Neural Targeting Spinal Cord Stimulation Superior in Treatment of Axial Low Back Pain

SCS due to the anatomy of the region.

A new spinal cord stimulation (SCS) device incorporating anatomically guided (3D) neural targeting provides superior, consistent, and long-term chronic axial back pain relief compared with a traditional SCS device, according to the observational SCS-LUMINA study published in Pain Medicine.¹

The findings are encouraging, as axial low back pain has been particularly challenging to treat with SCS due to the anatomy of the region, which renders it difficult to stimulate low back fibers. However, patients receiving 3D neural targeting went from severe or moderate pain levels to consistently mild levels that were maintained for the 24-month study period. Patients with chronic leg pain or a combination of chronic back and leg pain also experienced superior relief with 3D neural targeting vs traditional SCS.

“Unlike traditional SCS, which utilizes a trial-and-error method of turning on and off contact electrodes in a trial-and-error fashion to achieve desired paresthesia, the novel anatomically guided 3D neural targeting relies on a prioricalculations to target the ‘sweet spot’ of stimulation,” the researchers wrote. In addition, the 3D neural targeting device (Precision Spectra SCS System; Boston Scientific Corporation, Valencia, CA) features additional contacts and leads, enabling better precision and customization than is possible with a traditional SCS device, allowing use of 32 contacts and 4 leads vs 16 contacts and 2 leads.

The current study included 2 well-matched cohorts: 213 consecutive patients treated with 3D neural targeting SCS and 213 patients previously treated with the traditional SCS device who were selected from the pool of all such consecutively treated patients using the propensity score matching (PSM) system to ensure unbiased comparison in a nonrandomized study. The investigators defined treatment response as pain relief ≥50% from baseline on the pain numeric rating scale (NRS). Pain levels were assessed by clinical site personnel, without sponsor involvement, at baseline, trial implant, and at 3, 6, 12, and 24 months after pulse generator implantation.

Overall, 64% of patients treated with 3D neural targeting achieved treatment response at 3 months, with 73% achieving response by 6 months, a level that remained stable throughout the study, with 74% having response by 24 months. When examining only patients with axial low back pain, responses were similar, with 58%, 72%, and 71% achieving treatment response at 3, 6, and 24 months, respectively. In contrast, response rate with traditional SCS was only 41% at 24 months in patients with axial low back pain.

NRS pain scores were significantly improved in the 3D neural targeting cohort. The mean overall NRS pain score at baseline was 7.17 ±2.06, which decreased to 3.21 ±2.06 at 3 months, 2.92 ±2.07 at 6 months, and 2.94 ±2.62 at 24 months, indicating a long-term difference of 4.23 NRS points, a finding that reached statistical significance (P <.0001). Findings were similar when examining only patients with axial low back pain. These patients had a baseline mean NRS pain score of 7.21 ±1.96, which was reduced to 3.1 ±2.6 at 24 months, indicating a long-term difference of 4.1 NRS points (P <.0001). Those with severe axial low back pain at baseline (mean NPS, 8.6 ±0.7) experienced the greatest pain relief, achieving a statistically significant difference of 5.6 NPS points (P <.0001).

The rate of complications with 3D neural targeting was low. Of the 213 patients treated, 3 needed to have the device removed, 3 required a lead replacement, 5 had a lead revision, and 8 had inadequate stimulation. In addition, pulse generator implantation site pain was reported by 7 patients, high impedance across ≥1 contact by 6 patients, and stimulation in a non-target area by 1 patient.

Summary and Clinical Applicability

“[This study demonstrates] the long-term effectiveness of the applied 3D neural targeting algorithm applied for SCS and even its superiority over traditional SCS in the treatment of overall pain, leg pain, and axial low back pain,” the researchers concluded.

Limitations and Disclosures

The investigators note that “the combination of an observational design with statistical cohort matching is a powerful way of achieving valid comparisons between two treatment groups without compromising the pragmatic generalizability of the study results,” but acknowledge that unknown confounding variables could have affected their findings.

The study was funded by Boston Scientific Neuromodulation Corporation, manufacturer of the SCS devices assessed, and several authors disclosed affiliations with this organization.

Reference

Veizi E, Hayek SM, North J, et al. Spinal cord stimulation (SCS) with anatomically guided (3D) neural targeting shows superior chronic axial low back pain relief compared to traditional SCS-LUMINA study [published online January 20, 2017]. Pain Med. pii: pnw286. doi:10.1093/pm/pnw286