Efficacy of peroneal nerve functional electrical stimulation (FES) for the reduction of bradykinesia in Parkinson’s disease: an assessor-blinded randomised controlled trial (STEPS II)—study protocol

Introduction Difficulty with walking can lead to reduced quality of life for people with Parkinson’s disease (pwPD); improving walking is considered a treatment priority. Drug therapies can control PD symptoms; however, pwPD often still experience mobility problems. Functional electrical stimulation (FES) induces movement in weak muscles via external electrical stimulation. FES is used in stroke and multiple sclerosis patients to correct dropped foot by stimulating the common peroneal nerve and is associated with improved quality of life and mobility. The randomised feasibility study preceding this definitive study showed that daily FES can produce a clinically meaningful improvement in walking speed in pwPD; this was sustained 4 weeks after FES was withdrawn. STEPS II is the first definitive randomised controlled trial, with blinded outcome assessment, aiming to determine the efficacy of FES in pwPD. Methods and analysis STEPS II is a two-group, parallel, assessor-blinded, superiority randomised controlled trial with an internal pilot, designed to compare FES plus usual care versus usual care alone. 234 participants will be randomised across eight UK sites. Telephone pre-screening and face-to-face screening will determine eligibility. The intervention group will attend four unblinded FES visits to receive the device and assess walking with and without FES. All participants have blinded assessments at baseline and weeks 2, 6, 18 and 22. The primary objective is to compare whole body bradykinesia at 18 weeks post-baseline via changes in 10m walking speed. Secondary objectives will assess the wider effects of FES on Parkinsonian gait and quality of life. An embedded qualitative component will explore wider experiences of FES. Ethics and dissemination This study received ethical approval from the Yorkshire and The Humber-Sheffield Research Ethics Committee (reference 23/YH/0193). A Data Monitoring Committee and Trial Steering Committee will provide independent oversight. Dissemination will be via publications, conferences and social media. FES intervention and training materials will be made open access.