Researchers have uncovered a major clue about what causes Parkinson’s disease, a progressive brain disorder that affects movement, sleep, and thinking.
An international team led by scientists in China and the United States has identified a specific brain network that appears to drive the core symptoms of the condition.
Their findings, published in Nature, could lead to more precise and effective treatments.
Parkinson’s disease affects more than 10 million people worldwide.
It is known for symptoms such as tremors, stiffness, slow movement, and balance problems, along with sleep disturbances and cognitive changes.
Current treatments, including medications and deep brain stimulation surgery, can ease symptoms but do not stop the disease from getting worse.
The new study points to a brain system called the somato-cognitive action network, or SCAN, as a central player in Parkinson’s disease.
This network sits in the motor cortex, the region that controls body movement, and helps turn plans into physical actions while monitoring how those actions turn out. Because Parkinson’s affects both movement and thinking, scientists suspected that problems in this network might explain the wide range of symptoms.
To investigate, researchers analyzed brain imaging data from more than 800 people, including patients with Parkinson’s disease, individuals receiving various treatments, and healthy volunteers. They discovered that in Parkinson’s patients, SCAN is overly connected to deeper brain regions involved in emotion, memory, and movement. This abnormal “hyperconnectivity” appears to disrupt the normal coordination between planning and executing actions.
Importantly, the team found that treatments worked best when they reduced this excessive connection. This was true for several different therapies, including medication, deep brain stimulation, focused ultrasound, and transcranial magnetic stimulation, a noninvasive method that uses magnetic pulses to influence brain activity.
Using this insight, researchers developed a precision approach to target the SCAN directly with transcranial magnetic stimulation. Unlike deep brain stimulation, this technique does not require surgery.
In a small clinical trial, patients who received stimulation focused on the SCAN showed more than double the improvement in symptoms compared with those who received stimulation in nearby brain areas. After two weeks of treatment, more than half of the targeted group responded positively, compared with about one-fifth of the control group.
Scientists say the discovery changes how Parkinson’s disease is understood. Instead of viewing it as a problem limited to specific brain structures, the findings suggest it involves a broader network malfunction that affects both physical and mental functions.
Researchers hope that targeting the SCAN early in the disease could slow or even alter its progression rather than simply treating symptoms. Because noninvasive therapies can be applied without surgery, they could be used earlier and more widely than current invasive treatments.
Further studies are planned to explore how different parts of the network relate to specific symptoms and to test new technologies, including ultrasound-based methods that can adjust brain activity without incisions.
The discovery offers fresh hope for people living with Parkinson’s disease. By identifying the brain circuitry behind the disorder, scientists are moving closer to treatments that address the root cause rather than just managing the effects.
