patients

Presently, there is only limited evidence about the cost-effectiveness of peripheral nerve field stimulation (PNFS) and no evidence to date on the cost-effectiveness of PNFS as an add-on therapy to spinal cord stimulation (SCS). In a multicenter randomized controlled trial, PNFS as add-on therapy to SCS demonstrated clinical effectiveness in treating chronic low back pain in failed back surgery syndrome (FBSS) patients. We report here the cost-effectiveness of PNFS as additional therapy. Cost-effectiveness analysis was performed from a health-care perspective using the general principles of cost-utility analysis, using empirical data from our multicenter randomized controlled trial on the effectiveness of hybrid SCS + PNFS on low back pain in FBSS patients, who were back pain non-responders to initial SCS-therapy, over a time-horizon of three months. Outcome measures were costs and quality-adjusted life-years (QALYs). Cost and QALYs were integrated using the net monetary benefit (NMB). Differences in costs, effects, and NMB were analyzed using multilevel regression. Uncertainty surrounding the NMB was presented by cost-effectiveness acceptability curves. A total of 52 patients implanted with both SCS and PNFS, randomly assigned to a group with PNFS either activated or inactive, completed the controlled part of the study. With mean total costs for the SCS + active PNFS group of €1813.86 (SD €109.78) versus €1103.64 (SD €123.43) for the SCS + inactive PNFS group at three months, we found an incremental cost-utility ratio of €25.311 per QALY gained and a probability being cost-effective of more than 80% given a willingness to pay for a QALY of about €40.000. From a Dutch national health-care context, when the willingness to pay threshold is up to 60.000 Euros per QALY, PNFS as an add-on therapy to SCS for the treatment of low back pain in FBSS patients has a high probability of being cost-effective.