Simister Robert J, Woermann Friedrich G, McLean Mary A, Bartlett Philippa A, Barker Gareth J, Duncan John S
MRI Unit, The National Society for Epilepsy and The Department of Clinical and Experimental Epilepsy, and NMR Research Unit, Department of Neuroinflammation, Institute of Neurology, University College London, England.
Epilepsia. 2002 Sep;43(9):1021-31. doi: 10.1046/j.1528-1157.2002.50701.x.
We used short-echo-time proton magnetic resonance spectroscopy imaging (MRSI) to study metabolite concentration variation through the temporal lobe in patients with temporal lobe epilepsy (TLE) with and without abnormal MRI.
MRSI was performed at TE = 30 ms to study 10 control subjects, 10 patients with TLE and unilateral hippocampal sclerosis, and 10 patients with TLE and unremarkable MRI (MRI negative). We measured the concentrations of N-acetyl aspartate +N-acetyl aspartyl-glutamate (NAAt), creatine (Cr), choline (Cho), glutamate + glutamine (Glx), and myoinositol, in the anterior, middle, and posterior medial temporal lobe (MTL), and in the posterior lateral temporal lobe. Segmented volumetric T1-weighted MRIs gave the tissue composition of each MRSI voxel. Normal ranges were defined as the control mean +/- 3 SD.
In the hippocampal sclerosis group, seven of 10 had abnormally low NAAt in the ipsilateral anterior MTL. In the MRI-negative group, four of 10 had low NAAt in the middle MTL voxel ipsilateral to seizure onset. Metabolite ratios were less sensitive to abnormality than was the NAAt concentration. Group analysis showed low NAAt, Cr, and Cho in the anterior MTL in hippocampal sclerosis. Glx was elevated in the anterior voxel contralateral to seizure onset in the MRI-negative group. Metabolite concentrations were influenced by voxel position and tissue composition.
(a) Low NAAt, Cr, and Cho were features of the anterior sclerotic hippocampus, whereas low NAAt was observed in the MRI-negative group in the middle MTL region. The posterior temporal lobe regions were not associated with significant metabolite abnormality; (b) The two patient groups demonstrated different metabolite profiles across the temporal lobe, with elevated Glx a feature of the MRI-negative group; and (c) Voxel tissue composition and position influenced obtained metabolite concentrations.
我们使用短回波时间质子磁共振波谱成像（MRSI）来研究伴或不伴有MRI异常的颞叶癫痫（TLE）患者颞叶内代谢物浓度的变化。
在TE = 30 ms时进行MRSI，研究10名对照受试者、10名患有TLE和单侧海马硬化的患者以及10名患有TLE且MRI无异常（MRI阴性）的患者。我们测量了颞叶内侧前、中、后部（MTL）以及颞叶外侧后部中N - 乙酰天门冬氨酸 + N - 乙酰天门冬氨酰 - 谷氨酸（NAAt）、肌酸（Cr）、胆碱（Cho）、谷氨酸 + 谷氨酰胺（Glx）和肌醇的浓度。分段容积T1加权MRI给出了每个MRSI体素的组织成分。正常范围定义为对照平均值±3标准差。
在海马硬化组中，10名患者中有7名患侧MTL前部的NAAt异常低。在MRI阴性组中，10名患者中有4名在癫痫发作起始同侧的MTL中部体素中NAAt较低。代谢物比率对异常的敏感性低于NAAt浓度。组间分析显示海马硬化患者MTL前部的NAAt、Cr和Cho较低。MRI阴性组中癫痫发作起始对侧前部体素中的Glx升高。代谢物浓度受体素位置和组织成分影响。
（a）NAAt、Cr和Cho降低是硬化海马前部的特征，而在MRI阴性组的MTL中部区域观察到NAAt降低；颞叶后部区域与显著的代谢物异常无关；（b）两组患者在整个颞叶表现出不同的代谢物谱，Glx升高是MRI阴性组的一个特征；（c）体素组织成分和位置影响所获得的代谢物浓度。
