癫痫预测面临问题的分析与展望

癫痫是神经科常见疾病,具有反复发作和难以治愈的特征。对癫痫发作的预测可以使医护人员或患者提前采取有效措施来降低或避免癫痫发作所带来的损伤。从20世纪90年代至今,癫痫预测算法得到了长足发展,同时也面临着如算法精确度、数据处理方式、预测能力有限等方面的问题。本文对上述问题进行了整理阐述,并对癫痫预测算法的发展趋势做了进一步分析。     

癫痫预测方法的分析与研究

癫痫预测目的有两个从技术的层面去理解癫痫发作的机理,并对癫痫发作进行测量和改善,探索引发癫痫发作的周期性及先兆;开发出可靠的“癫痫发作前预警及治疗装置”。癫痫预测的主要研究方法有频域分析方法;时序分析方法;智能系统工程方法;非线性动力学方法。目前,越来越多的研究集中在非线性动力学的方法上,且来自多种方法的很多证据证明癫痫可以预测。     

新生儿对语音的感知、辨别和学习

新生儿自娩出起便开始利用臻于成熟的听觉系统对语音的各要素进行大脑表征和学习记忆。考察新生儿语音加工特点,不仅能揭示语言功能在人类发展最初阶段的认知神经机制,还能对自闭症等神经发育性疾病的早期预警和临床诊断提供有价值的线索。我们回顾并总结了新生儿对语音的感知、辨别和学习以及语言发展对自闭症的预测作用,发现新生儿对特定语音存在感知偏好;新生儿具备独特的音素辨别能力;婴儿期语言加工的脑功能或结构指标对自闭症具有一定的预测价值。我们建议未来研究从三个方面开展工作。在基础研究方面：第一,严格控制语音材料的韵律因素,重新审查新生儿语言加工特征及大脑偏侧化问题;第二,揭示新生儿语音学习的认知神经机制以及睡眠的记忆巩固作用。在临床转化研究方面,以高风险自闭症新生儿为追踪对象,基于纵向多模态脑观测数据,建立疾病风险评估系统,揭示出生早期语言发展脑指标对自闭症的预测价值。     

癫痫预测方法的分析与研究

癫痫预测目的有两个:从技术的层面去理解癫痫发作的机理,并对癫痫发作进行测量和改善,探索引发癫痫发作的周期性及先兆;开发出可靠的"癫痫发作前预警及治疗装置".癫痫预测的主要研究方法有:频域分析方法;时序分析方法;智能系统工程方法;非线性动力学方法.目前,越来越多的研究集中在非线性动力学的方法上,且来自多种方法的很多证据证明癫痫可以预测.     

癫痫大发作患儿智力及影响因素的研究

引言癫痛是小儿时期最常见的一种神经系统综合征。据报道,国外癫痛患者约占人群的5一7脉,国内为078～6％。关于小儿癫痛的患病率未见报道。癫病对患儿认知和行为的影响早已引起儿科临床、患儿家长、医学心理学工作者以及有关人士的关注。H0ldsworth和whitmr。在117例患）L中发现有69％的患儿平均作业水平下降,21％有行为异常,其注意力和智能均比同龄儿童差,Scheffner的报道为：初辅大发作患儿智力低下者占40－50％．也有报道认为除了疾病发作的影响之外,多种抗癫病药物（AEDS）也程度不同的影响儿童的认知和行为,尤其是多种药物的…     

脑电图判读对癫痫诊断和治疗的影响

脑电图(EEG)是癫痫诊断中最重要的实验室检查方法,对确定癫痫类型,合理选择抗癫痫药物发挥了重要作用。但由于EEG操作不规范,对EEG结果不适当或错误的判读和解释,以及临床医生缺乏对EEG临床应用的理解,导致将很多非癫痫性事件误诊为癫痫,或对已经长期控制发作的癫痫病人过度治疗,由此带来一系列的医疗和社会问题。这些现象在国内外均普遍存在,应引起相关学科的高度重视。应强调规范的EEG记录,提高对EEG的判读水平,并对神经科、儿科或癫痫专科医生进行必有的EEG培训,以更好的发挥EEG在癫痫诊治中的作用。     

脑电图判读对癫痫诊断和治疗的影响

脑电图(EEG)是癫痫诊断中最重要的实验室检查方法,对确定癫痫类型,合理选择抗癫痫药物发挥了重要作用.但由于EEG操作不规范,对EEG结果不适当或错误的判读和解释,以及临床医生缺乏对EEG临床应用的理解,导致将很多非癫痫性事件误诊为癫痫,或对已经长期控制发作的癫痫病人过度治疗,由此带来一系列的医疗和社会问题.这些现象在国内外均普遍存在,应引起相关学科的高度重视.应强调规范的EEG记录,提高对EEG的判读水平,并对神经科、儿科或癫痫专科医生进行必有的EEG培训,以更好的发挥EEG在癫痫诊治中的作用.     

神经病学临床教学中治疗矛盾的运用

1　提出矛盾,强调正确处理治疗矛盾的重要性癫痫为神经科常见疾病,是由多种病因引起的大脑神经元反复发作性异常放电所致的临床症候群。由于放电部位不同,临床表现也多种多样。癫痫的主要治疗原则是寻找病因、对因治疗及早期应用抗癫痫药物控制发作。但所有抗癫痫药物都有...     

群体隔离对大白鼠听源性癫痫的影响及其与脑内单胺类神经介质含量变化的关系

使群体隔离大白鼠接受急性和慢性铃声刺激,以观察隔离对大白鼠听源性癫痫的发生和适应过程的影响,同时观察其与脑内单胺类神经介质含量变化的关系。 结果表明急性声音应激时群体隔离动物癫痫发生率高。在铃声应激后隔离鼠端脑内NE含量显著减少。在连续6天的慢性声音应激时隔离大白鼠的适应过程稍慢。在6天中发生癫痫和狂跑的总次数隔离鼠也明显高于群居鼠。在第六天测定时发现隔离鼠脑干内NE含量明显低于群居鼠。群居鼠端脑和脑干内5-HT含量及隔离鼠端脑内5-HT含量明显增高。第七天测定时群居鼠端脑内NE含量明显增高,隔离鼠端脑与脑干内5-HIAA含量明显增高。上述结果表明隔离动物对铃声刺激的应付能力减弱,适应过程减慢。这种现象可能与隔离动物脑内NE和5-HT的生物合成受限有关。     

左乙拉西坦与丙戊酸钠分别治疗婴幼儿癫痫综合征的疗效观察

探讨左乙拉西坦治疗婴幼儿癫痫综合征的临床疗效和对患儿智能发育的影响。选择确诊为癫痫综合征的87例患儿,随机分为治疗组44例,对照组43例,治疗组给予左乙拉西坦、对照组给予丙戊酸钠,治疗6个月后评价癫痫控制情况。在治疗前、治疗后6个月、12个月分别采用婴幼儿智力发育量表检测智力发育指数(MDI)和运动发育指数(PDI)评估患儿智能发育情况。治疗组41例完成治疗,症状完全控制29例、好转10例、无效3例,总有效率92.86%;对照组39例完成治疗,症状完全控制28例、好转9例、无效3例,总有效率94.87%;两组总有效率无显著差异(P0.05)。治疗前、治疗后6个月时段两组患儿MDI和PDI值无统计学差异(P0.05);治疗12个月后,治疗组患儿的MDI和PDI明显高于对照组,两组有统计学差异(P0.01)。左乙拉西坦治疗婴幼儿癫痫综合征的临床疗效与丙戊酸钠相同;且左乙拉西坦治疗对婴幼儿癫痫患者的智力及运动发育有一定改善作用。     

Age-dependent consequences of seizures: relationship to seizure frequency, brain damage, and circuitry reorganization

Seizures in the developing brain pose a challenge to the clinician. In addition to the acute effects of the seizure, there are questions regarding the impact of severe or recurrent seizures on the developing brain. Whether provoked seizures cause brain damage, synaptic reorganization, or epilepsy is of paramount importance to patients and physicians. Such questions are especially relevant in the decision to treat or not treat febrile seizures, a common occurrence in childhood. These clinical questions have been addressed using clinical and animal research. The largest prospective studies do not find a causal connection between febrile seizures and later temporal lobe epilepsy. The immature brain seems relatively resistant to the seizure-induced neuronal loss and new synapse formation seen in the mature brain. Laboratory investigations using a developmental rat model corresponding to human febrile seizures find that even though structural changes do not result from hyperthermic seizures, synaptic function may be chronically altered. The increased understanding of the cellular and synaptic mechanisms of seizure-induced damage may benefit patients and clinicians in the form of improved therapies to attenuate damage and changes induced by seizures and to prevent the development of epilepsy.     

Brain mechanisms of altered consciousness in focal seizures

Consciousness is a central concept in epileptology, relevant to the understanding of both focal and generalized seizures. Within focal seizures, impairment of consciousness has long been considered as the main criterion differentiating complex partial seizures (CPS) from simple partial seizures With the development of improved tools for investigating human brain function, new insights into the brain mechanisms of altered consciousness in CPS have become available. This paper reviews the existing literature on how the currently available methods can be used to address the fundamental issue of how CPS alter consciousness.     

Effects of early seizures on later behavior and epileptogenicity

Both clinical and laboratory studies demonstrate that seizures early in life can result in permanent behavioral abnormalities and enhance epileptogenicity. Understanding the critical periods of vulnerability of the developing nervous system to seizure-induced changes may provide insights into parallel or divergent processes in the development of autism. In experimental rodent models, the consequences of seizures are dependent on age, etiology, seizure duration, and frequency. Recurring seizures in immature rats result in long-term adverse effects on learning and memory. These behavioral changes are paralleled by changes in brain connectivity, changes in excitatory neurotransmitter receptor distribution, and decreased neurogenesis. These changes occur in the absence of cell loss. Although impaired cognitive function and brain changes have been well-documented following early-onset seizures, the mechanisms of seizure-induced dysfunction remain unclear.     

Genealogic studies in genuine partial epilepsy

Clinical--electroencephalographic (EEG) investigation was performed in 12 families. In the study were included 12 epileptics with partial seizures in whom the katamnestic follow up from 2 to 6 years provided clinical, EEG and genetic data for the so called primary partial epilepsy 24 parents and 14 siblings. In four of the Children with epilepsy the seizures were of the "Rolandic" type; in 5--"psychomotor"; and in 3--hemiconvulsive. No data for structural brain lesion investigation were found. Rapid and long lasting therapeutic effect was achieved in all of the cases. The EEG showed focal paroxysmal activity in all of the diseased and in 11 of the siblings, in 5 of them were found epileptic seizures of the same type as in the probands. The possibilities of a genetic predisposition to development of an epileptogenic focus and its clinical Expression in members of the families in discussed.     

Developmental seizures induced by common early-life insults: short- and long-term effects on seizure susceptibility

The immature brain is highly susceptible to seizures induced by a variety of insults, including hypoxia, fever, and trauma. Unlike early life epilepsy associated with congenital dysplasias or genetic abnormalities, insults induce a hyperexcitable state in a previously normal brain. Here we evaluate the epileptogenic effects of seizure-inducing stimuli on the developing brain, and the age and regional specificity of these effects.     

Hypersexuality and limbic system seizures

Hypersexual behavior was induced in adult male cats by repeatedly evoked limbic system seizures. Accentuation of Dopaminergic activity with drugs was used to facilitate development of the seizure induced hypersexuality. Hypersexuality consisted of biting knap of neck, mounting, thrusting and coital intromission. The gradual development and eventual disappearance of hypersexuality was correlated with the progressive prolongation of the seizures in their evolution. There are three stages of seizure evolution in relation to sexuality. First stage-normal sexuality, intermediate stage-hypersexuality and late stage-hyposexuality. A theoretical “hypersexual growth and decay curve” was constructed in relation to the evolution of limbic seizure durations in the intermediate stage. It was suggested that the observed hypersexuality was related to the early discharge activation of hypothalamic, preoptic and basal ganglia neurohumeral facilitatory mechanisms for sexuality, and the late effects were related to discharge activation of brain stem serotonergic inhibitory mechanisms. The discussion attempts also to use these experimental findings to explain clinically observed hyposexuality and hypersexuality. It was suggested that either hypersexuality or hyposexuality may be associated with psychomotor seizures and that the predominating sexual state at a given moment is dependent upon the evolutionary stage of the seizure at that moment. Consequently, psychomotor seizures with associated hypersexuality should not be considered a clinical anachronism. In fact, these observations support the impression that rape may be a manifestation of a psychomotor seizure.     

Structural and functional imaging in children with partial epilepsy

Imaging plays an increasingly important role in the evaluation of children with complex partial seizures. Most partial epilepsy, especially of temporal lobe origin, begins during childhood. Structural imaging with high-resolution MRI can help identify the etiology of partial seizure disorders in many children. MRI studies also show the more widespread effect of seizures on brain structure. Progressive volume loss of the hippocampal formation in some patients with temporal lobe epilepsy provides evidence that continued seizures may be associated with progressive neuronal injury. FDG-PET studies show regional decreases in glucose consumption in the cortical zone from which seizures arise. Functional abnormalities often are more extensive than the seizure focus. Studies in children with recent-onset epilepsy show that metabolic abnormalities are considerably less common than in adults with partial epilepsy, supporting the notion that in some patients there may be progressive metabolic changes that occur with continued seizures. Functional MRI may be used to identify language areas in children with partial epilepsy. fMRI language tasks reliably identify the dominant hemisphere for language dominance when compared to the intracarotid amytal procedure. Tests of verbal fluency and semantic decision identify frontal lobe language areas, while reading text paradigms and auditory passage paradigms are better for identifying temporal language areas. A panel of paradigms is best used to identify language areas in children being considered for epilepsy surgery. fMRI is a valuable tool for elucidating the impact of chronic neurologic disease states on the functional organization of language networks during development.     

The consequences of uncontrolled epilepsy

The consequences of epilepsy can be quite severe and include shortened lifespan, excessive bodily injury, neuropsychological and psychiatric impairment, and social disability. There is evidence that seizures cause brain injury, including neuronal death and physiological dysfunction. Mortality rates are 4-7 times higher in people with medically refractory seizures, and injury rates are substantial, ranging from one per 20 person-years to as much as one per 3 person-years. Quality of life is impaired in epilepsy, and relates to seizure control. Psychosocial disabilities, including lower social interaction with reduced marriage rates and reduced employment levels, are more common in people with refractory seizures. Complete seizure control is desirable, since seizures potentially constitute a serious threat to health and well-being. Therefore, satisfactory seizure control should be defined as having no seizures. Treatment should be directed to preventing seizures whenever possible and achieving control early in the course of illness. The risks of uncontrolled seizures outweigh the risks of aggressive medical or surgical therapy.     

Language outcome after perinatal stroke: does side matter?

The goal of this study was to examine structured language skills in children with perinatal strokes. Participants were 28 school-age children with early focal brain lesions (17 with left hemisphere [LH] damage, 11 with right hemisphere [RH] damage), and 57 controls. A standardized test of language (Clinical Evaluation of Language Fundamentals-Revised) was administered. Receptive, Expressive, and Total Language scores, as well as subtest scores, were analyzed. Control participants scored within the normal range, whereas the LH and RH groups scored significantly more poorly than did controls. There were no differences between the LH and RH groups on any of the language scores, and all scores were below the 14th percentile. Within the lesion group as a whole, scores were not related to lesion laterality, site, or severity. Results also were not accounted for by socioeconomic status or IQ. However, children who experienced seizures demonstrated significantly poorer performance than did children who did not experience seizures. Damage to either the LH or RH early in development adversely affects later language abilities, particularly on tasks with structured and complex linguistic demands. Although lesion side has little effect, the presence or absence of seizures is a major contributor to language outcome.