title: The atypical subthalamic nucleus--an anatomical variant relevant for stereotactic targeting.
abstract: BACKGROUND
  The improvement of PD motor symptoms by DBS of the STN depends on exact targeting.
  
  
  METHODS
  A combination of MRI and multitrajectory microrecordings was used for localization of the STN in a group of 228 consecutive PD patients.
  
  
  RESULTS
  In 1% of our cases, the STN was consistently shifted in the anterior (3.3 ± 0.8mm) and medial (3.0 ± 0.9 mm) direction within the target plane, compared to controls. Adjustment of the original target coordinates after intraoperative reevaluation of the MRI and confirmation by typical subthalamic neuronal recordings along the deviant trajectory allowed the implantation of clinically effective electrodes in all cases. The relative improvement of the motor UPDRS at 6-months follow-up in patients with an atypical and typical STN was comparable.
  
  
  CONCLUSIONS
  An atypical position of the STN does not need to complicate DBS surgery, if detected by a combination of MRI-based targeting and electrophysiological guidance.
authors.affiliation: Department of Neurology, Christian-Albrechts-University, Kiel, Germany.
authors.forename: René
authors.initials: R
authors.lastname: Reese
authors.forename: Markus O
authors.initials: MO
authors.lastname: Pinsker
authors.forename: Jan
authors.initials: J
authors.lastname: Herzog
authors.forename: Fritz
authors.initials: F
authors.lastname: Wodarg
authors.forename: Frank
authors.initials: F
authors.lastname: Steigerwald
authors.forename: Monika
authors.initials: M
authors.lastname: Pötter-Nerger
authors.forename: Daniela
authors.initials: D
authors.lastname: Falk
authors.forename: Günther
authors.initials: G
authors.lastname: Deuschl
authors.forename: H Maximilian
authors.initials: HM
authors.lastname: Mehdorn
authors.forename: Jens
authors.initials: J
authors.lastname: Volkmann
mesh_terms: D015331:Cohort Studies; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010300:Parkinson Disease / Q000628:therapy*; D013238:Stereotaxic Techniques; D020531:Subthalamic Nucleus / Q000502:physiology*