Paradoxical reduction of cerebral blood flow after acetazolamide loading:a hemodynamic and metabolic study with ^(15)O PET  

作　　者：Tadashi Watabe Eku Shimosegawa Hiroki Kato Kayako Isohashi Mana Ishibashi Mitsuaki Tatsumi Kazuo Kitagawa Toshiyuki Fujinaka Toshiki Yoshimine Jun Hatazawa 

机构地区：[1]Department of Molecular Imaging in Medicine [2]Department of Nuclear Medicine [3]Department of Nuclear Medicine and Tracer Kinetics [4]Stroke Center,Osaka University Hospital [5]Department of Radiology [6]Department of Neurology [7]Department of Neurosurgery,Osaka University Graduate School of Medicine

出　　处：《Neuroscience Bulletin》2014年第5期845-856,共12页神经科学通报（英文版）

基　　金：partly supported by the Molecular Imaging Program, a grant(21591561) from the Ministry of Education,Culture,Sports, Science,and Technology and the Japan Science and Technology Agency,Japan;the Research Promotion Program on Health from the National Institute of Biomedical Innovation,Japan;a Grant-in-Aid(H21-019 and H21-5) from the Ministry of Health, Welfare,and Labour,Japan

摘　　要：Paradoxical reduction of cerebral blood flow （CBF） after administration of the vasodilator acetazolamide is the most severe stage of cerebrovascular reactivity failure and is often associated with an increased oxygen extraction fraction （OEF）. In this study, we aimed to reveal the mechanism underlying this phenomenon by focusing on the ratio of CBF to cerebral blood volume （CBV） as a marker of regional cerebral perfusion pressure （CPP）. In 37 patients with unilateral internal carotid or middle cerebral arterial （MCA） steno-occlusive disease and 8 normal controls, the baseline CBF （CBFb）, CBV, OEF, cerebral oxygen metabolic rate （CMRO2）, and CBF after acetazolamide loading in the anterior and posterior MCA territories were measured by （15）~O positron emission tomography. Paradoxical CBF reduction was found in 28 of 74 regions （18 of 37 patients） in the ipsilateral hemisphere. High CBFb （〉47.6 mL/100 mL/min, n = 7） was associated with normal CBFb/CBV, increased CBV, decreased OEF, and normal CMRO2. Low CBFb （〈31.8 mL/100 mL/min, n = 9） was associated with decreased CBFb/CBV, increased CBV, increased OEF, and decreased CMRO2. These findings demonstrated that paradoxical CBF reduction is not always associated with reduction of CPP, but partly includes high- CBFb regions with normal CPP, which has not been described in previous studies.Paradoxical reduction of cerebral blood flow （CBF） after administration of the vasodilator acetazolamide is the most severe stage of cerebrovascular reactivity failure and is often associated with an increased oxygen extraction fraction （OEF）. In this study, we aimed to reveal the mechanism underlying this phenomenon by focusing on the ratio of CBF to cerebral blood volume （CBV） as a marker of regional cerebral perfusion pressure （CPP）. In 37 patients with unilateral internal carotid or middle cerebral arterial （MCA） steno-occlusive disease and 8 normal controls, the baseline CBF （CBFb）, CBV, OEF, cerebral oxygen metabolic rate （CMRO2）, and CBF after acetazolamide loading in the anterior and posterior MCA territories were measured by （15）~O positron emission tomography. Paradoxical CBF reduction was found in 28 of 74 regions （18 of 37 patients） in the ipsilateral hemisphere. High CBFb （〉47.6 mL/100 mL/min, n = 7） was associated with normal CBFb/CBV, increased CBV, decreased OEF, and normal CMRO2. Low CBFb （〈31.8 mL/100 mL/min, n = 9） was associated with decreased CBFb/CBV, increased CBV, increased OEF, and decreased CMRO2. These findings demonstrated that paradoxical CBF reduction is not always associated with reduction of CPP, but partly includes high- CBFb regions with normal CPP, which has not been described in previous studies.

关 键 词：ACETAZOLAMIDE cerebral blood flowparadoxical reduction positron emission tomographyvasodilatation 

分 类 号：R743[医药卫生—神经病学与精神病学]