Extended Reality Rehabilitation in Parkinson's Disease

Extended reality is being used increasingly within neurological rehabilitation. However, there are different forms of extended reality that can be used while wearing a head-mounted display (a VR headset). For example, sometimes the patient no longer sees the environment at all and is thus completely immersed in virtual reality (Virtual Reality), or sometimes the patient still sees part of the environment alongside the virtual reality (Mixed Reality). There are therapeutic arguments for using both forms, but to date, it is not known which is preferred for individuals with Parkinson's disease.

In a previous study (ONZ-2022-0404), a new type of therapy was tested in individuals with Parkinson's disease: visual perturbation training. This study took place in a large VR lab at Ghent University Hospital. To make this therapy accessible to more patients, this study will investigate the effect using a VR headset. Therefore, first the subjective preference in a small group of individuals with Parkinson's disease will be examined, and this study will also investigate whether there is a difference in the use of various forms of extended reality regarding a number of physical parameters (heart rate, heart rate variability, changes in skin conductance, etc.) measured in the patient using a wearable device, as well as mental load via questionnaires.

The participants will perform an exercise twice in which they have to pop balloons in a virtual world (Virtual Reality or Mixed Reality). During the exercise, participants will be secured in the Rysen, a weight-bearing system that ensures the participant cannot fall in the event of loss of balance. After each exercise, participants will complete the questionnaires on Redcap via a tablet provided by the department.

One test session lasts approximately 45 minutes.

All devices used (VR headset, Rysen weight-bearing system to guarantee patient safety, Shimmer to measure heart rate variability and skin conductance) are CE marked and are used within their scope. All tests will take place at the Rehabilitation Center of UZ Ghent. The VR headset and Rysen are devices owned by UZ Ghent. The Shimmer wearable is being made available by UGent for the duration of the study.

This information can help us with targeted follow-up research and applying for the necessary funding.

• Extended reality balance training (Device): Participants perform a balloon-popping task for balance training using a VR headset in two conditions: Virtual Reality (fully immersive) and Mixed Reality (real-world combined with virtual elements). The task includes visual changes to challenge how participants see and respond to their environment, including eye movements. The goal is to compare how these two formats affect mental effort and experience.

Primary outcomes

• Score on the Igroup presence questionnaire (IPQ) [Immediately after each condition (within one study session)]: The Igroup Presence Questionnaire (IPQ) is a scale for measuring the sense of presence experienced in a virtual environment. It will be used as one of the measures to identify the subjective preference during Virtual Reality (fully immersive) and Mixed Reality (real-world combined with virtual elements). This questionaire consists of 14 items where participants indicate their spatial presence, involvement or realness on a Likert scale (1-7). Max score is 98. Higher score is higher feeling of presence, immersion and engagement.
• Score on the NASA Task Load Index (Nasa-TLX) [Immediately after each condition (within one study session)]: The NASA-TLX is a questionnaire to examine the subjective workload. It contains 6 items where participants again score each item on a 7 point Likert scale. A higher score indicates more cognitive workload.
• Score on the Virtual Reality Sickness Questionnaire [Immediately after each condition (within one study session)]: Questionnaire to document potential side effects of using extended reality (e.g. cybersickness). Participants are asked to indicate for 9 symptoms on a 4 point Likert scale if they experience side effects and how intense they are present. A higher score indicates more adverse events.
• Hartrate (variability) during the extended reality sessions [During the MR and VR condition (within one study session)]: Physiological responses during VR and MR conditions are measured continuously using a wearable device. These measures reflect autonomic nervous system activity and objective load during task performance. Differences between VR and MR conditions will be analyzed.
• Skin conduction during the extended reality sessions [During the MR and VR condition (within one study session)]: Physiological responses during VR and MR conditions are measured continuously using a wearable device. These measures reflect autonomic nervous system activity and objective load during task performance. Differences between VR and MR conditions will be analyzed.

Secondary outcomes

• Eye tracking during the extended reality task as a measure of visual function [During the MR session]: Exploration of the relationship between visual function and subjective cognitive load scores obtained after the MR condition, to assess whether eye movement behavior contributes to perceived mental effort.
• Education level [Before the intervention]: Participants will be questioned to know their highest education level. This will be used to assess if this a co-variate for the primary outcome measures
• Experience with the use of extended reality [Before the intervention]: Participants will be questioned to know if they have any experience using extended reality. This will be used to assess if this a co-variate for the primary outcome measures
• Technological skilled [Before the intervention]: Participants will be questioned to know if they consider themselves technological skilled. This will be used to assess if this a co-variate for the primary outcome measures

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* you have been diagnosed with Parkinson's disease
* you can walk independently without the use of aids
* you are not experiencing pain at the time of the test
* you are 18 years of age or older
* you have normal or corrected normal (glasses/lenses) vision
* you do not have a known, excessive susceptibility to motion sickness (e.g. car sickness)
* you do not have a medication pump
* you do not have a brain stimulator

Exclusion Criteria:

* you have a known, excessive sensitivity to motion sickness (e.g. car sickness)
* you have a medication pump
* you have a brain stimulator