🧠 A method to detect Alzheimer's years in advance

Detecting Alzheimer's well before memory problems become apparent: a research team now provides elements to achieve this by directly scrutinizing the activity produced by our brain.

Scientists from Brown University have identified a characteristic trace within the signals emitted by the brain. Observed in individuals with mild cognitive impairment, this signature seems to highlight those who will develop Alzheimer's disease within the following thirty months. This method, which relies on magnetic recording of brain activity, offers an innovative and direct study angle.


The novelty of this discovery stems from an unprecedented analytical approach. Instead of averaging the signals, the designed computer tool isolates brief episodes of neuronal activity. It thus enables a fine measurement of their number, length, and amplitude. This technique, already proven, has highlighted marked differences within a brain frequency associated with memory.

In participants whose condition deteriorated into Alzheimer's, these neuronal episodes, called beta events, were fewer, shorter, and of reduced intensity. These changes were recorded approximately thirty months before the diagnosis established by doctors. The researchers' ambition is to isolate a more immediate indicator of neuronal response to pathological mechanisms.

This breakthrough outlines practical applications for the medical field. After validation by complementary work, the procedure could be used by clinicians for extremely early detection. It would also offer the possibility to assess the effectiveness of treatments by checking if brain activity returns to normal. These results are published in the journal Imaging Neuroscience.

The team is now continuing its investigations to understand the origin of this unusual signal. By simulating what is lacking in the brain, the goal is to determine targets for new treatments.

What are brain oscillations and frequency bands?

Our brain is the seat of constant and rhythmic electrical activity. These rhythms, or oscillations, are the result of the synchronous activity of large groups of neurons. They are classified into different frequency bands, named by Greek letters, each associated with specific mental states or functions.

The beta band, which is typically between 12 and 30 Hertz, is particularly interesting. It is often linked to an active awake state, when we are focused, engaged in a cognitive task, or actively processing information. It plays an important role in motor control and executive functions, like planning.

Oscillations are not static; their power, frequency, and duration change depending on what we are doing or thinking. Disturbances in these rhythms can reflect underlying dysfunctions. For example, abnormally weak or disorganized beta activity can indicate problems in the neural circuits involved in memory.

The study of brain oscillations thus provides valuable clues about the health and functioning of our gray matter. By analyzing these signals, scientists can identify early markers of various neurological conditions, well before the appearance of clear clinical symptoms.