Klistorner Alexander, Wang Chenyu, Yiannikas Con, Graham Stuart L, Parratt John, Barnett Michael H
Department of Ophthalmology, Save Sight Institute, University of Sydney, Sydney, Australia.
Australian School of Advanced Medicine, Macquarie University, Sydney, NSW, Australia.
PLoS One. 2016 Feb 22;11(2):e0149245. doi: 10.1371/journal.pone.0149245. eCollection 2016.
To evaluate the longitudinal integrity of white matter tracts in patients with relapsing remitting multiple sclerosis (RRMS) as determined by changes in diffusivity indices of lesional and non-lesional white matter in the optic radiation over 12 months.
The optic radiation (OR) was identified in sixty RRMS patients using probabilistic tractography. MS lesions were segmented on FLAIR T2 images and a lesion mask was intersected with the co-registered OR. Lesions within the OR were identified in 39 patients. Voxel-based analysis of axial diffusivity (AD) and radial diffusivity (RD) within OR lesions and non-lesional normal appearing white matter (NAWM) was performed at baseline and 12 months in 34 patients (five patients excluded due to new OR lesions).
Both RD and AD demonstrated much higher values within the lesions compared with non-lesional NAWM. There was a significant (p<0.001) increase of lesional AD and RD during the follow-up period. This increase, however, was driven almost entirely by the male cohort, in which a significantly greater change in both AD (M-2.7%, F-0.9%) and RD (M-4.6%, F-0.7%) was observed during the follow-up period. Non-lesional NAWM also demonstrated an increase in both AD and RD, albeit on a much lesser scale (1.0% and 0.6% respectively). In contradistinction to lesions, the diffusivity change in non-lesional NAWM was similar between sexes.
The evolution of AD and RD in chronic MS lesions over 12 months suggests ongoing inflammatory demyelinating activity accompanied by axonal loss. In addition, our findings are consistent with the recently observed trend of more rapid clinical progression in males and establish a potential in vivo biomarker of gender dichotomy by demonstrating a significantly faster rate of microstructural change in the chronic lesions of male patients with MS.
通过观察视辐射病灶及非病灶白质扩散率指标在12个月内的变化，评估复发缓解型多发性硬化症（RRMS）患者白质纤维束的纵向完整性。
采用概率性纤维束成像技术在60例RRMS患者中识别视辐射。在液体衰减反转恢复（FLAIR）T2图像上分割MS病灶，并将病灶掩码与配准后的视辐射相交。在39例患者中识别出视辐射内的病灶。对34例患者（5例因新发视辐射病灶被排除）在基线期和12个月时对视辐射病灶及非病灶正常表现白质（NAWM）进行基于体素的轴向扩散率（AD）和径向扩散率（RD）分析。
与非病灶NAWM相比，病灶内的RD和AD值均显著更高。随访期间病灶内的AD和RD显著增加（p<0.001）。然而，这种增加几乎完全由男性队列驱动，随访期间男性的AD（男性-2.7%，女性-0.9%）和RD（男性-4.6%，女性-0.7%）变化明显更大。非病灶NAWM的AD和RD也有所增加，尽管幅度小得多（分别为1.0%和0.6%）。与病灶不同，非病灶NAWM的扩散率变化在两性之间相似。
慢性MS病灶在12个月内AD和RD的演变表明存在持续的炎症性脱髓鞘活动并伴有轴突丢失。此外，我们的研究结果与最近观察到的男性临床进展更快的趋势一致，并通过证明男性MS患者慢性病灶的微观结构变化速率明显更快，建立了一种潜在的体内性别二分法生物标志物。
