title: Edema and elasticity of a fronto-temporal decompressive craniectomy.
abstract: BACKGROUND
  Decompressive craniectomy is undertaken for relief of brain herniation caused by acute brain swelling. Brain stiffness can be estimated by palpating the decompressive cranial defect and can provide some relatively subjective information to the neurosurgeon to help guide care. The goal of the present study was to objectively evaluate transcutaneous stiffness of the cranial defect using a tactile resonance sensor and to describe the values in patients with a decompressive window in order to characterize the clinical association between brain edema and stiffness.
  
  
  METHODS
  Data were prospectively collected from 13 of 37 patients who underwent a decompressive craniectomy in our hospital during a 5-year period. Transcutaneous stiffness was measured as change in frequency and as elastic modulus.
  
  
  RESULTS
  Stiffness variables of the decompressive site were measured without any adverse effect and subsequent calculations revealed change in frequency = 101.71 ± 36.42 Hz, and shear elastic modulus = 1.99 ± 1.11 kPa.
  
  
  CONCLUSIONS
  The elasticity of stiffness of a decompressive site correlated with brain edema, cisternal cerebrospinal fluid pressure, and brain shift, all of which are related to acute brain edema.
authors.affiliation: Department of Neurosurgery, Shimane University Faculty of Medicine, Izumo, Shimane, Japan.
authors.forename: Daikei
authors.initials: D
authors.lastname: Takada
authors.forename: Hidemasa
authors.initials: H
authors.lastname: Nagai
authors.forename: Kouzo
authors.initials: K
authors.lastname: Moritake
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Akiyama