Differences in the distribution of certain proteins and markers in the brain may explain why some people first experience vision changes instead of memory loss in Alzheimer’s disease, finds a new study by UCL researchers.

Posterior cortical atrophy (PCA) is a rare form of Alzheimer’s disease that, rather than causing problems with memory, leads to difficulties with reading, navigating, and recognizing objects. Studies suggest that one in 10 patients with Alzheimer’s disease has a form which is visual, rather than memory-led.

As well as presenting with unusual symptoms, individuals with PCA typically develop symptoms younger than most people with Alzheimer’s disease, with onset usually in their 50s and 60s.