Britannica Sources used in this answer

Why can spatial disorientation be an early sign of Alzheimer disease?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Patient H.M. and short-term memory loss explained — hippocampus Learn about Henry Molaison (better known as “patient H.M.”), whose short-term memory loss following a lobotomy helped researchers to understand how brain structures are related to brain function.

Spatial disorientation is an early sign of Alzheimer disease because the disease causes significant atrophy and cell loss within the hippocampus and surrounding medial temporal lobes.12

These brain regions are essential for spatial memory, the process that allows individuals to form mental representations of their environment, plan routes, and navigate effectively. The hippocampus facilitates this through specialized neurons, such as place cells, which help map an environment and track one's current location. Because the hippocampus is a primary site for these spatial processing functions, its early degeneration in Alzheimer patients directly impairs their ability to orient themselves and navigate, leading to the disorientation frequently observed in the early stages of the condition.12