Department of Neurology, AIIMS, New Delhi, India.
Department of NMR & MRI, AIIMS, New Delhi, India.
Neurol India. 2021 Sep-Oct;69(5):1210-1216. doi: 10.4103/0028-3886.329584.
Corticospinal tracts (CST) forms the basis of motor neurophysiology after stroke. Motor skill recovery has been correlated well to the microstructural properties of CST in both hemispheres. Functional imaging has opened up new possibilities of imaging functionality of cortex and fiber tracts in the brain. We studied therapy-induced changes in blood oxygenation level-dependent (BOLD) and DTI imaging on 20 chronic stroke patients at baseline, 8, and 24 weeks.
All the patients were subjected to MR imaging on a 1.5 T MR scanner. We used block design for BOLD with alternate baseline and activation cycles (repetition time (TR) =4520 ms, echo time (TE) = 44 ms, slices = 31, slice thickness = 4 mm). DTI parameters were as follows: TE = 76 ms, TR = 10,726 ms, EPI factor = 127, resolution = 128 × 128 matrix, field of view = 230 mm and a slice thickness of 4.0 mm.
The data was analyzed on SPSS software and tractography/DTI processing software (M/s. Siemens Medical Solutions, Erlangen Germany.
The mean axial diffusivity (λ[INSIDE:1]) and radial diffusivity (λ[INSIDE:2]) in the affected hemisphere were 0. 30 and 0.18, respectively. The mean number (FN) ratio (± SD) was 0.27 ± 0.14 at baseline, 0.33 ± 0.19 at 8 weeks, and 0.41 ± 0.23 at 24 weeks. Multivariate regression analysis at baseline showed that rFA was well-correlated to the Fugl-Meyer score (regression coefficient: 0.198, F = 10.382, P = 0.001), MI followed by signal intensity.
All patients had high % signal intensity after 8 weeks of physiotherapy regime with a greater percentage change in rFA as compared at follow-up suggesting that a focused exercise regime in stroke patients helps in the reconnection of neural and myelin networks.
Clinical and functional recovery after stroke is well-correlated with the DTI and BOLD parameters i.e., rFA ratios, CST involvement fiber numbers, and % signal intensity of the ipsilesional cortex.
皮质脊髓束（CST）是中风后运动神经生理学的基础。运动技能的恢复与两个半球 CST 的微观结构特性密切相关。功能成像为大脑皮层和纤维束的功能成像开辟了新的可能性。我们在基线、8 周和 24 周时对 20 例慢性中风患者进行了血氧水平依赖（BOLD）和 DTI 成像的治疗诱导变化研究。
所有患者均在 1.5 T 磁共振扫描仪上进行磁共振成像。我们使用 BOLD 块设计，交替基线和激活周期（重复时间（TR）= 4520 ms，回波时间（TE）= 44 ms，切片= 31，切片厚度= 4 毫米）。DTI 参数如下：TE = 76 ms，TR = 10,726 ms，EPI 因子= 127，分辨率= 128×128 矩阵，视野= 230 毫米，切片厚度= 4.0 毫米。
数据在 SPSS 软件和束流/DTI 处理软件（西门子医疗解决方案公司，德国埃朗根）上进行分析。
患侧半侧平均轴向扩散率（λ[INSIDE:1]）和径向扩散率（λ[INSIDE:2]）分别为 0.30 和 0.18。基线时平均纤维数（FN）比值（±SD）为 0.27±0.14，8 周时为 0.33±0.19，24 周时为 0.41±0.23。基线时多元回归分析显示 rFA 与 Fugl-Meyer 评分相关性良好（回归系数：0.198，F = 10.382，P = 0.001），其次是 MI 后信号强度。
所有患者在物理治疗 8 周后均有较高的信号强度百分比，rFA 的百分比变化较大，提示中风患者的集中运动治疗方案有助于神经和髓鞘网络的重新连接。
中风后的临床和功能恢复与 DTI 和 BOLD 参数密切相关，即 rFA 比值、CST 受累纤维数和对侧皮质的信号强度百分比。
