颞叶癫痫海马硬化定侧的质子磁共振波谱研究

Analysis of Lateralization in Temporal Lobe Epilepsy by 1H-MR Spectroscopy

目的分析颞叶癫痫病例的海马磁共振波谱(1 H-MRS)成像、海马体积测量与脑电图间的关系,探讨1 H-MRS在颞叶癫痫海马硬化定侧中的应用价值。方法收集非病灶性颞叶癫痫患者57例和相匹配的正常健康人20例,测定双侧海马体积及海马1 H-MRS的NAA/(Cr+Cho)值。根据发作间歇期癫痫性放电(IEDs)优势对病例进行定侧,探讨1 H-MRS对颞叶癫痫海马硬化定侧的应用价值。结果根据IEDs能够提供定侧信息的有41例(71.9%),其中左侧颞叶癫痫组(L-TLE)24例,右侧颞叶癫痫组(R-TLE)17例,双侧颞叶癫痫组(B-TLE)16例。海马测量分析结果如下:(1)癫痫组中有56例(98.2%)双侧海马NAA/(Cr+Cho)值均低于对照组。病灶侧海马NAA/(Cr+Cho)值小于对侧海马(P均<0.001)。(2)海马体积测量发现海马萎缩的有28例(49.1%),其中4例双侧海马萎缩;而海马1 H-MRS异常56例(98.2%)。两种检查手段的阳性检出率差别有统计学意义(P<0.001)。(3)根据海马体积提供定位价值的有28例(49.1%),其中15例与IEDs定位符合(符合率53.6%);1 H-MRS结果(双侧差值>0.04)提供定位价值的有41例(71.9%),其中32例与IEDs定位符合(符合率78.0%),比海马体积符合率高(P<0.05)。结论(1)颞叶癫痫伴有较为普遍的双侧生化物质的改变,表现为NAA/(Cr+Cho)值下降。(2)海马1 H-MRS显示的生化改变对于颞叶癫痫的异常发现较海马体积测量更为敏感。(3)海马1 H-MRS有较高的定侧能力。

Objective To determine the value of 1 H-MR spectroscopy in lateralization of patients with temporal lobe epilepsy （TLE） . Methods Fifty-seven patients with nonlesional TLE and 20 controls were investigated by high resolution MRI and 1 H-MRS . Hippocampal volume and the ratios of NAA/Cr＋Cho were measured and compared between two groups . Lateralization of the patients was classified by the predominance of interictal epileptiform discharges （IED） . The lateralization rate was compared be-tween diffirent methods . Results Fourty-one patients（71 .9% ） were lateralized to one temporal lobe ac-cording to characteristic of the interictal EEG ,with 24 patients diagnosed as left temporal lobe epilepsy （L-TLE） and 17 as right temporal lobe epilepsy （R-TLE） . The other 16 patients were diagnosed as bilateral temporal lobe epilepsy （B-TLE） . （1）NAA/（Cho＋ Cr） ratios decreased in bilateral hippocampus in 56 TLE patients（98 .2% ） compared with controls . NAA/（Cho＋Cr） ratios were significantly lower in the ipsilateral （affected） compared with contralateral （non-affected） hippocampus in both L-TLE group （P＆lt;0 .001） and R-TLE group（P＆lt; 0 .001） . （2）Hippocampus atrophy was found in 28 TLE patients （49 .1% ） and 4 of them were bilateral . （3）28 patients （49 .1% ） were lateralized by hippocampal volume and 15 of them were accordant with IEDs （coincidence rate 53 .6% ） ,while 41 patients （71 .9% ） were lat-eralized by 1 H-MRS abnormalities and 32 of them were accordant with IEDs （coincidence rate 78 .0% ） . Conclusions Temporal lobe epilepsy is associated with widespread metabolic abnormalities in bilateral hip-pocampus . The degree of NAA/（Cho＋Cr） ratios reduction is more sensitive than hippocampal volume in evaluating hippocampal dysfunction . 1 H-MRS can be used in hemispheric lateralization of nonleisional TLE .