To investigate the effects of using motor imagery (MI) in combination with a virtual reality (VR) program on healthy volunteers and stroke patients. In addition, this study investigated whether task variability within the VR-guided MI programs would influence corticomotor excitability.
The present study included 15 stroke patients and 15 healthy right-handed volunteers who were presented with four different conditions in a random order: rest, MI alone, VR-guided MI, and VR-guided MI with task variability. The corticomotor excitability of each participant was assessed before, during, and after each condition by measuring changes in the various parameters of motor-evoked potentials (MEPs) of the extensor carpi radials (ECR). Changes in intracortical inhibition (ICI) and intracortical facilitation (ICF) were calculated after each condition as percentages of inhibition (%INH) and facilitation (%FAC) at rest.
In both groups, the increases in MEP amplitudes were greater during the two VR-guided MI conditions than during MI alone. Additionally, the reductions in ECR %INH in both groups were greater under the condition involving VR-guided MI with task variability than under that involving VR-guided MI with regular interval.
The corticomotor excitability elicited by MI using a VR avatar representation was greater than that elicited by MI with real body observations. Furthermore, the use of task variability in a VR program may enhance neural regeneration after stroke by reducing ICI. The present findings support the use of various VR programs as well as the concept of combining MI with VR programs for neurorehabilitation.
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To investigate the effectiveness of commercial gaming-based virtual reality (VR) therapy on the recovery of paretic upper extremity in subacute stroke patients.
Twenty patients with the first-onset subacute stroke were enrolled and randomly assigned to the case group (n=10) and the control group (n=10). Primary outcome was measured by the upper limb score through the Fugl-Meyer Assessment (FMA-UL) for the motor function of both upper extremities. Secondary outcomes were assessed for motor function of both upper extremities including manual function test (MFT), box and block test (BBT), grip strength, evaluated for activities of daily living (Korean version of Modified Barthel Index [K-MBI]), and cognitive functions (Korean version of the Mini-Mental State Examination [K-MMSE] and continuous performance test [CPT]). The case group received commercial gaming-based VR therapy using Wii (Nintendo, Tokyo, Japan), and the control group received conventional occupational therapy (OT) for 30 minutes a day during the period of 4 weeks. All patients were evaluated before and after the 4-week intervention.
There were no significant differences in the baseline between the two groups. After 4 weeks, both groups showed significant improvement in the FMA-UL, MFT, BBT, K-MBI, K-MMSE, and correct detection of auditory CPT. However, grip strength was improved significantly only in the case group. There were no significant intergroup differences before and after the treatment.
These findings suggested that the commercial gaming-based VR therapy was as effective as conventional OT on the recovery of upper extremity motor and daily living function in subacute stroke patients.
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To investigate the effect of virtual reality (VR) and a tetra-ataxiometric posturography (Tetrax) program on stroke patients with impaired standing balance.
Thirty acute stroke patients with impaired standing balance were recruited and randomly assigned to a VR, Tetrax, or control group. All patients received conventional balance training as a baseline; and VR and Tetrax patients received VR or Tetrax treatment, in addition. The primary outcome measures to evaluate the overall standing balance were the Berg Balance Scale (BBS) and the falling index (FI). The secondary outcome measures were the stability index (SI) and the weight distribution index (WDI), which were used to evaluate the balance status according to specific body positions. The FI, SI, and WDI were measured using the Tetrax instrument.
The BBS and FI scores were improved in all groups, with no significant differences between groups. In open-eyed positions, the VR group showed significantly greater improvement in SI and WDI scores than the control group (p<0.017). In closed-eyed positions, the Tetrax group showed significantly greater improvement in SI and WDI scores than the control group (p<0.017).
The inclusion of VR and Tetrax programs did not lead to an overall benefit in balance. VR and Tetrax did, however, demonstrate a benefit in specific positions. A Tetrax program may benefit patients with abnormal proprioceptive function, whereas a VR program may benefit patients with normal sensory function.
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