ZAP // Sara Moser / WashU Medicine
A newly identified brain network could be the true cause of Parkinson’s disease — and its precise targeting has just provided a significant improvement in symptom relief.
Parkinson’s disease is a progressive neurological condition that affects more than 10 million people all over the world. It causes a wide range of disabling symptoms, including tremors, movement difficulties, sleep problems and decline in cognitive abilities and memory.
Os existing treatmentssuch as long-term pharmacological therapy and deep brain stimulation (DBS), an invasive technique, can alleviate symptoms, but they do not halt the progression of the disease or provide a cure.
In a new study, an international team of researchers led by the Changping Laboratory in China, in collaboration with Washington, USA, and other institutions, identified a specific brain region linked to the central problems of Parkinson’s disease.
In , published this Wednesday in Naturethe team focused on a brain network known as somato-cognitive action network (SCAN).
When this network was stimulated through a non-invasive experimental approach called transcranial magnetic stimulation (EMT), patients recorded a improvement in symptoms greater than twice that observed when nearby brain regions were stimulated.
The study’s findings reshape how scientists understand the neurological basis of Parkinson’s and point to therapeutic strategies more accurate and potentially more effectiveexplains .
“This work demonstrates that Parkinson’s is a SCAN disturbanceand the data we obtained strongly suggests that if SCAN is stimulated in a personalized and precise way, Is it possible to treat Parkinson’s disease? with greater success than was previously possible”, states Nico U. Dosenbachresearcher at the University of Washington and co-author of the study.
“Changing the activity within SCAN could slow or reverse the progression of the disease, and not just treat the symptoms”, adds the researcher.
Sara Moser / WashU Medicine
The brain network that links thought to movement, called SCAN, was first described by WashU Medicine researchers in 2023 and identified in a new study as the neurological basis of Parkinson’s disease.
Dosenbach first described SCAN in a 2023 publication in the journal Nature. This network located in the motor cortexthe area of the brain that controls voluntary movement, and helps translate action plans into physical movement, while simultaneously monitoring the unfolding of these actions.
O Parkinson affects much more than just movementinfluencing the digestion, sleep, motivation and cognition. To investigate whether problems within SCAN could explain the disease’s overarching symptoms and offer a new therapeutic target, Dosenbach teamed up with Hesheng Liuresearcher at Changping Laboratory and lead author of the study.
To explore this hypothesis, Liu’s team analyzed several types of data from brain imaging of more than 800 participants in the United States and China.
The study included people with Parkinson’s disease receiving DBS or non-invasive therapies, such as transcranial magnetic stimulationfocused ultrasound stimulation and medications. Healthy volunteers and individuals with other movement disorders were equally included for comparison.
Abnormal brain connectivity
Researchers have discovered that Parkinson’s disease is characterized by unusually strong connections between the SCAN and the subcortexa brain region involved in emotion, memory and motor control.
Across all four treatments examined in the study, therapies worked best when reduced this excessive connectivity. In doing so, they helped restore more normal activity in the brain circuit responsible for planning and coordinating actions.
“For decades, Parkinson’s disease was mainly associated with motor deficits and deficits in the basal ganglia,” the part of the brain that controls muscle movements, Liu said.
“Our work shows that the disease is rooted in a much broader network dysfunction. 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.”
Using these findings, researchers developed a precision treatment system designed to stimulate SCAN without surgery and with precision to the millimeter. They resorted to transcranial magnetic stimulation, which delivers magnetic impulses to the brain through a device placed on the scalp.
In a clinical trial, 18 patients who received SCAN-directed stimulation had a response rate of 56% after two weeks. In comparison, only 22% of the 18 patients who received stimulation in nearby brain areas experienced improvement, which represents a 2.5 times increase in effectiveness.
“With non-invasive treatments, we could start treating with neuromodulation much earlier than is currently done with DBS“, because they do not require brain surgery, said Dosenbach.
For the future, Dosenbach plans to lead clinical trials with Turing Medical, a spin-off company from the University of Washington School of Medicine, which he co-founded.
These studies will testing a non-invasive therapy which uses surface electrode strips placed over regions of the SCAN to improve walking difficulties in people with Parkinson’s disease.
