Could a Newly Discovered Brain Network Explain Parkinson’s Disease?
Yes. A large international study of 863 patients found that a brain network called the somato-cognitive action network (SCAN) is central to Parkinson’s disease. When treatments targeted this network directly, symptom improvement more than doubled compared to targeting other brain areas.
Parkinson’s disease has always been hard to explain. It starts with sleep problems and digestive issues. Then it moves to tremors, stiffness, and trouble walking. It even affects thinking and motivation. No single brain region can account for all of that, and that has puzzled researchers for decades.
This new study, published in Nature in February 2026, finally offers an explanation. A specific brain network, the SCAN, connects movement, thinking, organ function, and arousal all in one system. In people with Parkinson’s, this network becomes overconnected to deeper brain structures. And when treatments reduce that overconnectivity, symptoms improve.
What the Data Show
Researchers from Changping Laboratory and Washington University School of Medicine analyzed brain scans from 863 participants across multiple centers. Here is what they found:
- Network specificity: Six key brain structures involved in Parkinson’s (including the substantia nigra and subthalamic nucleus) were all more strongly connected to the SCAN than to traditional motor regions
- Overconnectivity: People with Parkinson’s showed abnormally high connectivity between the SCAN and the subcortex, which is the brain’s deep relay center
- Treatment response: When transcranial magnetic stimulation (TMS) targeted the SCAN directly, the response rate was 56% compared to just 22% when it targeted other areas, a 2.5-fold improvement
- Across therapies: Deep brain stimulation, focused ultrasound, and levodopa medication all worked by reducing that same SCAN-to-subcortex overconnectivity
How It Works
Think of the SCAN as a master switchboard. It does not control just your hand or your foot. It coordinates whole-body movement, organ function, arousal, and the motivation to act. In a healthy brain, the SCAN communicates with deeper structures at a normal level.
In Parkinson’s, the neurons that produce dopamine in the substantia nigra start to die. This causes the SCAN to overcompensate by forming too many connections with the subcortex. That excess wiring disrupts everything the SCAN controls: walking, balance, digestion, sleep, and even the drive to do things.
The breakthrough here is that every effective Parkinson’s treatment, whether it is a pill, brain surgery, magnetic stimulation, or focused ultrasound, works by dialing down that same overconnectivity.
Dr. Kumar’s Take
This is one of those studies that reframes how we think about a disease. For years, we treated Parkinson’s as a movement disorder. We targeted the motor system. But the motor system alone could never explain why people with Parkinson’s also get constipation years before tremors, or why their sleep falls apart, or why motivation drops.
The SCAN concept ties all of that together into one framework. And the treatment data is striking. Doubling the TMS response rate just by aiming at the right network is a significant finding. It suggests that many current treatments could become more effective simply by being more precisely targeted.
I would not call this a cure. But it is a genuine shift in how we understand and potentially treat this disease. The researchers themselves noted that targeting the SCAN could eventually “slow or reverse the progression of the disease, not just treat symptoms.” That is worth paying attention to.
Practical Takeaways
- If you or a family member has Parkinson’s, ask your neurologist about SCAN-targeted treatments as they become available
- TMS (transcranial magnetic stimulation) is a non-invasive option that showed strong results when aimed at the SCAN
- Current treatments like levodopa and deep brain stimulation already work partly through this mechanism, even if they were not originally designed to
- Non-motor symptoms like sleep problems and digestive issues are now understood as part of the same brain network disruption, not separate problems
- Precision brain mapping before treatment may become standard practice for improving outcomes
Related Studies and Research
Understanding brain networks is a growing area of research, especially in neurological and mental health conditions. Here are related articles from our site:
- Weakened Brain Network Connectivity in Adolescent Depression explores how disrupted brain networks contribute to mood disorders in young people
- How TMS Rewires Your Brain: The Science Behind Depression Recovery covers the same TMS technology used in this Parkinson’s study, applied to depression
- Mindfulness-Based Cognitive Therapy for Major Depressive Disorder examines another approach to changing brain network activity
- Brain Network Changes in Depression: Frontostriatal Salience Network Expansion looks at how brain networks expand abnormally in depression, similar to the overconnectivity seen in Parkinson’s
FAQs
What is the somato-cognitive action network (SCAN)?
The SCAN is a brain network discovered in recent years that coordinates whole-body movement, organ function, arousal, and behavioral motivation. It alternates with traditional motor regions along the brain’s central sulcus. Unlike regions that control specific body parts (hand, foot, mouth), the SCAN manages actions that involve the entire body.
Does this mean Parkinson’s is not really a movement disorder?
Not exactly. Parkinson’s does cause movement problems. But this study shows it is better understood as a disorder of a network that controls movement, cognition, organ function, and arousal all at once. That is why people with Parkinson’s experience such a wide range of symptoms beyond just tremors and stiffness.
Is TMS available as a treatment for Parkinson’s right now?
TMS is FDA-approved for conditions like depression, and it has been explored for Parkinson’s. However, SCAN-targeted TMS as described in this study is still in the research phase. Future clinical trials will test whether this more precise targeting can become a standard treatment option.
How many people were in this study?
The researchers analyzed brain imaging data from 863 participants across multiple research centers, including people with Parkinson’s, healthy controls, and patients with other movement disorders like essential tremor and dystonia.
Bottom Line
This Nature study represents a major shift in understanding Parkinson’s disease. By identifying the SCAN as the central network involved, researchers have explained why Parkinson’s affects so much more than just movement. They have also shown that targeting this network precisely can double treatment effectiveness. For the millions of people living with Parkinson’s worldwide, this opens the door to more effective therapies, both invasive and non-invasive, that address the full scope of the disease rather than just its most visible symptoms.
