Recent Advances In Brain Imaging May Allow Very Early Diagnosis Of Alzheimer's And Other Dementias

Imaging techniques such as PET are near to becoming useful in diagnosing Alzheimer's disease earlier, according to research reported today at the 9th International Conference on Alzheimer’s Disease and Related Disorders (ICAD), presented by the Alzheimer’s Association.

Researchers View the Early Stages of Alzheimer's In the Brain

Advances in positron emission tomography (PET) allow researchers to evaluate brain changes of people whose mild cognitive impairment (MCI) may represent the early stages of Alzheimer's. William E. Klunk, M.D., Ph.D., and colleagues at the University of Pittsburgh have recently developed a compound known as Pittsburgh Compound-B (PIB) — visible on PET scans — that sticks to abnormal clumps of protein in the brain called amyloid plaques. Plaques and other abnormal protein aggregates called tangles are the hallmarks of Alzheimer's disease. The main component of the plaques, a toxic protein fragment called beta-amyloid, is a primary suspect in the death of brain cells in Alzheimer's.

Some people with MCI progress to Alzheimer’s while others do not. It may be that levels of amyloid in the brain are related to who develops the disease. The researchers will attempt to replicate these results in a much larger study.

"Amyloid imaging with PET may become useful for predicting which people with MCI will progress to Alzheimer's in the near future. The technology might also help to determine the effectiveness of anti-amyloid therapies in people with MCI and Alzheimer's," said Klunk.

First Visualization of “Tangles” in Frontotemporal Dementia

Another PET development allows researchers to see — for the first time — accumulations of the abnormal protein tau in the brains of people with a rare form of dementia. Gary Small, M.D., of the University of California, Los Angeles, and his colleagues have developed a PET compound that “sticks” both to amyloid plaques and the tangles of abnormal tau protein in the brains of Alzheimer's patients. In their report at ICAD, the researchers used this new compound to map the tangles also found in frontotemporal dementia (FTD), a rare disorder with symptoms similar to Alzheimer's disease.

"We believe this is the first time tau accumulation has been visualized in living patients," said Small. "The new technique may help us better differentiate between Alzheimer's and other forms of dementia—leading to more effective treatments."

The researchers compared PET scans of people with FTD and Alzheimer’s. They found very different distributions of protein accumulations. The different patterns may serve as a useful tool to differentiate Alzheimer and FTD patients. The researchers hope the technique also can be used to monitor the effectiveness of drugs to clear abnormal proteins such as tau from the brain.

Adapted from the following source: 9th International Conference on Alzheimer’s Disease and Related Disorders (ICAD), presented by the Alzheimer’s Association

Zurück zur Übersicht