The use of fully immersive virtual reality for screening neurodegenerative diseases: A systematic review of behavioral and diagnostic outcomes.

Comprehensive Summary

Clay et al. conducted a systematic review examining whether immersive virtual reality (iVR) technology could aid in detecting and treating Alzheimer's disease (AD) and mild cognitive impairment (MCI). The researchers searched five major medical databases from inception through July 2019, following PRISMA guidelines, with studies selected independently by at least two reviewers. Nine studies met the inclusion criteria: five assessment studies and four treatment studies, comprising case-control studies, validation studies, and case reports with a total of several hundred participants across all studies. None of the nine studies reported any tolerability issues with iVR equipment in participants with MCI or AD. One study by Howett et al. demonstrated that an iVR navigation task could detect prodromal AD with 90% accuracy (area under the curve 0.90) in distinguishing biomarker-positive MCI from biomarker-negative MCI, significantly outperforming standard cognitive tests like the Addenbrooke's Cognitive Examination (0.53 accuracy). Two additional studies showed iVR could differentiate AD participants from controls with high accuracy, though these lacked hypothesis-driven design or adequate control measures. The authors concluded that iVR assessment shows the strongest benefits when integrated with theoretical models of neurodegeneration, while treatment studies showed positive participant ratings but no reliable cognitive benefit.

Outcomes and Implications

Early and accurate AD detection is critical because current diagnostic methods often miss patients until significant cognitive decline has occurred, limiting treatment effectiveness. iVR offers advantages for assessing spatial navigation deficits, which appear specifically in early AD and precede the episodic memory problems that current screening tools measure. The technology proved well-tolerated even in patients with significant disease burden, addressing earlier concerns about motion sickness in older adults. However, Clay et al. emphasize that randomized controlled trials integrated with clinical populations are necessary before iVR can be recommended for routine diagnostic use. The treatment applications remain preliminary, though participants reported enjoying iVR-based rehabilitation more than traditional repetitive exercises, suggesting potential for improving engagement in physical therapy and occupational therapy that patients with AD often find difficult to sustain.