Department of Nuclear Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, 310009, Zhejiang, China.
Eur J Nucl Med Mol Imaging. 2010 May;37(5):954-61. doi: 10.1007/s00259-009-1342-3. Epub 2010 Jan 27.
Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive method to excite neurons in the brain. However, the underlying mechanism of its therapeutic effects in stroke remains unclear. The aim of this study was to investigate the neuroprotective effect of high-frequency rTMS in a rat model of transient cerebral ischaemia using positron emission tomography (PET).
Sprague-Dawley rats (n=30) were anaesthetized with chloral hydrate and subjected to 90 min of intraluminal middle cerebral artery occlusion (MCAO) with subsequent reperfusion in three groups: control (n=10), rTMS (n=10), or sham-rTMS groups (n=10). In the rTMS group, rTMS was given 1 h after ischaemia and every 24 h for 7 days after MCAO. In all three groups, small-animal PET (microPET) imaging with (18)F-FDG was used to evaluate brain glucose metabolism. Apoptotic molecules were measured in the infarct margin using immunohistochemical staining.
The neurological scores of the rats in the rTMS group were higher than in those of the control group over the whole 7-day observation period. The total, cortical and striatal infarct volumes were significantly less in the rTMS group than in the control group, as measured by 2,3,5-triphenyltetrazolium chloride staining. (18)F-FDG microPET images showed significantly higher standardized uptake values in the cortex and striatum in the rTMS group than in the control group in the affected hemisphere. The number of cells positive for caspase-3 was significantly lower in the rTMS group than in the control group, while the Bcl-2/Bax ratio was significantly higher in the rTMS group than in the control group.
rTMS therapy increased glucose metabolism and inhibited apoptosis in the ischaemic hemisphere. (18)F-FDG PET could be used to monitor rTMS therapy in transient cerebral ischaemia in animal studies and in future clinical trials.
重复经颅磁刺激（rTMS）是一种非侵入性方法，可兴奋大脑中的神经元。然而，其在中风治疗中的作用机制尚不清楚。本研究旨在使用正电子发射断层扫描（PET）研究高频 rTMS 在短暂性脑缺血大鼠模型中的神经保护作用。
用氯醛水麻醉 Sprague-Dawley 大鼠（n=30），并进行 90 分钟的大脑中动脉阻塞（MCAO）腔内阻塞，随后再灌注，分为三组：对照组（n=10）、rTMS 组（n=10）或假 rTMS 组（n=10）。rTMS 组在缺血后 1 小时开始 rTMS，MCAO 后每天 24 小时进行 7 天。在所有三组中，使用小动物 PET（microPET）成像和（18）F-FDG 评估脑葡萄糖代谢。使用免疫组织化学染色测量梗塞边缘的凋亡分子。
rTMS 组大鼠的神经评分在整个 7 天观察期间均高于对照组。rTMS 组的总梗塞体积、皮质和纹状体梗塞体积明显小于对照组，2,3,5-三苯基四唑氯染色测定。（18）F-FDG microPET 图像显示 rTMS 组受影响半球的皮质和纹状体的标准化摄取值明显高于对照组。rTMS 组 caspase-3 阳性细胞数明显低于对照组，而 rTMS 组 Bcl-2/Bax 比值明显高于对照组。
rTMS 治疗增加了缺血半球的葡萄糖代谢并抑制了细胞凋亡。（18）F-FDG PET 可用于监测动物研究和未来临床试验中短暂性脑缺血的 rTMS 治疗。
