Third Military Medical University, Chongqing, China.
Neurorehabil Neural Repair. 2011 Mar-Apr;25(3):275-84. doi: 10.1177/1545968310389183.
Neuroimaging techniques, such as diffusion tensor imaging (DTI) and blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI), provide insights into the functional reorganization of the cortical motor system after stroke. This study explores the relationship between upper extremity motor function, white matter integrity, and BOLD response of cortical motor areas.
Seventeen patients met study inclusion criteria; of these 12 completed DTI assessment of white matter integrity and 9 completed fMRI assessment of motor-related activation. Primary clinical outcome measures were the Wolf Motor Function Test (WMFT) and the upper limb portion of the Fugl-Meyer (FM) motor assessment. Structural integrity of the posterior limb of the internal capsule was assessed by examining the fractional anisotropy (FA) asymmetry in the PLIC. Laterality index of motor cortical areas was measured as the BOLD response in each patient during a finger pinch task. Linear regression analyses were performed to determine whether clinical outcome was associated with structural or functional MRI measures.
There were strong relationships between clinical outcome measures and FA asymmetry (eg, FM score [R(2) = .655, P = .001] and WMFT asymmetry score [R(2) = .651, P < .002]) but relationships with fMRI measures were weaker.
Clinical motor function is more closely related to the white matter integrity of the internal capsule than to BOLD response of motor areas in patients 3 to 9 months after stroke. Thus, use of DTI to assess white matter integrity in the internal capsule may provide more useful information than fMRI to interpret motor deficits following supratentorial brain injury.
弥散张量成像（DTI）和血氧水平依赖功能磁共振成像（BOLD fMRI）等神经影像学技术可深入了解卒中后皮质运动系统的功能重组。本研究探讨了上肢运动功能、白质完整性和皮质运动区 BOLD 反应之间的关系。
17 名患者符合研究纳入标准；其中 12 名完成了白质完整性 DTI 评估，9 名完成了运动相关激活的 fMRI 评估。主要临床结局测量指标为 Wolf 运动功能测试（WMFT）和 Fugl-Meyer（FM）运动评估的上肢部分。通过检查内囊后肢的各向异性分数（FA）不对称性来评估内囊后肢的结构完整性。通过每位患者在手指捏合任务期间的 BOLD 反应来测量运动皮质区的侧化指数。进行线性回归分析以确定临床结局是否与结构或功能 MRI 测量值相关。
临床结局测量指标与 FA 不对称性之间存在很强的相关性（例如，FM 评分[R²=0.655，P=0.001]和 WMFT 不对称评分[R²=0.651，P<0.002]），但与 fMRI 测量值的相关性较弱。
在卒中后 3 至 9 个月的患者中，临床运动功能与内囊白质完整性的关系比运动区 BOLD 反应更密切。因此，与 fMRI 相比，使用 DTI 评估内囊白质完整性可能为解释幕上脑损伤后的运动障碍提供更有用的信息。
