Subjective Outcomes of Subthalamic Nucleus Deep Brain Stimulation in Parkinson’s Disease: Insights from Patients and Caregivers

Abstract

Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective intervention for managing Parkinson’s disease (PD) refractory to optimal medical therapy. However, conventional clinical scales often overlook subjective outcomes perceived by patients and caregivers. This study aimed to assess these perceptions using a structured questionnaire featuring 18 items evaluating motor and non-motor outcomes, rated on a visual analog scale (VAS, 0–100), where 0 = no perceived change and 100 = maximum perceived magnitude of change compared to the pre-DBS state. Participants were asked to indicate separately whether the reported change represented improvement or deterioration for directional clarity of the VAS score. This retrospective, cross-sectional pilot study evaluated long-term outcomes following DBS at variable postoperative intervals, with an inherent risk of recall bias. Thirty-one patients with idiopathic PD who had undergone STN-DBS at least one year earlier were interviewed along with their primary caregivers. Treating neurologists also provided independent assessments. While 67.7% of patients reported initial motor improvement, 45.2% retained an overall improvement in clinical course over time. Significant improvements were observed in OFF-phase duration and daily functioning in 77.4% and 61.3% of patients, respectively. Caregivers reported perceived declines in cognition, psychiatric symptoms, and speech clarity in 58.1%, 54.8%, and 71% of participants, respectively. A significant observable difference was noted between neurologist-rated global improvement (90.3%) and caregiver-reported outcomes (67.7%). These findings highlight that integrating patient and caregiver perspectives may enhance comprehensive post-DBS care.