Horská A, Naidu S, Herskovits E H, Wang P Y, Kaufmann W E, Barker P B
Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
Neurology. 2000 Feb 8;54(3):715-22. doi: 10.1212/wnl.54.3.715.
To determine cerebral regional concentrations of N-acetyl aspartate (NAA), total choline (Cho), and total creatine (Cr) in Rett syndrome (RS) using 1H magnetic resonance spectroscopic imaging (MRSI).
The biochemical defect underlying RS is unknown. Because in vivo MRSI can detect important cerebral metabolites, MRSI has a potential to reveal impairment of regional cerebral metabolism in RS noninvasively.
High-resolution, multislice 1H MRSI was carried out in 17 girls with RS. The control group consisted of nine healthy children.
In patients with RS, average Cho concentration was 12% higher (p < 0.005) and average NAA concentration 11% lower (p < 0.0001) compared with the control group. Regional metabolic differences included significantly lower NAA concentration in the frontal gray and white matter, insula, and hippocampus in RS; no difference in regional Cho and Cr concentrations were found. A 20 to 38% higher Cho:NAA ratio in frontal and parietal gray and white matter, insular gray matter, and hippocampus (p < 0.05) and a 14 to 47% lower NAA:Cr ratio in frontal cortical gray matter, parietal and temporal white matter, insula, and putamen (p < 0.05) were found in subjects with RS compared with controls. Patients with seizures had higher average concentrations of Cho, Cr, and NAA compared with those without seizures (8-19%, p < 0.05).
Metabolic impairment in RS involves both gray and white matter and particularly involves frontal and parietal lobes and the insular cortex. Loss of NAA most likely reflects reduced neuronal and dendritic tree size; increased Cho concentration may result from gliosis.
使用氢质子磁共振波谱成像（MRSI）测定雷特综合征（RS）患者脑区N-乙酰天门冬氨酸（NAA）、总胆碱（Cho）和总肌酸（Cr）的浓度。
RS潜在的生化缺陷尚不清楚。由于活体MRSI能够检测重要的脑代谢物，因此MRSI有潜力无创地揭示RS患者脑区代谢的损害。
对17名RS女童进行高分辨率多层氢质子MRSI检查。对照组由9名健康儿童组成。
与对照组相比，RS患者的平均Cho浓度高12%（p<0.005），平均NAA浓度低11%（p<0.0001）。脑区代谢差异包括RS患者额叶灰质和白质、岛叶及海马的NAA浓度显著降低；脑区Cho和Cr浓度无差异。与对照组相比，RS患者额叶和顶叶灰质和白质、岛叶灰质及海马的Cho:NAA比值高20%至38%（p<0.05），额叶皮质灰质、顶叶和颞叶白质、岛叶及壳核的NAA:Cr比值低14%至47%（p<0.05）。与无癫痫发作的患者相比，有癫痫发作的患者Cho、Cr和NAA的平均浓度更高（8% - 19%，p<0.05）。
RS的代谢损害累及灰质和白质，尤其累及额叶、顶叶及岛叶皮质。NAA的减少很可能反映了神经元和树突大小的减小；Cho浓度升高可能是胶质增生所致。
