Changes in cerebral energy metobolism during chronic uasospasm in primates.

为探讨蛛网膜下腔出血（SAH）后慢性脑血管痉挛（CVS）发生发展过程中脑循环障碍对神经组织的影响，在灵长类动物慢性脑血管痉挛模型上，应用磷和质子磁共振波谱（MRS）技术研究了SAH后慢性脑血管痉挛时脑能量代谢和神经元代谢物的变化。蛛网膜下腔出血是由于右侧大脑中动脉（MCA）周围的血块进入而产生的。血管造影显示SAH诱导后第7天右侧大脑中动脉出现重度血管痉挛。磷MRS显示，药物诱导的全身性低血压（平均60 mmHg）导致第7天痉挛侧顶叶组织ATP水平显著降低。在SAH前、第7天和第14天进行质子MRS。计算双侧顶叶含胆碱化合物（Cho）、肌酸、磷酸肌酸（Cr）和N-乙酰天冬氨酸（NAA）的峰面积，以及Cho/Cr和NAA/Cr的比值。质子MRS研究显示，在痉挛侧右顶叶区，第7天和第14天NAA/Cr比值均显著降低，Cho/Cr比值显著升高。组织病理学研究表明，在痉挛动脉的领土中的一些（小于10%）皮层神经元中的缺血性神经元变化。结果表明，脑血管痉挛的发展引起脑循环和能量代谢障碍的血管痉挛动脉的领土，导致缺血性损害的一些皮层神经元。质子和（或）磷磁共振波谱可用于评价脑血管痉挛时缺血损伤对神经细胞的影响。

To study how neuronal tissues are affected by impairment of cerebral circulation during development of chronic cerebral vasospasm after subarachnoid hemorrhage (SAH), the changes in cerebral energy metabolism and neuronal metabolites during chronic cerebral vasospasm were evaluated by means of phosphorus and proton magnetic resonance spectrosopy (MRS), in a primate vasospasm model. The SAH was produced by introduction of blood clot around the right middle cerebral aretry (MCA). Angiography revealed severe vasospasm in the right middle cerebral artery on Day 7 after SAH induction. Phosphorus MRS revealed that drug-induced systemic hypotension (mean 60 mmHg) caused a significant decrease in the tissue ATP level in the spasm side parietal lobe on Day 7. Proton MRS was performed before SAH,on Day 7 and Day 14. The peak areas for choline-containing compounds (Cho), creatine and phosphocreatine (Cr) and N-acetyl-aspartate (NAA), and the ratios of Cho/Cr and NAA/Cr were evaluated in the bilateral parietal lobe. The proton MRS study revealed a significant reduction in NAA/Cr ratio on both Day 7 and Day 14, and a ignificant increase in Cho/Cr ratio, in the spasm side right parietal region. The histopathological study demonstrated the ischemic neuronal change in some (less than 10 %) of the cortical neurons in the territory of the spastic artery. The results suggest that the development of cerebral vasospasm caused impairment of cerebral circulation and energy metabolism in the territory of the vasospastic artery resulting in ischemic damage in some of the cortical neurons. The proton and/or phorphorus MRS may be useful to evaluate the effect of ischemic insult on neuronal cells during cerebral vasospasm.