INFARCTION AFTER ANEURYSM RUPTURE DOES NOT DEPEND ON DISTRIBUTION OR CLEARANCE RATE OF BLOOD

Background and Purpose: We sought to determine the contribution of the amount, distribution, and clearance rate of extravasated blood in relation to occurrence of infarction and outcome in patients with aneurysmal subarachnoid hemorrhage. Methods: We prospectively studied 59 consecutive patients with aneurysmal subarachnoid hemorrhage admitted within 72 hours by means of serial computed tomographic scanning, close clinical observation, and assessment of outcome after 3 months. Results: Infarction occurred in 17 of the 59 patients. The arterial territories involved hardly reflected the distribution of subarachnoid blood in the basal cisterns on computed tomography, and even the side of the infarcts corresponded only weakly with the side on which most extravasated blood was seen. Infarction occurred twice as often in patients with large amounts of subarachnoid blood; this difference was not significant on its own but is in agreement with previous studies. A low clearance rate of cisternal blood was not related to the occurrence of infarction; a relation between clearance rate and poor outcome was largely explained by the amount of subarachnoid blood on the initial computed tomogram and by a low Glasgow Coma Scale score on admission. Conclusions: The fact that infarction is related to the total amount but not to the distribution or clearance rate of extravasated blood argues against a direct role of extravasated blood and in favor of systemic factors, dependent on the severity of the initial hemorrhage.