Francis P L, Chia T L, Jakubovic R, O'Connor P, Lee L, Feinstein A, Aviv R I
Medical Imaging (P.L.F., T.L.C., R.J., R.I.A.), Sunnybrook Health Sciences Centre
Medical Imaging (P.L.F., T.L.C., R.J., R.I.A.), Sunnybrook Health Sciences Centre.
AJNR Am J Neuroradiol. 2014 Oct;35(10):1910-5. doi: 10.3174/ajnr.A3974. Epub 2014 May 15.
Cognitive impairment is a common, disabling symptom of MS. We investigated the association between cognitive impairment and WM dysfunction in secondary-progressive multiple sclerosis using DTI.
Cognitive performance was assessed with a standard neuropsychological battery, the Minimal Assessment of Cognitive Function in Multiple Sclerosis. Cognitive impairment was defined as scoring >1.5 standard deviations below healthy controls on ≥2 subtests. Fractional anisotropy maps were compared against cognitive status using tract-based spatial statistics with threshold-free cluster enhancement.
Forty-five patients with secondary-progressive multiple sclerosis (median age: 55 years, female/male: 27/18, median Expanded Disability Status Scale Score: 6.5) were prospectively recruited. Cognitively impaired patients (25/45) displayed significantly less normalized global GM and WM volumes (P = .001, P = .024), more normalized T2-weighted and T1-weighted WM lesion volumes (P = .002, P = .006), and lower WM skeleton fractional anisotropy (P < .001) than non-impaired patients. Impaired patients also had significantly lower fractional anisotropy (p(corr) < .05) in over 50% of voxels within every major WM tract. The most extensively impinged tracts were the left posterior thalamic radiation (100.0%), corpus callosum (97.8%), and right sagittal stratum (97.5%). No WM voxels had significantly higher fractional anisotropy in patients with cognitive impairment compared with their non-impaired counterparts (p(corr) > .05). After the inclusion of confounders in a multivariate logistic regression, only fractional anisotropy remained a significant predictor of cognitive status.
Cognitively impaired patients with secondary-progressive multiple sclerosis exhibited extensive WM dysfunction, though preferential involvement of WM tracts associated with cognition, such as the corpus callosum, was apparent. Multivariate analysis revealed that only WM skeleton fractional anisotropy was a significant predictor of cognitive status.
认知障碍是多发性硬化症常见的致残症状。我们使用弥散张量成像（DTI）研究继发进展型多发性硬化症中认知障碍与白质功能障碍之间的关联。
采用标准神经心理学成套测验“多发性硬化症认知功能简易评估”对认知表现进行评估。认知障碍定义为在≥2个分测验中的得分比健康对照者低>1.5个标准差。使用基于体素的空间统计学方法及无阈值聚类增强技术，将分数各向异性图与认知状态进行比较。
前瞻性招募了45例继发进展型多发性硬化症患者（中位年龄：55岁，女性/男性：27/18，扩展残疾状态量表中位得分：6.5）。认知受损患者（25/45）与未受损患者相比，表现出显著更低的标准化全脑灰质和白质体积（P = 0.001，P = 0.024），更多的标准化T2加权和T1加权白质病变体积（P = 0.002，P = 0.006），以及更低的白质骨架分数各向异性（P < 0.001）。受损患者在每一条主要白质束内超过50%的体素中分数各向异性也显著更低（p(corr) < 0.05）。受影响最广泛的白质束是左侧丘脑后辐射（100.0%）、胼胝体（97.8%）和右侧矢状层（97.5%）。与未受损患者相比，认知受损患者的白质体素分数各向异性没有显著更高（p(corr) > 0.05）。在多因素逻辑回归中纳入混杂因素后，只有分数各向异性仍然是认知状态的显著预测因子。
继发进展型多发性硬化症认知受损患者表现出广泛的白质功能障碍，尽管与认知相关的白质束如胼胝体有明显的优先受累情况。多因素分析显示，只有白质骨架分数各向异性是认知状态的显著预测因子。
