Rooney W D, Miller R G, Gelinas D, Schuff N, Maudsley A A, Weiner M W
Department of Veterans Affairs Medical Center, Department of Radiology, University of California, San Francisco, USA.
Neurology. 1998 Jun;50(6):1800-5. doi: 10.1212/wnl.50.6.1800.
The primary objectives of this study were to test whether 1) N-acetylaspartate (NAA), a neuronal marker, is reduced in motor cortex and corticospinal-tract (CST) brain regions of ALS patients; and 2) motor cortex NAA correlates to a clinical measurement of upper motor neuron function in ALS patients. Ten probable or definite ALS patients and nine neurologically normal control subjects were studied. Three axial planes of two-dimensional 1H MRSI data were collected, using a single spin-echo multislice sequence (TE140/TR2000). Two of the 1H MRSI planes were positioned superior to the lateral ventricles, and one plane was positioned at the level of the internal capsule. Spectroscopy voxels were selected from motor cortex, frontal cortex, parietal cortex, medial gray matter, centrum semiovale white matter, anterior internal capsule, and posterior internal capsule. Peak integrals were obtained for the three major 1H MRSI singlet resonances, NAA, creatine and phosphocreatine (Cr), and cholines (Cho). Maximum finger-tap rate was used as a clinical measurement of upper motor neuron function. In ALS, brain NAA/(Cho+Cr) was reduced 19% (p=0.024) in the motor cortex and 16% (p=0.021) in the CST (centrum semiovale and posterior internal capsule) regions. NAA/ (Cho+Cr) was not reduced in frontal cortex, parietal cortex, medial gray matter, or anterior internal capsule. There was a significant relation between ALS motor cortex NAA/(Cho+Cr) and maximum finger-tap rate (r=0.80; p=0.014). NAA/(Cho+Cr) was reduced in motor cortex and CST regions and unchanged in other brain regions of ALS patients when compared with controls. These findings are consistent with the known distribution of neuronal loss in ALS. The positive correlation between motor cortex NAA/(Cho+Cr) and maximum finger-tap rate suggests that reduced NAA/(Cho+Cr) is a surrogate marker of motor cortex neuron loss in ALS. These findings support the study of 1H MRSI NAA measurement as an objective and quantitative measurement of upper motor neuron dysfunction in ALS.
1）神经元标志物N-乙酰天门冬氨酸（NAA）在肌萎缩侧索硬化症（ALS）患者的运动皮层和皮质脊髓束（CST）脑区是否减少；以及2）运动皮层NAA是否与ALS患者上运动神经元功能的临床测量值相关。研究了10例可能或确诊的ALS患者和9例神经功能正常的对照受试者。使用单自旋回波多层序列（TE140/TR2000）收集二维1H磁共振波谱成像（MRSI）数据的三个轴向平面。其中两个1H MRSI平面位于侧脑室上方，一个平面位于内囊水平。从运动皮层、额叶皮层、顶叶皮层、内侧灰质、半卵圆中心白质、内囊前肢和内囊后肢中选择磁共振波谱体素。获得了1H MRSI的三个主要单峰共振峰（NAA、肌酸和磷酸肌酸（Cr）以及胆碱（Cho））的峰积分值。将最大手指敲击速率用作上运动神经元功能的临床测量指标。在ALS患者中，运动皮层的脑NAA/（Cho+Cr）降低了19%（p=0.024），CST（半卵圆中心和内囊后肢）区域降低了16%（p=0.021）。额叶皮层、顶叶皮层、内侧灰质或内囊前肢的NAA/（Cho+Cr）未降低。ALS运动皮层NAA/（Cho+Cr）与最大手指敲击速率之间存在显著相关性（r=0.80；p=0.014）。与对照组相比，ALS患者运动皮层和CST区域的NAA/（Cho+Cr）降低，而其他脑区则无变化。这些发现与ALS中已知的神经元丢失分布一致。运动皮层NAA/（Cho+Cr）与最大手指敲击速率之间的正相关表明，NAA/（Cho+Cr）降低是ALS中运动皮层神经元丢失的替代标志物。这些发现支持将1H MRSI NAA测量作为ALS中上运动神经元功能障碍的客观定量测量方法进行研究。
