title: Deep brain stimulation of pallidal versus subthalamic for patients with Parkinson's disease: a meta-analysis of controlled clinical trials.
abstract: BACKGROUND
  Parkinson's disease (PD) is a common neurodegenerative disorder that affects many people every year. Deep brain stimulation (DBS) is an effective nonpharmacological method to treat PD motor symptoms. This meta-analysis was conducted to evaluate the efficacy of subthalamic nucleus (STN)-DBS versus globus pallidus internus (GPi)-DBS in treating advanced PD.
  
  
  METHODS
  Controlled clinical trials that compared STN-DBS to GPi-DBS for short-term treatment of PD in adults were researched up to November 2015. The primary outcomes were the Unified Parkinson's Disease Rating Scale Section (UPDRS) III score and the levodopa-equivalent dosage (LED) after DBS. The secondary outcomes were the UPDRS II score and the Beck Depression Inventory (BDI) score.
  
  
  RESULTS
  Totally, 13 studies containing 1,148 PD patients were included in this meta-analysis to compare STN-DBS versus GPi-DBS. During the off-medication state, the pooled weighted mean difference (WMD) of UPDRS III and II scores were -2.18 (95% CI =-5.11 to 0.74) and -1.96 (95% CI =-3.84 to -0.08), respectively. During the on-medication state, the pooled WMD of UPDRS III and II scores were 0.15 (95% CI =-1.14 to 1.44) and 1.01 (95% CI =0.12 to 1.89), respectively. After DBS, the pooled WMD of LED and BDI were -254.48 (95% CI =-341.66) and 2.29 (95% CI =0.83 to 3.75), respectively.
  
  
  CONCLUSIONS
  These results indicate that during the off-medication state, the STN-DBS might be superior to GPi-DBS in improving the motor function and activities of daily living for PD patients; but during the on-medication state, the opposite result is observed. Meanwhile, the STN-DBS is superior at reducing the LED, whereas the GPi-DBS shows a significantly greater reduction in BDI score after DBS.
authors.affiliation: Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, People's Republic of China.
authors.forename: Fan
authors.initials: F
authors.lastname: Xu
authors.affiliation: Department of Neurology, Binzhou Medical University Hospital, Binzhou, Shandong, People's Republic of China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Ma
authors.affiliation: Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, People's Republic of China.
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, People's Republic of China.
authors.forename: Zhihai
authors.initials: Z
authors.lastname: Qiu
authors.affiliation: Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
keywords: Parkinson disease; deep brain stimulation; globus pallidus internus; subthalamic nucleus