Systematic review and network meta-analysis of neurostimulation for painful diabetic neuropathy

Background: Different waveforms of spinal cord stimulation (SCS) have now been evaluated for the management of painful diabetic neuropathy (PDN). However, no direct or indirect comparison between SCS waveforms has been performed to date.

Purpose: To conduct a systematic review and network meta-analysis (NMA) to evaluate the effectiveness of SCS for PDN.

Data sources: MEDLINE, CENTRAL, Embase and WikiStim were searched from inception until December 2021.

Study selection: Randomised controlled trials (RCTs) of SCS for PDN were included.

Data extraction: Pain intensity, proportion of patients achieving at least a 50% reduction in pain intensity and health-related quality-of-life (HRQoL) data were extracted.

Data synthesis: Significant reductions in pain intensity were observed for low-frequency SCS (LF-SCS) (mean difference [MD] -3.13, 95% confidence interval [CI] -4.19 to -2.08, moderate certainty) and high-frequency SCS (HF-SCS) (MD -5.20, 95% CI -5.77 to -4.63, moderate certainty) compared to conventional medical management (CMM) alone. There was a significantly greater reduction in pain intensity on HF-SCS compared to LF-SCS (MD -2.07, 95% CI -3.26 to -0.87, moderate certainty). Significant differences were observed for LF-SCS and HF-SCS compared to CMM for the outcomes proportion of patients with at least 50% pain reduction and HRQoL (very low to moderate certainty). No significant differences were observed between LF-SCS and HF-SCS (very low to moderate certainty).

Limitations: Limited number of RCTs and no head-to-head RCTs conducted.

Conclusions: Our findings confirm the pain relief and HRQoL benefits of the addition of SCS to CMM for patients with PDN. However, in the absence of head-to-head RCT evidence the relative benefits of HF-SCS compared to LF-SCS for patients with PDN remains uncertain.