Study of the cevebral blood flow and metabolisar in hydrocephalus

我们报告了婴儿脑积水的CBF和rCMR02的特征模式。在PET扫描上，OEF不会随着CBF的降低而增加。而高岭土悬液注射致大鼠实验性脑积水模型，早期rCMRglc升高，但与脑血流量下降无关。推测DG法测定的rCMRglc可能与无氧代谢有关，参与了脑积水的病理生理过程。在本研究中，我们试图通过比较DG法和仅代表有氧代谢的6-标记葡萄糖法测定的rCMRglc来阐明实验性脑积水大鼠糖代谢的无氧变化。对照组注射生理盐水。急性期DG代谢高于葡萄糖代谢。主要分布于大脑皮层、丘脑、下丘脑和胼胝体。感觉运动皮质和丘脑差异有统计学意义。然而，在慢性期模型中，只有感觉运动皮质才能识别出显著的图像差异。对照组之间无显著差异。提示脑积水早期存在无氧代谢改变。在急性期占主导地位的无氧代谢的激活，可以弥补能量的不足。慢性期无氧代谢和有氧代谢降低，提示存在不可逆转的组织损伤。

We reported characteristic pattern of CBF and rCMR02 in infantile hydrocephalus. OEF does not increase as CBF decrease on PET scan. However, in experimental hydrocephalus rat model made by Kaolin suspension injection, rCMRglc increased independent of decreased CBF in early stage. We speculated that rCMRglc measured by DG method may cotain the value of anaerobic metabolism which is involved in the pathophysiology of hydrocephalus. In the present study, we tried to clarify the anaerobic changes of glucose metabolism in experimental hydrocephalus rat by comparison of rCMRglc measured by DG method and 6-labeled glucose method which represents only aerobic metabolism.The phase of hydrocephalus was devided into acute phase of 2-weeks after the injection and chronic phase of 6-weeks after the injection. Saline was injected as control. In acute phase, the DG metabolism was higher than that of glucose. It was recognized mainly in the cerebral cortices, thalamus, hypothalamus and corpus callosum. There were significant differences in sensorymotor cortex and thalamus. However, notable deifference of images was recognized only in sensorymotor cortex in chronic phase model. There was no significant difference in control. These results suggest that anaerobic change of metabolism exists in the early stage of hydrocephalus. Activation of anaerobic metabolism, dominant in acute phase, may compensate for shortage of the energy. The decrease of anaerobic and aerobic metabolism in chronic phase may suggest the irreversible tissue damage.