Parkinson’s Disease: Brain Network Identified for New Treatments
A newly identified brain network is offering a more precise understanding of Parkinson’s disease, a progressive neurological disorder impacting over 1 million Americans and more than 10 million people worldwide. The condition is known for debilitating symptoms including tremors, movement difficulties, sleep disturbances and cognitive impairments.
Unveiling the Somato-Cognitive Action Network
For decades, Parkinson’s disease has been primarily associated with motor deficits. However, research led by China’s Changping Laboratory, in collaboration with Washington University School of Medicine in St. Louis and others, points to a broader network dysfunction as the root cause. This network, known as the somato-cognitive action network (SCAN), was first described in Nature in 2023.
How SCAN Functions
SCAN resides within the motor cortex, the brain region controlling body movements. It’s responsible for translating action plans into movements and processing feedback on those actions. Researchers discovered that Parkinson’s disease is characterized by hyperconnectivity between SCAN and the subcortex, the area governing emotion, memory, and motor control.
New Approaches to Treatment
Current treatments, including long-term medication and deep brain stimulation (DBS), focus on alleviating symptoms but do not halt the disease’s progression. This new research suggests a more targeted approach may be possible. Targeting SCAN with an experimental therapy called transcranial magnetic stimulation (TMS) showed promising results.
TMS and SCAN Targeting
In a clinical trial, 18 patients receiving SCAN-targeted TMS experienced a 56% response rate after two weeks. This is a 2.5-fold increase in efficacy compared to a control group of 18 patients receiving stimulation in adjacent brain areas. The study, published in Nature, suggests that personalized, precise targeting of SCAN could lead to more successful treatment outcomes.
According to Nico U. Dosenbach, a 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.” He also suggests that changing activity within SCAN “could slow or reverse the progression of the disease, not just treat the symptoms.”
What’s Next?
Researchers are exploring further applications of SCAN-targeted therapies. Clinical trials are planned with Turing Medical, a WashU Medicine startup, to test a noninvasive treatment for gait dysfunction using surface electrode strips. Investigations are also underway to modulate SCAN with low-intensity focused ultrasound, another noninvasive technique. These approaches could allow for earlier intervention than current DBS procedures, which require brain surgery.
Frequently Asked Questions
What are the typical symptoms of Parkinson’s disease?
Parkinson’s disease is characterized by debilitating symptoms such as tremors, movement difficulties, sleep disturbances, and cognitive impairments.
What is the somato-cognitive action network (SCAN)?
SCAN is a brain network located within the motor cortex responsible for turning action plans into movements and receiving feedback on how those plans are executed.
How did TMS targeting SCAN improve symptoms?
In a clinical trial, patients receiving SCAN-targeted TMS showed a 56% response rate after two weeks, a 2.5-fold increase in efficacy compared to stimulation of adjacent brain areas.
As research continues, could a deeper understanding of the SCAN network ultimately lead to a cure for Parkinson’s disease?