Simister Robert J, McLean Mary A, Salmenpera Tuuli M, Barker Gareth J, Duncan John S
MRI Unit, The National Society for Epilepsy and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, UK.
Epilepsy Res. 2008 Sep;81(1):36-43. doi: 10.1016/j.eplepsyres.2008.04.009. Epub 2008 May 27.
To investigate post-ictal changes in cerebral metabolites.
We performed a longitudinal quantitative proton magnetic resonance spectroscopy (MRS) study in 10 patients with epilepsy and 10 control subjects. The patients were studied on two occasions: immediately following a seizure, and on a second occasion at least 7h after the most recent seizure. Each study measured N-acetyl aspartate plus N-acetyl aspartyl glutamate (NAAt), Creatine plus phosphocreatine (Cr), Choline containing compounds (Cho) and glutamate plus glutamine (GLX) concentrations using a short-echo time sequence (TE=30ms), and NAAt, Cr and lactate using a second sequence with longer echo time (TE=144ms). The control group was studied on two occasions using the same sequences.
No inter-scan differences were observed for the control group. NAAt and NAAt/Cr levels were lower in the patient group at both measured TEs but did not change significantly between studies. The ratio of Cr at TE 144ms to TE 30ms (Cr(144)/Cr(30)) and GLX/Cr were higher and Cho lower in the post-ictal scan compared to the inter-ictal study. Change in Cr(144)/Cr(30) and NAAt(144)/Cr(144) correlated with the post-ictal interval. Lactate measurement at longer TE was not informative.
Proton MRS is sensitive to metabolite changes following epileptic seizures within the immediate post-ictal period. The ratio Cr(144)/Cr(30) is the most sensitive measure of metabolic disturbance and is highest in the post-ictal period but appears to normalise within 2h of the most recent seizure.
研究癫痫发作后大脑代谢物的变化。
我们对10例癫痫患者和10名对照者进行了纵向定量质子磁共振波谱（MRS）研究。对患者进行了两次研究：一次在癫痫发作后立即进行，另一次在最近一次发作至少7小时后进行。每次研究使用短回波时间序列（TE = 30ms）测量N-乙酰天门冬氨酸加N-乙酰天门冬氨酰谷氨酸（NAAt）、肌酸加磷酸肌酸（Cr）、含胆碱化合物（Cho）以及谷氨酸加谷氨酰胺（GLX）的浓度，并使用第二个回波时间较长的序列（TE = 144ms）测量NAAt、Cr和乳酸。对照组使用相同序列进行了两次研究。
对照组未观察到扫描间差异。在两个测量的TE时间点，患者组的NAAt和NAAt/Cr水平均较低，但两次研究之间无显著变化。与发作间期研究相比，发作后扫描中TE 144ms时的Cr与TE 30ms时的Cr之比（Cr(144)/Cr(30)）以及GLX/Cr较高，而Cho较低。Cr(144)/Cr(30)和NAAt(144)/Cr(144)的变化与发作后间隔相关。在较长TE时间测量乳酸无参考价值。
质子MRS对癫痫发作后即刻发作期内的代谢物变化敏感。Cr(144)/Cr(30)比值是代谢紊乱最敏感的指标，在发作后期最高，但在最近一次发作后2小时内似乎恢复正常。
