Cerebral circulation and metabolism in the acute stage of subarachnoid hemorrhage
Related Experiment Video
Updated: Oct 10, 2026

Pre-Chiasmatic, Single Injection of Autologous Blood to Induce Experimental Subarachnoid Hemorrhage in a Rat Model
Published on: June 18, 2021
T Hayashi1, A Suzuki, J Hatazawa
1Department of Surgical Neurology, Research Institute for Brain and Blood Vessels, Akita, Japan. hayashi@nsg.med.tohoku.ac.jp
Object:
The mechanism of reduction of cerebral circulation and metabolism in patients in the acute stage of aneurysmal subarachnoid hemorrhage (SAH) has not yet been fully clarified. The goal of this study was to elucidate this mechanism further.
Methods:
The authors estimated cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), O2 extraction fraction (OEF), and cerebral blood volume (CBV) preoperatively in eight patients with aneurysmal SAH (one man and seven women, mean age 63.5 years) within 40 hours of onset by using positron emission tomography (PET). The patients' CBF, CMRO2, and CBF/CBV were significantly lower than those in normal control volunteers. However, OEF and CBV did not differ significantly from those in control volunteers. The significant decrease in CBF/CBV, which indicates reduced cerebral perfusion pressure, was believed to be caused by impaired cerebral circulation due to elevated intracranial pressure (ICP) after rupture of the aneurysm. In two of the eight patients, uncoupling between CBF and CMRO2 was shown, strongly suggesting the presence of cerebral ischemia.
Conclusions:
The initial reduction in CBF due to elevated ICP, followed by reduction in CMRO, at the time of aneurysm rupture may play a role in the disturbance of CBF and cerebral metabolism in the acute stage of aneurysmal SAH.
Related Concept Videos
Hemorrhagic Stroke ll: Pathophysiology
Hemorrhagic Stroke l: Introduction
Ischemic Stroke ll: Pathophysiology
Cerebral Edema ll: Pathophysiology
Arteries of the Head and Neck
The internal carotid arteries supply blood to the anterior portion of the cerebrum. They enter the...
Stroke: Introduction and Types

