Optimizing PNS lead placement for chemotherapy-induced peripheral neuropathy: a preliminary clinical study

INTRODUCTION: Chemotherapy-induced peripheral neuropathy (CIPN) is a common and disabling complication of several chemotherapeutic agents. Peripheral nerve stimulation (PNS) has emerged as a potential neuromodulatory treatment, but its effectiveness in CIPN remains unclear. This study evaluates whether optimizing PNS lead placement improves clinical outcomes. METHODS: Four adults with moderate to severe CIPN (Numerical Rating Scale [NRS] ≥ 4) underwent PNS implantation. Lead placements were categorized as proximal (L5/S1), intermediate (femoral or sciatic at the subgluteal region), or distal (saphenous or popliteal nerves at the midthigh). Pain was assessed using the NRS, and neuropathy symptoms using the Treatment-Induced Neuropathy Assessment Scale (TNAS) at baseline and at 1, 2, and 3 months. RESULTS: Distal lead placement resulted in the greatest improvement, with 30-40% pain reduction and measurable decrease in TNAS scores. Proximal and intermediate placements demonstrated relatively minimal benefit. Two patients with distal placement also reduced their opioid use. No major adverse events occurred. CONCLUSION: Preliminary findings suggest that PNS lead placement closer to the symptomatic region may improve CIPN-related pain and neuropathic symptoms. These results validate the importance of optimizing lead positioning and support further prospective evaluation.