复发-缓解型多发性硬化患者初级视觉皮层及视放射DTI研究

DTI Study of the Primary Visual Cortex and Optic Radiation in Relapsing Remitting Multiple Sclerosis

目的利用DTI技术探讨复发-缓解型多发性硬化(RRMS)患者初级视觉皮层的结构改变及其与视放射结构改变的关系。方法 20例RRMS患者与20名年龄、性别匹配的健康志愿者纳入研究,采用扩展残疾状态量表(EDSS),经过修正的疲劳影响尺度(MFIS),同步听觉系列加法测验(PASAT)对所有RRMS患者进行临床评估。所有受试者行DTI扫描,选择初级视觉皮层和视放射分别作为感兴趣区,分别计算初级视觉皮层DTI值(FA、ADC、λ∥和λ⊥)和视放射的FA值,比较组间差异,并进行相关性分析。结果与对照组相比,RRMS患者初级视觉皮层ADC值(t=3.056,P=0.004)、λ∥(t=2.523,P=0.016)及λ⊥(t=3.007,P=0.005)均明显升高,但FA值改变差异无明显统计学意义,而患者组视放射的FA值显著降低(t=-2.405,P=0.021)。RRMS患者组初级视觉皮层的ADC值(r=0.538,P=0.017)、λ∥(r=0.531,P=0.019)及λ⊥(r=0.519,P=0.023)均与病程呈正相关,与其他临床参数均无显著相关性。患者组初级视觉皮层与视放射FA值之间无显著相关性。结论 RRMS患者初级视觉皮层和视放射均存在结构的损伤,两者间损伤程度无相关性,提示初级视觉皮层与视放射之间的病理改变过程可能是独立发生的。

Objective To explore the structural changes of the primary visual cortex （V1） and optical radiation （OR） in patients with relapsing remitting multiple sclerosis （RRMS）, and to analyze the relationship between the primary visual cortex and optical radiation by using diffusion tensor imaging （DTI）. Methods A total of 20 patients with RRMS （study group） and other 20 healthy volunteers （control group） were enrolled in this study. All patients with RRMS were evaluated by the expanded disability status scale （EDSS）, modified fatigue impact scale （MFIS） and paced auditory serial addition test （ PASAT）. Both conventional scanning and DTI scanning were performed in all subjects with a 3.0 T MR scanner. The DTI values of V1, including FA, ADC, λ// and λ⊥ and FA value of OR were measured respectively. The results were compared between the two groups and the correlation between them was analyzed. Results Compared with the control group, the DTI values of V1 in the study group were obviously increased ： ADC （ t = 3. 056, P = 0. 004）, λ/ // （ t = 2. 523, P = O. 016 ）, and ）λ⊥ （ t = 3. 007, P = 0. 005 ）, although no statistically significant difference in FA values existed between the two groups （ t = - 2. 405, P = 0. 021 ）. FA values of OR in the study group was markedly decreased. In the study group the ADC value of V1 （r=0.538, P=0.017）,λ// （r=0.531, P=0.019） and λ⊥ （r=0.519, P=0.023） values had a parallel relationship with the duration of disease, while they bore no significant relationship to other clinical parameters. In the study group, no significant correlation existed between FA value of V1 and FA value of OR. Conclusion In patients with RRMS structural damages do exist in both V1 and OR, although no correlation exists between the degrees of V1 and OR damage, suggesting that the pathological changes in V1 and in OR may develop independently .