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Ten kilohertz spinal cord stimulation (SCS) is usually initiated in a single‐bipolar configuration over the radiological reference point T9/T10 intervertebral disc space for neuropathic back and leg pain. Cascade is a duty‐cycled, multi‐bipolar contact configuration across an entire eight‐contact lead. Potential advantages by using a broader area of SCS coverage include mitigation against minor lead migration and a reduction in the need for reprogramming. We report here the results of a retrospective case series of 114 patients using Cascade. Retrospective data were collected over two years. We selected patients with neuropathic back with or without/leg pain who had a trial of SCS. Pain assessments using Numerical Rating Scales (NRS) and Patient Global Impression of Change (PGIC) scores were collected at baseline, six months, and last follow‐up beyond 12 months (mean 15.1 months). Patients were programmed with 10 kHz SCS using Cascade during the trial, which was continued unless reporting inadequate pain relief. Morbidity and deviations from Cascade programming were also obtained. At six months, 87 of 97 (90.6%) patients with active devices were using Cascade and 58 of 72 (81%) patients at the last follow‐up >12 months. There was a significant reduction in back NRS (8.3 vs. 3.9 [p< 0.0001], N = 97) and leg pain (7.53 vs. 3.83 [p< 0.0001], N = 77) at 6 months and last follow‐up >12 months back (8.3 vs. 3.95 [p< 0.0001] N = 72), leg (7.53 vs. 3.534 [p< 0.0001], N = 58). The PGIC score was 6 of 7 or all of 7 in 72% of patients (70/97) at six months and in 68% (49/72) of patients at the last follow‐up beyond 12 months. Cascade is an effective programming methodology that may have benefits over a single‐bipole configuration for 10 kHz SCS, particularly during a trial of stimulation. Results from this study suggest it is a durable program for patients with neuropathic back and leg pain.

Introduction: Recruitment into trials in rare chronic pain conditions can be challenging, so such trials consequently are underpowered or fail.Methods: Drawing from our experience in conducting, to date, the largest academic trial in a rare chronic pain condition, complex regional pain syndrome, we have identified recruitment and retention strategies for successful trial conduct.Results: We present 13 strategies grouped across the categories of ‘setting the recruitment rate’, ‘networking’, ‘patient information’, ‘trial management’ and ‘patient retention’. Moreover, six recruitment risks are also discussed. A conservative recruitment estimate, based on audits of newly referred patients to the trial centres without taking into account availability of ‘old’ patients or recruitment from outside centres, and assuming a 55% patient refusal rate yielded accurate numbers.Conclusion: Appreciation of these identified recruitment challenges and opportunities may contribute to supporting prospective investigators when they design clinical trials for chronic pain patient population groups where it has been historically difficult to conduct high-quality and robust clinical trials.

In this prospective, multicenter, double‐blinded, randomized, crossover study, we compared the therapeutic efficacy of burst SCS delivered using a lead implanted with the paresthesia mapping approach to a lead implanted with an anatomic placement approach. Subjects with chronic low back pain were implanted with two leads, one using paresthesia‐mapping approach (PM) and the second using anatomical placement procedure (AP). Stimulation contacts were chosen using the standard intraoperative paresthesia‐testing procedure for the paresthesia‐mapped lead or an activated bipole overlapping the T9‐T10 junction for the anatomical lead. Amplitude for either lead was selected such that no sensory percepts were generated. Subjects were assessed at baseline and after a trial period during which they tested each lead for two weeks in random order. Eligible subjects had the option to receive permanent implants using their preferred AP or PM approach at end‐of‐trial. Of the 53 subjects who completed both trial periods, 43 (81.1%) experienced at least 50% back pain relief with at least one lead. Nearly half of these (20; 46.5%) were profound responders who experienced at least 80% back pain relief with either leads. Primary and secondary outcomes, at the end of trial, showed significant improvements for both AP and PM leads from baseline yet were not significantly different from each other. The trial results of this study suggest that similar clinical outcomes can be achieved in burst SCS when performing lead placement either using paresthesia mapping or anatomical placement with imaging references.

The increasing use of high frequency paresthesia‐free spinal cord stimulation has been associated with improved outcomes in the therapy of neuropathic pain. What is unknown is the effect of varying frequency on pain relief and the placebo effect. This is a prospective, randomized, sham‐controlled double blind crossover study. Subjects with predominantly axial low back pain undergoing spinal cord stimulation therapy for failed back surgery syndrome were randomized to sham, 1200 Hz, 3030 Hz, and 5882 Hz with a four‐phase crossover design over 12 weeks. Twenty‐four patients were randomized in the study. The mean low back pain score at baseline was 7.75. The mean low back pain scores on a 10 cm visual analog scale during the randomized crossover phase were 4.83, 4.51, 4.57, and 3.22, for sham, 1200 Hz, 3030 Hz, and 5882 Hz, respectively, with the lowest low back pain score observed in the 5882 Hz frequency group (p= 0.002). Of note, sham stimulation resulted in a reduction of pain by −2.92 cm and was not significantly different from stimulation at 1200 Hz and 3030 Hz. This randomized crossover study demonstrated that 5882 Hz stimulation can produce significant pain relief for axial low back pain compared with lower frequencies and sham stimulation. Sham stimulation produced similar analgesic effects to 1200 Hz and 3030 Hz and this effect may influence future neuromodulation clinical trial designs.