November 2, 2017
For the first time, researchers have convincing evidence of where exactly Alzheimer’s starts in the brain. A team from Lund University in Sweden has found that the first signs of Alzheimer’s start in a part of the brain known as the default mode network.
The default mode network is located in the inner part of the brain, and is most active when a person is awake, but unstimulated by outside forces—for example, when daydreaming. It’s active when a person is thinking about themselves, others, the past or planning for the future.
“A big piece of the puzzle in Alzheimer’s research is now falling into place. We previously did not know where in the brain the earliest stages of the disease could be detected. We now know which parts of the brain are to be studied to eventually explain why the disease occurs”, said Sebastian Palmqvist, associate professor at Lund University and physician at Skåne University Hospital in Sweden.
The study is based on data from almost 800 people from the U.S. and Sweden who are at-risk for the disease. Their risk was evaluated by a test that combines cerebrospinal fluid test results with PET scan brain imaging to determine how quickly and how much beta-amyloid was accumulating in their brains. They were followed for two years and compared with a control group that did not have signs of Alzheimer’s.
The study is significant because this information can help scientists better target the drug before patients show symptoms. The accumulation of beta-amyloid in the brain can begin decades before patients show symptoms. “Now that we know where Alzheimer’s disease begins, we can improve the diagnostics by focusing more clearly on these parts of the brain, for example in medical imaging examinations with a PET camera,” said Oskar Hansson, professor at Lund University, and medical consultant at Skåne University Hospital.
The study was published in Nature Communications and a full write-up can be found here.