Combined T12 and S1 Dorsal Root Ganglion Stimulation for Chronic Back and Lower Extremity Pain

Introduction:

Introduction: Dorsal root ganglion stimulation (DRGS) has emerged as an effective therapy for chronic axial low back and lower extremity pain. Initially approved for complex regional pain syndrome (CRPS), DRGS has shown efficacy across a variety of chronic back and leg pain conditions in case series and observational studies. Early guidelines recommended lead placement strictly by dermatomal pain distribution; however, clinical experience demonstrates convergence at certain DRG levels that can cover pain beyond single dermatomes. Specifically, T12 DRGS can cover axial low back pain, and S1 DRGS can cover neuropathic pain in the legs outside of that single dermatome . These observations suggest T12 and S1 are optimal targets for diffuse back and leg pain.

Methods:

Methods: Patients were identified from a prospective registry with follow-up to 60 months post-implant. All received combined unilateral or bilateral T12 and S1 DRG leads targeting concurrent low back and lower extremity pain. Baseline demographics were recorded. Pain (0–10 NRS), quality of life (EQ-5D), and disability (ODI) were assessed before and after implant. Longitudinal outcomes were analyzed using a repeated-measures mixed model with Bonferroni-adjusted post hoc tests. ODI scores were also categorized (minimal, moderate, severe, crippled, bed bound) to analyze baseline vs. last follow-up distributions.

Results:

Results: 128 patients were included. Baseline characteristics are in Table 1. Mean NRS pain score decreased from 9.0 (95% CI 8.8–9.2) at baseline to 3.6 (2.9–4.3) at 36 months (~60% reduction, P<.001). Mean ODI improved from 62% (CI 60–65%) at baseline to 24% (18–30%) at 36 months (~60% improvement, P<.001). Quality of life (EQ-5D index) increased from 0.35 (CI 0.31–0.38) to 0.77 (0.73–0.81) at 36 months (P <.001). These gains were largely maintained through 60 months, despite smaller samples at 48 (n=12) and 60 months (n=8). At baseline, ~95% of patients had severe, crippled, or bed-bound disability; by last follow-up, ~75% had only minimal or moderate disability (Figure 4).

Conclusion:

Conclusion: Targeting DRGs at T12 + S1 provides broad coverage of lower back and leg pain, yielding sustained long-term pain relief, improved function, and enhanced quality of life. This strategy was effective for both post-surgical and non-surgical etiologies, addressing mixed nociceptive and neuropathic pain. Our findings suggest that focusing on convergent DRG levels (T12 and S1) rather than purely dermatomal targeting can successfully treat diffuse chronic lower back and extremity pain of multiple etiology.