PURPOSE Kearns Sayre syndrome (KSS) is a mitochondrial disorder characterized by development of visual impairment. Electroretinogram (ERG) and visual evoked potentials are not able to provide topographical information of optic damage. The purpose of this study was to explore retrochiasmatic optic pathway alteration in KSS with diffusion tractographic analysis and to compare it with different tracts. METHODS DTI from 8 KSS subjects (14.7 years) and 10 healthy controls (HC) were acquired on a 3T scanner. Optic radiations (OR), optic tracts (OT), inferior frontooccipital fasciculus (IFOF) and corticospinal tract (CST) were reconstructed with probabilistic tractography. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial (RD), and axial diffusivity (AD) were calculated, evaluating group differences. T test on diffusion parameters identified significantly different track portions among cohorts. RESULTS All patients had optic pathway alterations at electrophysiological examination. Significant lower FA were found in OT, IFOF, and CST of KSS group. RD was significantly higher in bilateral OR, IFOF, CST, and right OT, while ADC was higher in bilateral OR and CST. RD values were higher in the proximal and distal portion of OR bilaterally and in the distal portion of right OT, while widespread differences were found in IFOF and CST. No significant differences were found for AD. FA profiles analysis demonstrated significant differences between groups in several regions of OT, IFOF, and CST, while ADC assessment revealed spread differences in OR and CST. CONCLUSIONS DTI evaluation of retrochiasmatic tracks may represent a useful tool to topographically investigate retrochiasmatic visual impairment in KSS.

中文翻译：

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Kearns Sayre综合征的视觉通路评估：扩散张量成像研究。

目的Kearns Sayre综合征（KSS）是一种线粒体疾病，其特征是视力障碍。视网膜电图（ERG）和视觉诱发电位不能提供视觉损伤的地形信息。这项研究的目的是通过扩散束摄影术分析探索KSS中的后视交叉光学通路改变，并将其与不同的束进行比较。方法在3T扫描仪上获得了来自8名KSS受试者（14.7岁）和10名健康对照（HC）的DTI。用概率性眼压成像术重建视线（OR），视束（OT），额枕下束（IFOF）和皮质脊髓束（CST）。计算分数各向异性（FA），表观扩散系数（ADC），径向（RD）和轴向扩散率（AD），评估组差异。扩散参数的T检验确定了队列中显着不同的轨道部分。结果所有患者在电生理检查中均发生了光路改变。在KSS组的OT，IFOF和CST中发现了显着较低的FA。RD在双侧OR，IFOF，CST和右OT中显着升高，而ADC在双侧OR和CST中较高。RD的值在双侧OR的近端和远端部分以及右OT的远端部分较高，而IFOF和CST则存在广泛差异。没有发现AD有显着差异。FA谱分析表明，在OT，IFOF和CST的多个区域中各组之间存在显着差异，而ADC评估显示OR和CST的分布差异。