The stability of the blood oxygenation level-dependent functional MRI response to motor tasks is altered in patients with chronic ischemic stroke.
The stability of the blood oxygenation level-dependent functional MRI response to motor tasks is altered in patients with chronic ischemic stroke.
复制标题
慢性缺血性中风患者的血氧水平依赖性功能性 MRI 对运动任务反应的稳定性发生了改变。
DOI：
10.1161/strokeaha.110.590471
复制
发表时间：
2010
期刊：
影响因子：
8.3
通讯作者：
deAraujo,DraulioB
中科院分区：
文献类型：
--
作者：
Mazzetto-Betti,KelleyC;Leoni,RenataF;Pontes-Neto,OctavioM;Santos,AntonioC;Leite,JoaoP;Silva,AfonsoC;deAraujo,DraulioB
背景和目的——功能性 MRI 是研究中风患者脑功能恢复情况的有力工具。功能性 MRI 数据分析的一个固有假设是血氧水平相关 (BOLD) 信号在检查过程中保持稳定。在这项研究中，我们评估了这种假设在慢性中风患者中的有效性。方法——15 名患者在单独的运行中使用瘫痪手和未受影响的手执行了重复周期的简单运动任务。从两个半球的主要和辅助运动区提取相应的 BOLD 信号时间进程。通过传统的一般线性模型和参数化的一般线性模型获得统计图。结果——当用未受影响的手执行任务时，观察到稳定的 BOLD 幅度。相反，当用麻痹的手执行任务时，每个患者的主要运动区和辅助运动区的 BOLD 信号幅度都逐渐减弱。传统的一般线性模型分析未能检测到瘫痪手运动期间的大脑激活。然而，所提出的参数通用线性模型纠正了误检问题，并在主要和辅助运动区域显示出强大的激活。结论——使用建立在稳定的 BOLD 信号前提下的数据分析工具可能会导致中风患者功能区域的误检和大脑活动的低估。目前的数据敦促在依赖 BOLD 反应作为中风患者大脑重组的标志时要谨慎。
Background and Purpose—Functional MRI is a powerful tool to investigate recovery of brain function in patients with stroke. An inherent assumption in functional MRI data analysis is that the blood oxygenation level-dependent (BOLD) signal is stable over the course of the examination. In this study, we evaluated the validity of such assumption in patients with chronic stroke.Methods—Fifteen patients performed a simple motor task with repeated epochs using the paretic and the unaffected hand in separate runs. The corresponding BOLD signal time courses were extracted from the primary and supplementary motor areas of both hemispheres. Statistical maps were obtained by the conventional General Linear Model and by a parametric General Linear Model.Results—Stable BOLD amplitude was observed when the task was executed with the unaffected hand. Conversely, the BOLD signal amplitude in both primary and supplementary motor areas was progressively attenuated in every patient when the task was executed with the paretic hand. The conventional General Linear Model analysis failed to detect brain activation during movement of the paretic hand. However, the proposed parametric General Linear Model corrected the misdetection problem and showed robust activation in both primary and supplementary motor areas.Conclusions—The use of data analysis tools that are built on the premise of a stable BOLD signal may lead to misdetection of functional regions and underestimation of brain activity in patients with stroke. The present data urge the use of caution when relying on the BOLD response as a marker of brain reorganization in patients with stroke.