Researchers in Japan have identified a potential new way to detect Alzheimer’s disease years before symptoms become clinically visible. Using immersive virtual reality technology, the team found that subtle navigation errors in cognitively healthy adults were associated with early brain changes and blood biomarkers linked to Alzheimer’s disease.
The study, led by researchers from Fujita Health University, suggests that virtual reality-based navigation testing could become a future tool for identifying people at risk of neurodegenerative disease during the preclinical stage. The findings were published in Alzheimer's Research & Therapy.
Beyond memory loss
Alzheimer’s disease is typically diagnosed after memory problems and cognitive decline become noticeable. However, researchers increasingly recognize that biological changes in the brain can begin many years earlier. Among the first regions affected are the hippocampus and entorhinal cortex, areas that play a critical role in spatial navigation and orientation. This has led scientists to investigate whether difficulties in navigation could serve as an earlier marker of disease progression than traditional memory testing.
The Japanese research team focused specifically on “path integration,” a navigation function that allows individuals to track their position and direction using internal signals such as movement and balance, even without visual landmarks. According to the researchers, deterioration in this system may occur during the earliest phases of Alzheimer’s-related neurodegeneration.
VR navigation assessment
The study followed 71 cognitively healthy adults over approximately one year. At the start of the study, participants completed an immersive virtual reality navigation task designed to measure path integration performance. During the VR test, participants moved through a circular virtual environment, visited two checkpoints and then attempted to return to their original starting point without visual guidance. Researchers measured both positional errors and directional deviations.
Participants also underwent high-resolution MRI brain scans to evaluate changes in cortical thickness and brain volume over time. In addition, blood samples were analysed for Alzheimer’s-related biomarkers, including phosphorylated tau protein (p-tau181) and glial fibrillary acidic protein (GFAP). The researchers then compared baseline navigation performance with subsequent structural brain changes and biomarker levels.
Navigation errors and brain degeneration
The results showed a clear association between poor navigation performance and future neurodegeneration. Participants with larger path integration errors at baseline demonstrated greater cortical thinning and brain volume loss during follow-up. These changes appeared in brain regions commonly associated with early Alzheimer’s disease, including the parahippocampal gyrus, posterior cingulate cortex and middle temporal gyrus.
The study also found that higher navigation errors correlated with elevated levels of p-tau181 and GFAP in blood plasma, suggesting that the VR task reflects underlying biological processes linked to neurodegeneration.
According to lead researcher Kazuya Kawabata, the findings indicate that VR-based navigation testing captures both structural brain changes and molecular biomarkers before clinical symptoms become apparent. The ability to identify individuals showing the fastest rates of brain decline was particularly strong in regions associated with spatial memory and orientation.
Preventive neurology
The researchers believe the approach could eventually support earlier detection and monitoring of Alzheimer’s disease, potentially enabling intervention before significant cognitive decline occurs. Current Alzheimer’s diagnostics often rely on memory testing, brain imaging or invasive biomarker procedures once symptoms emerge. A behavioural assessment based on VR navigation could provide a non-invasive and scalable complement to existing screening methods.
The study also highlights the growing role of immersive technologies in digital neurology and precision medicine. By combining behavioural data, imaging and blood biomarkers, the approach reflects a broader trend toward multimodal early-detection strategies. While larger and longer-term studies are still needed, the researchers conclude that virtual reality navigation testing may offer a promising route toward earlier identification of neurodegenerative risk and more personalised preventive care for Alzheimer’s disease.
Blood test
In April, researchers showed that a simple blood test may detect Alzheimer’s disease risk earlier than current imaging methods. The study, published in Nature Communications, focused on the biomarker plasma phosphorylated tau 217 (pTau217), which appears to predict disease progression before abnormalities become visible on PET scans or symptoms emerge.
According to the researchers, blood-based diagnostics could offer a less invasive, more affordable and scalable alternative to PET imaging or lumbar punctures. The approach may support earlier screening, improve clinical trial selection and contribute to more preventive, personalised Alzheimer’s care in the future.
