title: Intracranial cerebrospinal fluid distribution and its postoperative changes in normal pressure hydrocephalus.
abstract: BACKGROUND
  This study was conducted to investigate the usefulness of intracranial cerebrospinal fluid (CSF) volume measurement using MR-based methods in the management of patients with normal pressure hydrocephalus (NPH).
  
  
  METHODS
  The study group comprised 19 patients with NPH who showed a favorable outcome after ventricular shunting, 15 normal volunteers (NV), and 15 patients with cerebrovascular disease (CVD). A 3D-fast asymmetric spin echo MR imaging sequence and the region-growing method were used to extract the CSF space from MR images. Ventricular volume (VV) and intracranial CSF volume (ICV) were measured and the VV/ICV ratio was calculated in each case. In NPH patients, the CSF volume was measured again after shunting.
  
  
  RESULTS
  The mean VV and VV/ICV ratio in the NPH group (91.1 mL and 45.2%, respectively) were significantly (p < 0.01) higher than those in the NV group (26.5 mL and 13.7%) and in the CVD group (44.5 mL and 17.8%). On the other hand, mean ICV values were not significantly different among the three groups. The VV was markedly decreased postoperatively (mean -40.7%), whereas the ICV was unchanged, resulting in a marked reduction in the VV/ICV ratio (mean -39.3%).
  
  
  CONCLUSIONS
  These results suggest that patients with NPH have a unique intracranial CSF distribution, with an enlarged VV and a slightly increased ICV, resulting in a high VV/ICV ratio. Shunting led to dramatic improvement in our patients. It is likely that CSF measurement can provide valuable information in the management of patients with NPH.
authors.affiliation: Department of Neurosurgery, Koshigaya Municipal Hospital, Koshigaya City, Saitama, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Tsunoda
authors.forename: H
authors.initials: H
authors.lastname: Mitsuoka
authors.forename: H
authors.initials: H
authors.lastname: Bandai
authors.forename: H
authors.initials: H
authors.lastname: Arai
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: J
authors.initials: J
authors.lastname: Makita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D002555:Cerebrospinal Fluid; D002557:Cerebrospinal Fluid Shunts; D002561:Cerebrovascular Disorders / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome