Evolution of cortical activation during recovery from corticospinal tract infarction
Evolution of cortical activation during recovery from corticospinal tract infarction
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DOI：
10.1161/01.str.31.3.656
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发表时间：
2000-03-01
期刊：
影响因子：
8.3
通讯作者：
DeLaPaz, RL
中科院分区：
文献类型：
--
作者：
Marshall, RS;Perera, GM;DeLaPaz, RL
背景和目的：由皮质脊髓束梗死引起的偏瘫的恢复是有文献记载的，但恢复的机制尚不清楚。功能性核磁共振成像（fMRI）提供了一种方法来识别与麻痹的手的运动有关的局灶性脑活动。虽然先前的研究表明，同侧和对侧半球的辅助运动区域在恢复中发挥作用，但对于这些区域在恢复过程中皮层激活的时间过程知之甚少。方法：8例首次出现皮质脊髓束凹陷导致偏瘫的患者在中风后的最初几天和3 ~ 6个月进行了连续的功能磁共振成像。6名健康受试者作为对照。统计显著体素在手指拇指对立任务被识别与自动图像处理程序。采用同侧与对侧活动指数来比较脑卒中急性期和慢性期大脑半球对运动功能的相对贡献。结果：对照组在对侧感觉运动皮层（SMC）、运动前区和辅助运动区显示预期的激活。与对照组相比，卒中患者在同侧SMC、同侧后顶叶和双侧前额叶区域表现出更大的激活。与非麻痹手相比，麻痹手运动过程中对侧与同侧SMC活动的比例随着麻痹手功能的恢复而显著增加。SMC从早期对侧活动到晚期同侧活动的激活演变表明，在偏瘫恢复过程中，运动网络发生了动态的双半球重组。
Background and Purpose-Recovery from hemiparesis due to corticospinal tract infarction is well documented, but the mechanism of recovery is unknown. Functional MRI (fMRI) provides a means of identifying focal brain activity related to movement of a paretic hand. Although prior studies have suggested that supplementary motor regions in the ipsilesional and contralesional hemisphere play a role in recovery, little is known about the time course of cortical activation in these regions as recovery proceeds.Methods-Eight patients with first-ever corticospinal tract lacunes causing hemiparesis had serial fMRIs within the first few days after stroke and at 3 to 6 months. Six healthy subjects were used as controls. Statistically significant voxels during a finger-thumb opposition task were identified with an automated image processing program. An index of ipsilateral versus contralateral activity was used to compare relative contributions of the 3,hemispheres to motor function in the acute and chronic phases after stroke.Results-Controls showed expected activation in the contralateral sensorimotor cortex (SMC), premotor, and supplementary motor areas. Stroke patients differed from control patients in showing greater activation in the ipsilateral SMC, ipsilateral posterior parietal, and bilateral prefrontal regions. Compared with the nonparetic hand, the ratio of contralateral to ipsilateral SMC activity during movement of the paretic hand increased significantly over time as the paretic hand regained function.Conclusions-The evolution of activation in the SMC from early contralesional activity to late ipsilesional activity suggests that a dynamic bihemispheric reorganization of motor networks occurs during recovery from hemiparesis.