When does Alzheimer’s begin?
January 9, 2008 by Michael Davidsen
Filed under ALZHEIMER'S
Alzheimer’s experts now believe that the disease, and even the symptoms, begins many years before any formal diagnosis. German researchers Drs. Heiko and Eva Braak theorize that, if you looked, Alzheimer’s structures (plaques and tangles) could be found in the brains of teenagers, 60 years before serious symptoms develop. They have already found such structures in twenty-year-olds.
Current tests for Alzheimer’s are actually psychological and cognitive tests – the only absolute test for Alzheimer’s is a brain dissection. But according to the New York Times, a radioactive dye, PIB, has been developed that allows researchers to locate amyloid protein deposits, considered a sign of Alzheimer’s disease, in the brains of living people. The problem is that there are not yet any reliable medications to prevent the disease, so tests with PIB would tell more people they have the disease without being able to stop it.
According to the New York Times article, Finding Alzheimer’s Before a Mind Fails:
“I’m speculating that it does affect you throughout life,” said Dr. Richard Mayeux, a professor of neurology, psychiatry and epidemiology at Columbia University, and co-director of its Taub Institute for Research on Alzheimer’s Disease and the Aging Brain. “I think there’s a very long phase where people aren’t themselves.”
If Dr. Mayeux asks family members when a patient’s memory problem began, they almost always say it started a year and a half before. If he then asks when was the last time they thought the patient’s memory was perfectly normal, many reply that the patient never really had a great memory.
Among other research strategies, Dr. David Snowden’s
Nun Study compared the mental condition of elderly nuns with the personal biographies they had written when they joined the religious order in their twenties. The ones who later developed Alzheimer’s disease had fewer verbal skills. The ones who could juggle several concepts in their brains at once tended not to get the disease. That’s one of the main reasons why I think I might not get it myself. I’ve always been forgetful, but I’ve always been very good at random daydreaming.
What this tells me is that perhaps half the people you know have the beginnings of undiagnosed Alzheimer’s disease. Or rather, if serious symptoms never appear, it will never be called that. One of the requirements for an Alzheimer’s diagnosis is to live long enough for it to get bad enough to notice. You may have the beginnings of Alzheimer’s. I may have them. All the more reason to be humble about the capacities and limits of our minds. And to be patient with those whose mental capacities are less than ours. So far.

This is an important question (When does AD begin?) that is often debated ineffectively because their are vastly differing perspectives on what constitutes “the beginning”. Is it the first trace of abnormal pathology (researcher view), the first symptoms of cognitive decline (patient view), or when the patient’s health finally declines to meet the clinical definition of AD (physician view)? This problem is explored in the Brain Today blog here.