Even with successful spinal cord stimulation (SCS) therapy, pain of peripheral nerve origin can occur. Such areas of focal pain may be suitable for peripheral nerve stimulation (PNS). We report on the early clinical and technical aspects of a retrospective case series of PNS used for superior cluneal neuropathy as an adjunct to SCS. The patients included had successful prior SCS therapy and new focal peripheral neuropathic pain associated with the superior cluneal nerves. This pain could not be addressed with conventional medical management or reprogramming of SCS. A microimplantable pulse generator PNS device with advanced programming capabilities was used. Outcomes included mean pain scores, assessed using a standard ten-point numeric rating scale, measured at baseline and at three and six months after PNS device implantation. Response was defined as ≥50% pain relief. Patients also provided prespecified treatment-related quality-of-life (QoL) goals before PNS and reported on QoL goal success after PNS. In total, 21 patients (mean age 78 years, 62% female) were included. All underwent a successful PNS trial and received permanent PNS implantation. The mean baseline pain score was 8.9. At three months, the patients' mean pain score was 2.5 (range, 1-4), representing a 72% pain reduction and 100% response rate. At six months, the patients' mean pain score was 2.7 (range, 1-6), representing a 71% pain reduction and 91% response rate. All patients reported improvement in some or all QoL goals. There were no serious adverse events, device effects, or issues with existing SCS therapy. Patients continue to be observed on a regular basis. Adjunctive PNS can be feasibly used to successfully treat superior cluneal neuropathy in patients with otherwise successful SCS.
Skaribas et al. (Tue,) studied this question.