无先兆偏头痛发作间期的静息态功能磁共振研究

目的本研究采用静息态功能磁共振(rf MRI)方法通过对比无先兆偏头痛(Mwo A)患者与健康对照的大脑自发脑活动的局部一致性(Re Ho)差异,为偏头痛的发病机制提供新的见解。方法对23例发作间期的Mwo A患者和25例性别、年龄、受教育程度相匹配的健康被试者进行临床资料的采集及rf MRI检查。应用Re Ho方法分析每个被试者大脑的相邻体素的血氧水平依赖(BOLD)信号在同一时间序列中波动的一致性,并对两组被试者的Re Ho值的脑图行统计学分析。结果与对照组Re Ho脑图相比,偏头痛组右侧丘脑、右侧壳核、右侧前额叶皮质及右侧海马的Re Ho值显著高于对照组(P0.05)。结论 Mwo A患者发作间期疼痛处理及调节与应激反应相关的脑区存在功能异常。     

偏头痛与静息态脑功能连接研究

目的本文研究采用静息态功能磁共振成像(rfMRI)技术描述偏头痛患者静息态脑功能连接改变,为探索偏头痛的发病机制提供影像学资料。方法收集16例偏头痛患者与16例健康对照,采集rfMRI成像,计算低频振幅,找出感兴趣区做功能连接进行统计分析。结果偏头痛患者左侧岛叶、左侧额下回低频振幅显著低于对照组,右侧视觉皮质低频振幅显著高于对照组;以左侧额下回、右侧枕中回为感兴趣区,发现左侧额下回与脑干之间的功能连接增强,与双侧枕叶之间的功能连接减弱;右侧枕中回与双侧楔前叶延伸至扣带回中部区域之间的功能连接增强,与双侧中央前回、双侧缘上回、双侧颞上回及双侧额下回之间的功能连接减弱。结论偏头痛患者无头痛发作时神经元活动强度改变,大脑功能连接异常,这导致大脑整合信息过程改变,并与偏头痛发病相关。     

不同亚型轻度认知障碍患者静息态脑功能局部一致性研究

目的探讨遗忘型和非遗忘型轻度认知障碍(mild cognition impairment,MCI)患者局部自发脑活动特点。方法纳入遗忘型MCI(amnesicMCI,aMCI)患者25例,非遗忘型MCI(non-amnesticMCI,naMCI)患者21例和正常对照(normal control,NC)15名进行静息态功能磁共振扫描,通过计算每个给定体素与其最邻近26个体素时间序列的相似性获得全脑局部一致性(regional homogeneity,ReHo)图,比较三组被试全脑ReHo差异。结果 aMCI组右侧额叶ReHo值低于NC组,左侧颞中回和左侧小脑ReHo值高于NC组(P0.05,Alphasim校正);naMCI组前扣带回和右侧额中回ReHo值低于NC组,右侧海马旁回、右侧颞中回和右侧楔前叶ReHo值高于NC组(P0.05,Alphasim校正);aMCI左侧前额叶和左侧颞中回ReHo值高于naMCI组,右侧小脑ReHo值低于naMCI组(P0.05,Alphasim校正)。结论 aMCI和naMCI患者左侧前额叶、左侧颞中回及右侧小脑自发脑功能活动存在差异,这为区别aMCI和naMCI两者脑功能活动特点提供了初步影像学依据。     

有先兆偏头痛患者发作间期的静息态功能磁共振变化

目的采用静息态功能磁共振成像技术探讨有先兆偏头痛患者的自发神经元活动,分析其脑功能网络的变化,以便更好地认识有先兆偏头痛的发病机制。方法对7例发作间期有先兆偏头痛患者和7例年龄、性别及受教育程度相匹配的健康对照行静息态功能磁共振成像扫描,分析原始数据,得出全脑低频振幅(ALFF),进行双样本t检验,并以ALFF差异脑区为感兴趣区(ROI)校正后行功能连接(FC)分析,比较两组之间影像学表现的差异。结果病例组双侧额上回、左侧眶额皮质低频振幅值显著高于对照组(t=2.18~5.12,P0.05)。病例组左侧颞中回、左侧颞下回、左侧尾状核、双侧丘脑、右侧运动前区低频振幅ALFF值显著低于对照组(t=-5.12~-2.18,P0.05);与对照组相比,病例组右侧眶额皮质、左侧额中回、双侧前扣带皮质、右侧缘上回与左侧额上回功能连接增强,病例组左侧小脑、右侧脑岛、脑干与左侧额上回之间的功能连接减弱。结论有先兆偏头痛患者头痛发作间期疼痛处理相关脑区功能异常,支持偏头痛并非单纯的发作性疾病。     

月经性偏头痛患者静息态功能磁共振研究

目的采用静息态功能磁共振成像(rf MRI)技术描述月经性偏头痛患者发作间期的脑功能改变,探索其可能的病理生理学机制。方法对10例发作间期的月经性偏头痛患者和10例受教育程度、年龄相匹配的健康对照行rf MRI扫描,计算低频振幅(ALFF),采用双样本t检验得到差异的脑区。结果偏头痛组左侧额叶ALFF值较对照组显著增强(P<0.05);偏头痛组双侧枕叶、双侧丘脑ALFF值较对照组明显减弱(P<0.05)。结论月经性偏头痛患者在头痛发作间期仍然存在皮质及皮质下脑区功能异常。     

偏头痛发作间期疼痛刺激的脑磁图研究

目的探讨偏头痛患者在发作间期大脑对疼痛电刺激的反应特点。方法收集30例发作间期的无先兆偏头痛患者(偏头痛组)和30名年龄、性别相匹配的健康对照者(对照组),利用脑磁图描记术记录正中神经疼痛电刺激下诱导的脑电磁信号。比较偏头痛组与对照组之间在痛觉处理上的差异。结果与对照组相比,偏头痛组疼痛电刺激疼痛阈值显著降低(P0.05),疼痛电刺激产生的体感诱发磁场M20潜伏期明显延长(P0.01)。偏头痛组疼痛诱发Gamma振荡平均能量较对照组显著增强(P0.01),且Gamma震荡能量值与视觉模拟评分法(VAS)、偏头痛残疾程度评估量表(MIDAS)评分均呈正相关(VAS左手:r=0.45,P0.05;VAS右手:r=0.46,P0.05;MIDAS左手:r=0.47,P0.01;MIDAS右手:r=0.59,P0.01)。结论偏头痛患者发作间期存在疼痛感觉异常,且痛觉刺激相关的皮质兴奋性增高。     

帕金森病患者静息态脑功能局部一致性研究

目的探讨帕金森病(PD)患者静息态脑功能局部一致性(ReHo)的变化。方法采集22例原发性PD患者(PD组)和22名健康对照者(正常对照组)的静息态功能磁共振(fMRI)数据,并进行比较。分析PD患者"开"期和"关"期局部一致性(ReHo)值差异有统计学意义的脑区的Re Ho值与PD患者左手对指改善率的相关性。结果与正常对照组比较,PD组"关"期ReHo值的减少主要集中在左侧壳核、双侧小脑半球,而增加的脑区集中在右侧丘脑、左侧额中回、左侧运动前区、右侧顶下小叶、右侧中央后回、双侧辅助运动区、楔前叶。PD组患者"开"期双侧小脑、颞下回、右侧壳核、右侧楔前叶、右侧丘脑、双侧辅助运动区ReHo值较"关"期显著增加;而右侧小脑后叶、右侧颞中回、右侧颞上回、左侧额中回、左侧额上回、右侧后扣带回较"关"期显著。PD患者左手对指改善率为1.59%~126.67%,平均(54.15±38.02)%。Pearson相关性分析结果显示,PD患者右侧丘脑ReHo值与左手对指改善率呈正相关(r=0.637,P0.01)。结论 PD患者静息态脑功能存在广泛异常,左旋多巴对于PD患者的大脑功能环路具有修饰作用。丘脑作为运动环路的一个重要节点,在PD患者中其神经元代谢、功能等也发生了改变。     

无先兆偏头痛患者的经颅多普勒和皮肤交感反应的对比分析

目的探讨无先兆偏头痛(MWA)患者发作间期的脑血管血液动力学异常和自主神经功能失常。方法对48例MWA患者和36例健康人群(HC)的经颅多普勒(TCD)和皮肤交感反应(SSR)进行对比分析。结果 MWA组的TCD大脑中动脉最高平均流速(MFV-MCA)异常率和SSR异常率分别为64.6%和58.3%,与HC组相比,均具有非常显著性差异(P<0.01);MWA组的SSR主要异常表现为潜伏期延长,与HC组相比,差异具有显著性(P<0.05)。MWA组TCD的异常改变和SSR的异常具有较好的一致性(总符合率=68.7%,Kappa值=0.343,P=0.017)。结论在发作间期无先兆偏头痛患者确实存在脑血液动力学的改变和自主神经功能的异常;TCD与SSR存在一致性异常有助于鉴别无先兆偏头痛患者的发病机制和原因。     

负性情绪刺激对发作间期偏头痛患者Gamma振荡的脑磁图研究

目的研究负性情绪刺激对发作间期偏头痛患者Gamma频带振荡的影响。方法应用脑磁图仪记录30例发作间期偏头痛患者和30例年龄、性别相匹配的健康对照者在正性、中性、负性面部表情图片刺激诱导的Gamma频段的脑磁信号。采用汉密尔顿焦虑量表(HAMA)及汉密尔顿抑郁量表(HAMD)对偏头痛患者进行评分。结果与正常对照组比较,偏头痛组负性情绪刺激后M100成份时间窗低频和高频Gamma振荡频谱平均功率值均显著降低(t=-2.319,P=0.024;t=-2.610,P=0.012);M170成份时间窗低频和高频Gamma振荡频谱平均功率值也显著降低(t=-2.233,P=0.029;t=-2.299,P=0.025)。偏头痛组发作间期在负性表情刺激后M100成份时间窗低频和高频Gamma振荡频谱平均功率与HAMD评分呈负相关(r=-0.480,P=0.007;r=-0.407,P=0.025);M170成份时间窗低频和高频Gamma振荡频谱平均功率与HAMD评分呈负相关(r=-0.593,P=0.001;r=-0.398,P=0.029)。结论偏头痛患者发作间期处理负性情绪刺激存在脑功能异常,这种脑功能异常可能是偏头痛和情绪因素共同作用的结果。     

精神病超高危人群的局部一致性研究

目的:探索精神病超高危(UHR)人群在静息状态下的脑功能异常情况。方法:入组36名精神病UHR人群(UHR组)以及36名性别、年龄相匹配的健康对照者(对照组)进行静息态功能磁共振(fMRI)扫描以获取局部一致性(ReHo)值。采用精神病高危症状量表(SOPS)评估UHR组的临床症状,并分析ReHo值与临床症状的关系。结果:与对照组相比,UHR组右侧颞上回、右侧角回、左侧内侧和旁扣带脑回、左侧楔前叶ReHo值增高,左侧距状裂周围皮质、左侧楔叶ReHo值降低(TFCE矫正,P0.01)。相关分析显示右侧颞上回ReHo值与阴性症状、解体症状、一般症状及SOPS总分呈负相关(TFCE矫正,P0.05)。结论:UHR人群存在广泛的脑功能异常,且这种异常与患者的临床症状有一定相关性。     

Cortical afterdischarge and functional response thresholds: results of extraoperative testing

We have evaluated the afterdischarge thresholds and functional response thresholds in 21 patients with chronically implanted arrays of subdural electrodes. Afterdischarge thresholds varied from 2 to greater than 15 mA over the tested cortex, by as much as 12 mA in individual patients, and by as much as 12 mA between adjacent electrodes. Thresholds for functional alteration varied from 2 to 15 mA in tested cortex, by as much as 9.5 mA in individually tested patients, and by as much as 6.5 mA between adjacent electrodes. We conclude that the optimal localization of functional cortical areas requires different stimulation intensities at different points. The use of too high an intensity would produce afterdischarges at some positions. The use of too low an intensity would falsely make others appear functionally "silent."     

Widespread cortical morphologic changes in juvenile myoclonic epilepsy: evidence from structural MRI

Purpose: Atypical morphology of the surface of the cerebral cortex may be related to abnormal cortical folding (gyrification) and therefore may indicate underlying malformations of cortical development (MCDs). Using magnetic resonance imaging (MRI)–based analysis, we examined cortical morphology in patients with juvenile myoclonic epilepsy (JME). Methods: MRI data was collected for 24 patients with JME and 40 demographically matched healthy controls. FreeSurfer, an automated cortical surface reconstruction method, was applied to compare cortical morphology between patients and controls. Areas of anomalous cortical morphology were defined as regions of interest (ROIs) to contrast regional cortical parameters, such as surface area, average thickness, and mean curvature between patients and controls. Key Findings: In patients with JME, changes to cortical morphology were detected in several regions. In the left hemisphere, these were in insular and cingulate cortices, occipital pole, and middle temporal and fusiform gyri. In the right hemisphere, changes were detected in insular cortex, inferior temporal gyrus, and precuneus. Further analysis of ROIs revealed that these changes are related to differences in surface area rather than average cortical thickness. In addition, mean curvature abnormalities were detected in the insula bilaterally, the left cingulate cortex, and right inferior temporal gyrus. Significance: The morphologic findings in this study suggest that structural abnormalities in JME extend beyond mesial frontal lobe regions of the brain. These may be indicative of areas of subtle cortical folding abnormality related to early disruption of cortical development.     

Planum temporale asymmetry to the right hemisphere in first-episode schizophrenia

In schizophrenia patients reduced cerebral asymmetry is an important finding and this may reflect a disturbance in cortical development. We investigated planum temporale (PT) volume and asymmetry in 23 first-episode schizophrenia patients compared to healthy controls and found for the first time an in vivo volume asymmetry of PT to the right hemisphere.     

Les micrencéphalies familiales par malformation cérébrale

Summary Five cases of a familial cerebral malformation with micrencephaly are studied. Four of them are characterized by an extreme reduction of the brain volume with only a moderately modified convolutional pattern. The cortical dysplasia which is relatively unimportant, sometimes minimal, predominates in the superficial layers of the cortex, and is associated with anomalies reproducing certain aspects of the fetal cortex during development. The morphogenesis of this malformation is discussed.There are at least three others types of familial malformations giving rise to extreme micrencephalies: familial pachygyrias and agyrias to which one of our cases belongs, familial arhinencephalies and micrencephalies of the Von Monakow type.Associated somatic malformations seem to be frequent. Micrencephalies of the first type seem usually due to a recessive autosomic gene. In the other types a multifactorial heredity is possible.

     

Removable, conforming device for cooling the cortical surface

A technique for cooling the cerebral cortex is described. It makes use of a neoprene bladder through which cold fluids is circulated. The flexible bladder is contained within a cylinder permanently attached to the skull. The bladder itself can be quickly installed and removed and conforms to the cortical surface with minimal pressure.     

皮层电极在颅内动脉瘤术中监测中的应用研究

目的 研究颅内动脉瘤术中应用皮层电极进行皮层脑电图(EEG)和皮层运动诱发电位(MEP)监测的价值和意义.方法 42例颅内动脉瘤患者,翼点开颅夹闭动脉瘤术中常规行头皮EEG、体感诱发电位(SEP)、MEP和皮层EEG、MEP监测,将监测变化结果与术后神经功能做前瞻性研究.结果 36例可诱发出皮层MEP,8例监测出现了变化,其中SEP 4例、皮层EEG 6例、头皮EEG 2例、皮层MEP 7例、头皮MEP 5例.皮层MEP出现变化的6例非大脑前动脉系统动脉瘤中仅3例头皮MEP出现了变化.结论 皮层MEP所需刺激量小,较适合于非大脑前动脉动脉瘤的术中监测,其敏感性高于头皮MEP.皮层EEG监测的敏感性明显高于头皮EEG.     

Structure and pathogenesis of cortical nodules induced by prenatal X-irradiation in the rat

Summary Segmentation of the cerebral cortex with formation of nodules, predominating in the upper cortical levels, was found in the rat after 200 cGy X-ray exposure at embryonic days 15, 17 or 19. Nodules were composed of pyramidal and nonpyramidal neurons occupying normal positions at different levels of the cerebral cortex as revealed with parvalbumin and calbindin D-28k immunocytochemistry. The nodules, which were large in animals irradiated at embryonic day 15 but reduced to groups of a few cells in rats irradiated at embryonic day 19, were separated by low cell density zones. Autoradiographic studies using tritiated methylthymidine injections given to pregnant irradiated rats at different days of gestation further demonstrated a preserved inside-out gradient of cortical neurogenesis in this cortical malformation. Morphological studies of irradiated embryos disclosed that groups of dead cells were separated by patches of preserved cells in the germinal layer 6 h after irradiation. Columns of migrating neuroblats separated by low cell density zones were seen 24 h later. These features suggest that cortical nodules observed after prenatal X-irradiation were the result of multifocal cell death in vulnerable (at the moment of X-ray exposure) proliferative units of the germinal neuroepithelium, combined with normal neurogenesis and migration of neuroblats from the preserved germinal zones. These findings also suggest that cell proliferation is not uniform through the germinal layer but occurs synchronously in alternate proliferative units. These proliferative units probably co-generate pyramidal and nonpyramidal cells.Supported by the CEC Programme B17-0003-C and by a grant FIS 90E1263     

Autosomal dominant early-onset cortical myoclonus, photic-induced myoclonus, and epilepsy in a large pedigree

PURPOSE: Cortical tremor, a form of rhythmic cortical myoclonus (rhythmic CM), and epilepsy have been described in families with autosomal dominant inheritance. Linkage analyses revealed two putative loci on chromosome 2p and 8q. Clinical photosensitivity was not a prominent feature in such families. We describe a large Italian family with rhythmic CM, photosensitivity, and epilepsy. METHODS: Twenty-three individuals of a five-generation family were studied. Linkage analyses for the loci on chromosome 2p11.1 and 8q23.3 were performed. RESULTS: Of the 23 studied family members, 16 were affected. Rhythmic CM of childhood onset was present in all 16 individuals (onset ranging from 3 to 12 years), was associated with photic-induced myoclonic jerks in seven, and with epileptic seizures in six (onset ranging from 23 to 34 years). Five children of the V generation manifested also episodes of arousal with generalized tremor in early infancy ("tremulous arousals"). Jerk-locked back-averaging of rhythmic CM of six affected individuals, documented a premyoclonic EEG correlate. C-reflex at rest was present in two affected adults. Linkage analyses excluded mapping to the 2p11.1 and 8q23.3 loci. CONCLUSIONS: Clinical variability and severity of the phenotypes in this family are in line with those of previously described pedigrees with autosomal dominant cortical myoclonus and epilepsy. In this family, a progression of symptoms was found: rhythmic CM and tremulous arousals occurred in childhood, whereas visually induced manifestations and epileptic seizures occurred during adolescence-adulthood. Exclusion of linkage to the two known loci is consistent with genetic heterogeneity of such familial clustering of symptoms.     

Stereological studies of capillary length density in the frontal cortex of schizophrenics

The presence of microvasculature abnormalities in the prefrontal cortex of schizophrenics was proposed in a recent study of molecular signatures of schizophrenia [Prabakaran et al (2004) Mol Psychiat 9:684–697]. To assess this possibility further, we investigated capillary length densities in prefrontal cortex area 9 and anterior cingulate cortex area 24 in postmortem brains from 13 schizophrenics and 13 age- and sex-matched controls. To check that our sample of brains shared cardinal neuropathological features of schizophrenia with previously reported case studies, we also measured cortical gray matter volumes and cortical thickness in areas 9 and 24. The mean cortical gray matter volume was significantly reduced in brains from schizophrenics compared to controls. Mean cortical thickness was significantly reduced in area 24, but not in area 9, in schizophrenics. There were no differences in mean capillary length densities in either area 9 or 24 between the two groups. Thus, alterations in capillary length density in the prefrontal cortex cannot be considered a general feature of schizophrenia. Compromised brain metabolism and occurrence of oxidative stress in the brain of schizophrenics are likely caused by other mechanisms.