fMRI对皮层运动功能区脑膜瘤外科治疗的意义

目的提高脑皮层运动功能区脑膜瘤的显微手术效果。方法12例皮层运动功能区脑膜瘤患者术前均行CT、MRI及fMRI检查,5例行DSA检查,7例行MRA检查。术中在显微镜下分离肿瘤包膜,肿瘤予以瘤内分块切除。结果肿瘤全切除10例,近全切除2例,无手术死亡。术后肌力好转4例,肌力无改变6例,肌力下降或加重2例,其中1例经脱水、激素及高压氧治疗后好转,1例无变化。功能保护率91.7%(11/12)。12例术后随访1～2年,无肿瘤复发。结论采用显微神经外科技术可提高皮层运动功能区脑膜瘤的全切率,术前行fMRI及DSA或MRA检查,则有助于术中保护脑功能区皮质、矢状窦和中央沟静脉,减少并发症。     

脑磁图在运动区脑膜瘤手术中的应用研究

目的 探讨脑磁图（MEG）在手术治疗皮质运动区脑膜瘤中的应用价值。方法 选择21例脑皮质运动区或其附近脑膜瘤患者，常规行影像学和MEG检查，配合神经导航系统行肿瘤显微手术切除。结果 肿瘤切除按Simpson分级，Ⅰ级10例，Ⅱ9例，Ⅳ级2例。术后神经功能障碍完全恢复正常17例，明显好转3例，加重1例。结论 MEG是无创性功能区定位、确定病变与皮质运动区位置关系的重要方法，对皮质功能区病变的手术方案制定和功能区脑组织的保护具有重要的指导价值。     

功能核磁共振引导显微外科手术切除运动区脑肿瘤

目的探索功能核磁共振(fMRI)在运动区脑肿瘤显微外科手术切除中作用.方法采用GEMEDICALSYSTEMSMri1.5机作功能核磁共振扫描,然后通过辅助计算机计算采样图象重建,得到肿瘤与功能区图像,根据fMRI确定病灶与功能区位置选择手术切口和手术入路,显微外科切除运动区脑肿瘤12例,其中脑膜瘤10例,星形细胞瘤2例.按病灶与功能区关系,分为三组病灶在功能前5例,病灶在功能区后4例和病灶在功能区下3例.结果功能区在病灶后,采用中央沟前切除肿瘤,病灶在功能区后和功能下采用中央沟静脉后入路切肿瘤.¨病灶被切除,1例星形细胞瘤次全切除,病人术后运动功能未加重.结论功能核磁共振引导运动区肿瘤显微外科手术对保护运动功能有重要价值.     

脑功能区胶质瘤手术中的新技术

目的探讨切除脑功能区胶质瘤手术新技术与方法。方法48例脑功能区胶质瘤经术前常规MRI、弥散张力成像(DTI)和fMRI定位大脑皮层功能区及功能投射纤维束,以神经导航为前导,在术中全麻唤醒状态下,通过术中B超定位脑内病灶,皮层体感诱发电位(Co-SEP)及皮层直接电刺激术(Co-ST)脑功能区定位,并在清醒状态下切除病变。术后随访时间3-42个月。结果16例Co-SEP确定中央沟,42例Co-ST明确运动区,16例Co-ST确定语言运动区;肿瘤全切35例,次全切除9例,部分切除4例。术后1个月神经症状好转44例,术后出现暂时性局部神经症状36例;长期局部神经症状加重4例,无手术死亡。全部患者无手术痛苦回忆。结论术中全麻唤醒、皮层-皮层下电刺激术和脑超声技术是切除功能区胶质瘤必备的三项基本技术;术前fMRI与DTI为脑功能区手术提供十分重要信息,神经功能导航为术中功能区定位提供重要前导,综合使用这些现代技术能够在术中明确脑功能区与肿瘤切除范围的关系,做到最大限度地切除脑功能区病变和保护脑功能。     

fMRI辅助脑功能区病变手术设计的应用

目的探讨功能性磁共振成像(fMRI)在脑运动区病变手术设计中的应用。方法对20例累及运动区的脑内占位病变病人术前行手握拳运动block激发模式fMRI，分析病变与运动区的关系及功能重塑情况，据此在手术中尽可能切除肿瘤并保留运动皮质的完整。结果肿瘤全切除6例，次全切除12例，部分切除2例。术前10例上肢肌力下降病人术后上肢肌力好转7例．余3例及术前肌力正常10例术后保持术前水平、结论fMRI用于运动区病变病人运动功能的客观评估和手术计划，对于降低手术带来功能缺陷的发生率具有重要意义。     

核磁共振脑功能成像指导切除脑功能区肿瘤(附6例报告)

目的应用核磁共振脑功能成像(fMRI)定位脑功能区,指导手术切除脑功能区肿瘤。方法对6例右额顶叶区胶质瘤病人术前行复杂手指运动fMRI,激活脑皮质功能区,明确兴奋灶与肿瘤的位置关系,进而确定手术方案。结果额叶切除1例,显微镜下全切2例,次全切2例,右顶叶前半部分切除1例;仅后者出现左侧肢体肌力减弱,且逐渐恢复。余无并发症。结论fMRI可以明确右额顶叶皮质功能区,提示功能区与胶质瘤的位置关系,指导肿瘤的切除范围和程度。     

功能性磁共振辅助神经导航手术治疗运动功能区病变

目的 研究功能性磁共振成像(fMRI)辅助神经外科导航系统在运动功能区病变手术中的应用价值。方法 利用血氧水平依赖性测量(BOLD)成像技术，对14例运动功能区病变病人(胶质瘤11例，脑膜瘤2例，转移癌1例)行fMRI检查，将有关数据及图像进行相关分析处理，得到活化功能区图像，将功能像与结构像融合，输入神经外科导航系统，术中进行功能区定位，指导手术。结果病人术中病灶影像均获得等体积全切除，术后神经功能障碍未加重。结论 fMRI检查可以为功能区病变术前手术计划的制定提供有价值的信息，结合导航系统，可在术中精确定位功能区，避免损伤，降低致残率。     

功能性磁共振和皮质脑电图在伴继发性癫(癎)脑肿瘤手术中的应用(附13例分析)

目的探讨术前功能磁共振成像（fMRI）和术中皮质脑电图（ECoG）在伴继发性癫疒间脑肿瘤手术中的应用价值。方法回顾性分析13例脑运动皮质区附近肿瘤病人的临床资料。术前通过fMRI了解相应脑功能区皮质和白质纤维束的形态和分布;术中在切除肿瘤前后行ECoG检测,确定致疒间灶的位置,指导肿瘤及致疒间灶的切除。结果手运动功能区受肿瘤推挤而出现功能转移或重组9例,行肿瘤全切除;功能区局部重叠2例,行肿瘤次全切除;大部分重叠2例,行肿瘤部分切除。ECoG确定的致疒间灶距肿瘤2 cm以内9例,3～5 cm 2例,与肿瘤重叠2例。术后出现短暂性失语1例,一过性偏瘫2例。结论fMRI能准确显示运动皮质中枢位置,对脑肿瘤术前手术方案制定和手术时减少重要功能区损伤具有重要意义。ECoG确定致疒间灶大多距肿瘤2 cm以内。     

脑磁图神经导航引导下的脑功能区手术

目的 研究大脑半球功能区的手术治疗,提高神经功能的保护.方法 本组15例大脑半球内病灶包括:脑胶质瘤、脑膜瘤、海绵状血管瘤、脑脓肿,涉及运动区及语言区.手术前均行脑磁图功能定位,采取脑磁图-神经导航引导下的手术切除.结果 术前肢体运动功能正常的8例中7例术后肌力依然正常,1例对侧肌力减弱;术前肌力减弱的4例中3例术后恢复正常,无变化1例;2例语言区的肿瘤术后功能正常.结论 脑磁图可以准确定位神经功能区域,与神经导航联合应用可以设计合理的手术入路;对皮层表面的腩胶质瘤采用经硬脑膜病灶-脑界面栅栏分隔法,可有效地防止手术早期脑移位的误差,提高手术的准确性,有效地保护神经功能.     

fMRI与DTI联合应用在神经导航下切除运动区附近病变

目的 探讨fMRI与DTI联合应用在大脑皮层运动区附近病变手术中的价值.方法 对18例大脑皮层运动区附近病变的患者,采用组块设计,利用血氧水平依赖性功能磁共振成像(BOLD-fMRI)获得运动区皮层激活,利用磁共振弥散张量成像技术(DTI)获得白质纤维束走行,应用神经导航系统进行影像融合后,术中定位皮层运动区与锥体束,经神经电生理检查验证后,避开功能区在显微镜下切除病变.结果 fMRI确定的功能区与术中电生理检查结果基本一致.12例病变全切,6例大部切除.术后肢体肌力好转或无变化14例,3例出现一过性加重,1例遗留永久性功能损害.结论 在神经导航辅助下fMRI与DTI联合应用可以准确定位大脑皮层运动区和锥体束,提高病变切除程度,减少术后运动功能障碍.     

视频脑电图在小儿癫痫诊断中的应用

目的评价视频脑电图(video-EEG)在小儿癫诊断中的应用价值。方法对126例具有发作性症状的患儿进行连续8h的包括清醒、睡眠、诱发试验及必要的认知测验的视频脑电图监测。结果经发作期视频脑电图证实,39例初诊为癫性发作的患儿中14例(35%)为非癫性发作;15例其他症状发作中13例(86%)为非癫性发作。64例样放电患儿中51例(80%)确定发作类型,22例(34%)确定癫类型。视频脑电图可发现短暂轻微的癫发作及样放电引起的一过性认知损伤。结论视频脑电图在排除非癫性发作、确定癫性发作的类型、评价脑电-临床关系方面可提供准确可靠的证据,进一步提高癫的临床诊断水平。     

Neuroprotective properties of memantine in different in vitro and in vivo models of excitotoxicity

The pathogenesis of stroke, trauma and chronic degenerative diseases, such as Alzheimer's disease (AD), has been linked to excitotoxic processes due to inappropriate stimulation of the N-methyl-D-aspartate receptor (NMDA-R). Attempts to use potent competitive NMDA-R antagonists as neuroprotectants have shown serious side-effects in patients. As an alternative approach, we were interested in the anti-excitotoxic properties of memantine, a well-tolerated low affinity uncompetitive NMDA-R antagonist presently used as an anti-dementia agent. We explored in a series of models of increasing complexity, whether this voltage-dependent channel blocker had neuroprotective properties at clinically relevant concentrations. As expected, memantine protected neurons in organotypic hippocampal slices or dissociated cultures from direct NMDA-induced excitotoxicity. However, low concentrations of memantine were also effective in neuronal (cortical neurons and cerebellar granule cells) stress models dependent on endogenous glutamate stimulation and mitochondrial stress, i.e. exposure to hypoxia, the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP+) or a nitric oxide (NO) donor. Furthermore, memantine reduced lethality and brain damage in vivo in a model of neonatal hypoxia-ischemia (HI). Finally, we investigated functional rescue (neuronal capacity to migrate along radial glia) by memantine in cerebellar microexplant cultures exposed to the indirect excitotoxin 3-nitropropionic acid (3-NP). Potent NMDA-R antagonists, such as (+)MK-801, are known to block neuronal migration in microexplant cultures. Interestingly, memantine significantly restored the number of neurons able to migrate out of the stressed microexplants. These findings suggest that inhibition of the NMDA-R by memantine is sufficient to block excitotoxicity, while still allowing some degree of signalling.     

Storage of lipofuscin in neurons in mucopolysaccharidosis

Summary A histochemical and ultrastructural study was made on the brain of a 23-year-old man with Sanfilippo's syndrome. In accordance with previous reports the cortical nerve cells contained a PAS-positive lipid storage substance. This showed intense autofluorescence in UV-light and was positive with various stains for lipofuscin. The storage material appeared ultrastructurally as inclusion bodies composed of short lamellated membranes, granular material, and vacuoles. In addition, concentrically and transversely lamellated membranous cytoplasmic bodies were observed in the nerve cells. It is concluded that the PAS-positive lipid storage material in the neurons was composed partly of lipofuscin in addition to other lipids presumably glycosphingolipids.Supported by a grant from the Expressen Prenatal Research Foundation     

Role of vincristine in the inhibition of angiogenesis in glioblastoma

Objective: Vincristine, a microtubule-destabilizing drug, was found to exhibit anti-angiogenic effects and anti-tumoral activity. However, the precise mechanism by which vincristine inhibits angiogenesis in glioblastomas is not well understood. Our aim was to investigate whether vincristine affects vascular endothelial growth factor (VEGF) expression in glioblastoma cells and determine whether it is mediated by the downregulation of hypoxia-inducible factor-1α (HIF-1α).

Methods: We investigated the expression of HIF-1α in glioblastoma tissues resected from patients and in human glioblastoma cell lines using immunohistochemistry, Western blot analysis, and immunocytochemistry. In addition to an MTT assay assessing the effect of vincristine on cell proliferation and viability, the effects of vincristine on VEGF mRNA expression and HIF-1α protein were examined using real-time RT-PCR and Western blot analysis under 1% O₂ (hypoxia).

Results: HIF-1α was expressed in the majority of glioblastoma tissues and was detected mainly in the nucleus. Strong immunoreactivity for HIF- 1 α was found often in the hypercellular zones. Under hypoxic conditions, HIF-1α protein levels in the glioblastoma cell lines increased, primarily localizing into the nucleus similar to glioblastoma tissues. Exposure of glioblastoma cells to vincristine resulted in enrichment of the G₂-M fraction of the cell cycle, which suggests that vincristine-mediated growth inhibition of glioblastoma is correlated with mitotic inhibition. Using doses lower than those found to reduce the viability and proliferation of cells by 50% (IC₅₀), vincristine decreased both the expression of VEGF mRNA and the level of HIF-1α protein in hypoxic glioblastoma cells. In addition, following exposure to vincristine, the expression of VEGF mRNA was correlated with HIF-1α protein levels.

Conclusions: Our results suggest that the mechanism by which vincristine elicits an anti-angiogenic effect in glioblastomas under hypoxic conditions might be mediated, in part, by HIF-1α inhibition.     

自噬参与帕金森病发病的研究进展

近年来,蛋白质的降解障碍被认为是帕金森病（Parkinson’Sdisease,PD）发病过程中的重要因素,人们已经公认泛素一蛋白酶体系统（ubiquitin--pro—teasomesystem,UPS）功能异常或衰竭能够导致细胞内异常蛋白蓄积、细胞功能障碍,甚至细胞凋亡。与此同时,蛋白降解的另一条途径——自噬-溶酶体途径（autophagy—lysosomepathway,ALP）也已成为了生命科学领域的研究热点,自噬与神经变性疾病,尤其是PD的关系日益受到人们的重视。     

Midazolam in treatment of various types of seizures in children

Midazolam is a recently developed water-soluble benzodiazepine that shares anxiolytic, muscle relaxant, hypnotic and anticonvulsant actions with other members of this class. There are limited studies that midazolam can be used successfully to treat seizures in adults and children. In this study, 0.2 mg/kg intramuscular (IM) midazolam was administered to 11 children (eight boys and three girls), aged 3 days to 4 years (mean age 1.8±1.4 years), with seizures of various types. In all but one child, seizures stopped in 15 s–5 min after injection. No side effects were observed. These results suggest that IM administration of midazolam may be useful in a variety of seizures during childhood, especially in case of intravenous (IV) line problem.     

脑电图预测痫性发作研究进展

癫痫(epilepsy)是由脑部神经元高度同步化异常放电所致的临床综合征,系神经系统的常见病,困扰着全世界约1%的人群.每次神经元的阵发性放电或短暂的脑功能异常称为痫性发作(seizures).     

Developmental effects of in vivo and in vitro inhibition of nitric oxide synthase in neurons

The diffusible chemical messenger nitric oxide (NO) is involved in neuronal plasticity and it is, therefore, supposed to play a role in brain development. A shortage of NO during the critical period of brain maturation may theoretically have long-lasting consequences on the organization of the adult brain. We have performed in neonatal rats a chronic inhibition of the enzyme responsible for NO production, nitric oxide synthase (NOS), from postnatal day 3 to postnatal day 23, through administration of the competitive antagonist N-nitro-L-arginine methylester (L-NAME). The calcium-dependent catalytic activity resulted almost completely inhibited throughout the period of treatment and it took more than 4 days after its suspension to get a full recovery. The expression of the neuronal isoform of the enzyme (nNOS), revealed by immunoblotting, was unchanged during the treatment and after it. The histochemical reaction for NADPH diaphorase was reduced at the end of the treatment and recovered in concomitance with the recovery of the catalytic NOS activity. No gross structural alterations were detected in brain morphology. The levels of three neurotransmitter-related and one astrocytic marker were unchanged in the cerebellum, hippocampus and cortex of 60-day-old rats which had been neonatally treated. A similar lack of significant effects on neurochemical brain maturation was also noticed in a parallel series of experiments, in which a short pulse of NOS inhibition was performed at a critical prenatal time of brain development, from gestational day 14 to gestational day 19. In vitro, chronic exposure of cerebellar granule cells to L-NAME (500 microM) resulted in slight decrease of surviving neurons after 8 days in culture and in better resistance to the challenge of stressful culture conditions. The present results suggest that the basic plan of brain organization can be achieved despite an almost complete NOS inhibition during the maturation period. In vitro, NOS inhibition may bring to more pronounced consequences on neuronal viability and function.     

Issues in evaluation of cognition in the elderly in developing countries

Background:

Developing regions of the world host the majority of elderly subjects who are at risk for dementia. Reliable epidemiological data from these countries is invaluable in tackling this global problem. Scarcity of such data in literature is largely attributable to problems that are unique to developing communities worldwide.

Objective:

To classify and describe the problems that interfere with the collection of reliable epidemiological data on cognitive impairment in the elderly in developing communities, and to suggest practical solutions for some of them.

Methods:

Inferring from the experiences of a large, ongoing, population-based study on the cognitive impairments in the elderly in South India and from the review of literature.

Conclusion:

A fatalistic attitude regarding aging in the communities, significant heterogeneity in educational abilities and activities of daily living, high illiteracy among rural subjects, and lack of an organized health care system and updated demographic figures are some of the major factors that contribute to technical, namely, methodology-related problems and practical, namely, subject-related problems in such epidemiological studies.