title: Subthalamic deep brain stimulation for Parkinson's disease: correlation of active contacts and electrophysiologically mapped subthalamic nucleus.
abstract: BACKGROUND
  Subthalamic deep brain stimulation (STN-DBS) has been shown to be effective in the treatment of Parkinson's disease. The site for permanent stimulation is still in debate. This study aimed to assess the position of active contacts in relation to the subthalamic nucleus.
  
  
  METHODS
  We reviewed the location of 40 electrodes in 34 patients who underwent STN-DBS. The position of electrode was evaluated by postoperative magnetic resonance imaging (MRI). The position of active contacts was compared with the subthalamic nucleus (STN) determined by intraoperative electrophysiological mapping and postoperative MRI.
  
  
  RESULTS
  The average position of the 40 active contacts was (11.7 + or - 1.2) mm lateral, (0.6 + or - 1.3) mm anterior, and (0.7 + or - 1.4) mm vertical to the midcommissural point. The dorsal margin of the STN was (11.6 + or - 1.1) mm lateral, (0.2 + or - 1.1) mm anterior, and (1.3 + or - 1.1) mm vertical to the midcommissural point. When compared with the dorsal margin of the STN, the active contacts were located more dorsally (P = 0.033) and anteriorly (P = 0.012), no significant difference was found in the lateral direction (P = 0.107). When compared with the position of the STN, 26 (65%) of active contacts were located in the region dorsal to the STN, only 13 (32.5%) were located in the upper two-thirds portion of STN.
  
  
  CONCLUSIONS
  The site for permanent stimulation appears to be in the subthalamic region dorsal to the STN, close to the dorsal margin of the STN. Besides the dorsal portion of the STN, other structures such as fields of Forel H and zona incerta may also be involved in the therapeutic benefit of deep brain stimulation.
authors.affiliation: Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zheng
authors.forename: Yu-qing
authors.initials: YQ
authors.lastname: Zhang
authors.forename: Jian-yu
authors.initials: JY
authors.lastname: Li
authors.forename: Xiao-hua
authors.initials: XH
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Zhuang
authors.forename: Yong-jie
authors.initials: YJ
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D046690:Deep Brain Stimulation; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000473:pathology / Q000503:physiopathology*