颞叶癫痫伴海马硬化MRI诊断研究进展

伴海马硬化的颞叶癫痫是较常见的一种癫痫类型,临床上常采用手术治疗,因而致癫痫灶的定位十分重要。MRI能够清晰显示病灶,超高场强MRI在疾病早期即可清晰显示海马超微结构,而多种功能MRI如血氧水平依赖（BOLD）、磁共振波谱成像（MRS）、扩散加权成像（DWI）、扩散张量成像（DTI）在颞叶癫痫的诊断中具有不同的优势。就MRI对伴海马硬化的颞叶癫痫的诊断价值进行综述。     

难治性颞叶癫痫海马和同侧前颞叶MRI特征及其与临床相关性

目的：探讨难治性颞叶癫痫海马硬化（HS）与同侧前颞叶 MRI特征及其与临床的相关性。方法：搜集经影像学或病理诊断为难治性颞叶癫痫 HS的34例患者的临床和影像资料,其中25例行手术治疗。34例中女15例,男19例,平均年龄（22．4±8．2）岁。观察海马及同侧前颞叶 MRI征象,根据海马及前颞叶 MRI 征象将34例分为同侧前颞叶正常组与前颞叶异常组,后者再分为同时出现灰白质分界模糊和颞叶萎缩组与仅出现一种征象组两亚组,比较各组间临床特征的差异。结果：34例中,22例（64．7％）出现 HS及同侧前颞叶异常,12例同侧颞叶正常。前颞叶异常组首次癫痫发作年龄低于前颞叶正常组（t＝－3．438,P＝0．002）,病程时间比前颞叶正常组长（t＝2．453,P＝0．020）。前颞叶同时出现灰白质分界模糊和颞叶萎缩组与仅存在一种征象组间临床特征无统计学差异。结论：难治性颞叶癫痫伴有前颞叶异常的颞叶癫痫多数首次发病年龄小,病程长,MRI特征与临床病情具有紧密的相关性,对于手术侧别选择意义重大。     

Transneuronal degeneration in patients with temporal lobe epilepsy: evaluation by MR imaging

The aim of this study was to assess the MR imaging findings of transneuronal degeneration of limbic system in the patients with temporal lobe epilepsy, and to detect the influence of surgery on the anatomy of the limbic system. Axial and coronal T1- and T2-weighted MR images were retrospectively analyzed in 34 patients with temporal lobe epilepsy, focusing on transneuronal degeneration. In 17 of the 34 patients, MR images were also analyzed after selective amygdalo-hippocampectomy. Atrophy of the fornix, mamillary body, mamillothalamic tract (MTT), and thalamus ipsilateral to the epileptic focus was demonstrated on MR images in 14.7, 17.6, 8.8, and 11.8% of the 34 patients, respectively. Focal hyperintensity of the thalamus was found on T2-weighted images in 8.8% of the 34 patients. In 17 patients who were evaluated before and after surgery, transneuronal degeneration was seen more frequently after surgery: fornix (11.8 vs 29.4%), mamillary body (11.8 vs 52.9%), MTT (5.9 vs 11.8%), and thalamus (11.8 vs 11.8%). Transneuronal degeneration of the limbic system is clearly demonstrated by MR imaging in patients with temporal lobe epilepsy, and surgical intervention induces transneuronal degeneration more frequently.     

MRI of the fornix and mamillary body in temporal lobe epilepsy

We performed MRI on 27 patients with clinically proven temporal lobe epilepsy (TLE), all with prior EEG lateralisation, and 10 volunteers, studied to evaluate disparity in size arising from biological variation (group 1). Three-dimensional spoiled GRASS (3DSPGR) sequences provided 2-mm contiguous sections of the limbic system, enabling assessment of the hippocampus (HC), fornix (FN) and mamillary body (MB). Measurements of FN and MB width were made from a workstation. Any percentage difference in size was computed. In 19 cases there was unilateral abnormality in the HC (group 2); in 18 and 19 cases respectively there was a smaller FN and MB on the same side as the abnormal HC. This percentage difference in size was significantly greater than that in group 1 in the FN and MB in 17 and 17 cases respectively. Comparison of percentage difference computations for FN and MB between groups 1 and 2 showed high statistical significance (P < 0.0002). In 5 patients with clinical TLE the HC was normal on MRI (group 3). Unequal FN and MB sizes were found in 4, significant in 2. Comparison of percentage difference computations for FN and MB showed statistical significance (P < 0.0005 and P < 0.0003 respectively). There was no case of discordance between the sides of hippocampal abnormality and the smaller FN or MB or between the sides of smaller FN and MB. The strong concordance between the changes in the HC and those in the FN and MB suggests that this combination will play an important role in the assessment of TLE and limbic system abnormality. Received: 12 March 1996 Accepted: 12 August 1996     

颞叶癫痫的MRI研究

研究颞叶癫痫患者的ＭＲＩ表现，并测量ＴＬＥ患者海马结构的体积以确定癫痫灶的侧别。在１．０ＴＭＲ机对３８例ＴＬＥ患者进行研究，用正中矢状面定位，作平行于脑干的倾斜冠状面Ｔ１和Ｔ２加权像。在所有的倾斜冠状面Ｔ１加权像上手工描出ＨＰＦ的边界，把所有层在的体积相加即得到ＨＰＦ的体积，并进行标准处理以消除头颅大小的影响。     

难治性颞叶癫痫的分子影像学研究与病理对照

目的:对照难治性颞叶癫痫(TLE)手术病理资料,探讨联合单光子发射计算机断层(SPECT)和质子磁共振波谱(1 H-MRS)两种分子影像学技术对TLE定位的临床价值。方法:选择29例经手术病理证实的单侧TLE。所有患者术前均行SPECT发作间期脑血流(CBF)灌注显像、常规磁共振(MRI)扫描和1 H-MRS成像。将两种分子影像学技术,发作间期CBF灌注显像和1 H-MRS,对TLE的定位表现与病理结果进行对比分析。结果:病理改变最常见的是海马硬化和皮质发育不良,共27例(93.10%),此两种改变伴随出现于16例中(55.17%)。对于双重病理TLE,MRI、SPECT定位阳性率均为100%(16/16),MRS为87.50%(14/16)。对于单纯性海马硬化,MRI为阴性,SPECT仅为14.29%(1/7),而MRS高达57.14%(4/7)。对于单纯性皮质发育不全,MRS为阴性,MRI为50.00%(2/4),而SPECT高达75.00%(3/4)。联合应用SPECT和MRS对TLE定位率高达86.20%(25/29),尤其是对MRI阴性的患者,两种技术联合能发现54.55%(6/11)TLE的致痫灶。结论:联合SPECT发作间期脑血流灌注显像和1 H-MRS两种分子影像学技术能为难治性TLE提供更为全面和准确的定位诊断信息,可进一步提高定位MRI阴性TLE患者致痫灶的比例。     

神经梅毒颞叶内侧损害的MRI表现

目的 探讨颞叶内侧损害的神经梅毒患者的MRI表现,以提高对该病的认识.方法 报道5例表现为颞叶内侧损害的、经临床证实的神经梅毒患者的临床资料及MRI表现.结果 本组神经梅毒患者临床表现为认知功能障碍及精神障碍.5例表现为单侧或双侧颞叶内侧长T2及FLAIR高信号,2例DWI像呈高信号,4例伴不同程度脑萎缩.经过正规抗梅毒治疗后症状好转.结论 MRI表现为颞叶内侧损害是神经梅毒影像学特征表现之一,对临床诊断及治疗预后有重要意义.     

Bilateral cingulum fiber reductions in temporal lobe epilepsy with unilateral hippocampal sclerosis

PurposeTo evaluate whether white matter tracts within the Papez circuit are altered in patients with unilateral hippocampal sclerosis (HS).MethodsTwenty patients with histologically proven unilateral HS and 20 age-matched controls were studied with a 3 T Epilepsy-dedicated MRI protocol including a MPRAGE sequence for hippocampus volumetry and a diffusion tensor imaging (DTI) sequence (61 diffusion-encoding directions, 2 × 2 × 2 mm³ voxels) for diffusion tensor tractography (DTT). An energy-based global tracking algorithm was used to calculate streamline counts (SC) and fractional anisotropy (FA) of cingulate, fornix, and mammillo-thalamic tracts, respectively.ResultsSclerotic hippocampi were significantly smaller compared to the contralateral side and to age-matched controls. Cingulum SC but not FA were reduced on the hippocampal sclerosis (258 + 81.0) and contralateral side (271 + 85.6) compared to age-matched controls (447 + 138).ConclusionFocusing on white matter tracts of the Papez circuit we showed that in patients with intractable temporal lobe epilepsy unilateral hippocampal sclerosis is associated with a bilateral reduction of cingulum association fibers projecting from the cingulate gyrus to the parahippocampal gyrus.     

磁共振波谱与颞叶癫痫痫样放电的相关性研究

目的：探讨颞叶癫痫（TLE）患者氢质子磁共振波谱（1H-MRS）与癫痫发作之间的关系。方法：对45例手术证实为单侧TLE患者的单体素1H-MRS及视频脑电图（VEEG）进行回顾性分析,计算代谢产物氮-乙酰天门冬氨酸（NAA）、肌酸（Cr）、胆碱复合物（Cho）的值,分析代谢产物变化与临床癫痫发作程度的相关性。癫痫发作程度以24h内VEEG所记录的痫样放电的次数及程度来描述。结果：病变侧和对侧NAA、Cr和Cho均值分别为（52.31±12.78）ppm和（42.78±8.06）ppm、（43.36±10.43）ppm和（58.04±13.25）ppm、（40.49±10.02）ppm和（42.42±10.68）ppm,NAA值和发作间期痫样放电频率呈明显负相关（r=-0.67,P〈0.05）,而Cr水平与癫痫发作症状呈明显正相关（r=0.86,P〈0.05）。结论：1H-MRS分析能够反映TLE的严重程度,是TLE患者术前评价的一种有价值的辅助检查方法。     

伴海马硬化及占位性内侧颞叶癫痫脑灰质形态学研究

目的 研究伴海马硬化及占位性内侧颞叶癫痫(mTLE)脑灰质形态改变的差异,并探讨不同类型mTLE脑结构损伤特征及潜在的病理生理机制.方法 对30例伴海马硬化mTLE(mTLE-HS)、30例颞叶占位性mTLE患者(mTLE-OL)以及30名健康受试者进行全脑扫描,采用磁化准备快速梯度回波成像(MPRAGE)序列获得三维T1结构图像.运用代价函数对图像预处理,应用非线性映射空间变换的基于体素的形态学测量(VBM)进行分析,比较不同病因mTLE颞叶外脑灰质体积(GMV)的改变,并观察mTLE患者GMV改变与病程的相关性.结果 相比于正常对照组,两组mTLE均有颞叶外的GMV改变,但变化脑区分布模式不同:mTLE-HS显示更广泛的脑灰质萎缩(P＜0.01,Alpha-Sim校正).mTLE-HS患者局部GMV与病程无明显相关性;mTLE-OL患者对侧顶下叶及患侧基底节区GMV与病程负相关.结论 不同类型mTLE脑灰质形态学改变不同,提示两者存在的癫痫网络有所不同,进一步证实了mTLE-HS为一种特异性癫痫综合征.     

Magnetic Resonance Imaging of the Temporal Lobe: Normal Anatomy and Diseases

Objective

This pictorial essay will review the magnetic resonance imaging anatomy of the temporal lobes and describe the major pathologic processes of this complex area.

Conclusions

Magnetic resonance imaging is an essential tool in the investigation of a patient with suspected temporal lobe pathology. Various conditions may affect this anatomic region, and, therefore, classification of imaging findings into specific groups may help provide a more focused differential diagnosis.     

颞叶癫痫的功能MRI研究进展

颞叶癫■（TLE）是癫■中最常见的难治性类型,临床上对于药物难以控制的癫■,手术切除致■灶具有良好的治疗效果。随着MRI技术的迅速发展,功能磁共振成像（fMRI）在癫■研究中的优势越来越显著,尤其在癫■灶的定侧、定位方面明显优于常规MRI,具有更好的临床应用价值。fMRI对TLE脑网络、认知功能的研究,及在TLE病因、病理生理机制、治疗预后等方面的应用取得了诸多进展。     

Uncinate fasciculus fiber tracking in mesial temporal lobe epilepsy. Initial findings

In temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS), ictal discharge spread to the frontal and insulo-perisylvian cortex is commonly observed. The implication of white matter pathways in this propagation has not been investigated. We compared diffusion tensor imaging (DTI) measurements along the uncinate fasciculus (UF), a major tract connecting the frontal and temporal lobes, in patients and controls. Ten right-handed patients referred for intractable TLE due to a right HS were investigated on a 1.5-T MR scanner including a DTI sequence. All patients had interictal fluorodeoxyglucose PET showing an ipsilateral temporal hypometabolism associated with insular and frontal or perisylvian hypometabolism. The controls consisted of ten right-handed healthy subjects. UF fiber tracking was performed, and its fractional anisotropy (FA) values were compared between patients and controls, separately for the right and left UF. The left-minus-right FA UF asymmetry index was computed to test for intergroup differences. Asymmetries were found in the control group with right-greater-than-left FA. This asymmetrical pattern was lost in the patient group. Right FA values were lower in patients with right HS versus controls. Although preliminary, these findings may be related to the preferential pathway of seizure spread from the mesial temporal lobe to frontal and insulo-perisylvian areas.     

难治性颞叶癫痫定位诊断的SPECT与质子MR波谱对照研究

目的：探讨单光子发射计算机断层（SPECT）和质子磁共振波谱（1H-MRS）两种分子影像学技术对难治性颞叶癫痫定位诊断的临床价值。方法：选择经手术病理证实的单侧TLE患者29例。所有患者术前均行发作间期SPECT脑血流灌注显像、常规MRI扫描和1H-MRS成像。将两种分子影像学检查技术,发作间期脑血流灌注显像和1H-MRS,对颞叶癫痫致痫灶的定位诊断结果进行对比分析。结果：29例单侧TLE患者,常规MRI发现异常18例,其中海马硬化16例,定位率62.07%。SPECT异常21例,定位率72.41%,其中,MRI阴性病例中27.27%（3/11）的患者SPECT为阳性1。H-MRS发现异常18例,定位率62.07%,但MRI阴性病例中36.36%（4/11）的患者MRS为阳性。结论：SPECT对TLE功能异常脑区敏感,尤其是颞叶新皮质的异常1。H-MRS对早期海马硬化比MRI敏感。此两种分子影像学技术都能有效定位颞叶致痫灶,相互不可替代。     

Effect of seizure on hippocampus in mesial temporal lobe epilepsy and neocortical epilepsy: an MRS study

This study was performed to evaluate the effect of seizures on the bilateral hippocampus in mesial temporal lobe epilepsy (mTLE) and neocortical epilepsy by single voxel proton magnetic resonance spectroscopy (MRS). Forty-one patients with mTLE having unilateral hippocampal sclerosis and 43 patients with a neocortical epilepsy who underwent subsequent epilepsy surgery were recruited. Ninety-five percent confidence intervals of N-acetyl aspartate/choline (NAA/Cho) and NAA/creatine (NAA/Cr) ratios in 20 healthy control subjects were used as threshold values to determine abnormal NAA/Cho and NAA/Cr. NAA/Cho and NAA/Cr were significantly lower in the ipsilateral hippocampus of mTLE and neocortical epilepsy. Using asymmetry indices for patients with bilaterally abnormal ratios of NAA/Cho and NAA/Cr in addition to using unilateral abnormal ratio, the seizure focus was correctly lateralized in 65.9% of patients with mTLE and 48.8% of neocortical epilepsy patients. Bilateral NAA/Cho abnormality was significantly related to a poor surgical outcome in mTLE. No significant relationship was found between the results of NAA/Cho or NAA/Cr and surgical outcome in neocortical epilepsy. The mean contralateral NAA/Cr ratio of the hippocampus in mTLE was significantly lower in patients with a history of secondary generalized tonic-clonic seizure (SGTCS) than in those without. Our results demonstrate effects of seizures on the hippocampi in neocortical epilepsy and the relation between SGTCS and NAA/Cr of the contralateral hippocampus in mTLE. This proves the presence of a seizure effect on the hippocampus in neocortical epilepsy as well as in mTLE.     

原发性颞叶内侧癫痫伽玛刀治疗后放射性坏死的MRI诊断

目的：探讨原发性颞叶内侧癫痫伽玛刀治疗后出现放射性坏死的磁共振表现。方法：搜集2002年～2009年经伽玛刀治疗原发性颞叶内侧癫痫后MRI复查出现放射性坏死患者共13例,评价其磁共振表现。结果：放射性坏死出现时间9～67个月,平均时间为26.2个月。放射性坏死的MRI表现：照射侧颞叶内部大片状长T1长T2信号,静脉注射Gd-DTPA病灶中心不规则花环状强化,周围大片水肿,占位效应明显,强化灶大于照射野,治疗后病灶可缩小。结论：原发性颞叶内侧癫痫伽玛刀治疗后放射性坏死的出现时间及其磁共振表现具有特征性,磁共振检查有助于放射性坏死的早期诊断并指导临床治疗。     

中国汉族正常成人颞叶体积的高分辨率MRI测量

目的 研究中国汉族正常成人颞叶MRI形态特征,为建立中国标准脑提供颞叶形态学测量数据.方法 采用全国多中心临床研究形式,选取18～70岁健康志愿者300名,按照年龄18～30、31～40、41～50、51～60、61～70岁进行分组,分别定义为A、B、C、D、E组,每组男、女各30名.所有受试者均行3D磁化强度预备梯度回波序列T1WI采集颞叶体积,并对不同性别和年龄段标准化后的左、右侧颞叶体积分别进行方差分析.结果 男性左、右侧颞叶体积分别为(97 126±15 703)、(97 015±15 545)mm3,女性左、右侧颞叶体积分别为(95 123±14 564)、(96 423±13 407)mm3,左、右侧颞叶体积在性别上差异无统计学意义(F值分别为1.336、0.127,P值分别为0.249、0.722).5组左侧颞叶体积分别为(93 873±13 351)、(95 566±11 964)、(101 890±14 511)、(93 972±14 050)、(95 636±19 864)mm3,右侧颞叶体积分别为(93 409±10 984)、(98 158±16 392)、(102 079±15 112)、(95 448±11 123)、(94 658±16 928)mm3,5组间左、右侧颞叶体积差异有统计学意义(F值分别为2.940、3.514,P值分别为0.021、0.008).进一步两两间比较,C组左、右侧颞叶体积高于A、D组(p值均<0.05),其余各组间差异无统计学意义(P值均>0.05).结论 高分辨率MRI能提供较为精确的颞叶图像和测量数据,为建立中国标准脑提供了科学数据.     

海马测量对颞叶癫痫的研究

目的 :探讨MRI海马测量对颞叶癫痫的诊断价值。方法 :正常成人对照组 2 0例 ,测量海马体积 ;脑电图检查发现颞叶有癫痫波的患者 2 8例 ,用 1.5T超导磁共振仪检查 ,作垂直于海马长轴的倾斜冠状位 ,同时测量双侧海马。结果 :正常成人海马体积 ,右侧下限为 2 .60cm3 ,左侧下限为 2 .42cm3 。 2 8例患者中 15例未见海马萎缩 ,但其中有 5例颞叶病变 ,10例未发现异常病变 ;13例有海马萎缩 ,其中 9例单纯海马萎缩 (2例为双侧萎缩 ) ,2例为胶质瘤 ,其它 2例分别为海绵状血管瘤与囊肿。结论 :海马的萎缩是颞叶癫痫的重要原因 ,萎缩以单侧多见 ;T2 WI信号的升高反映了海马的硬化程度 ;MR的海马成像是脑外科开展癫痫外科手术治疗的不可缺少的部分。     

单侧颞叶癫痫病人双侧基底节区多体素MRS研究

目的 采用多体素MRS探讨单侧颞叶癫痫（TLE）病人双侧基底节区代谢物改变。方法 选取根据临床发作症状和脑电图综合诊断的左侧TLE病人10例,右侧TLE病人10例,正常志愿者10例纳入研究。所有TLE病人均进行利物浦痫性发作严重程度量表2.0（LSSS 2.0）评估,采用Simens 3.0 T超导MR设备进行多体素1H-MRS数据采集,对称性测量双侧尾状核头、豆状核和丘脑的N-乙酰天门冬氨酸（NAA）、乙酰胆碱（Cho）、肌酸（Cr）含量,计算各兴趣区NAA/Cr和Cho/Cr比值并进行统计学分析,将代谢物比值与LSSS 2.0评分进行Pearson相关分析。结果 左侧TLE组双侧丘脑NAA/Cr比值分别为1.92±0.15（左）和2.02±0.26（右）,右侧TLE组双侧丘脑NAA/Cr比值分别为2.19±0.16（左）和1.79±0.16（右）,均明显低于对照组[2.37±0.14（左）和2.36±0.10（右）,P＜0.05]。右侧TLE组,其致痫灶同侧丘脑的NAA/Cr比值较对侧丘脑要低（P＜0.05）。TLE组致痫灶同侧丘脑NAA/Cr比值与LSSS 2.0评分呈负相关（左侧 r=-0.667;右侧r=-0.643,均P＜0.05）。结论 单侧TLE病人存在双侧丘脑神经元丢失和/或功能障碍,且致痫灶同侧丘脑NAA/Cr比值与LSSS 2.0评分可以一致性反映近期痫性发作严重程度。     

Lateralisation with magnetic resonance spectroscopic imaging in temporal lobe epilepsy: an evaluation of visual and region-of-interest analysis of metabolite concentration images

We carried out spectroscopic imaging (MRSI) on nine consecutive patients with temporal lobe epilepsy being assessed for epilepsy surgery, and nine neurologically healthy, age-matched volunteers. A volume of interest (VOI) was angled along the temporal horns on axial and sagittal images, and symmetrically over the temporal lobes on coronal images. Images showing the concentrations of N-acetylaspartate (NAA) and of choline-containing compounds plus creatine and phosphocreatine (Cho + Cr) were used for lateralisation. We compared assessment by visual inspection and by signal analysis from regions of interest (ROI) in different positions, where side-to-side differences in NAA/(Cho + Cr) ratio were used for lateralisation. The NAA/(Cho + Cr) ratio from the different ROI was also compared with that in the brain stem to assess if the latter could be used as an internal reference, e. g., for identification of bilateral changes. The metabolite concentration images were found useful for lateralisation of temporal lobe abnormalities related to epilepsy. Visual analysis can, with high accuracy, be used routinely. ROI analysis is useful for quantifying changes, giving more quantitative information about spatial distribution and the degree of signal loss. There was a large variation in NAA/(Cho + Cr) values in both patients and volunteers. The brain stem may be used as a reference for identification of bilateral changes. Received: 19 July 2000/Accepted: 21 December 2000