New electrical signal in the brain may help better treat Parkinson's disease

A team of researchers from the Max Planck Institute for Neuroscience and leading neurological centers in Europe has identified a new electrical signature of Parkinson's disease. The discovery could lead to the development of more precise methods of deep brain stimulation—a therapy that alleviates the symptoms of the disease. The study results were published in the journal eBioMedicine.

For years, scientists have been trying to understand the changes occurring in the brains of people with Parkinson's disease , especially when characteristic movement disorders appear. A method already used in treatment has proven helpful in these studies: deep brain stimulation (DBS), which involves implanting electrodes in the brain that send electrical impulses that alleviate symptoms.

These same electrodes enable the recording of electrical signals from otherwise inaccessible areas of the brain . This allows scientists to track how neuronal activity changes during the course of the disease.

As part of an international project, researchers from the Max Planck Institute collaborated with centers in Berlin, Düsseldorf, London, and Oxford. The goal was to understand so-called beta waves—rhythmic electrical signals that oscillate at a frequency of about 20 times per second, which are believed to be associated with the severity of motor symptoms in patients.

As Vadim Nikulin from the Max Planck Institute explained, previous studies have yielded very different results.

To test this, the researchers combined data from over 100 patients—significantly more than in previous studies—and conducted a unified analysis. The result? A link between beta waves and symptoms does exist, but it's weaker than previously thought.

The team led by Moritz Gerster, however, discovered something much more important. Previous studies often failed to distinguish between two types of brain activity—rhythmic and non-rhythmic. However, as Gerster vividly explains, "you can imagine the brain as a concert hall full of musicians before a rehearsal. Some groups play together, creating a distinct rhythm. Others practice independently, blending into the non-rhythmic 'noise.' If we only measure overall loudness, we lose this distinction."

New analysis methods have allowed us to separate "rhythm" from "neural noise." This distinction has proven to better explain the severity of disease symptoms.

The diversity of patients in terms of age, disease duration, and symptoms posed a significant research challenge. It was also impossible to compare the results with a healthy control group, as deep brain stimulation is only used in patients with severe disease .

But researchers found a clever solution: they took advantage of the fact that Parkinson's disease often affects one side of the body more severely than the other.

Analysis revealed that in the more affected hemisphere of the brain , non-rhythmic, noise-like activity was significantly higher . This suggests increased neuronal activation—a phenomenon previously observed in animal models of Parkinson's disease.

The discovered activity pattern could be used in the future to more precisely control deep brain stimulation. Instead of continuously sending electrical impulses, the device could respond only when it detects a characteristic signal of disturbed neural activity.

The first "intelligent" stimulators capable of such real-time operation already exist . Now, scientists want to test whether the newly discovered electrical signature will prove useful in clinical practice. If so, it could represent a breakthrough in therapy—one that is more precise, effective, and tailored to each patient's individual brain rhythm.