Early Alzheimer’s Symptoms: Losing One’s Way More Often Can Occur Well Before Memory Problems

Memory loss has long been considered the first thing to go in Alzheimer’s disease. Some studies of cognitively normal adults found something different: people at higher risk, or with Alzheimer’s-related changes on brain scans, made bigger errors on one specific navigation task, while memory problems had not yet shown up on testing.

A 2024 systematic review in Alzheimer’s & Dementia gathered 27 navigation studies of people at risk of dementia-causing diseases, some with no symptoms and some with early ones. Several measures, including path integration, separated at-risk groups from comparison groups, and the authors concluded that navigation measures may help detect people at high risk before or early in symptoms. Two of the review’s authors, Coco Newton and Dennis Chan, also wrote the PREVENT study described below.

What Is The Brain Actually Calculating?

Position, using nothing but its own sense of movement.

Path integration is the brain’s running tally of how far a person has traveled and how much they have turned, which allows them to point back toward a starting spot without a street sign. Researchers test it separately from other spatial skills, such as remembering the layout of a scene. Grid cells in the entorhinal cortex, part of the medial temporal lobe, are thought to support it. That region is among the first to show tau buildup in Alzheimer’s disease (tau is one of two proteins, along with amyloid, that accumulate in the condition).

In the PREVENT experiment, volunteers wore a virtual-reality headset and walked between three cones in an open virtual field, then tried to return to the first cone on their own. On some trials, distant landmarks vanished before the return leg. Without those cues, only the body’s own movement tracking remains, which may expose problems that landmarks help cover up.

Why Is This Not A Screening Test Yet?

Because the evidence is promising but early.

A 2024 study in Alzheimer’s & Dementia analyzed data from 99 adults ages 43 to 66 with no symptoms from the United Kingdom’s PREVENT Dementia program. Higher risk was defined by a parent with dementia, a version of the APOE gene called ε4, or a higher score on a dementia risk calculator built from health factors such as blood pressure, cholesterol and physical activity. When distant landmarks vanished, higher-risk participants made larger return errors, mostly from turning too far. Memory tests did not show the same pattern across all risk types, though higher risk-calculator scores tracked with weaker name-and-face recall.

Risk here meant family history, genes and health scores rather than confirmed brain changes, and nobody was followed to a diagnosis. Authors called the sample relatively small for comparing risk factors and asked for larger studies with biomarkers. About a third of trials were thrown out because people walked past the edge of the virtual test space, which the authors described as a major drawback for clinical use.

Closer to the biology, a 2025 study in Alzheimer’s Research & Therapy from a UCLouvain team in Belgium tested 102 adults over 50 without dementia: 75 with normal thinking and 27 with mild cognitive impairment. Amyloid was measured with PET scans (or, for some participants, spinal fluid tests) and tau with PET scans. Participants completed a visual task with no body movement, traveling through a virtual arena and then trying to return to the starting spot. Clinically normal adults with amyloid buildup (19 people) made larger errors when relying on movement cues alone, but did better once a landmark was added. People with mild cognitive impairment made errors that did not improve with a landmark, and amyloid status did not change their results.

Across all participants, errors in judging turn angle rose with tau in the medial temporal lobe, while errors in judging distance did not and tracked age instead. Amyloid’s link faded once tau was accounted for, which points to tau more than amyloid itself. Limits the authors listed include a task averaging about 30 minutes, the lack of body movement cues, PET resolution too coarse to separate parts of the medial temporal lobe, and fewer than 20 clinically normal participants with amyloid. As a cross-sectional study, it captured a single point in time.

Back in the 2024 review, 21 of the 27 studies were cross-sectional and six followed people over time. Only two of those 21 explained how they chose their sample sizes, and three reported no navigation effect, which the authors said hinted at a slight bias toward positive reporting. All of the navigation studies enrolled participants of European or North American descent, and only 18% reported racial or ethnic breakdowns.

When Does Getting Lost Warrant Attention?

When it happens in places the person already knows well.

Among signs that may point to dementia, the Centers for Disease Control and Prevention (CDC) lists getting lost in a familiar neighborhood, along with forgetting the name of a close relative or friend, and advises seeing a health care provider about any of them. Normal age-related changes, such as sometimes forgetting where car keys went, should not affect daily life, according to the agency.

None of the studies above tested everyday wrong turns. They measured performance on controlled virtual-reality or computer tasks, so one missed exit or a lifelong weak sense of direction is not evidence of Alzheimer’s.

So is losing one’s way the first thing to go in Alzheimer’s disease? For some people, it may be among the earliest changes, and researchers are actively testing the idea. Memory remains on the CDC’s list of dementia symptoms, and these studies add a possible early clue alongside it rather than replacing it.