Activities of Daily Living and Their Relationship to Health-Related Quality of Life in Patients with Parkinson Disease After Subthalamic Nucleus Deep Brain Stimulation

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) can reduce motor symptoms in patients with Parkinson disease (PD) and improve their health-related quality of life (HRQoL). The effect of STN DBS on activities of daily living (ADL), an important component of quality of life, is poorly understood. We aimed to investigate effects of STN DBS on HRQoL and ADL in patients with PD. METHODS: HRQoL and ADL were assessed using the following disease-specific and generic questionnaires at baseline and 3, 6, and 12 months after surgery: the Parkinson's Disease Questionnaire 39 (PDQ-39), the Short-Form 36 health survey questionnaire, the World Health Organization Quality of Life Scale-Brief version, the Unified Parkinson's Disease Rating Scale part II, the ADL scale, and the Instrumental Activities of Daily Living scale. RESULTS: We reported significant early improvements (3 months) in the HRQoL and ADL, and these benefits increased over time (6 months); however, further improvement between 6 and 12 months was nonsignificant. Two PDQ-39 subdomains (social support and communications) and a Short-Form 36 health survey questionnaire subdomain (social functioning) showed declines after surgery. Changes in the Instrumental Activities of Daily Living scale were significantly correlated with changes in the PDQ-39 summary index and other PDQ-39 subdomains, including mobility, emotional well-being, social support, and cognition, at all follow-up points. CONCLUSIONS: STN DBS caused a marked improvement in HRQoL at 3 and 6 months; however, HRQoL remained stable at the 12-month postoperative follow-up. Moreover, we have shown a significant correlation between ADL performance and HRQoL after STN DBS.