When people show the very first symptoms of dementia, it's very hard to tell whether they have Alzheimer's disease, another kind of dementia, or just a mild cognitive impairment. Doctors often get the diagnosis wrong.
Now a new test -- not of the brain, but of the skin -- can tell which of these people have early Alzheimer's disease. The test provides a score called the "Alzheimer's index" by BRNI researchers Tapan K. Khan, PhD, and Daniel L. Alkon, MD.
"When the Alzheimer's index agrees with the clinical diagnosis of the presence of Alzheimer's, there is a high probability of accurate diagnosis," Alkon said, in a news release.
Early diagnosis is important because future treatments for Alzheimer's disease will work best if started as soon as possible.
"Potential treatments of Alzheimer's are likely to have their greatest efficacy before the devastating and widespread impairment of brain function that inevitably develops after four or more years," Alkon says.
Alzheimer's: Not Just the Brain
Why test skin cells for a brain disease? New research suggests that Alzheimer's disease does not just affect the brain. Its effects appear throughout the body.
One effect of Alzheimer's disease is a change in the way cells in the body communicate with each other. Alzheimer's disease alters a set of signals involved in inflammatory signaling pathways. The new test detects Alzheimer's-specific signals in skin cells.
Kahn and Alkon report their findings in the early online edition of the Proceedings of the National Academy of Sciences.
SOURCES: Khan, T.K. and Alkon, D.L. Proceedings of the National Academy of Sciences 2006; early online edition. News release, Blanchette Rockefeller Neurosciences Institute.
By Daniel J. DeNoon
Reviewed by Louise Chang, M.D.
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