Tajima Y, Isonishi K, Kashiwaba T, Tashiro K
Department of Neurology, Kushiro Rosai Hospital, Japan.
No To Shinkei. 1998 Nov;50(11):1023-7.
We report herein a case of herpes simplex encephalitis (HSE) in which magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT) and proton magnetic resonance spectroscopy (1H-MRS) were performed sequentially. Both MRI and SPECT demonstrated a lesion on the left temporal lobe in its early stage. However, SPECT seemed more sensitive because it could detect subtle alterations of the blood flow. Hyperperfusion identified by SPECT had returned to normal levels while the abnormal MRI findings still remained. This may indicate that normalization of the blood perfusion precedes the tissue recovery. Contrast enhancement using Gd-DTPA was observed along the surface of the cerebral cortex on MRI, but that involved only part of the hyperperfusion areas depicted with SPECT. In the affected left temporal lobe, 1H-MRS exhibited reduction of N-acetyl-asparate (NAA), and an elevated lactate level. The former represented the neuronal loss, and the latter indicated impairment of oxidative metabolism. Furthermore, alterations of NAA/creatine (Cr) and choline (Cho)/Cr ratios were also observed in the seemingly normal right temporal lobe. Those ratios returned to nearly normal levels in accordance with the patient's clinical recovery. Subsequently, our results indicate that 1H-MRS might be a very useful tool in qualifying the tissue damage and possibly estimating the prognosis.
我们在此报告一例单纯疱疹病毒性脑炎（HSE），该病例先后进行了磁共振成像（MRI）、单光子发射计算机断层扫描（SPECT）和质子磁共振波谱（1H-MRS）检查。MRI和SPECT在早期均显示左侧颞叶有病变。然而，SPECT似乎更敏感，因为它能检测到血流的细微变化。SPECT显示的高灌注已恢复到正常水平，而MRI的异常表现仍然存在。这可能表明血液灌注的正常化先于组织恢复。MRI上使用钆喷酸葡胺（Gd-DTPA）观察到沿大脑皮质表面有对比增强，但仅涉及SPECT显示的部分高灌注区域。在受影响的左侧颞叶，1H-MRS显示N-乙酰天门冬氨酸（NAA）减少，乳酸水平升高。前者代表神经元丢失，后者表明氧化代谢受损。此外，在看似正常的右侧颞叶也观察到NAA/肌酸（Cr）和胆碱（Cho）/Cr比值的变化。随着患者临床恢复，这些比值恢复到接近正常水平。随后，我们的结果表明，1H-MRS可能是评估组织损伤和可能预测预后的非常有用的工具。
