Van Au Duong My, Audoin Bertrand, Le Fur Yann, Confort-Gouny Sylviane, Malikova Irina, Soulier Elisabeth, Viout Patrick, Ali-Cherif André, Pelletier Jean, Cozzone Patrick J, Ranjeva Jean-Philippe
Centre de Résonance Magnétique Biologique et Médicale UMR CNRS 6612, Faculté de Médecine, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France.
J Neurol. 2007 Jul;254(7):914-23. doi: 10.1007/s00415-006-0474-7. Epub 2007 Apr 20.
Proton magnetic resonance spectroscopic imaging ((1)H-MRSI) was used to study metabolic abnormalities inside the gray matter (GM) during or distant to white matter (WM) inflammatory processes reflected by T(1) gadolinium-enhancing lesions in patients at the very early stage of multiple sclerosis (MS). The spectroscopic examination was performed in the axial plane using a home-designed acquisition-weighted, hamming shape, 2D-SE pulse sequence (TE = 135 ms; TR = 1,600 ms). Bilateral thalami and the medial occipital cortex were explored in 35 patients (15 with and 20 without T(1)-Gd enhancing lesions) with clinically isolated syndrome suggestive of MS and in 30 controls. The mean duration since the first presenting symptom was 9.1 (+/-6.7) months. The two groups of patients (with or without T(1) Gd-enhancing lesions) did not differ in terms of time elapsed since the first clinical onset and T(2) lesion load. The spatial contamination of surrounding WM tissues was obtained in each GM region by determining the tissue component in the ROI from GM and WM probability maps smoothed with the point spread function of the MRSI acquisition. Contribution of WM signal was important (60%) inside thalami while the region centered on the medial occipital cortex was well representative of GM metabolism (>70%). Comparisons of relative metabolite levels (ratios of each metabolite over the sum of all metabolites) between all patients and controls showed significant decrease in relative N-acetyl aspartate (NAA) levels, increase in relative choline-containing compounds (Cho) levels and no change in relative creatine/phosphocreatine levels inside the three ROIs. Decrease in relative NAA levels and increase in relative Cho levels were found in patients with inflammatory activity, while no metabolic alterations were present in patients without T(1) Gd-enhancing lesions. These results suggest that abnormalities in GM metabolism observed in patients at the very early stage of MS are mainly related to neuronal dysfunction occurring during acute inflammatory processes.
质子磁共振波谱成像（(1)H-MRSI）用于研究多发性硬化症（MS）极早期患者中，由钆增强T(1)病变所反映的白质（WM）炎症过程期间或远离该过程时灰质（GM）内的代谢异常。使用自行设计的采集加权、汉明形状的二维自旋回波脉冲序列（TE = 135毫秒；TR = 1600毫秒）在轴位平面进行波谱检查。对35例临床孤立综合征提示为MS的患者（15例有T(1)-钆增强病变，20例无）和30例对照者进行双侧丘脑和枕叶内侧皮质的检查。自首次出现症状以来的平均持续时间为9.1（±6.7）个月。两组患者（有或无T(1)钆增强病变）在自首次临床发病以来的时间和T(2)病变负荷方面无差异。通过从GM和WM概率图中确定ROI中的组织成分，并利用MRSI采集的点扩散函数进行平滑处理，获取每个GM区域周围WM组织的空间污染情况。丘脑内部WM信号的贡献很大（60%），而以枕叶内侧皮质为中心的区域能很好地代表GM代谢（>70%）。所有患者与对照者之间相对代谢物水平（各代谢物与所有代谢物总和的比值）的比较显示，三个ROI内相对N-乙酰天门冬氨酸（NAA）水平显著降低，相对含胆碱化合物（Cho）水平升高，相对肌酸/磷酸肌酸水平无变化。有炎症活动的患者中发现相对NAA水平降低和相对Cho水平升高，而无T(1)钆增强病变的患者未出现代谢改变。这些结果表明，MS极早期患者中观察到的GM代谢异常主要与急性炎症过程中发生的神经元功能障碍有关。
