People at risk of Alzheimer’s disease have impaired spatial navigation prior to problems with other cognitive functions, including memory, finds a new study led by UCL researchers. The research, published in Alzheimer’s & Dementia, used virtual reality to test the spatial navigation of 100 asymptomatic midlife adults, aged 43-66, from the PREVENT-Dementia prospective cohort study.
Participants had a hereditary or physiological risk of Alzheimer’s disease, due to either a gene (the APOE-ε4 allele) that puts them at risk of the condition, a family history of Alzheimer’s disease, or lifestyle risk factors such as low levels of physical activity. Crucially, these participants were around 25 years younger than their estimated age of dementia onset.
Led by Professor Dennis Chan, the study used a test designed by Dr. Andrea Castegnaro and Professor Neil Burgess (all from UCL Institute of Cognitive Neuroscience), in which participants were asked to navigate within a virtual environment while wearing VR headsets. The researchers found that people at greater risk of developing Alzheimer’s disease, regardless of risk factor, were selectively impaired on the VR navigation task, without a corresponding impairment on other cognitive tests. The authors say their findings suggest that impairments in spatial navigation may begin to develop years, or even decades, before the onset of any other symptoms.
First author, Dr. Coco Newton (UCL Institute of Cognitive Neuroscience), who carried out the work while at University of Cambridge, said, “Our results indicated that this type of navigation behavior change might represent the very earliest diagnostic signal in the Alzheimer’s disease continuum—when people move from being unimpaired to showing manifestation of the disease.”
The researchers also found that there was a strong gender difference in how participants performed, with the impairment being observed in men and not women.
