The first line reads: "she sits on the bed with a helpless expression. What is your name? Auguste. Last name? Auguste. What is your husband's name? Auguste, I think." The 32 pages of medical records that follow are the oldest medical description of Alzheimer's disease. Psychiatrist Konrad Maurer and his colleagues at Johann Wolfgan Goethe University in Frankfurt found the file in their hospital's archive, where it had been missing for nearly 90 years, and published experts from it last May in The Lancet. The notes, in a cramped, archaic German script, were written by Alois Alzheimer the physician who first described the disease.

His patient, Auguste D, was a 51-year-old woman who had suffered fits of paranoid jealousy and memory lapses so disturbing that her family finally brought her to a local hospital known as the Castle of the Insane. Over the next four years Alzheimer tracked her condition. Upon her death he examined her brain tissue and found the distinctive lesion that are now hallmark of the disease.

Today Alzheimer's afflicts some 4 million Americans. Although it still cannot be cured, or even treated very well, several recent studies hint that some treatments—from estrogen to vitamin E to anti-inflammatory drugs—can reduce either the risk of developing the disorder or its symptoms. And more is being learned about its distinctive pathology. This past year, for instance, researchers discovered a new kind of lesion in Alzheimer's patients. A genetic study also pinpointed a mutation that is present in some 60 percent of them—a mutation in the DNA of mitochondria, the energy-producing organelles of the cells.

But nearly a century ago, it was Alois Alzheimer who first described the disease an in so doing became one of the first physicians to offer a biological basis for a psychiatric condition. Finding the file, Maurer says, "is like holding history in your hands."