In France, 900,000 people are affected by Alzheimer’s disease, according to the Pasteur Institute, and this figure is likely to increase significantly in the coming years with the aging of the population. There Alzheimer’s disease is a neurodegenerative disease that affects the brain and lastingly disrupts cognitive functions linked to Memory, language, reasoning, or even learning. It can lead to a loss of autonomy which really disrupts the patient’s daily life. If there is no treatment to treat it, it is essential to detect it at an early stage, in order to be able to slow its progression, before a real loss of autonomy.
A study from University College London (United Kingdom) published on February 29, 2024 in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association identified a new sign likely to predict early the development of Alzheimer’s disease. Researchers used virtual reality to test the spatial navigation of 100 asymptomatic adults aged 43 to 66, who were at hereditary or physiological risk of Alzheimer’s. These participants were on average approximately 25 years younger than the estimated age of onset of cognitive disorders linked to the disease. As part of the study, their task was to complete a triangle by passing between three numbered cones, in a virtual open field environment.
The space navigation is defined by the Encyclopedia of the Sciences of Learning as the process by which we use “multiple cue sources, such as path integration, magnetic cues, landmarks, and beacons, to determine and navigate the path to a goal“.
Alzheimer’s disease: navigation problems could be a warning sign
At the end of the study, the researchers noticed that people most at risk of Alzheimer’s disease, whatever the risk factorpresented selective impairments during the navigation task in virtual reality, without other cognitive tests showing corresponding deficiencies. According to the scientists, these results suggest that spatial navigation disorders may begin to develop many years before the onset of any other symptom of Alzheimer’s disease.
Furthermore, the study researchers also noticed a strong gender difference in the participants’ performance. Indeed, this impairment during navigation tasks was observed in men, and not in women.
Alzheimer’s: results that could help early diagnosis of the disease, according to scientists
For researchers, this discovery represents an advance in the early detection of Alzheimer’s disease, essential for implementing treatments likely to slow its development. “Our results indicate that this type of change in browsing behavior could represent the very first diagnostic signal in the Alzheimer’s disease continuum – when people move from an unaltered state to a manifestation of the disease“, Coco Newton, one of the authors of the study, said in a statement. She added: “We are now building on these results to develop a clinical decision support tool in the years to come, which represents a completely new way of approaching le diagnostic and which we hope will help people get a faster and more accurate diagnosis”.
According to the study scientists, these findings also raise new questions that need to lead to more research, particularly on gender differences in Alzheimer’s disease. “This study also highlights the need to further study the different vulnerability of men and women to Alzheimer’s disease and the importance of considering sex for both diagnosis and future treatments.”, a conclu Coco Newton.
Sources :
- Entorhinal-based path integration selectively predicts midlife risk of Alzheimer’s disease – Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association – 29 février 2024
- Poor spatial navigation could predict Alzheimer’s disease years before the onset of symptoms – UCL News – 29 février 2024
- Alzheimer’s disease – Institut Pasteur
- Place Learning and Spatial Navigation – Encyclopedia of the Sciences of Learning – pp 2639–2641
