title: Cerebral microdialysis and positron emission tomography after surgery for aneurysmal subarachnoid hemorrhage in grade I patients.
abstract: BACKGROUND
  Using cerebral microdialysis, baseline values for energy-related chemical markers have been reported in awake patients. Radionuclide studies have demonstrated a locally decreased metabolism, thought to be the result of brain retraction. These baseline values, however, may not be applicable to patients after surgical aneurysm repair following a subarachnoid hemorrhage (SAH). We assessed metabolic chemical marker levels in World Federation of Neurological Surgeons Committee (WFNS) grade I SAH patients after aneurysm surgery and compared them with previously reported baseline values.
  
  
  METHODS
  In 5 WFNS grade I SAH patients, energy-related chemical marker levels were obtained using microdialysis in the area of brain retraction after aneurysm surgery. In addition, an [(18)F]2-deoxy-d-glucose positron emission tomography (FDG-PET) was performed.
  
  
  RESULTS
  The FDG-PET showed a decrease of glucose metabolism in the frontotemporal area. Comparing the mean values for chemical markers of this study with reported baseline values, the most striking difference was a mild decrease of pyruvate and an increase of the lactate/pyruvate ratio. In individual patients, some markers indicated possible ischemia. A consistent pattern or ischemic profile for all markers, however, was not found.
  
  
  CONCLUSIONS
  FDG-PET scanning confirmed postoperative metabolic changes found in previous studies. Mean interstitial chemical marker levels ranged from normal to mildly deviant compared with reference chemical marker levels for awake patients and are likely to be applicable in SAH patients after aneurysm repair.
authors.affiliation: Department of Neurosurgery, VU University Medical Center, 1007 MB Amsterdam, The Netherlands.
authors.forename: D P
authors.initials: DP
authors.lastname: Noske
authors.forename: S M
authors.initials: SM
authors.lastname: Peerdeman
authors.forename: E F I
authors.initials: EF
authors.lastname: Comans
authors.forename: C M F
authors.initials: CM
authors.lastname: Dirven
authors.forename: D L
authors.initials: DL
authors.lastname: Knol
authors.forename: A R J
authors.initials: AR
authors.lastname: Girbes
authors.forename: W P
authors.initials: WP
authors.lastname: Vandertop
mesh_terms: D000328:Adult; D000368:Aged; D001923:Brain Chemistry; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications*; D008297:Male; D017551:Microdialysis; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012016:Reference Values; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000601:surgery*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose