Long-Term Impact of Subthalamic Nucleus Deep Brain Stimulation on Quality of Life in Parkinson Disease

A recent trial published in JAMA Network Open found that patients with advanced Parkinson disease (PD) who received subthalamic nucleus (STN-DBS) had stable quality of life (QOL) at their 5-year follow-up, primarily due to improved mobility.  

While STN-DBS is a proven treatment for improving quality of life, nonmotor symptoms, and motor symptoms in patients with advanced PD, there are conflicting results on quality-of-life outcomes for long-term studies studying positive effects of STN-DBS compared to medication alone on motor complications up to 5 years after surgery.  

The reported study is a 1- and 5-year follow-up of 2 arms, STN-DBS and MED, in the Non-Motor International Longitudinal Study (NILS). A total of 167 patients were enrolled in the study, with 108 patients included in the final analysis after excluding 2 patients who switched treatment arms. The STN-DBS group underwent surgery based on international guidelines and selection criteria, while the MED group consisted of patients with advanced PD who preferred non-surgical pharmacotherapy. Patients in the STN-DBS group could switch off neurostimulation during the study, while patients in the MED group could choose to undergo DBS. Only patients in the MED group with 5-year follow-up assessments of quality of life were included in this analysis to serve as a control group for assessing the long-term clinical efficacy of STN-DBS. 

Assessments included:  

• Parkinson’s Disease Questionnaire 8 (PDQ-8) 
• Unified PD Rating Scale–motor examination 
• Scales for Outcomes in PD–activities of daily living (ADL) and motor complications  
• Levodopa-equivalent daily dose.  

Within-group longitudinal outcome changes, between-group differences, and correlations of change scores were analyzed, said researchers.  

Of the total 108 patients included, the mean age was 63.7 years. Most of the participants were male, accounting for 61.1% of the study population. After a 5-year follow-up, it was observed that PDQ-8 and ADL worsened only in the MED group. On the other hand, both outcomes remained stable in the STN-DBS group. The changes in PDQ-8 and ADL showed a moderate correlation. Notably, the outcomes for motor complications, mobility, and levodopa-equivalent daily dose reduction were favorable in the STN-DBS group compared to the MED group. 

“This study provides evidence of differences in QOL outcomes at 5-year follow-up between STN-DBS (stable) and MED (worsened), mainly driven by the favorable effect of STN-DBS on mobility (class IIb evidence),” said researchers. “The association between changes in QOL and ADL, but not motor impairment or complications, highlights the relative importance of ADL outcomes for long-term DBS assessments.”  

Reference

Jost ST, Aloui S, Evans J, et al. Neurostimulation for advanced Parkinson Disease and quality of life at 5 years: A nonrandomized controlled trial. JAMA Netw Open. 2024;7(1):e2352177. doi:10.1001/jamanetworkopen.2023.52177