Corticomotor Excitability in Parkinson's Disease During Observation, Imagery and Imitation of Action: Effects of Rehabilitation Using Wii Fit and Comparison to Healthy Controls

Abstract

Parkinson's disease (PD) is responsible for a progressive motor impairment. Wii Fit game represents an innovative treatment modality using external visual cueing, which can be used to help patients with PD in executing motor tasks and improving function. The objectives of this study were (1) to compare lower limb corticomotor activation in subjects with and without PD during action observation (OBS), motor imagery (IMAG), and imitation (IMIT), and (2) to evaluate the effects of a 6-week training program using Wii Fit on corticomotor excitability during these 3 conditions. Using transcranial magnetic stimulation, we assessed motor evoked potentials (MEPs) in Quadriceps Femoris (QF) and Soleus (SOL) muscles in 8 subjects with moderate PD (PD group) and 8 healthy subjects (HS group) before and after 6 weeks of training using Wii Fit during OBS, IMAG and IMIT of a mini-squat action. At baseline, PD showed significantly less MEPs in QF during OBS, IMAG and IMIT compared with HS. In SOL, MEPs were reduced in PD only during IMIT. Following training, PD increased QF MEPs during OBS, which was opposite to the decrease in QF MEPs noted in HS. During IMAG, increased MEPs were found only in PD for SOL. During IMIT, both groups significantly reduced MEPs in both QF and SOL. Subjects with PD may have improved their dual-task ability considering changes observed during OBS and IMIT. Visual cueing training using Wii Fit may provide an interesting rehabilitation method for PD.