Long-term efficacy of 10 kHz spinal cord stimulation in managing painful diabetic neuropathy: A post-study survey.

OBJECTIVE: To evaluate the longer-term efficacy of 10 kHz spinal cord stimulation (SCS) in managing painful diabetic neuropathy (PDN) in a routine clinical setting after the transition from the 24-month SENZA-PDN study.

METHODS: We contacted 142 participants who completed 24 months of postimplantation follow-up in the former randomized controlled trial (SENZA-PDN). Of these, 57 consented and responded to this longer-term post-study survey. Outcomes assessed included pain relief, health-related quality of life (HRQoL) measured using the EuroQol 5-Dimensional 5-Level (EQ-5D-5L) instrument, Patient Global Impression of Change (PGIC), HbA1c, and weight.

RESULTS: Our survey captured patient-reported outcomes at a median of 4.1 years after implantation of a permanent 10 kHz SCS system. Among the surveyed participants, 76.8% (43 of 56) reported clinically meaningful pain relief (≥2 points), and 84.6% (44 of 52) achieved a clinically meaningful improvement in their EQ-5D-5L index score, with a final mean EQ-5D-5L index score of 0.825. Additionally, 74.5% (38 of 51) reported being "Better" or "A great deal better" on the PGIC scale. The surveyed participants reported a mean HbA1c level decrease of 0.4% (p = 0.027), with a more substantial improvement of 1.6% (p < 0.001) among those with type 2 diabetes (T2D) and a higher preimplantation HbA1c (>8%). Significant weight loss was also observed, with a mean reduction of 7.0 kg (p < 0.001) in the overall cohort and 8.7 kg (p < 0.001) in the subgroup with T2D and a higher BMI at preimplantation (≥35 kg/m2).

CONCLUSIONS: High-frequency SCS at 10 kHz provided sustained and clinically meaningful improvements in pain and HRQoL for PDN patients at 4.1 years postimplantation, with no explants in the cohort due to inefficacy. Alongside these benefits, participants experienced metabolic changes that included reductions in body weight and HbA1c beyond that achieved at 24 months, although changes in lifestyle and medication were not accounted for in this analysis. Notably, the cohort's final mean EQ-5D-5L index score was comparable to the US norm. These findings support 10 kHz SCS as a durable and effective treatment option for PDN in routine clinical practice.