Alzheimer's Diagnosis: More Tests Improve Chance Of Early Detection

Two or three tests are better than one, when it comes to predicting the onset of Alzheimer's disease, a new study suggests. 

The research, published in the Journal Radiology, shows that using more than one diagnostic test could better predict which people with mild cognitive impairment will go on to develop Alzheimer's disease. 

"Misdiagnosis in very early stages of Alzheimer's is a significant problem, as there are more than 100 conditions that can mimic the disease. In people with mild memory complaints, our accuracy is barely better than chance," study researcher P. Murali Doraiswamy, MBBS, professor of psychiatry and medicine at Duke Medicine, said in a statement. "Given that the definitive gold standard for diagnosing Alzheimer's is autopsy, we need a better way to look into the brain." 

The study, conducted by Duke Medicine researchers, included 97 people with mild cognitive impairment who were part of the Alzheimer's Disease Neuroimaging Initiative. Researchers had the study participants undergo the typical diagnostic procedures for Alzhiemer's - which includes cognitive testing -- as well as three other diagnostic tests. They included magnetic resonance imagine (MRI), cerebrospinal fluid analysis and fluorine 18 fluorodeoxyglucose positron emission tomography (also known as FDG-PET). 

The study participants were followed for up to four years. Researchers found that the rate of misdiagnosis was highest when the study participants only received the typical cognitive testing - 41.3 percent. However, that percentage went down with each additional test the person was given, with the lowest percentage of misdiagnosis occurring when all three tests were administered - 28.4 percent. 

And of all the tests, the FDG-PET seemed to add the most diagnostic value, the researchers noted. 

According to the Alzheimer's Association, the earlier memory loss conditions are discovered, the better. That's because doctors are then able to know which medications to prescribe - and not to prescribe - early on, and patients can be aware of potential safety issues that may crop up.

(Source:  Huffpost Healthy Living, 21 January 2013)