title: Avoiding the ventricle: a simple step to improve accuracy of anatomical targeting during deep brain stimulation.
abstract: OBJECTIVE
  The authors examined the accuracy of anatomical targeting during electrode implantation for deep brain stimulation in functional neurosurgical procedures. Special attention was focused on the impact that ventricular involvement of the electrode trajectory had on targeting accuracy.
  
  
  METHODS
  The targeting error during electrode placement was assessed in 162 electrodes implanted in 109 patients at 2 centers. The targeting error was calculated as the shortest distance from the intended stereotactic coordinates to the final electrode trajectory as defined on postoperative stereotactic imaging. The trajectory of these electrodes in relation to the lateral ventricles was also analyzed on postoperative images.
  
  
  RESULTS
  The trajectory of 68 electrodes involved the ventricle. The targeting error for all electrodes was calculated: the mean +/- SD and the 95% CI of the mean was 1.5 +/- 1.0 and 0.1 mm, respectively. The same calculations for targeting error for electrode trajectories that did not involve the ventricle were 1.2 +/- 0.7 and 0.1 mm. A significantly larger targeting error was seen in trajectories that involved the ventricle (1.9 +/- 1.1 and 0.3 mm; p < 0.001). Thirty electrodes (19%) required multiple passes before final electrode implantation on the basis of physiological and/or clinical observations. There was a significant association between an increased requirement for multiple brain passes and ventricular involvement in the trajectory (p < 0.01).
  
  
  CONCLUSIONS
  Planning an electrode trajectory that avoids the ventricles is a simple precaution that significantly improves the accuracy of anatomical targeting during electrode placement for deep brain stimulation. Avoidance of the ventricles appears to reduce the need for multiple passes through the brain to reach the desired target as defined by clinical and physiological observations.
authors.affiliation: Unit of Functional Neurosurgery, Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London. l.zrinzo@ion.ucl.ac.uk
authors.forename: Ludvic
authors.initials: L
authors.lastname: Zrinzo
authors.forename: Arjen L J
authors.initials: AL
authors.lastname: van Hulzen
authors.forename: Alessandra A
authors.initials: AA
authors.lastname: Gorgulho
authors.forename: Patricia
authors.initials: P
authors.lastname: Limousin
authors.forename: Michiel J
authors.initials: MJ
authors.lastname: Staal
authors.forename: Antonio A F
authors.initials: AA
authors.lastname: De Salles
authors.forename: Marwan I
authors.initials: MI
authors.lastname: Hariz
mesh_terms: D002552:Cerebral Ventricles; D015331:Cohort Studies; D046690:Deep Brain Stimulation / Q000295:instrumentation*; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009069:Movement Disorders / Q000473:pathology / Q000601:surgery*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D016896:Treatment Outcome