Video: Alzheimer’s brain

PET scans could be used to detect Alzheimer’s plaques before symptoms of dementia appear (Image: Tim Beddow/SPL)

Attempts to treat the world’s most common form of dementia may have been attacking its symptoms, not its root cause

I HAVE lost myself,” cried Auguste Deter to her physician. Deter was trying to write her name, scrawling “Mrs” in a spidery script, only to forget the rest every time.

“What are you eating?” the doctor asked Deter on her second day at the hospital for the mentally ill in Frankfurt, Germany, as the confused 51-year-old lunched on cauliflower and pork. “Potatoes,” she replied.

That was in 1901. When Deter died five years later, an autopsy revealed that her brain was riddled with strange tangles and plaques of a fibrous material containing the remnants of dead brain cells. She became the first described case of a form of dementia now known by the name of her doctor – one Alois Alzheimer.

Over a century later, research into Alzheimer’s disease still revolves around efforts to understand those mysterious plaques and tangles. Despite decades of work, no effective treatment exists, never mind a cure. The world’s population is ageing, so that search is becoming more urgent. Alzheimer’s disease is now recognised as the most common form of dementia, with over 25 million people living with the disease worldwide, and that number is expected to pass 100 million by 2050 (see diagram). Yet today, even definitively diagnosing the disease can still only be done at autopsy.

The situation is starting to change, however. Thanks to a new imaging technique, the plaques can now …