A recent small feasibility study, funded by the National Institutes of Health (NIH), revealed that an implanted device that responds to brain activity may offer continuous and enhanced treatment for Parkinson’s disease (PD) symptoms in certain individuals. This innovative treatment approach, referred to as adaptive deep brain stimulation (aDBS), represents an advancement over traditional methods that have been utilized for managing PD and other neurological disorders for many years. The findings indicated that aDBS significantly outperformed standard DBS in controlling PD symptoms.
“This study represents a significant advancement towards creating a DBS system that tailors itself to the specific needs of each patient at any given moment,” explained Megan Frankowski, Ph.D., program director for NIH’s Brain Research Through Advancing Innovative Neurotechnologies® Initiative, known as The BRAIN Initiative®, which provided funding for this project. “By effectively managing lingering symptoms without aggravating others, adaptive DBS has the potential to enhance the quality of life for some individuals with Parkinson’s disease.”
Deep brain stimulation (DBS) involves using fine wires called electrodes implanted in certain areas of the brain. These electrodes deliver electrical impulses that can alleviate symptoms of neurological disorders, including PD. Unlike traditional DBS, which delivers a steady level of stimulation and can sometimes lead to adverse effects due to the varying treatment needs of the brain, aDBS leverages real-time data from the brain and employs machine learning to modify the stimulation levels according to the individual’s changing requirements.
In the study, four individuals already undergoing conventional DBS were asked to identify their most troublesome symptom that persisted despite their treatment—commonly involuntary movements or difficulty starting movement. These participants were then equipped to receive aDBS treatment in conjunction with their ongoing DBS therapy. After training the aDBS system for several months, the participants were allowed to go home, where they alternated between conventional DBS and aDBS treatments every two to seven days.
The results showed that aDBS helped alleviate each participant’s most troublesome symptom by about 50% when compared to conventional DBS. Remarkably, even though they were unaware of which treatment they were receiving at any point, three out of the four participants could often accurately identify when they were receiving aDBS due to the notable improvement in their symptoms.
This research builds on years of work led by Philip Starr, M.D., Ph.D., and colleagues at the University of California, San Francisco. In 2018, they announced the creation of an adaptive DBS system, known as a “closed loop” system, which adjusted based on brain feedback. In 2021, they reported advancements in recording brain activity in individuals during their everyday activities.
In this study, these two findings were merged, utilizing brain activity captured during daily activities to operate the aDBS system. However, because DBS treatment altered brain activity significantly, the expected signals for controlling the aDBS system became undetectable. As a result, researchers had to adopt a data-driven approach to identify alternative signals within the brains of PD patients undergoing conventional DBS treatment.
General treatment for Parkinson’s disease frequently includes the medication levodopa, which replenishes dopamine levels in the brain that have diminished due to the disorder. Since the concentration of the medication in the brain can vary—rising soon after administration and then gradually decreasing—aDBS could help stabilize these levels by adjusting stimulation according to the varying drug levels, making it potentially beneficial for patients who require high dosages of levodopa.
Despite these encouraging results, significant obstacles still exist before this therapy can become widely accessible. The initial setup of the device demands substantial expertise from skilled clinicians. Researchers anticipate a future where most operations could be managed autonomously by the device, significantly minimizing the necessity for multiple clinic visits for adjustments.
This level of automation is critical for allowing other groups to test and ultimately provide aDBS therapy in clinical environments.
“One major challenge facing DBS, even in established conditions like Parkinson’s, is accessibility—for patients in terms of location and for doctors who need specialized training to program these devices,” noted Frankowski. “If a system could locate the optimal settings at the click of a button, it would greatly broaden the reach of this treatment to more individuals.”
This research received support from the NINDS and NIH’s The BRAIN Initiative (NS10054, NS129627, NS080680, NS120037, NS131405, NS113637), along with contributions from the Thiemann Foundation and the TUYF Charitable Trust Fund.
