An implantable device that detects nerve signals to deliver personalized deep brain stimulation can improve the movement and sleep of people with Parkinson’s disease, a pilot trial has found.
The findings, in four patients, are the first time that adaptive deep brain stimulation (aDBS) using “closed loop” brain implant technology has been found to work in Parkinson’s patients during their daily lives.
The system was able reduce the length of motor symptoms by half compared with conventional deep brain stimulation, which is widely used in Parkinson’s but does not dynamically respond to a patient’s changing clinical or neural state.
The novel implantable device, described in Nature Medicine, uses AI-derived information to monitor brain activity and includes continuous feedback system that allows it to deliver personalized bursts of electricity.
It can work in tandem with Parkinson’s medications, providing less stimulation when the drug is active and more as it wears off, and can also be used without the adaptive mode or be switched off entirely.
“This is the future of deep brain stimulation for Parkinson’s disease,” maintained senior author Philip Starr, PhD, co-director of the Movement Disorders and Neuromodulation Clinic at UCSF.
He added: “There’s been a great deal of interest in improving DBS therapy by making it adaptive and self-regulating, but it’s only been recently that the right tools and methods have been available to allow people to use this long-term in their homes.”
Parkinson’s disease results from the loss of  dopamine-producing neurons deep inside the brain that are responsible for controlling movement and can also affect mood and sleep.
The disease, which affects approximately 10 million people across the world, is usually first treated with the medication levodopa.
But this can lead to uncontrolled movements due to excess dopamine in the brain as the drug takes effect, before causing tremors and stiffness as it wears off.
For the blinded, randomized cross-over trial Starr and team initially implanted electrodes and neurostimulators to monitor brain activity of four male patients with Parkinson’s disease, who were undergoing DBS for motor symptoms.
The participants were monitored in the clinic and at home for several days, during which time their symptoms were tracked using self-reported motor diaries and smartwatches.
This revealed brain activity signals in the subthalamic nucleus and motor cortex that were reliable biomarkers of medication fluctuations and were associated with motor symptoms.
Based on each patient’s neural signals, adaptive algorithms were tailored to each patient’s most bothersome motor symptom.
The deep brain stimulation of each participant was then personalized and outcomes compared with those from conventional deep brain stimulation.
The researchers found that adaptive deep brain stimulation reduced the duration of motor symptoms by 50% relative to clinically optimized standard stimulation, a finding that was confirmed through wearable devices.
Three of the four patients also reported improvements in quality of life.
The team concludes: “The study supports clinically impactful aDBS in [Parkinson’s disease], highlights the 18. benefit of multi-site brain recordings and at-home neural recordings paired with wearable monitors for configuring aDBS, and may inform the development of aDBS for other neuropsychiatric conditions.”
