颞叶癫痫海马硬化定侧的质子磁共振波谱研究

目的：分析颞叶癫痫病例的海马磁共振波谱（1H-MRS）成像、海马体积测量与脑电图间的关系，探讨1H-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1H-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1H-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1H-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％）；1H-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1H-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1H-MRS有较高的定侧能力。

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

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 .