Work is about to begin on a new study to find the earliest signs of Alzheimer's disease, many years before symptoms like memory loss and confusion become obvious.

Scientists believe this is the best time to be using drugs to stop Alzheimer's from developing further.

Finding a treatment that can combat the disease has been one of medicine's major challenges. Results from drug trials have repeatedly been disappointing.
This new study will involve up to 50 tests on 250 volunteers and will include brain scans, cognitive testing and measure the way people walk.

The difficulty that doctors face is that the disease can start to affect the brain several years before the symptoms are visible.

Patricia Latto, who is in her nineties, has Alzheimer's. Evidence from her diary suggests the disease had begun to take hold more than a decade before being recognized.

Patricia's story: 'My mind is full of holes'

Patricia Latto was clearly upset and concerned about her mental deterioration in her mid-60s and kept a diary.

"I am writing this because I'm afraid I have Alzheimer's…" the diary entry begins, dated 12 May 1990.

"And now I have slipped into a no-man's land - no, a limbo, of not remembering and what has shocked me most - not being able to write clearly."