Sub-threshold DRG Stimulation vs Sham in Established Responders

Continuous electrical stimulation delivered through an implanted DRG neurostimulator. Amplitude is set individually to 80% of each participant's perception threshold, ensuring no paresthesia is produced. Frequency and pulse width remain unchanged from the participant's established therapeutic settings. This sub-threshold programming distinguishes the intervention from suprathreshold (paresthesia-based) DRG stimulation used in earlier studies.

The implanted DRG stimulator remains switched off for the entire 5-day period. Device interrogation logs are masked to maintain blinding. No electrical stimulation is delivered, allowing a placebo-controlled comparison with active sub-threshold stimulation.