title: Effect of Cranial Window Diameter During Deep Brain Stimulation Surgery on Volume of Pneumocephalus.
abstract: OBJECTIVE
  Successful deep brain stimulation (DBS) surgery necessitates high accuracy in targeting specific intracranial nuclei. Brain shift due to pneumocephalus can contribute to decreased accuracy. Larger burr holes and dural openings may increase pneumocephalus volume due to a greater degree of communication between the subdural space and extracranial air. The aim of this study is to determine if there is a statistically and clinically significant difference in postoperative pneumocephalus volume related to burr hole and durotomy size.
  
  
  METHODS
  DBS electrodes were surgically implanted through either large (14 mm) burr holes or small (4 mm) twist drill holes. Immediate postoperative computerized tomography (CT) scans of 165 electrode implantations in 85 patients from 2010 to 2013 were retrospectively analyzed. Student's t-test and Mann-Whitney U-test were employed with a threshold of significance set at p ≤ 0.05.
  
  
  RESULTS
  No significant difference in pneumocephalus was identified between patients who had implantation of DBS electrodes through 4 mm twist drill holes (N = 71 hemispheres, 12.84 ± 9.79 cm(3) ) and those with large 14 mm burr holes (N = 87, 11.70 ± 7.46 cm(3) , p = 0.42). Volume of pneumocephalus did not correlate with duration of surgery or patient age. The groups did not differ significantly with respect to other aspects of surgical implantation technique or surgical duration.
  
  
  CONCLUSIONS
  While identifying factors that may reduce pneumocephalus volume may be critical to improving stereotactic accuracy and targeting, the current results suggest that burr hole size may not alter the degree of brain shift.
authors.affiliation: Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Justin
authors.initials: J
authors.lastname: Sharim
authors.affiliation: Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Pezeshkian
authors.affiliation: Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Antonio
authors.initials: A
authors.lastname: DeSalles
authors.affiliation: Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Nader
authors.initials: N
authors.lastname: Pouratian
mesh_terms: D000368:Aged; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D020329:Essential Tremor / Q000628:therapy; D005260:Female; D005917:Globus Pallidus / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000628:therapy; D011007:Pneumocephalus / Q000209:etiology* / Q000473:pathology*; D011183:Postoperative Complications / Q000473:pathology*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D015898:Tomography Scanners, X-Ray Computed
keywords: Brain shift; cranial window; deep brain stimulation; pneumocephalus; retrospective study