Long-term outcome of young onset Parkinson's disease after subthalamic stimulation--a cross-sectional study.

Objective: Age of onset is considered a poor prognostic factor for subthalamic deep brain stimulation (STN-DBS) outcome in the case of Parkinson's disease (PD). The goal of current study is to identify the long-term impact of STN-DBS for young onset PD (YOPD) patients.
Methods: 17 YOPD patients with a mean disease onset at 32.3 years were prospectively followed up at 1, 2, 5 and 7 years after STN-DBS. Unified Parkinson's disease rating scale (UPDRS) was evaluated in 4 combinations of Med/DBS on/off.
Results: UPDRS part II-IV improved significantly 7 years after operation. While a slowly progressive worsening of levodopa response on part III, synergistic effect of medication and stimulation consistently improves motor disabilities. STN-DBS could remarkably reduce levodopa equivalent daily dose at 7 years. The morbidity rates were low. However, these patients seem to have more transient stimulation dyskinesia (47.1%) and dopamine dysregulation syndrome (11.8%) after surgery.
Conclusions: STN-DBS remains effective to improve motor disabilities over 7 years for YOPD and is a safe procedure concerning cognitive outcome and morbidity. However, stimulation dyskinesia and dopamine dysregulation syndrome deserve attention for the causal relationship between DBS surgery and behavioral outcomes.
(Copyright © 2013 Elsevier B.V. All rights reserved.)