Parkinson’s disease affects more than a million Americans and over ten million people worldwide. The condition brings tremors, slowed movement, sleep disturbances, and declining cognition. Existing treatments—medications, deep‑brain stimulation, and other invasive options—can ease symptoms but do not halt disease progression.
A multinational team led by researchers at China’s Changping Laboratory, in collaboration with Washington University School of Medicine, has identified a previously overlooked brain circuit that appears central to the disorder. The somato‑cognitive action network, or SCAN, showed a strong link to both motor and cognitive deficits. When scientists used transcranial magnetic stimulation (TMS) to target SCAN, patients improved more than twice as much as when nearby regions were stimulated.
What is SCAN and why does it matter?
The researchers examined brain‑imaging data from over 800 participants recruited across the United States and China. The cohort included people with Parkinson’s receiving deep‑brain stimulation, TMS, focused‑ultrasound therapy, or standard medication, as well as healthy volunteers and patients with other movement disorders.
Abnormal wiring uncovered
Analysis revealed that Parkinson’s brains exhibit excessive connectivity between SCAN and deeper subcortical structures that regulate emotion, memory, and movement. All four therapeutic approaches performed best when they weakened this over‑connection, allowing the brain’s action‑planning circuit to regain a more balanced rhythm.
“For decades we have focused almost exclusively on the basal ganglia,” said lead investigator Liu. “Our data suggest that Parkinson’s is a network disorder, with SCAN acting as a hyper‑connected hub that disrupts movement, thought, and bodily functions.”
Precision, non‑invasive treatment shows promise
Building on these insights, the team designed a millimetre‑accurate TMS protocol that homes in on SCAN without surgery. In a small clinical trial, 18 participants who received SCAN‑focused stimulation showed a 56 % response rate after just two weeks, compared with a 22 % response when stimulation was applied to adjacent areas—a more than two‑fold improvement.
Next steps
The investigators plan to expand the work through a partnership with Turing Medical, a WashU spin‑out. Upcoming trials will test surface electrode strips placed over SCAN to improve gait, and they will explore low‑intensity focused ultrasound as another way to modulate the network.
These early results hint at a shift from broad‑stroke interventions toward highly targeted, non‑invasive therapies that address the root network dysfunction in Parkinson’s disease.