Ranjeva Jean-Philippe, Audoin Bertrand, Au Duong My Van, Confort-Gouny Sylviane, Malikova Irina, Viout Patrick, Soulier Elisabeth, Pelletier Jean, Cozzone Patrick J
Centre de Résonance Magnétique Biologique et Médicale, CRMBM UMR CNRS 6612, Faculté de Médecine, 27 Boulevard Jean Moulin 13385 Marseilles cedex 05, France.
J Neurol Sci. 2006 Jun 15;245(1-2):161-7. doi: 10.1016/j.jns.2005.09.019. Epub 2006 Apr 21.
Following our previous reports based on parametric MRI methods (T(2)-weighted MRI, statistical mapping analysis of magnetization transfer ratio images and functional MRI) applied to a population of 18 patients with clinically isolated syndrome suggestive of multiple sclerosis, we have reviewed the possible structural and functional surrogates of MS that could explain the subtle cognitive impairment related to attention and working memory deficits evaluated with paced auditory serial addition test (PASAT). We propose that the brain substrates underlying cognitive impairment observed at the very early stage of MS are multifactorial. Several components could influence PASAT performances in patients: i) the extent of diffuse white matter damage, ii) the location of visible and non visible lesions, iii) the connectivity efficiency between distant brain functional areas involved in working memory processes and iv) the cortical reorganization. Nevertheless, individually, each of these parameters may have few influences on PASAT performance in patients. Using a multiregression model built with independent MR parameters, a very good evaluation of PASAT scores has been obtained in this limited number of patients explaining 90% of the variance. In conclusion, the different aspects of tissue and functional pathological brain underpinnings must be accounted to monitor accurately new therapeutic strategies for the treatment of early cognitive deficits related to MS.
继我们之前基于参数磁共振成像方法（T2加权磁共振成像、磁化传递率图像的统计映射分析和功能磁共振成像）对18例临床孤立综合征提示多发性硬化症患者群体的报告之后，我们回顾了可能的多发性硬化症结构和功能替代指标，这些指标可以解释通过听觉连续加法测试（PASAT）评估的与注意力和工作记忆缺陷相关的细微认知障碍。我们提出，在多发性硬化症早期观察到的认知障碍背后的脑底物是多因素的。几个因素可能会影响患者的PASAT表现：i）弥漫性白质损伤的程度，ii）可见和不可见病变的位置，iii）参与工作记忆过程的远距离脑功能区之间的连接效率，以及iv）皮质重组。然而，单独来看，这些参数中的每一个对患者的PASAT表现可能影响很小。使用由独立磁共振参数构建的多元回归模型，在这一有限数量的患者中对PASAT分数进行了很好的评估，解释了90%的方差。总之，必须考虑组织和功能性脑病理基础的不同方面，以准确监测治疗与多发性硬化症相关的早期认知缺陷的新治疗策略。
