Wong John C T, Concha Luis, Beaulieu Christian, Johnston Wendy, Allen Peter S, Kalra Sanjay
Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
J Neuroimaging. 2007 Jul;17(3):234-40. doi: 10.1111/j.1552-6569.2007.00100.x.
Diffusion tensor imaging (DTI) was used as a noninvasive method to evaluate the anatomy of the corticospinal tract (CST) and the pattern of its degeneration in amyotrophic lateral sclerosis (ALS).
Fourteen patients with ALS and 15 healthy controls underwent DTI. Parameters reflecting coherence of diffusion (fractional anisotropy, FA), bulk diffusion (apparent diffusion coefficient, ADC), and directionality of diffusion (eigenvalues) parallel to (lambda( parallel)) or perpendicular to (lambda( perpendicular)) fiber tracts were measured along the intracranial course of the CST.
FA and lambda( parallel) increased, and ADC and lambda( perpendicular) decreased progressively from the corona radiata to the cerebral peduncle in all subjects. The most abnormal finding in patients with ALS was reduced FA in the cerebral peduncle contralateral to the side of the body with the most severe upper motor neuron signs. lambda( parallel) was increased in the corona radiata. Internal capsule FA correlated positively with symptom duration, and cerebral peduncle ADC positively with the Ashworth spasticity score.
There is a spatial dependency of diffusion parameters along the CST in healthy individuals. Evidence of intracranial CST degeneration in ALS was found with distinct diffusion changes in the rostral and caudal regions.
弥散张量成像（DTI）被用作一种非侵入性方法，以评估肌萎缩侧索硬化症（ALS）患者皮质脊髓束（CST）的解剖结构及其退变模式。
对14例ALS患者和15名健康对照者进行DTI检查。沿着CST的颅内走行测量反映弥散一致性（分数各向异性，FA）、整体弥散（表观弥散系数，ADC）以及与纤维束平行（λ∥）或垂直（λ⊥）的弥散方向性（特征值）的参数。
在所有受试者中，从放射冠到脑桥，FA和λ∥增加，而ADC和λ⊥逐渐降低。ALS患者最异常的表现是，在出现最严重上运动神经元体征的身体一侧对侧的脑桥中FA降低。放射冠中的λ∥增加。内囊FA与症状持续时间呈正相关，脑桥ADC与Ashworth痉挛评分呈正相关。
在健康个体中，沿着CST的弥散参数存在空间依赖性。在ALS患者中发现了颅内CST退变的证据，在头端和尾端区域有明显的弥散变化。
