Alzheimer's disease has frustrated researchers since it was identified by Bavarian neurologist Alois Alzheimer in 1906. The cause of the bizarre loss of memory and personality remained a stubborn mystery for almost a century. Without knowing what was wrong, doctors were at a loss to know how to fix it. For years, diagnosis followed death, not the other way around. Researchers now know that Alzheimer's disease results from the death of nerve cells in a key memory center of the brain.
New memories reside here temporarily before they're filed in the frontal cortex.
If the circuitry in these structures is damaged, vulnerable memories can be lost forever. Add to this the age-related changes that occur in the frontal cortex and other areas of the brain, which occur even in healthy people, and the result is the premature death of personality. Tangles - insoluble threads of a protein called tau that build up in nerve cells. New research suggests that these abnormalities begin accumulating in the brains of people with Alzheimer's up to 20 years before a diagnosis is made, says Albert, who studies pre-Alzheimer's memory loss. Now, thanks to rapid-fire advances in imaging, new tests are on the way.