Marker Identifies Dementia Type

PIB PET scans detect brain plaque differentiating between Alzheimers and other forms of dementia

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Symptoms of different types of dementia are similar, which can make it tough to give patients an accurate diagnosis. A marker that detects brain plaques can help doctors tell them apart.

The marker allows doctors to tell whether the type of dementia is Alzheimer’s disease or frontotemporal lobar degeneration (FTLD).

"Ask your neurologist about the appropriate dementia treatment."

Dr. Gil D. Rabinovici, study author of the University of California San Francisco Memory and Aging Center, noted that the two types of dementia share similar symptoms, so telling them apart can be challenging. However, identifying the type ensures that patients receive the most appropriate treatment.

Researchers performed a PET scan using a PIB marker capable of detecting amyloid plaque in the brain that is a hallmark in Alzheimer's disease but not related to FTLD. The study included 107 participants diagnosed either with early onset Alzheimer's or FTLD.

A second PET scan was also performed on participants using a FDG marker, which detects changes in the brain’s metabolism. This marker aids in differentiating between the two types of dementia.

Investigators found that scans with both markers performed equally well in determining whether a patient had FTLD or Alzheimer's. However, the PIB PET scan had better accuracy, precision and sensitivity. PIB sensitivity was 89.5 percent as compared to 77.5 percent for FDG.

PIB PET scans are not yet widely available, but similar amyloid markers are in development for clinical use. Rabinovici noted that the findings support a role for amyloid imaging in correctly diagnosing the type of dementia a patient is suffering from.

The study is published in the Nov. 30 issue of Neurology, the medical journal of the American Academy of Neurology.

Reviewed by: 
Review Date: 
November 29, 2011
Last Updated:
December 4, 2011