Diffusion tensor imaging detects early Wallerian degeneration of the pyramidal tract after ischemic stroke
Diffusion tensor imaging detects early Wallerian degeneration of the pyramidal tract after ischemic stroke
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DOI：
10.1016/j.neuroimage.2004.03.041
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发表时间：
2004-08-01
期刊：
影响因子：
5.7
通讯作者：
Röther, J
中科院分区：
文献类型：
--
作者：
Thomalla, G;Glauche, V;Röther, J
我们使用扩散张量成像（DTI）评估缺血性卒中后前2周内锥体束的沃勒变性，并将沃勒变性的程度与运动缺陷相关联。9例大脑中动脉卒中患者于卒中后2-16天行DTI和T2加权MRI检查。我们测量了分数各向异性（FA），平均扩散率（Dav），弥散张量和T2加权信号的特征值在大脑脚和比较这些值之间的影响和未受影响的一方和患者和6个对照。与未受累侧和对照组相比，受累侧的FA显著降低。最大的特征值减少，而最小的特征值升高的影响侧。T2加权信号和Dav无显著性差异。各向异性的降低与脑卒中后90天DTI检查时的运动功能障碍呈正相关。各向异性的减少反映了轴突结构的解体，因为它发生在沃勒变性的早期阶段。DTI检测脑卒中后前2周内与开始锥体束变性相关的水扩散变化，这些变化在常规T2加权或方向平均弥散加权MRI中尚不可见。我们首次证明了锥体束损伤的早期DTI结果与运动缺陷的相关性。在亚急性期早期，DTI可以帮助预测脑卒中后运动功能的恢复。(C)2004年爱思唯尔公司All rights reserved.
We used diffusion tensor imaging (DTI) to assess Wallerian degeneration of the pyramidal tract within the first 2 weeks after ischemic stroke, and correlated the extent of Wallerian degeneration with the motor deficit. Nine patients with middle cerebral artery stroke were examined 2-16 days after stroke by DTI and T2-weighted MRI. We measured fractional anisotropy (FA), averaged diffusivity (Dav), eigenvalues of the diffusion tensor and T2-weighted signal in the cerebral peduncle and compared these values between the affected and the unaffected side and between patients and six controls. FA was significantly reduced on the affected side compared to the unaffected side and compared to the control group. The largest eigenvalue was reduced, whereas the smallest eigenvalue was elevated on the affected side. There was no significant difference in T2-weighted signal and Dav. The decrease of anisotropy correlated positively with the motor deficit at the time of DTI study and 90 days after stroke. The reduction of anisotropy mirrors the disintegration of axonal structures, as it occurs in the early phase of Wallerian degeneration. DTI detects changes of water diffusion related to beginning pyramidal tract degeneration within the first 2 weeks after stroke that are not yet visible in conventional T2-weighted or orientationally averaged diffusion weighted MRI. We demonstrated for the first time a correlation of early DTI findings of pyramidal tract damage with the motor deficit. DTI can help prognosing recovery of motor function after stroke within the early subacute phase. (C) 2004 Elsevier Inc. All rights reserved.