Relationship between cognitive function and central neurotransmitter in chronic cerebral ischemia

由于苯二氮卓类受体(BZR)在大脑皮层中含量丰富，可选择性地与BZR结合的氟马西尼可作为神经元密度的标记物。本研究的目的是阐明神经元密度与脑氧代谢的关系，并探讨~(11)&gt；C-flumazenil PET在检测痛苦灌流中的作用。受试者包括16名颈内动脉或大脑中动脉闭塞症患者，他们接受了PET检查。计算局部脑血流量(CBF)、局部脑氧摄取分数(OEF)、局部脑氧代谢率(CMRO2)和局部脑血管储备容量(CVRC)。在CBF研究后，用氟马西尼团注入法测定氟马西尼的结合电位。16例共获得48个感兴趣区。氟马西尼结合势与CMRO_2呈正相关(r=0.337，p=0.0069)，但在48个感兴趣区中，有7个感兴趣区的CMRO_2降低，而氟马西尼结合势无变化。CVRC降低的29个ROI中17个表现为高OEF，其余12个表现为正常。氟马西尼结合电位值正常的ROI显著低于高OEF的ROI(p=0.0003)。本研究表明，11&gt；C-flumazenil PET可用于检测血流动力学缺血患者的痛苦血流灌注情况。

Because benzodiazepine receptors (BZR) are abundant in the cortex, an accumulation of ^<11>C-flumazenil which selectively bind to BZR may be useful as markers of neuron density. The aims of this study were to clarify the relationship between neuron density and cerebral oxygen metabolism and to investigate usefulness of ^<11>C-flumazenil PET for detecting of misery perfusion. Subjects consisted of 16 patients with either internal carotid or middle cerebral arterial occlusive disease who underwent PET. Regional cerebral blood flow (CBF), regional cerebral oxygen extraction fraction (OEF), regional cerebral metabolic rate for oxygen (CMRO_2) and regional cerebrovascular reserve capacity (CVRC) to acetazolamide were calculated. After CBF study, flumazenil binding potential was measured using [^<11>C]flumazenil bolus injection method. Forty eight ROIs were obtained in 16 patients. Flumazenil binding potential was correlated to CMRO_2 (r=0.337, p=0.0069), but in 7 of 48 ROIs, CMRO_2 decreased whereas flumazenil binding potential did not change. Seventeen of 29 ROIs with decreased CVRC showed high OEF and the remaining 12 showed normal OEF. Flumazenil binding potentials in ROIs with normal OEF were significantly lower than those with high OEF (p=0.0003). This study demonstrated that ^<11>C-flumazenil PET is useful for detecting of misery perfusion in patients with hemodynamic ischemia.