Corben Louise A, Kashuk Saman R, Akhlaghi Hamed, Jamadar Sharna, Delatycki Martin B, Fielding Joanne, Johnson Beth, Georgiou-Karistianis Nellie, Egan Gary F
Bruce Lefroy Centre for Genetic Health Research, Murdoch Childrens Research Institute, Parkville 3052, Victoria, Australia; Monash Medical Centre, Monash Health, Clayton, Victoria 3168, Australia; School of Psychological Sciences, Monash University, Clayton, Victoria 3800, Australia.
Monash Biomedical Imaging, Monash University, Clayton, Victoria 3800, Australia; College of Engineering and Science, Victoria University, Melbourne 8001, Victoria, Australia.
J Neurol Sci. 2014 Aug 15;343(1-2):138-43. doi: 10.1016/j.jns.2014.05.057. Epub 2014 Jun 2.
The dentate nucleus (DN) is the major relay station for neural connection between the cerebellum and cerebrum via the thalamus, and is a significant component of the neuropathological profile of Friedreich ataxia (FRDA). We have previously shown that the size of the superior cerebellar peduncle (SCP), which links the DN to cortical and subcortical structures via the thalamus, is significantly reduced in individuals with FRDA compared to control participants. This study used magnetization transfer imaging (MTI) to examine and contrast the integrity of white matter (WM) in the SCP and the corpus callosum (CC) (control region) in ten individuals with FRDA and ten controls. Individuals with FRDA demonstrated a significant reduction in the magnetization transfer ratio (MTR) in the SCP compared to control participants. However, there was no significant difference between groups in MTR in the CC. When comparing regions within groups, there was a significant reduction in MTR in the SCP compared to CC in participants with FRDA only. We suggest that the reduction in MTR in the SCP may be indicative of lack of myelin secondary to axonal loss and oligodendroglial dysfunction in WM tracts in individuals with FRDA.
齿状核（DN）是小脑与大脑之间经丘脑进行神经连接的主要中继站，并且是弗里德赖希共济失调（FRDA）神经病理学特征的重要组成部分。我们之前已经表明，与对照参与者相比，FRDA患者中经丘脑将DN与皮质及皮质下结构相连的上小脑脚（SCP）的大小显著减小。本研究使用磁化传递成像（MTI）对10名FRDA患者和10名对照者的SCP及胼胝体（CC，对照区域）中的白质（WM）完整性进行检查和对比。与对照参与者相比，FRDA患者的SCP中磁化传递率（MTR）显著降低。然而，两组之间CC的MTR没有显著差异。在组内区域比较时，仅FRDA患者中SCP的MTR相比于CC显著降低。我们认为，SCP中MTR的降低可能表明FRDA患者WM束中继发于轴突损失和少突胶质细胞功能障碍的髓鞘缺乏。
