Objectives Subperception spinal cord stimulation (SCS) is described mostly utilizing waveforms that require high energy. However, the necessity of these waveforms for effective subperception has not been established. We aimed to explore whether effective subperception pain relief can be achieved using frequencies below 1 kHz. Materials and Methods Thirty chronic pain patients implanted with SCS were enrolled as part of a multicenter, real-world, consecutive, observational case series. An effective stimulation location was determined using a novel electric field shape designed to preferentially modulate dorsal horn elements. Subsequently, programs at lower frequencies (600, 400, 200, 100, 50, and 10 Hz) were provided with pulse-width and amplitude adjusted to optimize response. Results All tested frequencies (1 kHz down to 10 Hz) provided effective subperception relief, yielding a mean of 66–72% reduction in back, leg, and overall pain. It was found that to maintain analgesia, as frequency was decreased, the electrical or “neural” dose had to be adjusted according to parameter relationships described herein. With the reduction of frequency, we observed a net reduction of charge-per-second, which enabled energy savings of 74% (200 Hz) and 97% (10 Hz) relative to 1 kHz. Furthermore, pain reduction was sustained out to one year, with 85% of patients reporting a preference for frequencies of 400 Hz or below. Conclusions We have derived an electric field configuration and, along with previous learnings in the kHz range, a set of neural dosing parameter relationships (10–10,000 Hz), which enable the expansion of effective subperception SCS to low frequency and achieve major energy savings.

Occipital nerve stimulation (ONS) is a surgical treatment proposed for drug-resistant chronic cluster headache (drCCH). Long-term series assessing its efficacy are scarce. We designed a retrospective observational study with consecutive sampling, evaluating the follow-up of 17 drCCH patients who underwent ONS. Our main endpoint was the reduction the rate of attacks per week. We also evaluated the pain intensity through the Visual Analogue Scale (VAS), patient overall perceived improvement and decrease in oral medication intake. After a median follow-up of 6.0 years (4.5–9.0), patients decreased from a median of 30 weekly attacks to 22.5 (5.6–37.5, p = 0.012), 7.5 at 1 year (p = 0.006) and 15.0 at the end of follow-up (p = 0.041). The VAS decreased from a median of 10.0 to 8.0 (p = 0.011) at three months, to 7.0 (p = 0.008) at twelve months and 7.0 (p = 0.003) at the end of the follow-up. A total of 23.5% had an overall perceived improvement of ≥70% at 3 months, 41.2% at 1 year and 27.8% at the end of follow-up. Reducing prophylactic oral medication was possible in 76.5% and it was stopped in 17.7%. Triptan use decreased in all the responder patients and 17.7% stopped its intake. A total of 41.2% presented mild adverse events. In conclusion, our long-term experience suggests that ONS could be an interesting option for drCCH-selected patients, as it is a beneficial and minimally invasive procedure with no serious adverse events.

Given the differing mechanisms thought to underlie therapeutic sub- and supra-perception-based neurostimulative modalities, Spinal Cord Stimulation (SCS) systems designed for combined delivery of these approaches may help improve analgesic outcomes and quality of life, and reduce treatment failures. This multicenter, observational case-series evaluated 188 patients with chronic back and/or leg pain implanted with an SCS device capable of sequential or simultaneous delivery of sub-perception and supra-perception stimulation programming (i.e., combination therapy) at 16 sites in Europe. Following implantation, patients were provided with an array of advanced supra-perception programs (e.g., paresthesia-based SCS using multiple independent current sources), and a custom set of sub-perception programs optimized with specific waveforms and/or field shapes. A mean overall pain score of 7.9 ± 1.7 (Standard Deviation (SD)) was reported pre-trial (Baseline). Overall pain was reduced by 4.4 ± 2.8 points (NRS) at 3-months (n = 117) and at 12 months post-implant (n = 90), respectively (p < 0.0001). Substantial quality-of-life (EQ-5D-5L) improvement as assessed at last follow-up was also observed (n = 60). These results suggest that an implanted SCS device capable of combination therapy, while also enabled with patient-specific waveform optimization and stimulation field targeting capabilities, can enable highly effective pain relief and improve quality of life in patients suffering with chronic pain.

Background/Objectives: Over the last 20 years, spinal cord stimulation (SCS) has seen the development of various paresthesia-free paradigms. Recently, a novel modality has emerged (Fast-Acting Sub-perception Therapy, FAST) that engages the surrounding inhibition mechanism of action. We evaluated long-term, real-world outcomes of preferential FAST-SCS use in patients with chronic pain. Methods: In this multi-center, observational, consecutive case series, medical chart data from chronic pain patients preferentially using FAST-SCS (no exclusions) were retrospectively reviewed. Results: Data from 167 patients in 13 European centers were analyzed; 74% of patients suffered from persistent spine pain syndrome type 2 and 87% presented with low back and/or leg pain. At the last follow-up (mean 1.6 years), the numerical rating scale (NRS) overall pain score decreased by 5.1 ± 2.5 points versus baseline, from 8.0 ± 1.2 to 2.9 ± 2.2 (n = 167, p < 0.0001). 87% of patients reported ≥50% pain relief, and 55% were “high responders” with overall NRS pain scores ≤2/10. At the last follow-up, functional disability improved significantly (the Oswestry Disability Index reduced by 29.2 ± 21.5 points, n = 65, p < 0.0001) and patients had a significant gain in quality of life (EQ-5D-5L visual analog scale increased by 52.0 ± 26.9 points, n = 86, p < 0.0001). Results at the 2-year follow-up showed a sustained, substantial reduction in pain; 67% of patients were high responders and the NRS overall pain score decreased by 5.6 ± 2.4 versus baseline (n = 52, p < 0.0001). Conclusions: Our real-world outcomes suggest that in patients with chronic low back and/or leg pain, FAST-SCS therapy provided durable and profound pain relief and led to significant improvements in disability and quality of life.

Chronic pain inflicts damage in multiple spheres of patient's life and remains a challenge for health care providers. Real-world evidence derived from outcome registries represents a key aspect of the ongoing systematic assessment and future development of neurostimulation devices. The objective of the present study was to assess the long-term effectiveness of neurostimulation as a treatment for spinal chronic pain. The patients analyzed in the present study represent a singlecenter cohort of 52 individuals. Primary outcome measures included numeric pain rating scale, Beck depression index II and Oswestry disability index variation from baseline to 36-month visits. Secondary outcomes included its evaluation at 6-month, 12-month and 24-month visits. A significant improvement in targeted pain, depression and disability values were observed at 36-month follow-up (P ​< ​0.001, P ​= ​0.009 and P ​< ​0.001 respectively). Those results were consistent in the leg and back pain subgroup but not in the neck, chest and arm pain subgroup. The decrease in pain, depression and disability values happened progressively through time, with the exception of the 12-month visit, where a mild stagnation was observed. Our results suggest that spinal cord stimulation is an effective long-term treatment for spinal chronic pain in real-world conditions when applied to a variety of patients and conditions usually seen in routine practice. Nevertheless, some fluctuations may occur during treatment so prolonged follow-up periods should be considered before rendering an unsuccessful therapy diagnosis.