Davie C A, Silver N C, Barker G J, Tofts P S, Thompson A J, McDonald W I, Miller D H
NMR Research Unit. Institute of Neurology, Queen Square, London WC1N 3BG, UK.
J Neurol Neurosurg Psychiatry. 1999 Dec;67(6):710-5. doi: 10.1136/jnnp.67.6.710.
To determine non-invasively the relation between the degree of axonal loss and the extent of demyelination in chronic lesions visible on MRI in patients with different subgroups of clinically definite multiple sclerosis using (1)H magnetic resonance spectroscopy ((1)H MRS) and magnetisation transfer imaging (MT). Conventional MRI is unable to differentiate between the various pathological processes occurring in the multiple sclerosis lesion. There are, however, newer MR techniques which show promise in this respect.
(1)H MRS and MT were performed in 18 patients with clinically definite multiple sclerosis who had a wide range of disability and disease duration.
A significant correlation was found between a reduction in the concentration of N-acetyl aspartate (NAA; an in vivo marker of axonal loss or dysfunction) and a reduction in MT ratio (a probable marker of demyelination) in patients who had entered the secondary progressive stage of the disease. Patients with minimal disability after a disease duration of greater than 10 years-so called benign multiple sclerosis-showed a relative preservation of NAA and MT.
Because a reduction in MT seems to be a relative marker for demyelination and a reduction of NAA from chronic lesions is indicative of axonal loss, this study supports the hypothesis that demyelination and axonal loss occur in the same chronic multiple sclerosis lesions. In addition, the degree of axonal loss and demyelination correlates with clinical heterogeneity.
使用氢磁共振波谱（¹H MRS）和磁化传递成像（MT），以无创方式确定临床确诊的不同亚组多发性硬化症患者中，MRI可见的慢性病灶内轴突损失程度与脱髓鞘程度之间的关系。传统MRI无法区分多发性硬化症病灶中发生的各种病理过程。然而，有一些更新的磁共振技术在这方面显示出了前景。
对18例临床确诊的多发性硬化症患者进行了¹H MRS和MT检查，这些患者的残疾程度和病程范围广泛。
在进入疾病继发进展期的患者中，发现N - 乙酰天门冬氨酸（NAA，轴突损失或功能障碍的体内标志物）浓度降低与MT比率降低（脱髓鞘的可能标志物）之间存在显著相关性。病程超过10年后残疾程度最小的患者，即所谓的良性多发性硬化症患者，显示出NAA和MT相对保留。
由于MT降低似乎是脱髓鞘的相对标志物，而慢性病灶中NAA降低表明轴突损失，本研究支持脱髓鞘和轴突损失发生在同一慢性多发性硬化症病灶中的假说。此外，轴突损失和脱髓鞘程度与临床异质性相关。
