The first noticeable signs of Alzheimer's include memory loss and cognitive decline, but not all people who develop such problems get the disease. So what sets those with the degenerative brain disorder apart?
Researchers working with its hallmark protein, amyloid, believe they have an answer. Alzheimer's occurs when patients fail to clear amyloid from the brain; as it builds up, the protein forms sticky plaques, eventually strangling and killing delicate nerves. Scientists say it's now possible to pick up traces of an early form of amyloid in the spinal fluid well before the first memory lapses start. In a group of patients with memory problems known as mild cognitive impairment, which can lead to Alzheimer's, they found that patients with higher levels of this amyloid precursor in their spinal fluid were more likely to develop Alzheimer's than those with less of the protein. This measure, combined with the results of a test for a protein formed during nerve death and the patient's age, can predict Alzheimer's with about 80% accuracy.