Short-Term Patient-Reported Outcomes of Multi-Contact Independent Current Control Spinal Cord Stimulation in Patients...

The effect of multi-contact independent current control (MICC) spinal cord stimulation (SCS) on patient-reported outcomes in those who have lost therapeutic efficacy of a conventional SCS is not well described. We prospectively evaluated self-reported pain, disability, and quality of life in patients with persistent spinal pain syndrome type 2 (PSPS-2) who were converted from a conventional to MICC SCS.

Patients with PSPS-2 who had lost therapeutic efficacy with a constant current control (CCC) or voltage control (VC) system were enrolled, and had a MICC generator implanted. All participants were followed prospectively with standardized assessments of pain (Visual Analog Scale [VAS]), condition-specific function (Oswestry Disability Index [ODI]), and quality of life (Short-Form-36) at 3 and 6 months post-implantation.

Fifteen participants were eligible for inclusion; 3 were lost to follow-up. Mean VAS scores were significantly decreased at 3 months (5.3 ± 2.5, p = 0.009) and 6 months (5.1 ± 2.8, p = 0.005) relative to pre-implantation (VAS 8.3 ± 0.8). At 30 months, mean VAS remained significantly decreased (5.8 ± 1.6, p < 0.001). The mean disability score was significantly decreased at 6 months (ODI 40.5 ± 14.7, p = 0.029) compared to the mean preoperative score (53.6 ± 14.7). At 6 months, the minimum clinically important difference for VAS was met by 90% of patients and for ODI by 100%.

This exploratory study suggests that MICC programming may represent a reasonable short-term salvage option for patients with PSPS-2 who have lost therapeutic efficacy with a CCC or VC SCS system. A larger study is required to evaluate superiority in terms of long-term pain control of MICC versus conventional SCS.