Title: The Effectiveness of Peroneal Nerve Functional Electrical STimulation (FES) for Improving Mobility in Parkinson’s Disease: A Pragmatic Two Site Feasibility Study for an Assessor Blinded Randomised Control Trial (STEPS).
Funder: Department of Health and Social Care

Abstract: Functional Electrical Stimulation (FES) is a means of producing functional movement in paralysed muscle where the paralysis results from neural damage in the brain or cervical / thoracic spine. Its most common clinical application is to correct dropped foot following stroke and multiple sclerosis, where the common peroneal nerve is stimulated to cause the foot to lift (dorsiflexion) in the swing phase of gait. Three observational studies have investigated the use of FES in people who have walking difficulty due to Parkinson's disease (PD) and have shown clinically meaningful improvements in walking speed, freezing and step length19,20,21. In two of these studies the improvements were maintained after the device was subsequently turned off, indicating that FES had had a training effect on gait. These changes were associated with improved functional walking and reduction in the symptoms of PD. Participants in these studies have reported that the intervention had a useful impact on their daily lives and it was an intervention that they may choose to use as a long term mobility aid. A feasibility study is proposed to determine recruitment, willingness to be randomised, loss-to-follow-up rates and the appropriate outcome measures for a subsequent Randomised Controlled Trial (RCT) to evaluate the effectiveness and cost-effectiveness of FES in a standard clinical setting. In order to obtain a realistic estimate of probable loss-to-follow-up rate, the feasibility study will follow the design we currently envisage for the subsequent full RCT. Sixty-eight people with gait deficit due to idiopathic PD will be recruited. A gait deficit is defined as a self-selected walking speed of less the 0.8 metres per second (ms-1; half normal walking speed) and reduced dorsiflexion or eversion in the swing phase of gait. All participants will continue with usual care; in general this comprises medication, attendance at medical clinics or visits from PD nurses; exercise therapy may be accessed by individuals although this is not routinely prescribed. Participants will record usual care during the 22 week study. The participants will be randomly allocated to one of two groups. Group 1 (control group) will not receive any additional intervention over their usual care. Group 2 (FES) will use the device in addition to their usual care. The standard clinical application protocol established for the provision of FES in other neurological groups will be followed for Group 2, who will be taught to use the device over two clinic appointments with follow up 6 and 18 weeks. Both groups will be assessed at weeks 0, 6, 18 and 22, (4 weeks after withdrawal of the device from group 2), by an assessor blind to the group allocation. The primary aim is to determine recruitment and retention rate. We will record the outcome measures currently envisaged for the future RCT, enabling refinement of data collection methods and determine their acceptability to the participants. Results will also be used to derive estimates of sample size for that RCT. Semi-structured interviews will be used to explore the experience of the participants in the study and the relevance of the outcome measures to the participants. The findings of feasibility study will be used to underpin the design of the subsequent RCT, ensuring the design is costed appropriately, practical, adequately powered and utilises outcome measures relevant to lives of the participants.

Lay abstract: People with Parkinson s disease (PD) often have difficulty in walking, which causes them to walk slowly and fall, leading to a reduced quality of life. Functional Electrical Stimulation (FES) can be used to produce useful movements in under active muscles, by applying small electrical impulses to their nerves, using a small battery powered device worn on the leg (Annex figure 3a). In previous small studies, we have shown that patients are able to walk faster and have reduced PD symptoms after using FES. We want to carry out a larger study to investigate whether FES would be beneficial to patients in the longer term when compared to routine care and whether it would be value for money for the NHS. Before setting up a larger study, we need to run a smaller study to ensure we design the full study properly. We especially want to know how many people will complete the study and the reasons why some people don t. Sixty-eight people who have PD will be randomly allocated to have either FES with routine care or routine care alone. Over 22 weeks we will measure the changes in walking speed, falls, quality of life and PD symptoms. We also want to determine if we are asking the right questions, and if the study methods are acceptable. We will interview participants to find out what they think about the study and whether there are things we should improve. A Patient Advisory Group has been formed from participants of the earlier studies. They have contributed to the design of this research and will advise on all aspects of the study. Our results will be used to plan the larger full study. They will be made available to other people doing research into Parkinson s Disease and summarised on the Parkinson s Society website.

Research activity codes: 6.7 PHYSICAL
Health categories: NEUROLOGICAL