Abnormal hyperactivation in the brain may be an early biomarker of Alzheimer’s disease

Extremely hyperactive areas in the brain may help better predict the onset of Alzheimer’s disease, according to the findings of a research team led by Université de Montreal professor of psychology Sylvie Belleville, scientific director of the Institut universitaire de gériatrie research center of Montreal.

Hyperactivation could be an early biomarker of Alzheimer’s disease, the researchers say in their study published today in Alzheimer’s & Dementia: Diagnosis, Diagnosis & Diagnosis, co-authored with Belleville and Nick Corriveau-Lecavalier, a doctoral student she leads.

Worried about their memory

In their research, the team found a major stimulus in some brain areas in people who had not yet been diagnosed with Alzheimer’s but were concerned about their memory and exhibited risk factors for the disease.

The study marks an important milestone in this area of ​​research, as a large mass of Alzheimer’s-prone regions was observed as evidenced by magnetic resonance imaging (fMRI) imaging in people without clinical symptoms. and before the onset of mental disorders detected by routine tests.

This study shows that abnormal activity in these areas could be observed several years before it is confirmed. “

Sylvie Belleville, Professor of Psychology, University of Montreal

This finding is essential for the advancement of knowledge about the disease., She continued.

“Alzheimer’s disease is advanced and may appear in the brain 20 to 30 years before being diagnosed. So it’s very important to identify bioomarkers – that is, physical and recognizable signs of the disease – and gain a better understanding. on the initial effects on the brain. Hyperactivation may therefore be one of the first signs of Alzheimer’s disease. “

Invertebrate U shape

The team noticed that as the disease progresses, neuronal activity follows an inverted U-shaped pathway. In fact, activity in some areas of the brain in the early stages of Alzheimer’s may increase dramatically before the neuronal loss caused by the disease leads to a marked decrease in activity.

“This form may be part of the basic process of pathology and help doctors to determine the extent of the disease,” explained Corriveau-Lecavalier, the study’s first author. “When combined with other symptoms such as blood work and mental tests, this type of neuroimaging study may help with possible earlier detection. “

For their study, the team used data from the Consortium for early detection of Alzheimer’s disease to study brain activity in groups of people at high risk for developing Alzheimer’s disease who had achieved memory function. while scanned by fMRI. One group consisted of 28 people who were concerned about their memory but did not show mental deficits on traditional clinical trials. In the other group were 26 people with weak mental health problems.

The researchers found that those in the first group, or those with memory complaints but who did not show reasonable mental deficits, had high functional levels in several key areas of the brain affected by Alzheimer’s disease. Individuals with debilitating mental disorders, who are thought to be at a more advanced stage of the disease, tended to show less activity in these brain regions.