title: Reliability of preoperative assessment of cerebrospinal fluid pressure in the management of spontaneous cerebrospinal fluid leaks and encephaloceles.
abstract: BACKGROUND
  The association of spontaneous cerebrospinal fluid (CSF) leaks with increased intracranial pressure (ICP) is well-documented. Accurate assessment of CSF pressure is paramount to optimal long-term outcomes, as failure of surgical repair or recurrent leaks may be associated with untreated intracranial hypertension. Many surgeons utilize a single opening pressure measured at the onset of the surgical procedure to determine if long-term acetazolamide or shunt placement will be necessary. However, preoperative measurement of CSF pressure may be inaccurate secondary to active drainage. The purpose of this study is to determine the accuracy of preoperative CSF pressure measurement in the setting of active CSF rhinorrhea.
  
  
  METHODS
  Retrospective review of 65 cases of endoscopic repair of active spontaneous CSF rhinorrhea performed at a tertiary care institution from 2002 to 2009. A total of 16 cases in which reliable preoperative opening pressure and 48-hour to 72-hour postoperative CSF pressures were recorded were included in the analysis. Cases in which measurements were potentially unreliable or in which acetazolamide therapy was used were excluded from analysis.
  
  
  RESULTS
  The average preoperative measurement was 26 ± 11 cm H20, and the average postoperative measurement was 15 ± 6 cm H20. The average change in CSF pressure from preoperative to postoperative was -10 ± 11 cm H20. Student paired t test was used to confirm statistical difference between the 2 sets of measurements.
  
  
  CONCLUSIONS
  Our results suggest that a single preoperative measurement of CSF pressure in patients with active CSF rhinorrhea may not be sufficiently reliable to make subsequent long-term clinical decisions.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Vijay R
authors.initials: VR
authors.lastname: Ramakrishnan
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Suh
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Chiu
authors.forename: James N
authors.initials: JN
authors.lastname: Palmer
mesh_terms: D065634:Cerebrospinal Fluid Leak; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology*; D002559:Cerebrospinal Fluid Rhinorrhea / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D004677:Encephalocele / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D019586:Intracranial Hypertension / Q000175:diagnosis; D008297:Male; D011182:Postoperative Care / Q000379:methods; D011300:Preoperative Care / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies