Use of Immersive Virtual Reality on Treadmill to Improve Gait in Parkinson's Disease: a Single Blinded, Randomized Controlled Trial

BACKGROUND

Parkinson's disease (PD) is the second most common degenerative neurological disease. PD induces gait disorders that lead to increased risk of falls. These falls seriously affect patients' quality of life and generate significant health care costs. Unfortunately, gait disorders do not respond well to drug treatments and their management is mainly based on rehabilitation treatment. The rehabilitation approach comprises two steps: a functional assessment of locomotor capacities followed by completion of a therapeutic physical exercise program.

Like heart rate, stride duration varies in the short and long term according to a complex dynamic of temporal variations. These variations present long-range autocorrelations (LRA): the stride duration does not vary randomly but in a structured way. The study of LRA is based on complex mathematical methods requiring recording of 512 consecutive gait cycles. LRA are altered in PD patients whose gait rhythm is excessively random. Alteration of LRA is correlated with neurological impairments (Hoehn & Yahr scale and UPDRS) and patients' locomotor stability (ABC scale & BESTest). Measurement of LRA would be the first available objective and quantitative biomarker of stability and risk of falling in patients with PD.

Guidelines concerning rehabilitation programs for PD patients are based on education (prevention of falls and inactivity,...), physical exercises, functional training (double task, complex tasks,...), learning, adaptation strategies (cueing) and action observation. The combination between immersive virtual reality (iVR) and treadmill walking will be developped.

Treadmill walking has shown long-term effectiveness on PD patients' gait and quality of life. A study carried out recently has shown that a single treadmill session reduces the stride duration variability during the intervention. There remains then to determine the long-term effect of this rehabilitation method on LRA, apart from the intervention, when walking overground. Combining iVR with treadmill walking rehabilitation offers interesting insights. Indeed, for stroke patients, this combination is more effective than classical techniques. For PD patients, non-immersive virtual reality methods (Wii, Kinect) have shown relative efficacy. Indeed, the use of non-immersive virtual reality on treadmill induces more efficient cognitive engagement and frontal lobe activation among PD patients. Non immersive VR gives longer-term effects and a greater decrease in the number of falls than without virtual reality. Furthermore, iVR makes it possible to give a functional character to reeducation and to enrich feedbacks. Indeed, iVR allows to give patients a visual flow when walking on treadmill as if they were walking overground and patients could benefit from it. But apart from a feasibility study, the therapeutic interest of iVR has not been studied yet for PD patients, especially iVR combined with treadmill walking. iVR is now easily accessible and its price is reduced, suggesting a potential for everyday clinical practice. Indeed, these new devices of good quality seem to have a good potential for neurorehabilitation. The purpose of this single blinded randomized controlled trial is then to study the effect of a comibination of immersive virtual reality and treadmill walking on LRA.