Brain Network Discovery Offers Latest Hope for Parkinson’s Disease Treatment
Parkinson’s disease, a progressive neurological disorder affecting over 1 million individuals in the U.S. And more than 10 million worldwide, is characterized by debilitating symptoms including tremors, movement difficulties, sleep disturbances, and cognitive impairments. While current treatments, such as long-term medication and deep brain stimulation (DBS), can manage symptoms, they do not halt disease progression or offer a cure. However, a new international study has identified a key brain network—the somato-cognitive action network (SCAN)—that appears to be central to the development of Parkinson’s, potentially paving the way for more effective, precision treatments.
Identifying the Root of Parkinson’s: The SCAN Network
The study, led by China’s Changping Laboratory in collaboration with Washington University School of Medicine in St. Louis, published in Nature on February 4, 2026, redefines the neurological basis of Parkinson’s disease. Researchers found that targeting the SCAN with a non-invasive therapy called transcranial magnetic stimulation (TMS) more than doubled symptom improvement in a small group of patients compared to TMS applied to surrounding brain areas.
The SCAN, first described by WashU Medicine researchers in 2023, lies within the motor cortex—the brain region controlling body movements—and is responsible for translating action plans into movements and processing feedback on their execution. According to co-author Nico U. Dosenbach, MD, PhD, the David M. & Tracy S. Holtzman Professor of Neurology at WashU Medicine, “This work demonstrates that Parkinson’s is a SCAN disorder, and the data strongly suggest that if you target the SCAN in a personalized, precise manner you can treat Parkinson’s more successfully than was previously possible.”
How SCAN Dysfunction Contributes to Parkinson’s Symptoms
Given the wide range of symptoms associated with Parkinson’s—affecting not only movement but also digestion, sleep, cognition, and motivation—researchers hypothesized that dysfunction within the SCAN, which links cognitive processes with movement, could explain the disease’s diverse manifestations.
Analysis of brain imaging data from over 800 participants, including those with Parkinson’s undergoing DBS or non-invasive treatments like TMS, focused ultrasound stimulation, and medication, revealed a key characteristic of the disease: hyperconnectivity between the SCAN and the subcortex, the brain region responsible for emotion, memory, and motor control. The study found that all four therapies tested were most effective when they reduced this hyperconnectivity, normalizing activity within the action-planning circuit.
Hesheng Liu, the study’s senior author, explained that for decades, Parkinson’s has been primarily associated with motor deficits and the basal ganglia. “Our work shows that the disease is rooted in a much broader network dysfunction. The SCAN is hyperconnected to key regions associated with Parkinson’s disease, and this abnormal wiring disrupts not only movement but also related cognitive and bodily functions.”
Precision Treatment with Targeted TMS
Building on this insight, researchers developed a precision treatment system capable of targeting the SCAN non-invasively with millimeter accuracy. In a clinical trial, 18 patients receiving SCAN-targeted TMS showed a 56% response rate after two weeks, compared to a 22% response rate in a control group of 18 patients receiving stimulation in adjacent brain areas—a 2.5-fold increase in efficacy.
Dosenbach notes that non-invasive treatments like TMS could allow for earlier intervention. “With noninvasive treatments, we could start treating with neuromodulation much earlier than is currently done with DBS” given that they don’t require brain surgery.
Future Directions and Ongoing Research
Researchers are continuing to investigate the SCAN to understand how different components of the network affect specific Parkinson’s symptoms. Dosenbach is planning clinical trials with Turing Medical, a WashU Medicine startup he co-founded, to test a non-invasive treatment using surface electrode strips placed over SCAN regions to address gait dysfunction in Parkinson’s patients. He also plans to explore modulating the SCAN with low-intensity focused ultrasound, a non-invasive technique for altering brain activity using acoustic energy.
This research represents a significant step forward in understanding and treating Parkinson’s disease, offering hope for more effective therapies that target the underlying neurological causes of the condition.