Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, UK.
Mult Scler. 2011 Nov;17(11):1324-32. doi: 10.1177/1352458511410341. Epub 2011 Jul 29.
To identify associations between cognitive impairment and imaging measures in a cross-sectional study of patients with primary progressive multiple sclerosis (PPMS).
Neuropsychological tests were administered to 27 patients with PPMS and 31 controls. Patients underwent brain conventional magnetic resonance imaging (MRI) sequences, volumetric scans and magnetization transfer (MT) imaging; MT ratio (MTR) parameters, grey matter (GM) and normal-appearing white matter (NAWM) volumes, and WM T2 lesion load (T2LL) were obtained. In patients, multiple linear regression models identified the imaging measure associated with the abnormal cognitive tests independently from the other imaging variables. Partial correlation coefficients (PCC) were reported.
Patients performed worse on tests of attention/speed of visual information processing, delayed verbal memory, and executive function, and had a worse overall cognitive performance index, when compared with controls. In patients, a lower GM peak location MTR was associated with worse overall cognitive performance (p < 0.001, PCC = 0.77). GM mean and peak height MTR showed the strongest association with the estimated verbal intelligence quotient (IQ) decline (p < 0.001, PCC = -0.62), and executive function (p < 0.001, PCC = 0.79). NAWM volume was associated with attention/speed of visual information processing (p < 0.001, PCC = 0.74), while T2LL was associated with delayed verbal memory (p = 0.007, PCC = -0.55).
The finding of strong associations between GM MTR, NAWM volume and T2LL and specific cognitive impairments suggests that models that predict cognitive impairment in PPMS should include comprehensive MRI assessments of both GM and WM. However, GM MTR appears to be the main correlate of overall cognitive dysfunction, underlining the role of abnormal GM integrity in determining cognitive impairment in PPMS.
在原发性进行性多发性硬化症（PPMS）患者的横断面研究中，确定认知障碍与影像学测量之间的关联。
对 27 例 PPMS 患者和 31 例对照组进行神经心理学测试。患者接受脑常规磁共振成像（MRI）序列、容积扫描和磁化转移（MT）成像；获得 MT 比（MTR）参数、灰质（GM）和正常表现的白质（NAWM）体积以及 WM T2 病变负荷（T2LL）。在患者中，多元线性回归模型确定了与其他影像学变量独立相关的异常认知测试的影像学测量值。报告了部分相关系数（PCC）。
与对照组相比，患者在注意力/视觉信息处理速度、延迟言语记忆和执行功能测试中表现更差，整体认知表现指数更差。在患者中，较低的 GM 峰位 MTR 与整体认知表现较差相关（p<0.001，PCC=0.77）。GM 平均和峰高 MTR 与估计言语智商（IQ）下降（p<0.001，PCC=-0.62）和执行功能（p<0.001，PCC=0.79）的关联最强。NAWM 体积与注意力/视觉信息处理速度相关（p<0.001，PCC=0.74），而 T2LL 与延迟言语记忆相关（p=0.007，PCC=-0.55）。
GM MTR、NAWM 体积和 T2LL 与特定认知障碍之间存在很强的关联，这表明预测 PPMS 认知障碍的模型应包括 GM 和 WM 的综合 MRI 评估。然而，GM MTR 似乎是整体认知功能障碍的主要相关因素，这强调了 GM 完整性异常在确定 PPMS 认知障碍中的作用。
