# Video Games in Rehabilitation Programs for People with Parkinson's Disease: A Systematic Review
## 4 Discussion
For example, treadmill gait training has been shown to improve gait performance and, in combination with VR simulating three different environments (countryside, city, and park), can be an effective tool, always under the supervision of a physical therapist [44]. [PERSON] et al. [32] took into account the impact of the VR intervention on psychological components, concluding that there was a positive impact on PD participants' psychological components and quality of life. Patient engagement and gamification likely play significant roles in treatment effectiveness, as they can increase motivation, enjoyment, and commitment to the therapy [39]. Future interventions could optimize these factors by tailoring VR activities to individual preferences, incorporating feedback and reward systems, and ensuring an appropriate balance between challenge and skill level. It would be important to take these variables into account in future research to promote adherence to treatment as well as motivation of the participants. In the literature reviewed, there is no consensus on how long benefits obtained through VR programs are maintained. [PERSON] et al. [31; 36] followed up with participants 6 months after the intervention and confirmed that the results were maintained in the elapsed time. However, in a study by [PERSON] et al. [45], improvements in cognitive tests were not maintained at 6 months after the intervention. In the rest of the articles reviewed [29; 30; 32; 33; 34; 35; 37], no follow-up assessment was administered to verify this. It would be critical for future research to evaluate the long-term sustainability of the improvements in people with PD, with follow-ups 1 month and 6 months after completing the VR interventions. There is also no consensus on the duration of treatment for VR protocols in people with PD. Some authors report that there is a tendency to improve with protocols that last between 4 and 12 weeks [29; 30; 31; 32; 33; 34; 35; 36; 37]. In the study conducted by [PERSON] et al. [31], it took 12 weeks to find improvements in the components analyzed after the intervention. There is also no consensus on the duration of each session, ranging from 30 to 90 min [29; 30; 31; 32; 33; 34; 35; 36; 37], nor on the total number of sessions. [PERSON] et al. [32] applied 10 sessions, while [PERSON] et al. [31] and [PERSON] et al. [37] applied 36 sessions. [PERSON] et al. [46] state that in people with PD, an intervention of between 18-88 h is necessary for minimal clinically important differences in walking gait and endurance to be observed, and at least 18.4 h is needed to improve overall physical health. Given these variations, it would be advisable to establish a standardized protocol, as this could help ensure consistency and improve the reliability of the results. Finally, after reviewing the published papers, extrapolating the results of VR protocols in people with PD is difficult. Most of the studies reviewed have very small samples (between 10 and 30 participants), making it difficult to reach conclusions about the interventions implemented [29; 30; 32; 33; 34; 35; 37]. In addition to small sample sizes and the need for long-term studies to assess the sustained effects of these interventions, there are further limitations in the available evidence. Future research should focus on standardizing treatment protocols, as well as exploring combinations of different technologies to maximize therapeutic benefits. This systematic review has several limitations that should be considered when interpreting the results. Firstly, the review included only articles published in English and Spanish, which may have excluded valuable research in other languages. Secondly, the inclusion criteria of this study restricted the search to RCTs, original clinical studies involving patients, and conference proceedings. This limitation may have significantly reduced the sample size and could have prevented the observation of a broader range of results.