Virtual reality programs can improve movement speed in Parkinson’s disease
MedWire News: Virtual reality (VR) may be useful in offering visual motion stimuli that can improve movement speed in patients with Parkinson's disease (PD).
One of the main conditions associated with PD is bradykinesia, which can significantly reduce patient quality of life. Motor speed and reflexes can be improved with external cuing techniques, and previous studies have noted that rapidly moving targets help patients with PD to reach items faster than using stationary targets.
VR offers moving-target cueing that can be easily and accurately controlled by the therapist and tailored to the patient's individual needs. However, in PD it has only been compared with physical reality in reaching for stationary targets. Hui-Ing Ma (National Cheng Kung University, Tainan, Taiwan) and colleagues studied the performance of reaching for stationary versus moving targets in both VR and physical reality situations in patients with PD, and assessed whether moving targets in VR would improve movement speed to the same extent they would in physical reality.
As reported in Archives of Physical Medicine and Rehabilitation, 29 patients with diagnosed PD (mean age 66.2 years) and 25 age-matched controls were asked to reach for and grab a ball in VR and physical reality. In one condition, the ball was stationary, and the participant had to reach as quickly as possible for the ball. In four conditions, the ball moved at different speeds. Participants were scored on amplitude of peak velocity, movement time (duration of arm movement execution), and percentage of total movement time represented by the acceleration phase.
Study results showed that in the VR and physical reality scenarios, patients with PD had longer movement time and lower peak velocity than controls during the stationary condition. However, in the moving target conditions, the PD group had greater improvement than the control group in movement time and peak velocity, giving them a performance level similar to controls. This was seen with all but the fastest moving speed.
Earlier studies noted that certain cortical areas in the brain selectively respond to rapid visual motion cues, and that visual motion stimuli may engage neural circuits that are generally less affected by PD, allowing patients with PD to make quick movements in response to a rapidly moving target. Ma and colleagues' findings suggest that patients with PD may respond to both virtual and physical reality visual motion stimuli.
The evidence found in this study provides rehabilitation therapists with new information about how to control task and environmental constraints in order to improve movement in patients with PD. The authors say that results "suggest that with an appropriate choice of cueing speed, VR is a promising tool for offering visual motion stimuli to increase movement speed in persons with PD. Research is needed to examine the long-term effect of VR training that incorporates target objects moving at appropriate speeds."
By Stephanie Leveene