It is sometimes difficult to accurately diagnose Alzheimer's
The brains of Alzheimer's patients are similar to child's brains in certain ways, a study has found.
The white matter in a specific area resembles that of immature brains, say US scientists.
Rather than being a normal phenomenon seen in infancy it is probably due to damage of certain brain cells.
The findings could yield clues to the cause of Alzheimer's disease, a form of dementia that affects around 500,000 people in the UK alone.
The brain contains grey matter and white matter - the grey is where the processing is done and the white contains the channels of communication.
The key to making real advances with this new knowledge will be to understand how these changes develop as the Alzheimer's disease starts
Richard Harvey, Alzheimer's Society
The findings of the latest study relate to white matter in the region that connects the two halves of the brain.
In people with Alzheimer's, water molecules can diffuse more freely compared with healthy adults, says Dr Jeffrey Lassig of the University of Michigan, Missouri. In this respect, they are like the immature brains of children.
The US team used a scanning technique known as diffusion tensor MR imaging to look at white matter in 13 Alzheimer's patients and 60 healthy people of all ages.
"When we compared 13 Alzheimer's patients' brains to 13 others of the same age with no signs of dementia, the Alzheimer's patients' brains showed significantly higher water molecule diffusion," he said.
The study could yield clues to the cause of Alzheimer's disease and lead to better diagnosis.
Richard Harvey, director of research at the UK Alzheimer's Society, said the development of novel imaging techniques is advancing our understanding of how the brain works in both health and disease.
He said the imaging method used in the study is a very new brain scanning technique, which is already throwing new light on what is happening in the brain in Alzheimer's disease.
"The key to making real advances with this new knowledge will be to understand how these changes develop as the Alzheimer's disease starts, and to work out what it means in terms of brain chemistry and function," Dr Harvey told BBC News Online.
"This would take us closer to identifying new therapies, and developing methods for monitoring treatment."
The MR scanning findings are to be presented at the American Roentgen Ray Society Annual Meeting in San Diego this week.