A fresh approach to brain stimulation could give people living with Parkinson’s disease better control over their symptoms and halve the duration of those that bother them the most, experts said.
Deep brain stimulation (DBS) is now a mainstream treatment for people with Parkinson’s and can help with symptoms such as stiffness, slowness and tremors.
The approach involves implanting fine electrodes in the brain to provide electrical stimulation to specific areas that control movement.
Currently, this stimulation is set at a constant level, regardless of what the patient is doing, or the severity of their symptoms. As a result, the technique can result in either understimulation, leading to a breakthrough of symptoms, or overstimulation, leading to erratic movements.
Now experts say a major step has been taken toward improving the technique by allowing the level of stimulation to be automatically adjusted in response to a patient’s needs, based on real-time signals in the brain.
The team behind the work say further trials are needed to confirm the results of the pilot study, adjustments are required to make it feasible for routine clinical practice, and clinicians will need training. However, they say the technology – known as “customizable” DBS – could become widespread within a matter of years, with costs expected to be similar to traditional DBS.
“Once these challenges are addressed, I am very optimistic that adaptive DBS will be a highly effective alternative to standard DBS for [Parkinson’s] and possibly other neurological and psychiatric conditions, providing more stable and personalized symptom control, with the potential to significantly improve patient outcomes,” says Dr. Carina Oehrn of the University of California, San Francisco, the lead author of the research.
Writing in the journal Nature Medicine, Oehrn and colleagues describe how the pilot study involved four men with Parkinson’s who were implanted with a DBS device provided by a research company.
“This device can sense brain activity and provide stimulation at the same time. Our job was to create the algorithms for the software that runs on this device,” Oehrn said.
The team discovered that an increase in a specific type of brain signal was associated with rising levels of dopamine as the participants’ medication kicked in, and an alleviation of their motor symptoms.
Oehrn said this allowed the team to create algorithms that could increase DBS stimulation when this signal was low and decrease it when this signal was high.
The team customized the algorithms for each individual and their most troublesome symptom, resulting in a system that continuously monitored participants’ brain signals and automatically adjusted the electrical stimulation in response to their needs.
The four participants received traditional DBS and this new approach for one month each, but were not told which technique was being used.
The results show that participants spent about 50% less waking time experiencing their most bothersome symptom when they received adaptive DBS compared to traditional DBS, while three of the four reported having a better quality of life.
The team says medication will still be needed along with adaptive DBS, although possibly at lower doses.
“Medication is often needed to support mood as well as movement in Parkinson’s disease, and therefore should not be stopped completely,” said Dr. Simon Little, another author of the study, also from the University of California, San Francisco.
Claire Bale, the associate director of research at Parkinson’s UK, welcomed the research.
“Current DBS can be life-changing, but this major step forward could help manage the varying symptoms people experience and reduce the number of side effects,” she said.
However, Bale said the study involved only a small number of participants.
“The promising results support the need for larger clinical trials to confirm the therapy’s safety and efficacy and provide the evidence needed for ‘adaptive’ DBS to become a much-needed, approved new treatment for people with Parkinson’s,” she added.
