Fujita Health University May 27 2026 Alzheimer's disease (AD) often begins long before it is clinically recognized, with subtle brain changes emerging years before noticeable memory loss or cognitive decline. Among the earliest regions affected are the hippocampus and entorhinal cortex, areas essential for spatial navigation. This has led researchers to look beyond memory and explore navigation ability as a potential early indicator of the disease. One key component of navigation is path