title: Quantitative assessment of brain shifting in the late phase postevacuation in unilateral and bilateral chronic subdural hematomas.
abstract: OBJECTIVE
  Recurrence is more common in bilateral chronic subdural hematomas (CSDHs) than in unilateral. Our aim was to quantitatively compare the late phase of brain shifting postevacuation in unilateral and bilateral CSDHs.
  
  
  METHODS
  We reviewed computed tomography (CT) scans and medical records of consecutive patients with CSDHs who underwent burr hole drainage. CT scan images (preoperative and postoperative days [PODs] 30 and 60) were imported to Adobe Photoshop, and temporal and spatial changes in brain shifting between PODs 30 and 60, and also the subdural space on POD 60, were analyzed.
  
  
  RESULTS
  The bilateral group exhibited a significantly greater late phase of brain shifting than the unilateral group between PODs 30 and 60 (P < 0.001). The median late phase of brain shifting of the bilateral group was 8.9 mm (interquartile range [IQR]: 8.3-9.0 mm) between PODs 30 and 60, while that of the unilateral group was 1.8 mm (IQR: 1.3-2.5 mm).
  
  
  CONCLUSIONS
  The postevacuation late phase of brain shifting is statistically greater in bilateral CSDHs than in unilateral CSDHs, which might facilitate bridging vein tearing and consequent rebleeding. This may be one factor accounting for the higher recurrence rate of bilateral CSDHs.
authors.affiliation: a Department of Surgery, Faculty of Medicine, School of Medicine , tf:institution-nameNational Yang-Ming University , Taipei , Taiwan.|b Department of Neurosurgery, Zhong Xiao Branch, Taipei City Hospital , Taipei , Taiwan.|c Department of Biotechnology and Animal Science, College of Bioresources , National Ilan University , Yilan , Taiwan.
authors.forename: Muh-Shi
authors.initials: MS
authors.lastname: Lin
authors.affiliation: d Department of Plastic Surgery, Aesthetic Medical Center, Chang Gung Memorial Hospital , Chang Gung University College of Medicine , Taoyuan , Taiwan.
authors.forename: Cheng-Jen
authors.initials: CJ
authors.lastname: Chang
authors.affiliation: c Department of Biotechnology and Animal Science, College of Bioresources , National Ilan University , Yilan , Taiwan.
authors.forename: Chai-Ching
authors.initials: CC
authors.lastname: Lin
authors.affiliation: e Department of Mathematics , Tunghai University , Taichung , Taiwan.
authors.forename: Shuo-Tsung
authors.initials: ST
authors.lastname: Chen
authors.affiliation: f Department of Pediatrics, Faculty of Medicine, School of Medicine , National Yang-Ming University , Taipei , Taiwan.|g Department of Pediatrics, Zhong Xiao Branch, Taipei City Hospital , Taipei , Taiwan.
authors.forename: Betau
authors.initials: B
authors.lastname: Hwang
authors.affiliation: h Department of Urology, Zhong Xiao Branch, Taipei City Hospital , Taipei , Taiwan.|i Department of Urology, Faculty of Medicine, School of Medicine , National Yang-Ming University , Taipei , Taiwan.
authors.forename: Shing-Hwa
authors.initials: SH
authors.lastname: Lu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003399:Craniotomy / Q000379:methods; D004322:Drainage / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D020200:Hematoma, Subdural, Chronic / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D017063:Outcome Assessment, Health Care; D012008:Recurrence; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: CNS; CT-quantitative; brain; chronic subdural hematomas; computer applications-detection; digital radiography; modalities/techniques; recurrence