Alzheimer’s early signs timeline developed

Posted 11/07/2012

Washington University School of Medicine scientists have carried out a study of people from the UK, US and Australia and consider that signs of Alzheimer’s appear up to 25 years before the onset of the disease.

Of the 128 people studied 50% had a chance of inheriting one of three mutations that are certain to cause early Alzheimer’s which often develops in people’s 30s and 40s, much earlier than the more common form which affects people in their 60s.  Those who carry the mutations will go on to develop the disease.  

Researchers studied the age the participants’ parents were when they developed the disease and how many years it was likely to be before they showed symptoms.  They had blood and spinal fluid tests as well as brain scans and mental ability assessments.  They now suggest that the earliest change, a drop in spinal fluid levels of the key ingredient of Alzheimer’s brain plaques, can be detected 25 years before the anticipated age of disease onset.

At 15 years before the anticipated age of disease onset, raised levels of tau, a structural protein in the brain cells, can be seen in the spinal fluid and shrinkage can also be detected within parts of the brain. Changes in the brain’s use of the sugar glucose and slight memory problems become apparent 10 years before symptoms would appear.

Prof Clive Ballard of the Alzheimer’s Society said: “This important research highlights that key changes in the brain linked to the inherited form of Alzheimer’s happen decades before symptoms show, which may have major implications for diagnosis and treatment in the future.  These findings are a good indicator that there may be key changes in the brain happening early in people who develop non-hereditary Alzheimer’s disease but we cannot be sure and further research into this complex condition is needed to confirm a definite link”.

Dr Eric Karran at Alzheimer’s Research UK said: “ These results from people with the inherited form of Alzheimer’s seem to be very similar to the chances in the non-genetic common form of the disease.  Any new treatment for Alzheimer’s would need to be given early to have the best chance of success.”

Julie Crossley, a medical injury lawyer from Ashtons Legal comments: “Alzheimer’s disease is a distressing and awful disease which affects the patient and their families.  Any research undertaken to detect it early and possibly prevent its symptoms or prolong their onset has to be welcomed.”