Matthews P M, Pioro E, Narayanan S, De Stefano N, Fu L, Francis G, Antel J, Wolfson C, Arnold D L
Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
Brain. 1996 Jun;119 ( Pt 3):715-22. doi: 10.1093/brain/119.3.715.
Quantitative measurement of MRI-defined brain lesions can provide an index of the extent and activity of disease in multiple sclerosis patients. However, the relationships between these indices and clinical features are not well-understood. Heterogeneity of the pathological changes underlying MRI lesions may be an important factor determining the correlation between MRI lesion volumes and clinical measures. Recent studies have suggested that with magnetic resonance spectroscopy (MRS), it may be possible to define chemical changes that better reflect the pathological changes in multiple sclerosis. Here we report results of combined quantitative brain T2-weighted MRI lesion volume and proton MRS examinations that demonstrate heterogeneity of the chemical pathology underlying brain lesions in patients selected on the basis of similar clinical disability but differing with respect to the presence or absence of clinical relapses. We examined 29 patients with disease characterized by either clear relapses with at least partial remissions (RR) or secondary, chronic progression after an earlier history of a more relapsing and remitting course (SP). Total hemispheric lesion volume was greater (P < 0.04) in the RR (32.5 +/- 20.9 cm3) than in the SP (16.2 +/- 9.0 cm3) patients, despite the longer duration of disease in the latter group. Central brain N-acetyl aspartate: creatine (NAA:Cr) ratios were reduced relative to normal controls (4.0 +/- 0.3, n = 19) by similar amounts in the two patients groups (RR, 3.1 +/- 0.5; SP, 3.2 +/- 0.4; P < 0.0001). The ratio lesion volume:(NAA:Cr) was greater for the RR group (11.7 +/- 9.3 cm3) than for the SP group (5.4 +/- 3.3 cm3, P < 0.05), implying a greater average degree of axonal loss per unit lesion volume defined by MRI for subjects in the SP group or, alternatively, a greater proportion of lesions without axonal damage or loss in the RR group. Our results emphasize a limitation of using T2-weighted MRI lesion volume alone and suggest that combined analysis of MR-based chemical and imaging data might allow improved non-invasive assessment of lesion pathology in order to better understand its relationship to clinical features of multiple sclerosis.
磁共振成像（MRI）定义的脑损伤定量测量可为多发性硬化症患者的疾病范围和活动情况提供一个指标。然而，这些指标与临床特征之间的关系尚未得到充分理解。MRI损伤背后病理变化的异质性可能是决定MRI损伤体积与临床指标之间相关性的一个重要因素。最近的研究表明，利用磁共振波谱（MRS），有可能确定能更好反映多发性硬化症病理变化的化学变化。在此，我们报告了联合进行脑T2加权MRI损伤体积定量和质子MRS检查的结果，这些结果显示，在基于相似临床残疾程度但有无临床复发情况不同而选取的患者中，脑损伤背后的化学病理学存在异质性。我们检查了29例患者，其疾病特征为要么有明确复发且至少有部分缓解（复发缓解型，RR），要么在早期有更多复发缓解病程后呈继发慢性进展（继发进展型，SP）。尽管SP组患者病程更长，但RR组（32.5±20.9立方厘米）的全脑半球损伤体积大于SP组（16.2±9.0立方厘米）（P<0.04）。相对于正常对照组（4.0±0.3，n = 19），两组患者的脑中央N-乙酰天门冬氨酸:肌酸（NAA:Cr）比值均有相似程度的降低（RR组为3.1±0.5；SP组为3.2±0.4；P<0.0001）。RR组的损伤体积:（NAA:Cr）比值（11.7±9.3立方厘米）大于SP组（5.4±3.3立方厘米，P<0.05），这意味着对于SP组受试者，每单位MRI定义的损伤体积的平均轴突损失程度更大，或者说，RR组中无轴突损伤或损失的损伤比例更大。我们的结果强调了仅使用T2加权MRI损伤体积的局限性，并表明基于磁共振的化学和成像数据的联合分析可能有助于改进对损伤病理的非侵入性评估，以便更好地理解其与多发性硬化症临床特征的关系。
