scholarly journals Pulse Width Programming in Spinal Cord Stimulation: A Clinical Study

2010 ◽  
Vol 4;13 (4;7) ◽  
pp. 321-335
Author(s):  
Thomas L. Yearwood

Background: With advances in spinal cord stimulation (SCS) technology, particularly rechargeable implantable, patients are now being offered a wider range of parameters to treat their pain. In particular, pulse width (PW) programming ranges of rechargeable implantable pulse generators now match that of radiofrequency systems (with programmability up to 1000µs). The intent of the present study was to investigate the effects of varying PW in SCS. Objective: To understand the effects of PW programming in spinal cord stimulation (SCS). Design: Single-center, prospective, randomized, single-blind evaluation of the technical and clinical outcomes of PW programming. Setting: Acute, outpatient follow-up. Methods: Subjects using fully-implanted SCS for > 3 months to treat chronic intractable low back and/or leg pain. Programming of a wide range (50-1000μs) of programmed PW settings using each patient’s otherwise unchanged ‘walk-in’ program. Outcome Measures: Paresthesia thresholds (perception, maximum comfortable, discomfort), paresthesia coverage and patient choice of tested programs. Results: We found strength-duration parameters of chronaxie and rheobase to be 295 (242 – 326) μs and 2.5 (1.3 – 3.3) mA, respectively. The median PW of all patients’ ‘walk-out’ programs was 400μs, approximately 48% higher than median chronaxie (P = 0.01), suggesting that chronaxie may not relate to patient-preferred stimulation settings. We found that 7/19 patients selected new PW programs, which significantly increased their paresthesia-pain overlap by 56% on average (P = 0.047). We estimated that 10/19 patients appeared to have greater paresthesia coverage, and 8/19 patients appeared to display a ‘caudal shift’ of paresthesia coverage with increased PW. Limitations: Small number of patients. Conclusions: Variable PW programming in SCS appears to have clinical value, demonstrated by some patients improving their paresthesia-pain overlap, as well as the ability to increase and even ‘steer’ paresthesia coverage. Key words: Spinal cord stimulation, pulse width, paresthesia, dermatome, implantable pulse generator, neurostimulation, chronic pain, neuropathic, dorsal column, dorsal root, chronaxie.

2017 ◽  
Vol 4 (20;4) ◽  
pp. 331-341
Author(s):  
Kerry Bradley

Background: Spinal cord stimulation (SCS) has been successfully used to treat chronic intractable pain for over 40 years. Successful clinical application of SCS is presumed to be generally dependent on maximizing paresthesia-pain overlap; critical to achieving this is positioning of the stimulation field at the physiologic midline. Recently, the necessity of paresthesia for achieving effective relief in SCS has been challenged by the introduction of 10 kHz paresthesia-free stimulation. In a large, prospective, randomized controlled pivotal trial, HF10 therapy was demonstrated to be statistically and clinically superior to paresthesia-based SCS in the treatment of severe chronic low back and leg pain. HF10 therapy, unlike traditional paresthesia-based SCS, requires no paresthesia to be experienced by the patient, nor does it require paresthesia mapping at any point during lead implant or post-operative programming. Objectives: To determine if pain relief was related to technical factors of paresthesia, we measured and analyzed the paresthesia responses of patients successfully using HF10 therapy. Study Design: Prospective, multicenter, non-randomized, non-controlled interventional study. Setting: Outpatient pain clinic at 10 centers across the US and Italy. Methods: Patients with both back and leg pain already implanted with an HF10 therapy device for up to 24 months were included in this multicenter study. Patients provided pain scores prior to and after using HF10 therapy. Each patient’s most efficacious HF10 therapy stimulation program was temporarily modified to a low frequency (LF; 60 Hz), wide pulse width (~470 μs), paresthesiagenerating program. On a human body diagram, patients drew the locations of their chronic intractable pain and, with the modified program activated, all regions where they experienced LF paresthesia. Paresthesia and pain drawings were then analyzed to estimate the correlation of pain relief outcomes to overlap of pain by paresthesia, and the mediolateral distribution of paresthesia (as a surrogate of physiologic midline lead positioning). Results: A total of 61 patients participated across 11 centers. Twenty-eight men and 33 women with a mean age of 56 ± 12 years of age participated in the study. The average duration of implantable pulse generator (IPG) implant was 19 ± 9 months. The average predominant pain score, as measured on a 0 – 10 visual analog scale (VAS), prior to HF10 therapy was 7.8 ± 1.3 and at time of testing was 2.5 ± 2.1, yielding an average pain relief of 70 ± 24%. For all patients, the mean paresthesia coverage of pain was 21 ± 28%, with 43% of patients having zero paresthesia coverage of pain. Analysis revealed no correlation between percentage of LF paresthesia overlap of predominant pain and HF10 therapy efficacy (P = 0.56). Exact mediolateral positioning of the stimulation electrodes was not found to be a statistically significant predictor of pain relief outcomes. Limitations: Non-randomized/non-controlled study design; short-term evaluation; certain technical factors not investigated.Conclusion: Both paresthesia concordance with pain and precise midline positioning of the stimulation contacts appear to be inconsequential technical factors for successful HF10 therapy application. These results suggest that HF10 therapy is not only paresthesia-free, but may be paresthesia-independent. Key words: Spinal cord stimulation, paresthesia, high frequency, 10kHz, pain relief, physiologic midline, paresthesia-free


Neurosurgery ◽  
2011 ◽  
Vol 68 (5) ◽  
pp. 1452-1461 ◽  
Author(s):  
Jan Holsheimer ◽  
Jan R. Buitenweg ◽  
John Das ◽  
Paul de Sutter ◽  
Ljubomir Manola ◽  
...  

Abstract BACKGROUND: In spinal cord stimulation for the management of chronic, intractable pain, a satisfactory analgesic effect can be obtained only when the stimulation-induced paresthesias cover all painful body areas completely or partially. OBJECTIVE: To investigate the effect of stimulus pulse width (PW) and contact configuration (CC) on the area of paresthesia (PA), perception threshold (VPT), discomfort threshold (VDT), and usage range (UR) in spinal cord stimulation. METHODS: Chronic pain patients were tested during a follow-up visit. They were stimulated monopolarly and with the CC giving each patient the best analgesia. VPT, VDT, and UR were determined for PWs of 90, 210, and 450 microseconds. The paresthesia contours at VDT were drawn on a body map and digitized; PA was calculated; and its anatomic composition was described. The effects of PW and CC on PA, VPT, VDT, and UR were tested statistically. RESULTS: Twenty-four of 31 tests with low thoracic stimulation and 8 of 9 tests with cervical stimulation gave a significant extension of PA at increasing PW. In 14 of 18 tests (low thoracic), a caudal extension was obtained (primarily in L5-S2). In cervical stimulation the extension was predominantly caudal as well. In contrast to VPT and VDT, UR is not significantly different when stimulating with any CC. CONCLUSION: PA extends caudally with increasing PW. The mechanism includes that the larger and smaller dorsal column fibers have a different mediolateral distribution and that smaller dorsal column fibers have a smaller UR and can be activated only when PW is sufficiently large. A similar effect of CC on PA is unlikely as long as electrodes with a large intercontact distance are applied.


2020 ◽  
Vol 1;23 (1;1) ◽  
pp. 87-98 ◽  
Author(s):  
Ramsin Benyamin

Background: Therapeutic approaches to spinal cord stimulation (SCS) continue to evolve and improve patient outcomes in patients receiving SCS therapy secondary to failed back surgery syndrome. Objectives: The aim of this study was to evaluate pain relief and other patient outcomes of SCS using selected high-dose programming parameters. Study Design: This was a prospective cohort study. Setting: This study took place at 11 centers in North America. Methods: Forty-four SCS-naive patients underwent trialing, starting with 1,000 Hz frequency, 90 µs pulse width followed by 300 Hz frequency, 800 µs pulse width, if pain relief was inadequate. Patients with 50% or greater pain relief were eligible for permanent implantation. Patient’s pain rating, global impression of change, health-related quality of life, functional disability, satisfaction/ recommendation, stimulation perception, device programming, and adverse events were assessed at 3 months postimplant. Results: There were significant improvements from baseline in mean Numeric Rating Scale (NRS11) pain scores for overall pain (7.5 to 3.8; P < 0.01), back pain (7.2 to 3.4; P < 0.01), leg pain (7.2 to 3.1; P < 0.01), Oswestry Disability Index (ODI) score (51.5 to 32.1; P < 0.01), and European Quality of Life–Five Dimensions, version 5L score (EQ-5D-5L) (0.58 to 0.74; P < 0.01). Twentyeight of 32 patients (88%) had significant, favorable improvement in Patient Global Impression of Change (PGIC). Eighty-four percent of patients were “satisfied,” and 78.1% would “definitely” recommend SCS. Eighteen patients (56%) used 1,000 Hz frequency and 90 µs pulse width exclusively; these patients experienced mean NRS-11 overall pain score improvement of 4.7 points. Device-, therapy-, or procedure-related adverse events were experienced in 19 patients (40%, 19 of 48), and all events resolved without reoperation and were similar to those observed with traditional SCS systems. Limitations: There was no active or sham comparator group, and therefore the reported effects may not be solely attributable to therapy effects and may be related to other, nonspecific effects of SCS. Conclusions: Improvements in pain relief, PGIC, EQ-5D-5L, ODI, and patient satisfaction were all clinically relevant and statistically significant. Future studies are needed to understand how these high-dose parameters perform versus a standard comparator. Key words: Spinal cord stimulation, high-frequency electrical stimulation, failed back surgery syndrome, neurostimulation, prospective, nonrandomized study


Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 644
Author(s):  
Vinicius Tieppo Francio ◽  
Keith F. Polston ◽  
Micheal T. Murphy ◽  
Jonathan M. Hagedorn ◽  
Dawood Sayed

Since the inception of spinal cord stimulation (SCS) in 1967, the technology has evolved dramatically with important advancements in waveforms and frequencies. One such advancement is Nevro’s Senza® SCS System for HF10, which received Food and Drug and Administration (FDA) approval in 2015. Low-frequency SCS works by activating large-diameter Aβ fibers in the lateral discriminatory pathway (pain location, intensity, quality) at the dorsal column (DC), creating paresthesia-based stimulation at lower-frequencies (30–120 Hz), high-amplitude (3.5–8.5 mA), and longer-duration/pulse-width (100–500 μs). In contrast, high-frequency 10 kHz SCS works with a proposed different mechanism of action that is paresthesia-free with programming at a frequency of 10,000 Hz, low amplitude (1–5 mA), and short-duration/pulse-width (30 μS). This stimulation pattern selectively activates inhibitory interneurons in the dorsal horn (DH) at low stimulation intensities, which do not activate the dorsal column fibers. This ostensibly leads to suppression of hyperexcitable wide dynamic range neurons (WDR), which are sensitized and hyperactive in chronic pain states. It has also been reported to act on the medial pathway (drives attention and pain perception), in addition to the lateral pathways. Other theories include a reversible depolarization blockade, desynchronization of neural signals, membrane integration, glial–neuronal interaction, and induced temporal summation. The body of clinical evidence regarding 10 kHz SCS treatment for chronic back pain and neuropathic pain continues to grow. There is high-quality evidence supporting its use in patients with persistent back and radicular pain, particularly after spinal surgery. High-frequency 10 kHz SCS studies have demonstrated robust statistically and clinically significant superiority in pain control, compared to paresthesia-based SCS, supported by level I clinical evidence. Yet, as the field continues to grow with the technological advancements of multiple waveforms and programming stimulation algorithms, we encourage further research to focus on the ability to modulate pain with precision and efficacy, as the field of neuromodulation continues to adapt to the modern healthcare era.


2016 ◽  
Vol 4;19 (4;5) ◽  
pp. 267-280 ◽  
Author(s):  
Dr Marc A. Russo

Background: High frequency spinal cord stimulation at 10 kHz (HF10 therapy) represents a prominent advance in spinal cord stimulation (SCS) therapy, having demonstrated enhanced efficacy in patients with back and leg pain and pain relief without paresthesia that is sustained at 24 months post implant. Objective: To report on the effectiveness HF10 SCS therapy for a wide range of intractable pain conditions in clinical practice. Study Design: Retrospective investigation of 256 patients who trialed HF10 SCS for chronic intractable pain of various etiologies. Setting: Three Australian pain clinics. Methods: Two hundred fifty-six patients trialed HF10 SCS with view of a permanent implant if successful. Pain distributions included back + leg, back only, head ± neck, and neck ± arm/ shoulder. About 30% of patients had previously failed traditional low-frequency paresthesiabased stimulation, while the remaining cohort were either highly refractory to treatment or not recommended by the pain physician for traditional SCS. Pain scores (numerical pain rating scale – NPRS) and functional outcome measures (Oswestry Disability Index – ODI; and activity tolerance times) were assessed at baseline, post-trial, and at 3 and 6 months post-implant as available in the medical records. Results: Of the 256 patients, 189 (73%) reported a positive trial and were implanted. Patients with back + leg pain demonstrated the highest trial success rate (81%). A mean reduction in pain, among those for whom data were available, of 50% was sustained up to 6 months postimplant across the entire patient population. Sixty-eight percent of patients who failed traditional SCS reported a positive trial and mean pain relief at 6 months was 49% (P < 0.001). An 8.6 point reduction in ODI (21%) at 6 months and improved sitting, standing, and walking tolerances were also reported. Limitations: As data was collected retrospectively, missing data points were unavoidable; this was primarily due to inconsistent data collection and patients being lost to follow-up. Patient populations were diverse and a control group was not appropriate in this setting. Conclusions: These retrospective results demonstrate a significant advancement for patients suffering with chronic intractable pain and are consistent with recently published clinical results for HF10 SCS. HF10 SCS appears to be a viable, paresthesia-free alternative to traditional SCS, with high trial success rates, demonstrated effectiveness in a range of pain distributions including those typically difficult to treat with traditional SCS, and the possibility to restore pain control in patients who have previously failed traditional SCS. Key words: Spinal cord stimulation, high frequency stimulation, HF10, paresthesia-free stimulation, back pain, leg pain, cervical pain, neuromodulation


2020 ◽  
Author(s):  
Awinita Barpujari ◽  
Michael A Erdek

Aim: Spinal cord stimulation (SCS) is used to clinically manage and/or treat several chronic pain etiologies. A limited amount is known about the influence on patients' use of opioid pain medication. This retrospective analysis evaluated SCS effect on opioid consumption in patients presenting with chronic pain conditions. Materials & methods: Sixty-seven patients underwent a temporary trial device, permanent implant or both. Patients were divided for assessment based on the nature of their procedure(s). Primary outcome was change in morphine equivalent dose (MED), ascertained from preoperative and postoperative medication reports. Results: Postoperative MED was significantly lower in patients who received some form of neuromodulation therapy. Pretrial patients reported an average MED of 41.01 ± 10.23 mg per day while post-trial patients reported an average of 13.30 ± 5.34 mg per day (p < 0.001). Pre-implant patients reported an average MED of 39.14 ± 13.52 mg per day while post-implant patients reported an average MED of 20.23 ± 9.01 mg per day (p < 0.001). There were no significant differences between pre-trial and pre-implant MED, nor between post-trial and post-implant MED. Of the 42 study subjects who reported some amount of pre-intervention opioid use, 78.57% indicated a lower MED (n = 33; p < 0.001), 16.67% indicated no change (n = 7) and 4.76% (n = 2) indicated a higher MED, following intervention. Moreover, SCS therapy resulted in a 26.83% reduction (p < 0.001) in the number of patients with MED >50 mg per day. Conclusion: Spinal cord stimulation may reduce opioid use when implemented appropriately. Neuromodulation may represent alternative therapy for alleviating chronic pain which may avoid a number of deleterious side effects commonly associated with opioid consumption.


Sign in / Sign up

Export Citation Format

Share Document