Virtual reality when used in a smart way can assist arm rehabilitation in some stroke patients, according to a clinical pilot study published in the open access Journal of NeuroEngineering and Rehabilitation. Building on their long-standing track record on stroke recovery and virtual reality, the researchers, from the SPECS laboratory at UPF Barcelona, found that using virtual reality with the aim to increase a patient’s confidence in using their paralyzed arm may be critical for recovery. Stroke patients with ‘hemiparesis’ - reduced control of one side of the body - often underuse their affected limbs even though they actually still do have motor function. Using their healthy limb may immediately improve the ease of their daily activities, but a long period of non-use of the affected ‘paretic’ limb can lead to further loss of function. This so-called ‘learned non-use’ is a well known effect in stroke patients and has been associated with a reduced quality of life.
- Research article: Belén Rubio Ballester, Jens Nirme, Esther Duarte, Ampar Cuxart, Susana Rodriguez, Paul Verschure and Armin Duff (2015), " The visual amplification of goal-oriented movements counteracts acquired non-use in hemiparetic stroke patients", Journal of NeuroEngineering and Rehabilitation, doi 10.1186/s12984-015-0039-z.
The small pilot study involved 20 hemiparetic stroke patients using the, so called, Rehabilitation Gaming System, RGS. The RGS system has pioneered an approach towards stroke rehabilitation where users control a virtual body via their own movements, seen from a first-person perspective on a computer screen with which they perform tasks in a virtual world. RGS is based on principles directly derived from the brain theory that Prof. Paul Verschure, ICREA at UPF, and his co-workers have developed and clinically validated with RGS.
Lead author, Belén Rubio from the Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems, at the Universitat Pompeu Fabra, Spain, said: “There is a need for designing new rehabilitation strategies that promote use of the affected limb in performing daily activities. Often we neglect the remarkable contribution of the patient’s emotional and psychological states to recovery, and this includes their confidence.”
Participants were asked to reach targets appearing in a virtual environment over several blocks of trials. In some of these, the researchers enhanced the movement of the paretic limb’s virtual representation, making it appear faster, more accurate and easier to reach the target on screen. These amplifications were introduced and suppressed in a gradual fashion to keep participants unaware of the manipulations.
Following these manipulations, the participants’ performance in the unamplified task was recorded, including the likelihood of them using their paretic limb.
Belén Rubio said: “We observed that after enhancement of movement, patients’ start using their paretic limb more frequently suggesting that by changing the patients' beliefs on their capabilities the use of the paretic limb significantly improved. Surprisingly, only ten minutes of enhancement was enough to induce significant changes in the amount of spontaneous use of the affected limb.”
Following the intervention, there was a significantly higher probability that the patient would select their paretic limb for reaching towards a virtual target. This was despite there being no amplification of movement in that session, and the patient reporting no awareness of the previous session’s manipulation.
Some current therapies for stroke patients involve forcing the patient to use the affected limb by constraining movement of the healthy limb or Constraint Induced Movement Therapy. This study suggests that an alternative focus on increasing the patient’s confidence in using the paretic arm may instead be critical for full recovery.
Belén Rubio said: “This therapy could create a virtuous circle of recovery, in which positive feedback, spontaneous arm use and motor performance can reinforce each other. Engaging patients in this ongoing cycle of spontaneous arm use, training and learning could produce a remarkable impact on their recovery process.”
The study will need to be repeated with a larger number of participants to provide more insight into the use of the specific feedback mechanisms that can further improve the RGS based virtual reality intervention as an effective therapy. This study is one among many in which RGS has been validated over the last 10 years and RGS is in daily use in a number of hospitals and treatment centres in Spain.
- RGS is being commercialized via Eosyne Systems, S.L., a spin-off of the Universitat Pompeu Fabra.
- Video and images of the research are available here: http://bit.ly/1cxFvEI, Please credit Belén Rubio Ballester in any re-use.