Evaluating the Effect of Spinal Cord Stimulation Frequency on Fast-Acting Sub-perception Therapy (FAST) for Chronic Pain

The study design is prospective, post-market, exploratory, single-centre, rate randomised, double-blinded (subject, evaluator blinded; programmer un-blinded). The study is designed to evaluate the wash-in and wash-out time of FAST (Fast Acting Sub-perception Therapy) at 90 Hz and various frequencies above and below 90 Hz. A prospective study design will eliminate the bias associated with case selection in a retrospective review and will ensure that identical procedures are followed for data capture and review. Randomization of rates will be used to minimise the sequence effects and the impact of carryover effects, as well as addressing issues that may be related to order effect. The electronic diary will be used to log the subjects' pain intensity and medication usage. Additionally, the numerical rating scale for measuring pain intensity is a validated measure and has been used in other randomized controlled trials to measure the outcomes of spinal cord stimulation (SCS). The electronic real-time NRS (Numerical rating score) recording will be used to log the subjects' pain intensity and time during wash-in evaluation session. This study aims to evaluate pain relief and wash-in/wash-out frequency sensitivity using FAST at different stimulation rates. The different randomization period included in the study design allows for comparing these treatments using one of the stimulation rates as an active control.