High-frequency spinal cord stimulation as rescue therapy for chronic pain patients with failure of conventional spinal cord stimulation

Background This study aims to evaluate the efficacy of 10-kHz high-frequency (HF10) devices as a rescue treatment in patients with failure of conventional spinal cord stimulation (SCS) therapy for chronic pain without the need to change the spinal hardware. Methods In this real-world prospective study, patients with neuropathic pain treated with conventional tonic SCS in whom the therapy had failed, either during the trial phase or after a period of optimal functioning, were recruited throughout 2 years for HF10-SCS therapy. Data on analgesia, functionality, analgesics use and treatment safety were collected 12 months after treatment. Results Eleven of the 18 (61%) patients included in the study were successfully rescued with HF10-SCS. Of them, 5 out of 12 (45%) were in the trial phase and six out of six (100%) had previously functioning implants. A significant improvement in low-back and limb pain was obtained (p = 0.003 and p = 0.0001, respectively). Treatment success was significantly associated with gender (p = 0.037), weight (p = 0.014), body mass index (BMI) (p = 0.007) and time of rescue (p = 0.015). A linear regression test confirmed a significant association between treatment failure and BMI and gender (p = 0.004). Conclusions Our results suggest that analgesic rescue with HF10-SCS is an effective therapeutic option for non-responders to conventional SCS, although obesity might be a limiting factor for treatment success. Nevertheless, more comprehensive studies are needed to corroborate our findings. Significance This study shows that high-frequency stimulation may be useful in patients with failure of conventional tonic stimulation for chronic pain, both in the trial phase and in previously implanted subjects. The novelty of this study lies in the use of the implanted epidural electrodes, which avoids the need for further surgery. The results in terms of pain control and recovery of functionality are satisfactory. In addition, variables such as male gender and high body mass index could be predictors of therapy failure.