Alzheimer’s disease attacks body decades before diagnosis

Changes in spinal fluid and the brain have been observed up to 25 years before people with a genetic predisposition for Alzheimer’s disease actually show signs of this devastating disease.

An international study published today in the New England Journal of Medicine examined people who have a genetic mutation inherited from their parents that means they will develop Alzheimer’s disease before the age of 60.

The study draws upon a group known as the Dominantly Inherited Alzheimer Network, or DIAN. Neuroscience Research Australia, based in Sydney, is one of ten study sites and Executive Director Prof Peter Schofield is co-author of the paper published today.

“This network is the first chance we have had to look for changes related to Alzheimer’s disease in living people that we know will develop the disease,” says Prof Schofield.

“There is currently no cure for Alzheimer’s disease and available treatments target symptoms of this disease only. By looking at changes in people before they show clinical signs of the disease, we will be able to develop more targeted treatments and identify the best window in which, one day, we may be able to prevent this disease altogether,” Prof Schofield says.

The researchers identified a number of major landmarks in the way Alzheimer’s disease progresses.

Around 25 years before Alzheimer’s disease symptoms are expected, levels of a protein called beta amyloid decline in cerebrospinal fluid.

Fifteen years before the onset of Alzheimer’s disease abnormal deposits of beta amyloid and increased levels of another protein called tau appear in the brain and sections of the brain begin to die.

Patients start to experience memory problems five years later, and show the range of symptoms needed to diagnose Alzheimer’s disease just three years after that.