title: Bilateral deep brain stimulation: the placement of the second electrode is not necessarily less accurate than that of the first one.
abstract: BACKGROUND
  Deep brain stimulation (DBS) is recognized as an effective treatment for movement disorders. We recently changed our technique, limiting the number of brain penetrations to three per side.
  
  
  OBJECTIVE
  The first aim was to evaluate the electrode precision on both sides of surgery since we implemented this surgical technique. The second aim was to analyse whether or not the electrode placement was improved with microrecording and macrostimulation.
  
  
  METHODS
  We retrospectively reviewed operation protocols and MRIs of 30 patients who underwent bilateral DBS. For microrecording and macrostimulation, we used three parallel channels of the 'Ben Gun' centred on the MRI-planned target. Pre- and post-operative MRIs were merged. The distance between the planned target and the centre of the implanted electrode artefact was measured.
  
  
  RESULTS
  There was no significant difference in targeting precision on both sides of surgery. There was more intra-operative adjustment of the second electrode positioning based on microrecording and macrostimulation, which allowed to significantly approach the MRI-planned target on the medial-lateral axis.
  
  
  CONCLUSIONS
  There was more electrode adjustment needed on the second side, possibly in relation with brain shift. We thus suggest performing a single central track with electrophysiological and clinical assessment, with multidirectional exploration on demand for suboptimal clinical responses.
authors: Neurosurgery Unit, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland.
authors: Yalda
authors: Y
authors: Sadeghi
authors: Etienne
authors: E
authors: Pralong
authors: Jean-François
authors: JF
authors: Knebel
authors: François
authors: F
authors: Vingerhoets
authors: Claudio
authors: C
authors: Pollo
authors: Marc
authors: M
authors: Levivier
authors: Jocelyne
authors: J
authors: Bloch
mesh_terms: D000368:Aged; D046690:Deep Brain Stimulation / Q000295:instrumentation* / Q000592:standards*; D004567:Electrodes, Implanted / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods / Q000592:standards; D009069:Movement Disorders / Q000175:diagnosis / Q000628:therapy*; D012189:Retrospective Studies; D020531:Subthalamic Nucleus / Q000502:physiology*