老年抑郁症首次发病与复发患者脑结构的磁共振研究

目的:基于磁共振探讨首发与复发老年抑郁症患者脑结构特点。方法:对首发与复发老年抑郁症患者30例(首发组20例,复发组10例)和正常人30名(正常对照组)进行脑磁共振成像检查并运用弥散张量成像(DTI)扫描,比较首发与复发抑郁症患者与正常对照组的异常脑区以及首发与复发患者脑白质、灰质容量及白质各向异性分数(FA)值的差异。结果:与正常对照组比较,患者组双侧额叶、右顶叶、左楔叶、左海马回灰质以及左颞上回白质T1信号强度减低;右扣带回灰质T1信号及白质T1信号强度升高(P0.01,像素集合30)。首发组和复发组患者脑白质容量未发现显著差异脑区,但复发组右海马区灰质容量较首发组明显减小(P0.01,像素集合30)。与首发组比较,复发组右额中回、左颞中回白质FA值减低(P均0.01,像素集合30)。结论:首发与复发老年抑郁症患者可能存在前额叶及右扣带回功能缺陷;双侧海马区灰质容量可能与临床症状有关。     

精神分裂症患者全脑白质纤维弥散张量成像的初步研究

目的运用能够提示白质纤维(white matter,WM)完整性的弥散张量成像(diffusion tensor imaging,DTI)技术,探讨精神分裂症患者全脑白质纤维是否受到损害。方法对21例精神分裂症患者(患者组)和21名健康人(对照组)进行全脑DTI扫描,用SPM2(Statistical Parametric Maps,SPM)软件对图像进行处理,采用以像素为基础的分析方法(voxel-based analysis,VBA)对两组的分数各向异性(fractional anisotropy,FA)值进行组间比较。结果患者组下列脑区的FA值显著低于对照组(P<0·001):左侧额眶区和右侧额中回的白质、双侧颞下回白质、双侧顶叶内侧白质、右侧前扣带、双侧海马、双侧大脑脚、双侧岛叶、右侧放射冠和右侧小脑上脚。结论精神分裂症多个部位脑白质纤维的完整性受到破坏。     

语义性痴呆结构性磁共振成像研究

目的分析语义性痴呆患者灰质和白质结构变化,提高对其病理改变和发生机制的认识。方法采用3.0T MRI扫描仪对16例语义性痴呆患者和17例正常对照者进行全脑扫描,扫描序列包括三维高分辨力结构像和扩散张量成像(DTI)。通过专业统计软件分别对全脑灰质密度和白质纤维束部分各向异性(FA)值进行分析,比较两组受试者全脑灰质密度(P0.001,Voxel338)和白质纤维束FA值(P0.005,Voxel103)。结果与对照组相比,语义性痴呆组患者双侧颞叶,特别是颞极表现为灰质密度显著降低,以左侧大脑半球额颞顶叶灰质密度减低区域更为广泛,包括左侧颞下回、缘上回、顶下回和额中回;同时双侧颞叶白质纤维束FA值显著降低,包括双侧钩束、左侧扣带(海马)纤维和双侧下额枕束。白质纤维束FA值分析结果与VBM法所显示的灰质密度在解剖学上呈现极高的一致性。结论本研究在体揭示了语义性痴呆的病理学和解剖学基础,为理解语义性痴呆的病理学机制提供了客观佐证。     

精神分裂症首次发病患者的脑扩散张量成像研究

目的 利用磁共振扩散张量成像(DTI)技术研究未经药物治疗的精神分裂症首次发病(以下简称首发)患者主要脑区白质纤维束的异常.方法 选取26例首发精神分裂症患者(患者组)和20名健康志愿者(对照组)行脑DTI扫描(两组均为右利手),测量胼胝体膝部、压部、双侧额叶白质、扣带束前部及海马头的部分各向异性(FA)值.结果 (1)对照组左侧扣带束FA值(0.428±0.067)大于右侧(0.375±0.079;P＜0.05).(2)患者组两侧相对应感兴趣区FA值差异均无统计学意义(P＞0.05).(3)患者组左右侧胼胝体压部FA值(均为0.734±0.085)、左右侧扣带束前部FA值(0.300±0.068和0.306 4±0.062)均低于对照组(0.785±0.045,0.428±0.067,0.375±0.079;均P＜0.05).结论 首发精神分裂症患者存在双侧扣带束、胼胝体压部白质纤维束的受损,支持脑内连接异常假说.     

首发精神分裂症阳性症状为主型患者脑弥散张量成像研究

目的 探讨首发精神分裂症阳性症状为主型患者主要脑区白质纤维束有无异常.方法 对未系统使用过精神药物治疗的20例首发精神分裂症阳性症状为主型患者和20名正常对照进行磁共振弥散张量成像(DTI)扫描,测量胼胝体膝部、压部、双侧额叶白质、双侧扣带束前部和双侧海马头部分各向异性(FA)值.结果 ①患者组及对照组组内比较,左右侧FA值差异均无统计学意义(P>0.05).②患者组左侧海马头和胼胝体压部FA值[(0.17±0.03),(0.73±0.09)]显著低于对照组[(0.20±0.02),(0.79±0.05)],差异均有统计学意义(P<0.05);③患者组左右侧扣带束前部FA值[(0.28±0.06),(0.29±0.05)]低于对照组[(0.43±0.07),(0.38±0.08)],差异均有统计学意义(P<0.01).结论 首发精神分裂症阳性症状为主型患者双侧扣带束前部、胼胝体压部及左侧海马头的白质纤维束完整性受损,提示其可能存在脑神经发育连接异常.     

首发偏执型精神分裂症患者的脑白质磁共振弥散张量成像研究

目的探讨首发未用药的偏执型精神分裂症患者的多个脑区白质磁共振弥散张量成像(diffusion tensor imaging,DTI)的特点,以期为精神分裂症"脑内连接异常的假说"提供依据。方法选取20例首发偏执型精神分裂症患者,应用DTI扫描,检测脑内21个感兴趣区(regions of interest,ROI)白质纤维的微细结构,并与20名年龄、性别和文化程度相匹配的正常对照比较。结果患者组额叶、内囊前肢、外囊的左右两侧FA值和左侧颞叶、左侧内囊膝部、胼胝体膝部FA值小于对照组(P0.05)。患者组额叶左右侧FA值差异无统计学意义(P0.05),而对照组左侧大于右侧(P0.05);患者组内囊膝部和后肢FA值右侧大于左侧(P0.05),而对照组左侧大于右侧(P0.05)。患者组双侧外囊FA值均小于对照组(P0.05)。结论未用药首发偏执型精神分裂症患者脑内多个白质区部分各向异性降低,尤其是额叶皮层下环路更加显著,数个白质区部分各向异性的正常"左右"的偏侧性缺失或倒置,支持精神分裂症脑内连接异常的神经病理假说。     

阿尔茨海默病患者脑白质损害与认知功能的关系

目的用磁共振扩散张量成像(DTI)研究阿尔茨海默病(AD)患者脑白质损害的特点及其与认知功能改变的相关性。方法对16例AD患者和12名年龄及性别相当的健康老年人行DTI、T1液体衰减反转恢复序列(FLAIR)及T2-FLAIR检查,测量胼胝体膝部和压部、内囊前肢和后肢、额颞顶枕叶白质的部分各向异性分数值(FA)和平均弥散度(MD),分析FA、MD值与简易精神状态量表(MMSE)评分之间的相关关系。结果AD患者胼胝体压部、额叶、顶叶、颞叶FA值分别为0.602±0.043、0.270±0.034、0.294±0.043、0.302±0.032,与健康老人组相比显著下降(P<0.05),且与MMSE评分呈正相关关系,而内囊前后肢、枕叶、胼胝体膝部的FA值则无明显变化(P>0.05);胼胝体压部、顶叶白质的MD值分别为(0.918±0.029)、(0.826±0.015)×10-9m2/s,与健康老人组相比显著升高(P<0.01),且与MMSE评分呈负相关,而内囊前后肢、额叶、颞叶、枕叶和胼胝体膝部的MD值则无明显变化(P>0.05)。结论AD患者表现为脑白质的选择性损害,且损害程度与认知功能密切相关;这种选择性损害反映了AD病理机制中皮质-皮质及皮质-皮质下联系的丢失;DTI技术可以用来监测疾病的进展情况及评价AD治疗药物的临床疗效。     

腔隙性脑梗死形似正常区的白质损害与超敏C反应蛋白的关系

目的 应用磁共振弥散张量成像(DTI)研究腔隙性脑梗死(LI)患者脑"形似正常区"白质损害(WML)的特点及其与血清超敏C反应蛋白(hs-CRP)的相关性.方法 选取南方医科大学南方医院神经内科自2008年3月至10月收治人院的32例LI患者和10名年龄及文化程度相当的健康志愿者分别做为研究组和对照组;行脑部T1WI、T2WI、DWI、水抑制反转恢复序列(FLAIR)和DTI扫描,选择双侧额叶白质、前部扣带回、前部扣带、半卵圆中心、视放射、前角周围白质、后角周围白质、尾状核头部、丘脑、海马旁回、外囊以及胼胝体膝部、胼胝体干、肼胝体压部等25个T1WI、T2WI"形似正常区"作为兴趣区(ROI),分别测量部分各向异性值(FA)、平均弥散系数(ADC)值;应用免疫透射比浊法检测血清hs-CRP水平.结果 与对照组比较,研究组左、右侧额叶白质,肼胝体膝部,左、右侧前部扣带,左、右侧半卵圆中心.左、右侧视放射,左侧前角、后角周围白质.左、右侧海马旁回.右侧外囊的FA值降低;胼胝体干、胼胝体压部、左侧半卵圆中心、左侧后角周围白质、左侧海马旁回的ADC值升高,差异均有统计学意义(P＜0,05).其中左、右侧额叶白质,胼胝体膝部的FA值与hs-CRP水平呈负相关关系(r=-0.642,P=0,021;r=0.388,P=0.016;r=-0.402,P=0.028).结论 LJ患者常规MRI上显示"形似正常区"的白质早期已存在广泛损害;部分受损白质区域FA值与hs-CRP水平呈负相关关系,提示动脉硬化可能在LI患者WML发病机制中超重要作用;DTI可作为早期发现WML、评估预后及治疗效果的一种重要工具.     

OSAHS患者认知功能与磁共振弥散张量成像的相关性分析

目的分析阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea-hypopnea syndrome,OSAHS)患者认知功能与磁共振弥散张量成像(diffusion tensor imaging,DTI)相关性。方法选取2016年08月至2019年07月在海南医学院第二附属医院诊治的40例OSAHS患者(中度组20例,重度组20例)及同期健康志愿者20例(对照组),行常规MRI及DTI检查,并填写中文版简易智能精神状态检查量表(minimentalstateexamination,MMSE),对三组入选者资料进行相关性分析。结果(1)三组入选者在记忆力、注意力和计算力、回忆能力及MMSE总分见比较差异有统计学意义(P0.05);(2)OSAHS中度组与重度组患者双侧额叶白质、前扣带回、后角周围白质及海马旁回等解剖结构的FA值分别与对照组比较明显降低(P0.0167);OSAHS中度组与重度组患者双侧额叶白质、前扣带回及后角周围白质等解剖结构的ADC值分别与对照组比较明显升高(P0.0167);(3)控制年龄、文化程度后选取右侧半球额叶白质、前扣带回、后角周围白质及海马旁回进行分析。记忆力与右侧额叶白质、前扣带回及海马旁回FA值呈正相关(r=0.526、0.467及0.573,P均0.05);注意力和计算力与右侧额叶白质及前扣带回FA值呈正相关(r=0.354、0.387,均P0.05);回忆能力与右侧额叶白质、前扣带回及海马旁回FA值呈正相关(r=0.475、0.375及0.377,均P0.05)。结论DTI是一种非侵入性评价现脑白质完整性、致密性及平行性的影像学检查方法,与MMSE量表结合可反映OSAHS患者认知功能损害程度。OSAHS患者存在多种不同走向的白质纤维受损,记忆力、注意力和计算力、回忆能力受损程度与右侧额叶白质、前扣带回及海马旁回受损程度呈正相关。     

首发未用药精神分裂症与精神分裂症患者健康子女静息态脑功能低频振幅研究

目的探讨首发未用药精神分裂症患者和精神分裂症患者健康子女脑功能磁共振低频振幅(amplitude of low frequency fluctuation,ALFF)的共性与差异。方法应用静息态功能磁共振ALFF的方法对年龄30岁的23例首发未用药精神分裂症患者、25名精神分裂症患者健康子女以及29名健康对照进行大脑范围内ALFF值比较。结果与对照组相比,患者组和患者子女组在左侧颞下回后部、左侧海马旁回、左侧海马、右侧中央后回、双侧楔前叶的ALFF值有统计学差异(P0.05),而患者组和患者子女组间在以上脑区的ALFF值无统计学差异(P0.05);与患者子女组和对照组相比,患者组在左侧颞下回前部、左侧颞上极、双侧距状裂周围皮层的ALFF值有统计学差异(P0.05),患者子女组和对照组间在以上脑区的ALFF值无统计学差异(P0.05)。结论首发未用药精神分裂症患者以及精神分裂症患者健康子女都存在脑功能异常;左侧颞下回后部、左侧海马旁回、左侧海马、右侧中央后回、双侧楔前叶可能是与精神分裂症遗传素质性相关的脑区;左侧颞下回前部、左侧颞上极、双侧距状裂周围皮层可能是与疾病状态性相关的脑区。     

抑郁症患者脑白质变化初步研究

目的：利用能够提示脑白质纤维完整性的磁共振弥散张量成像（DTI）探讨首发和复发重性抑郁症患者脑白质纤维的变化及其差异。方法：20例重性抑郁症患者（首发9例，复发11例）和20名正常对照者均经常规磁共振成像（MRI）平扫，未发现异常者继续进行DTI和结构MRI（3D）扫描，基于像素的全脑分析技术对DTI数据进行分析。结果：与对照组相比较，抑郁症组白质纤维结构在双侧额中回、右顶下小叶及双侧脑岛等区域白质的各向异性值（FA）显著降低（各脑区P均〈0.001，cluster〉30像素）;与首发抑郁症患者相比较，复发抑郁症患者右侧额上回、右顶叶、中央前回、中央后回及右顶下小叶等区域FA值降低更为显著（各脑区P均〈0.001，cluster〉10像素）。结论：重性抑郁症患者存在脑白质异常，抑郁反复发作会导致脑白质损害进一步加重。     

颞叶内侧结构弥散张量成像及白质纤维束成像在颞叶癫痫诊断中的应用价值

目的 通过磁共振弥散张量成像(DTI)及白质纤维束示踪(DTT)技术定量分析颞叶癫痫患者双侧颞叶内侧结构弥散参数值及局部纤维束变化特点,评价DTI技术对颞叶癫痫的诊断价值.方法 对广州医学院第二附属医院自2010年12月至2011年2月临床诊断为颞叶癫痫的16例患者和20例健康志愿者进行常规MRI及DTI扫描,测量双侧颞叶杏仁体、海马及颞叶皮质的部分各向异性(FA)、相对各向异性(RA)、表观弥散系数(ADC)等数值并进行统计学分析,同时应用DTT技术观察癫痫患者局部纤维束与正常对照者的差异.结果 正常对照者双侧颞叶内侧各结构FA、RA、ADC值比较差异均无统计学意义(P＞0.05).颞叶癫痫患侧、对侧与正常对照者颞叶内侧各结构FA、RA、ADC值比较差异均有统计学意义(P＜0.05),其中ADC值呈颞叶癫痫患侧＞颞叶癫痫对侧＞正常对照者的变化趋势,以海马尾部变化最为显著;而FA、RA值呈颞叶癫痫患侧＜颞叶癫痫对侧＜正常对照者的变化趋势,并且杏仁体、海马体部变化较海马尾部更显著.结论 DTI技术能充分了解癫痫患者颞叶内侧结构的弥散参数值及纤维束变化特点,有助于癫痫病灶定位的准确诊断,同时加深对颞叶内侧结构整体变化的了解亦有助于术前的整体评估及提高手术疗效.     

轻度认知功能障碍患者正电子发射计算机体层摄影术和神经心理学测定的初步研究

目的　探讨轻度认知功能障碍患者脑葡萄糖代谢与神经心理学特点及其相互关系。方法　采用正电子发射体层摄影术 (PET)、简易智能状态测定 (MMSE)、韦克斯勒记忆量表测定 (WMS)和总体衰退量表 (GDS)测定 10例轻度认知功能障碍 (MCI)患者和 10名健康志愿者 (HC)。结果 (1)MCI组MMSE[(2 4.6± 2 2 )分 ]、WMS[(6 9.4± 10 .4)分 ]分值低于HC组 [分别为 (2 8.9± 1.1)分和 (93.1± 9.0 )分 ;P〈0 .0 1];(2 )MCI组左侧眶回、右侧颞叶中回和右侧壳核的局部脑葡萄糖代谢率 (rCMRglc)较HC组低 (P〈0 .0 5～ 0 .0 1) ;(3)将年龄、受教育年限、MMSE、WMS与不同脑区用18F标记的脱氧葡萄糖放射性比值进行相关分析显示 ,与年龄呈负相关 (P〈0 .0 5或P〈0 .0 1)的脑区有 :眶回、左侧额上回、左侧额下回、颞叶中回、颞叶下回、左侧顶叶、左侧中央前回、右侧中央后回、左颞叶内侧皮质、左侧海马回、左侧海马旁回、右侧前扣带回、后扣带回、左侧杏仁核等。与文化程度呈正相关 (P〈0 .0 5或P〈0 .0 1)的脑区有 :左侧颞叶下回、中央前回、左侧中央后回等 ;而右侧壳核则呈负相关。与MMSE呈正相关 (P〈0 .0 5或P〈0 .0 1)的脑区有 :额下回、左侧颞叶上回、颞叶中回、颞叶下回、左侧顶叶、左侧中央前回、中央后回、颞叶内侧皮     

Cigarette smoking and white matter microstructure in schizophrenia

The majority of patients with schizophrenia smoke cigarettes. Both nicotine use and schizophrenia have been associated with alterations in brain white matter microstructure as measured by diffusion tensor imaging (DTI). The purpose of this study was to examine fractional anisotropy (FA) in smoking and non-smoking patients with schizophrenia and in healthy volunteers. A total of 43 patients (28 smoking and 15 non-smoking) with schizophrenia and 40 healthy, non-smoking participants underwent DTI. Mean FA was calculated in four global regions of interest (ROIs) (whole brain, cerebellum, brainstem, and total cortical) as well as in four regional ROIs (frontal, temporal, parietal and occipital lobes). The non-smoking patient group had a significantly higher intellectual quotient (IQ) compared with the patients who smoked, and our results varied according to whether IQ was included as a covariate. Without IQ correction, significant between-group effects for FA were found in four ROIs: total brain, total cortical, frontal lobe and the occipital lobe. In all cases the FA was lower among the smoking patient group, and highest in the control group. Smoking patients differed significantly from non-smoking patients in the frontal lobe ROI. However, these differences were no longer significant after IQ correction. FA differences between non-smoking patients and controls were not significant. Among smoking and non-smoking patients with schizophrenia but not healthy controls, FA was correlated with IQ. In conclusion, group effects of smoking on FA in schizophrenia might be mediated by IQ. Further, low FA in specific brain areas may be a neural marker for complex pathophysiology and risk for diverse problems such as schizophrenia, low IQ, and nicotine addiction.     

A voxel-based diffusion tensor imaging study of temporal white matter in patients with schizophrenia

Diffusion tensor imaging (DTI) is a relatively new technique used to detect changes in the anisotropic diffusion of white matter. The study of the disruption of brain connectivity may increase our understanding of cognitive deficits associated with schizophrenia. Here we analysed DTI data in 25 patients with DSM-IV schizophrenia and 24 healthy controls. Two complementary measures, fractional anisotropy (FA) and the apparent diffusion coefficient (ADC), were considered and analysed using voxel-based morphometry. Declarative memory functions were also investigated and their associations with DTI data were analysed. FA was significantly reduced, and the ADC increased in the left sub-gyral white matter of the temporal lobe, which involves the posterior part of the fornix. In the schizophrenic group, females had lower FA than males in the genu of the corpus callosum. Memory functions correlate with FA values. These data provide further evidence for the disruption of white matter connectivity in the left medial temporal lobe, and for its contribution to the declarative memory deficit in schizophrenia.     

Precentral degeneration and cerebellar compensation in amyotrophic lateral sclerosis: A multimodal MRI analysis

Amyotrophic lateral sclerosis (ALS) is a progressive and intractable neurodegenerative disease of human motor system characterized by progressive muscular weakness and atrophy. A considerable body of research has demonstrated significant structural and functional abnormalities of the primary motor cortex in patients with ALS. In contrast, much less attention has been paid to the abnormalities of cerebellum in this disease. Using multimodal magnetic resonance imagining data of 60 patients with ALS and 60 healthy controls, we examined changes in gray matter volume (GMV), white matter (WM) fractional anisotropy (FA), and functional connectivity (FC) in patients with ALS. Compared with healthy controls, patients with ALS showed decreased GMV in the left precentral gyrus and increased GMV in bilateral cerebellum, decreased FA in the left corticospinal tract and body of corpus callosum, and decreased FC in multiple brain regions, involving bilateral postcentral gyrus, precentral gyrus and cerebellum anterior lobe, among others. Meanwhile, we found significant intermodal correlations among GMV of left precentral gyrus, FA of altered WM tracts, and FC of left precentral gyrus, and that WM microstructural alterations seem to play important roles in mediating the relationship between GMV and FC of the precentral gyrus, as well as the relationship between GMVs of the precentral gyrus and cerebellum. These findings provided evidence for the precentral degeneration and cerebellar compensation in ALS, and the involvement of WM alterations in mediating the relationship between pathologies of the primary motor cortex and cerebellum, which may contribute to a better understanding of the pathophysiology of ALS.     

Correlation between white matter damage and gray matter lesions in multiple sclerosis patients

We observed the characteristics of white matter fibers and gray matter in multiple sclerosis patients, to identify changes in diffusion tensor imaging fractional anisotropy values following white matter fiber injury. We analyzed the correlation between fractional anisotropy values and changes in whole-brain gray matter volume. The participants included 20 patients with relapsing-remitting multiple sclerosis and 20 healthy volunteers as controls. All subjects underwent head magnetic resonance imaging and diffusion tensor imaging. Our results revealed that fractional anisotropy values decreased and gray matter volumes were reduced in the genu and splenium of corpus callosum, left anterior thalamic radiation, hippocampus, uncinate fasciculus, right corticospinal tract, bilateral cingulate gyri, and inferior longitudinal fasciculus in multiple sclerosis patients. Gray matter volumes were significantly different between the two groups in the right frontal lobe(superior frontal, middle frontal, precentral, and orbital gyri), right parietal lobe(postcentral and inferior parietal gyri), right temporal lobe(caudate nucleus), right occipital lobe(middle occipital gyrus), right insula, right parahippocampal gyrus, and left cingulate gyrus. The voxel sizes of atrophic gray matter positively correlated with fractional anisotropy values in white matter association fibers in the patient group. These findings suggest that white matter fiber bundles are extensively injured in multiple sclerosis patients. The main areas of gray matter atrophy in multiple sclerosis are the frontal lobe, parietal lobe, caudate nucleus, parahippocampal gyrus, and cingulate gyrus. Gray matter atrophy is strongly associated with white matter injury in multiple sclerosis patients, particularly with injury to association fibers.     

Diffusion tensor imaging patterns differ in bulbar and limb onset amyotrophic lateral sclerosis

Background

Amyotrophic lateral sclerosis (ALS) is characterized by pronounced clinical heterogeneity in terms of onset and disease progression. Widespread changes in white matter fibres could be observed by diffusion tensor imaging (DTI), which detects alterations in the degree (diffusivity, ADC) and directedness (fractional anisotropy, FA) of proton movement. The aim of the current study was to determine whether different ALS onset types were reflected in different DTI brain patterns.

Methods

Seventeen patients with a diagnosis of ALS (6 bulbar, 11 limb onset) and seventeen age-matched controls received 1.5T DTI, where FA and ADC were analyzed using statistical parametric mapping.

Results

In ALS patients, an increased diffusivity in the white matter was found below the precentral gyrus and along the corticospinal tract (CST) right into the internal capsule. The FA was decreased in the posterior limb of internal capsule and in the subcortical white matter in the precentral gyrus. In bulbar onset increased diffusivity was found in the CST, whilst in limb onset, frontal subcortical areas displayed an increased diffusivity.

Conclusion

DTI changes can be regarded as prominent features in ALS. Herein we were able to demonstrate discriminating brain DTI patterns due to bulbar or limb onset.     

Hippocampal and thalamic diffusion abnormalities in children with temporal lobe epilepsy

PURPOSE: Previous studies using diffusion MRI in patients with temporal lobe epilepsy have shown abnormal water diffusion in the hippocampus. Because thalamus and lentiform nuclei are considered important for the regulation of cortical excitability and seizure propagation, we analyzed diffusion tensor imaging (DTI) abnormalities in these subcortical structures and in hippocampus of children with partial epilepsy with and without secondary generalization. METHODS: Fourteen children with partial epilepsy involving the temporal lobe underwent MRI including a DTI sequence. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were obtained in the hippocampus, thalamus, and lentiform nucleus, and compared with DTI data of 14 control children with no epilepsy, as well as glucose positron emission tomography (PET) findings. RESULTS: Decreased FA (p < 0.001) and increased ADC (p = 0.003) values were found in the hippocampi ipsilateral to the seizure focus. Significant FA decreases (p = 0.002) also were seen in the contralateral hippocampi, despite unilateral seizure onset and excellent surgical outcome in patients who underwent surgery. ADC values showed a trend for increase in the thalami ipsilateral to the epileptic focus in the seven children with secondarily generalized seizures (p = 0.09). No group differences of ADC or FA were found in the lentiform nuclei. The DTI variables did not correlate with regional glucose metabolism in any of the structures analyzed. CONCLUSIONS: Increased ADC values in hippocampus can assist in lateralizing the seizure focus, but decreased FA in the contralateral hippocampus suggests that it too may be dysfunctional despite unilateral seizure onset. Less-robust thalamic abnormalities of water diffusion in patients with secondarily generalized seizures suggest secondary involvement of the thalamus, perhaps due to recruitment of this structure into the epileptic network; however, this must be confirmed in a larger population. DTI appears to be a sensitive method for detection abnormalities in children with partial epilepsy, even in structures without apparent changes on conventional MRI.     

弥散张量成像在继发全面性发作癫痫患者中的应用研究

目的 评价弥散张量成像(DTI)对于常规MRI未发现病灶的部分性继发全面性发作癫痫患者的病灶检出能力.方法 使用Siemens 3.0T磁共振成像系统对30例成年继发全面性发作癫痫患者和30例正常对照者进行扫描,得到弥散加权成像,采用基于体素的分析方法对癫痫患者和正常对照组的数据进行分析.结果 癫痫组右侧梭状回和楔前叶、右侧额内侧回和钩回、左侧扣带回、左侧颞下回、左侧小脑扁桃体和左侧中央前回的脑区FA值较正常对照组降低,差异有统计学意义(P＜0.001);癫痫组右侧海马旁回、右侧颞下回、右侧胼胝体、右侧额内侧回、右侧额下回、扣带回、右侧前扣带回、右侧舌回、右侧梭状回和枕中回,左侧颞中回、左侧钩回和左侧中央前回的脑区ADC值较正常对照组升高,差异具有统计学意义(P＜0.001);左侧直回的脑区ADC值较正常对照组降低,差异具有统计学意义(P＜0.001).结论 DTI检查可发现常规MRI检查为阴性的部分性继发全面性发作癫痫患者存在的广泛脑白质微结构异常.