title: Delayed neurological deficits detected by an ischemic pattern in the extracellular cerebral metabolites in patients with aneurysmal subarachnoid hemorrhage.
abstract: OBJECTIVE
  In the treatment of patients with aneurysmal subarachnoid hemorrhage (SAH), early occlusion of the aneurysm is necessary as well as monitoring and treatment of complications following the primary bleeding episode. Monitoring with microdialysis has been studied for its ability to indicate and predict the occurrence of delayed ischemic neurological deficits (DINDs) in patients with SAH.
  
  
  METHODS
  In 42 patients with aneurysmal SAH microdialysis monitoring of metabolites was performed using a 0.3-microl/minute perfusion flow over several days, and the results were correlated to clinical events and to brain infarction observed on computerized tomography scans. The microdialysis probe was inserted into the territory of the parent artery of the aneurysm. The authors defined an ischemic pattern as increases in the lactate/glucose (L/G) and lactate/pyruvate (L/P) ratios that were greater than 20% followed by a 20% increase in glycerol concentration. This ischemic pattern was found in 17 of 18 patients who experienced a DIND and in three of 24 patients who did not experience a delayed clinical deterioration. The ischemic pattern preceded the occurrence of a DIND by a mean interval of 11 hours. Maximum L/G and L/P ratios did not correlate with the presence of DIND or outcome, and there was no association between the glycerol level and subsequent brain infarction.
  
  
  CONCLUSIONS
  Microdialysis monitoring of the cerebral metabolism in patients with SAH may predict with high sensitivity and specificity the occurrence of a DIND. Whether an earlier diagnosis results in better treatment of DINDs and, therefore, in overall better outcomes remains to be proven, as it is linked to an efficacious treatment of cerebral vasospasm.
authors.affiliation: Department of Neurosurgery, Odense University Hospital, Odense, Denmark. j.skjoeth@dadlnet.dk
authors.forename: Jane
authors.initials: J
authors.lastname: Skjøth-Rasmussen
authors.forename: Mette
authors.initials: M
authors.lastname: Schulz
authors.forename: Soren Risom
authors.initials: SR
authors.lastname: Kristensen
authors.forename: Per
authors.initials: P
authors.lastname: Bjerre
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis* / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D011237:Predictive Value of Tests; D019289:Pyruvic Acid / Q000378:metabolism; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000378:metabolism / Q000601:surgery*
chemical_list: D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose; D005990:Glycerol