Delayed neurological deficits detected by an ischemic pattern in the extracellular cerebral metabolites in patients with aneurysmal subarachnoid hemorrhage

Object. 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-µl/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 expe...