A large, multi-center study confirms that deep brain stimulation (DBS) of the subthalamic nucleus delivers long-term benefits for people with Parkinson’s disease. Results from the INTREPID trial demonstrate that DBS not only improves motor symptoms and daily living activities but also reduces the need for anti-Parkinson’s medication by nearly 30% over five years.
The study followed 191 patients across 23 U.S. movement disorder centers. Participants who received bilateral STN-DBS showed significant and sustained improvements in motor function. On the Unified Parkinson’s Disease Rating Scale (UPDRS-III), patients improved by 51% after one year and maintained a 36% improvement at year five in the “medication-off, stimulation-on” condition. Dyskinesia scores also decreased by about 70%, while gait, tremor, rigidity, and bradykinesia all showed lasting gains, though some diminished over time.
Reduced reliance on medication
DBS also allowed for a sustained 28% reduction in levodopa equivalent daily dose, lowering the burden of drug-related complications. Patient-reported satisfaction remained high: 94% were satisfied after five years, with perceived improvement rated at 87% by patients, 93% by physicians, and 82% by caregivers.
Infections were the most common device-related complication, affecting nine patients, with most requiring surgical intervention. Other serious events included isolated cases of cerebral hemorrhage, seizures, and one suicide attempt attributed to the implant procedure. Importantly, none of the ten reported deaths were linked to DBS itself.
Looking ahead
The results, published in JAMA Neurology, underline DBS as a durable treatment option for motor symptoms in Parkinson’s disease, even as the condition progresses. While improvements in motor function and reduced medication needs were sustained, quality-of-life measures such as mood, cognition, and daily living activities showed decline by year five, reflecting the broader progression of the disease.
Still, the findings highlight DBS as a cornerstone of advanced Parkinson’s care—helping patients maintain independence longer, reducing medication burden, and offering meaningful relief from motor complications.
DBS innovations
Researchers at Amsterdam UMC recently conducted a large-scale analysis of 7,766 publications, narrowing to 22 studies with data from 294 patients. Their findings show that no reliable clinical or demographic predictors currently exist to determine who benefits from DBS. According to psychiatrist-in-training Gosse Mol, excluding patients based on unproven assumptions not only limits access to care but also slows knowledge development.
Amsterdam UMC therefore advocates individualised assessment and shared decision-making, involving both clinicians and patients. The study highlights the need to revise selection criteria, potentially expanding DBS access and advancing personalised psychiatric care.
Researchers at the University of California, San Francisco have developed a machine learning–based approach to optimize deep brain stimulation (DBS) for Parkinson’s patients with advanced gait impairments. While DBS is effective for symptoms like tremor and rigidity, its effect on gait has been inconsistent.
In the study, implanted DBS devices both stimulated the brain and recorded neural activity during walking. Patients’ DBS settings were systematically adjusted, and gait performance was assessed using a new Walking Performance Index (WPI) that quantified step length, stride velocity, and arm swing.
