Can’t remember how to get there? Navigation problems could indicate early Alzheimer’s

A new study from Washington University has identified a behavior that could be an indicator of early-onset Alzheimer’s: problems navigating. Senior author Denise Head said that assessing a cognitive mapping strategy through navigational tasks could “represent a powerful new tool for detecting the very earliest Alzheimer’s disease-related changes in cognition.

Head is an associate professor of psychological and brain sciences at Washington University in St. Louis. She said that the spatial navigation task that was used in the study was more sensitive at detecting preclinical Alzheimer’s disease than the standard episodic memory tests.

Problems with navigational skills have been well-documented in patients who are in the early stages of Alzheimer’s disease, but this new study is the first that looked at the symptom in seemingly normal patients. The study included 42 clinically normal individuals. These participants lacked any of the cerebrospinal fluid markers for Alzheimer’s. It also included 13 people who were clinically normal but were positive for the cerebrospinal fluid markers, and 16 individuals who already had early stage Alzheimer’s behavioral symptoms.

All participants were tested on their ability to navigate a computerized virtual maze. They were tested on how well they could form and use a cognitive map of the environment and how well they could learn and follow a pre-set route. After being given 20 minutes to study and learn the maze they were tested on their ability to find their way around or recreate the route.

The researchers found that those who already had the markers for preclinical Alzheimer’s disease had “significant difficulties” when asked to form a cognitive map of the environment. However, they had virtually no problems with route-learning tasks.

The participants with preclinical Alzheimer’s disease scored lower than cognitively normal study participants who were lacking any Alzheimer’s markers in their ability to learn the location of environmental objects in relationship to each other. This difficulty suggests deficits in the ability to form a cognitive map.

The researchers note that cerebrospinal fluid markers for preclinical Alzheimer’s is not a guarantee that a person will develop the disease. “Future research should examine whether cognitive mapping deficits in individuals in preclinical Alzheimer’s are associated with an increased risk of developing symptomatic Alzheimer’s,” they said.