A large international team of researchers has found that deep brain stimulation in the subthalamic nucleus continues to help people with Parkinson’s disease even five years after treatment.
This therapy not only improves movement but also helps patients do everyday activities with less medication.
Parkinson’s disease affects a person’s ability to move and be independent. It gradually worsens over time. Many people with the disease have problems like tremors, stiffness, slow movement, and difficulty walking.
Treatment usually involves medications like levodopa, but these drugs can have side effects, including uncontrolled movements (called dyskinesia).
Deep brain stimulation (DBS) is a surgical treatment where doctors implant small electrodes in specific areas of the brain. These electrodes send electrical impulses that help control abnormal brain activity. In this study, the researchers focused on the subthalamic nucleus, a region in the brain involved in movement control.
The INTREPID study included 191 patients from 23 movement disorder centers across the U.S. All participants had moderate to severe Parkinson’s disease. At the start, participants were randomly assigned in a 3:1 ratio to receive either active or subtherapeutic DBS settings for 12 weeks.
After this initial phase, all participants received regular DBS for the next five years. The team tracked their progress using the Unified Parkinson’s Disease Rating Scale (UPDRS), a tool used to measure different symptoms of Parkinson’s.
After one year of treatment, patients showed big improvements in motor function. On average, their motor scores improved by 51% in the medication-off, stimulation-on condition.
Even after five years, their scores remained 36% better than at the beginning. Activities of daily living also improved, with a 41% improvement in year one and 22% in year five.
Dyskinesia was reduced significantly, dropping 75% in the first year and remaining low five years later. Patients also needed 28% less Parkinson’s medication, and this reduction held steady over time.
Some symptoms responded better than others. Tremors and stiffness improved the most and remained better after five years. Slowness of movement and walking also improved at first, but these benefits decreased with time. Quality-of-life improvements were stronger in the first year and less noticeable by year five.
Satisfaction with the treatment was high. Across five years, 94% of patients were satisfied with their DBS. Surveys showed that 87% of patients, 93% of doctors, and 82% of caregivers noticed improvement, and these numbers stayed high over time.
As with any surgical treatment, there were some risks. Infections were the most common serious issue, affecting nine people, eight of whom needed surgery. Other serious problems included a suicide attempt linked to the procedure, two brain bleeds, four seizures, and ten deaths. However, none of the deaths were caused by the study or the treatment itself.
The researchers concluded that deep brain stimulation of the subthalamic nucleus provides long-term benefits for people with Parkinson’s. It helps improve movement, reduces the need for medication, and enhances daily living, though some effects may lessen over time. Still, the treatment offers meaningful support for patients living with a progressive disease.
If you care about Parkinson’s disease, please read studies about how to improve walking in people with Parkinson’s disease and Scientists find causes of Parkinson’s and Lewy body dementia.
For more about Parkinson’s disease, please read studies These common drugs may increase risk of Parkinson’s disease and Researchers find an important cause of Parkinson’s disease.
The study is published in JAMA Neurology.
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