Background

Microstructural alterations of corticospinal tract (CST) have been found in idiopathic normal pressure hydrocephalus (iNPH). No study, however, investigated the effect of ventricular dilatation on CST in Progressive Supranuclear Palsy (PSP).

Objective

The aim of this study was to investigate CST diffusion profile in a large cohort of PSP patients with and without ventricular dilatation.

Methods

Twenty-three iNPH patients, 87 PSP patients and 26 controls were enrolled. Evans index (EI) and ventricular volume (VV) were measured in all patients. CST tractography was performed to calculate FA, MD, AxD and RD in six different anatomical regions: medulla oblungata (MO), pons (P), cerebral peduncle (CP), posterior limb of internal capsule (PLIC), corona radiata (CR), subcortical white matter (SWM). ANCOVA was used for comparing CST diffusion profiles between the groups and association between CST microstructural metrics and measures of ventricular dilatation (EI and VV) was assessed.

Results

Thirty-three PSP patients had ventricular dilatation (EI > 0.30, PSP-vd) while 54 PSP patients had normal ventricular system (EI ≤ 0.30, PSP-wvd). iNPH patients had the most marked FA and AxD increase in PLIC and CR of CST followed by PSP-vd, PSP-wvd and controls; RD was altered only in iNPH. A strong correlation was found between CST diffusion metrics and EI or VV.

Conclusions

Our findings confirm the microstructural changes of CST in iNPH patients and demonstrate for the first time similar alterations in PSP-vd patients, suggesting a crucial role of ventricular dilatation in the mechanical compression of CST.

中文翻译：

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皮质脊髓束异常和心室扩张：一项跨诊断比较纤维束造影研究

背景

在特发性正常压力脑积水 (iNPH) 中发现了皮质脊髓束 (CST) 的显微结构改变。然而，没有研究调查心室扩张对进行性核上性麻痹 (PSP) 中 CST 的影响。

客观的

本研究的目的是调查一大群有和没有心室扩张的 PSP 患者的 CST 扩散曲线。

方法

招募了 23 名 iNPH 患者、87 名 PSP 患者和 26 名对照。测量所有患者的埃文斯指数 (EI) 和心室容积 (VV)。进行 CST 纤维束成像以计算六个不同解剖区域的 FA、MD、AxD 和 RD：延髓 (MO)、脑桥 (P)、脑脚 (CP)、内囊后肢 (PLIC)、放射冠 (CR) ，皮层下白质 (SWM)。ANCOVA 用于比较各组之间的 CST 扩散曲线，并评估了 CST 微观结构指标与心室扩张（EI 和 VV）测量值之间的关联。

结果

33 名 PSP 患者心室扩张（EI > 0.30，PSP-vd），而 54 名 PSP 患者心室系统正常（EI ≤ 0.30，PSP-wvd）。iNPH 患者在 CST 的 PLIC 和 CR 中 FA 和 AxD 增加最显着，其次是 PSP-vd、PSP-wvd 和对照组；RD 仅在 iNPH 中改变。在 CST 扩散指标和 EI 或 VV 之间发现了很强的相关性。

结论

我们的研究结果证实了 iNPH 患者 CST 的微观结构变化，并首次证明了 PSP-vd 患者的类似改变，表明心室扩张在 CST 机械压缩中的关键作用。