The Effect of Bilateral Subthalamic Nucleus Stimulation in Parkinson's Disease: Experiences From 6 Month Follow-up in Sinchon Severance Hospital

ABSTRACT

BACKGROUND: Bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) is known as an effective neurosurgical procedure for the treatment of advanced Parkinson disease (PD). Although short- and long-term effects of STN stimulation in PD are relatively well known, an interim analysis of its efficacy is essential for us to continue with this procedure in the future. We present the clinical outcome of 6 month follow-up in patients who were assessed in our hospital after bilateral STN stimulation. METHODS: Twenty-nine patients with PD treated with bilateral STN DBS were included in this study. The effect of STN DBS was assessed at 6 months after surgery, which included the followings; motor disability in 'DBS- off/on, medication-off/on' states, activity of daily living (ADL) in 'medication-off/on' states, levodopa-induced motor complication, daily levodopa and levodopa-equivalent dosage, neuropsychological assessment and quality of life. RESULTS: Nineteen patients completed the follow-up assessment. STN stimulation produced significant improvements in the motor disability score both during 'medication-off' and 'medication-on' states. The ADL score was improved only in 'medication-off' states. The amount of levodopa-induced dyskinesia and response fluctuation also significantly decreased. Scores of Korean version of Mini-mental status examination (K-MMSE), Korean version of Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K) and Beck Depression Inventory (BDI) did not change. Daily levodopa and levodopa-equivalent dosages were significantly reduced. No serious side effect was encountered. CONCLUSIONS: Bilateral STN DBS is a relatively safe and beneficial treatment for PD patients with levodopa- induced motor complications. In order to obtain a better prognosis in the future, we should assess the long-term outcome and the clinical predictive factors of STN DBS.