Cerebral Blood Flow Autoregulation in Transient Ischemic Tissue Expressed Delayed Hyperperfusion Two Days After Middle Cerebral Arterial Occlusion

Kazuhiro Nakamura¹, Yasushi Kondoh¹, Shigenori Mizusawa¹, Junko Yoshida¹, Hajime Miyata¹, Toshibumi Kinoshita¹

Strong hyperperfusion was observed in transient ischemic tissue 48-72 h after middle cerebral artery occlusion (MCAO). To investigate a physiological reason for the phenomena, we have performed experiments for revealing cerebral blood flow (CBF) autoregulation in transient ischemic tissue using a lower body negative pressure method. Using the lower body negative pressure method, we can avoid an estimation error in CASL from a blood oxygen dependent signal change. The results show CBF in ischemic tissue is higher than normal in all blood pressure range and it should indicate the autoregulatory failure of small pial artery in the ischemic tissue.