注意缺陷多动障碍的前扣带认知区功能磁共振成像研究

关于注意缺陷多动障碍(ADHD)的功能磁共振成像(fMRl)研究已经成为一个热点,而前扣带认知区(dACC)又是注意缺陷多动障碍研究中的一个最重要的研究对象。本文就前扣带回认知区在注意缺陷多动障碍中的功能磁共振成像的研究进展进行综述。     

注意缺陷多动障碍患者一级亲属的认知功能研究

本研究以注意缺陷多动障碍（ ADHD）患者未病一级亲属为对象,探查ADHD患者一级亲属在认知功能方面是否存在异常。     

成人注意缺陷多动障碍的诊断现状

注意缺陷多动障碍(Attention Deficit/Hyperactivity Disor- der,ADHD)是指一种以注意缺陷、多动、冲动的行为表现为主要特征的精神障碍(APA,1994)。尽管注意缺陷多动障碍是儿童期常见的一种广泛性发展障碍,但很少有随访研究那些儿童期被诊断为ADHD的个体进入成年期(Young,2000)后的情况。成人ADHD的概念于1980年在DSM-Ⅲ中首次得到公认。ADHD成人与儿童一样,均有三种初级特征,包括注意缺陷、活动过多以及冲动等。除了初级特征之外,成人ADHD还存在多种次级特征,包括物质滥用、学习困难、频繁迁居、车祸、监禁、工作记录不稳定以及赌博等。一般认为,30%至50%的儿童ADHD症状会持续进入成年期。Barkley认为追踪研究表明,持续症状学评估的变化为10%到70%,这取决于研究类型及研究者对这一障碍的定义。     

注意缺陷多动障碍的脑诱发电位研究进展

注意缺陷多动障碍(ADHD)是当前儿童精神卫生和心理卫生领域研究得最为广泛的疾病之一。最近研究发现ADHD患儿有多种脑诱发电位(BEP)成分的异常,BEP并且可以评价ADHD的治疗效果,提示脑诱发电位是研究注意缺陷多动障碍的一种有价值的神经电生理学方法。     

注意缺陷多动障碍的功能神经成像研究

本文就功能神经成像技术如PET、SPECT、fMRI对注意缺陷多动障碍患者的大脑代谢和局部脑血流及神经生化的研究进行综述 ,结果提示ADHD所涉及的脑区为前额叶、顶叶、颞叶、扣带回 ,纹状体 ,基底节等区域。另外也表明注意缺陷障碍的成人的功能神经影像方面不同于儿童。     

成人注意缺陷多动障碍临床特点与诊断的研究进展

注意缺陷多动障碍(attention deficitandhyperactivity disorder,ADHD)是儿童期常见的行为问题之一。ADHD起病于儿童期,临床上以持续存在且与年龄不相称的注意力不集中、多动、冲动为核心症状,同时患者的学业及其他功能也受到相应的损害。大量的研究提示,儿童ADHD患者的症状会持续到成人[13]。目前,国内对成人ADHD尚未引起足够的重视。通过复习近20余年尤其是近5年来的相关文献,了解国外关于成人ADHD临床特点及诊断的研究现状,为国内开展相关的研究进行铺垫。一、成人ADHD的临床表现与儿童症状的延续性虽然ADHD起病于儿童期,但…     

注意缺陷多动障碍的功能神经成像研究

本文就功能神经成像技术如PET、SPECT、fMRI对注意缺陷多动障碍患者的大脑代谢和局部脑血流及神经生化的研究进行综述，结果提示ADHD所涉及的脑区为前额叶、顶叶、颞叶、扣带回，纹状体，基底节等区域。另外也表明注意缺陷障碍的成人的功能神经影像方面不同于儿童。     

注意缺陷多动障碍脑白质纤维束异常的磁共振影像学研究

大脑白质的发育对个体正常行为和认知功能的建立至关重要,已有大量研究表明白质微结构改变和注意缺陷多动障碍(ADHD)核心症状以及认知功能缺陷有关,提示脑白质异常可能为该病的神经基础之一。本文旨在通过对儿童青少年ADHD患者的大脑白质磁共振影像学研究进行回顾与总结,归纳ADHD主要相关白质纤维束的改变特征及其与临床表现的关系,揭示ADHD潜在的脑白质病理机制,并对未来研究方向进行展望。     

注意缺陷多动障碍的功能磁共振和神经电生理的研究进展

本文就注意缺陷多动障碍(ADHD)的功能磁共振(fMRI)和神经电生理方面的研究进展作一综述。     

注意缺陷多动障碍的功能磁共振和神经电生理的研究进展

本文就注意缺陷多动障碍（ADHD）的功能磁共振（fMRI）和神经电生理方面的研究进展作一综述。     

Diagnostic Difficulties and Treatment Implications

Summary: Differentiation between types of epileptic seizures has been aided in recent years by the introduction of intensive neurodiagnostic techniques and the development of increasingly detailed classification systems. Paradoxically, these developments have not simplified the task of matching the appropriate antiepileptic drug to a particular seizure type. It is reasonable to assume that anticonvulsant drugs will have different effects on different types of seizures, but faulty, circular reasoning can enter the picture if one also assumes that responses of seizures to different drugs signify different seizure types. There are several examples of differential diagnoses that can fall prey to this problem, including the diagnosis between partial seizures with secondary generalization and generalized tonic-clonic seizures, and the diagnosis between complex partial seizures and absence seizures with automatisms, among others. Considerations of etiology in future classification systems can further complicate the problem: should one then choose an anticonvulsant drug on the basis of individual seizure type or on the basis of the type of epilepsy? Ramifications of this issue extend even to the drug approval process. Official sanction is not given for use of a drug for a seizure type not included in the original efficacy studies, even if later scientific evidence shows that seizure type to be related to a type that is included. New trials must be undertaken. These problems arise from how we choose to classify seizures.     

Cognitive Dysfunction Associated with Antiepileptic Drug Therapy

Summary: Epilepsy is frequently associated with cognitive dysfunction. However, the reasons for this correlation are unclear. Possible influential factors include patient age; duration, frequency, etiology, and type of seizures; hereditary factors; psychosocial issues; and antiepileptic drug (AED) therapy. Whereas many of these factors are beyond the physician's control, AED therapy is one element that can be addressed in treatment decisions by recognizing the potential cognitive effects of particular AEDs. For example, phenobarbital impairs memory and concentration; phenytoin affects attention, problem solving ability, and performance of visuomotor tasks. In contrast, carbamazepine may affect concentration, while valproate would appear to have minimal effects on cognition. Moreover, cognitive effects of AEDs are amplified with coadministration of multiple anticonvulsants (polytherapy). A review of studies on the cognitive effects of monotherapy with AEDs, as opposed to those of polytherapy, provides evidence that drug-related cognitive dysfunction can be reversed if patients are switched to a simpler therapeutic regimen. Future research should be directed toward developing reliable measures for assessing and monitoring cognition, and understanding the particular cognitive side effects of each AED. Physicians also need to revise their opinions about which side effects are "tolerable" for epileptic patients.     

Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.     

Carbamazepine Efficacy in Adults With Partial and Generalized Tonic-Clonic Seizures

Summary: Carbamazepine and phenytoin are drugs of choice in initial monotherapy for adult partial and secondarily generalized tonic-clonic seizures. These designations reflect the results of the Veterans Administration Epilepsy Cooperative Study Group of 1985. An earlier comparative study of carbamazepine and phenytoin by Ramsay and associates found both drugs equally effective in controlling new-onset seizures. Among the advantages of carbamazepine is that it causes relatively few cognitive and dysmorphic side effects. Its disadvantages are its unavailability in parenteral formulation and its metabolic autoinduction. The latter must be compensated for by planned dosage increases to maintain therapeutic plasma steady-state levels during the first 2 or 3 months of treatment. Carbamazepine is judged a drug of choice in the treatment of these secondarily generalized tonic-clonic seizures, and the drug of choice in children, adolescents, and women susceptible to the dysmorphic side effects associated with other anticonvulsant agents.     

Etiologic and Preventive Aspects of Epilepsy in the Child–Bridging the Gap Between Laboratory and Clinic

Summary: Four broad categories of basic phenomena are pertinent to developing ways to prevent epilepsy. These include mechanisms of epileptogenesis, ictal initiation and temporary entrainment by the seizure discharge of normally functioning brain, seizure propagation, and control mechanisms that function both to restrain the cascade of epileptic events culminating in a seizure and to arrest the epileptic event and restore the interictal state. In newborns and children, hypoxia-ischemia is a major factor leading to epileptogenesis, and several schemes are proposed to classify, quantify, and prevent hypoxic-ischemic encephalopathy. Control mechanisms must be better understood in order to develop prophylactic recommendations for epilepsy, and an experimental model of "kindling antagonism" may increase our understanding of these. Programs of prevention of seizures in children will evolve only if basic researchers and clinicians work productively together to develop an adequate understanding of factors important in epileptogenesis and antiepileptogenic control mechanisms.     

Predisposing and Causative Factors in Childhood Epilepsy

Summary: We review information from large studies of defined populations, examining the role of known factors and especially of prenatal and perinatal factors in contributing to nonfebrile seizure disorders of early childhood. We depend especially, but not exclusively, on the recently completed analyses from the Collaborative Perinatal Project of the National Institute of Neurological and Communicative Disorders and Stroke, the NCPP. About 4% of children in the NCPP who had at least one non-febrile nonsymptomatic seizure by the age of 7 years had a previous seizure during acute neurologic illness, such as meningitis or during the acute illness after trauma. Many such seizures should potentially be preventable. Of children with seizures, 10% had had a neonatal seizure and 13% had had a febrile seizure. Among the hundreds of prenatal and perinatal factors explored as predictors of childhood seizure disorders, the principal predictors identified were congenital malformations of the fetus, cerebral and noncerebral; family history of certain neurologic disorders; and neonatal seizures. In agreement with the British National Child Development Study, labor and delivery factors in the NCPP appeared to contribute very little to childhood seizure disorders. Maldevelopment, rather than damage at birth to an initially intact nervous system, appeared to be the more common mechanism. Most seizure disorders of early childhood remained unexplained by the large set of prenatal and perinatal characteristics examined.     

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.     

Treatment Considerations in Anticonvulsant Monotherapy

Summary: The long-standing practice of polypharmacy in treating epilepsy is giving way to use of monotherapy. Monotherapy can improve seizure control as well as reduce the risk of serious idiosyncratic reactions, dose-related side effects, and complex drug interactions. Monotherapy also offers improved compliance and cost-effectiveness. The basis of monotherapy is accurate diagnosis and assessment of the patient's seizure type(s), followed by selection of a single appropriate anticonvulsant drug. Many patients currently treated with multiple anticonvulsants can be successfully converted to monotherapy with a carefully monitored program in which troublesome and redundant drugs are gradually withdrawn from the therapeutic regimen.     

Anticonvulsant Drugs and Cognitive Function: A Review of the Literature

Summary: Alterations of cognitive function are separate from disturbances of behavior seen in association with epilepsy. The nature of the cognitive disability may to a certain extent depend on the seizure type. Partial seizures, mainly derived from a temporal lobe focus, impair memory tasks, while generalized seizures seem to have more effect on attentional abilities. A number of studies, reviewed in this paper, suggest that anticonvulsant drugs further impair cognitive function. Maximal impairments are seen in patients receiving polytherapy: rationalization of polytherapy improves cognitive abilities. Studies in children and adults have allowed differentiation of the effects of various commonly used antiepileptic agents. Maximal cognitive deficits are seen with. phenytoin, while phenobarbital and sodium valproate induce moderate disturbances, and carbamazepine seems relatively free from such toxicity. Further research is needed on the interrelationship between types of seizure disorders, types of anticonvulsant medications, and cognitive function.     

Dextromethorphan: Cellular Effects Reducing Neuronal Hyperactivity

Summary: Dextromethorphan is a dextrorotary morphinan without affinity for opioid receptors, commonly used as an antitussive medication. During the past 5 years, interest in the compound and its demethylated derivative, dextrorphan, has been revived because additional neuroprotective and an-tiepileptic properties were found in in vitro studies, animal experiments, and a few clinical cases. Both morphinans are able to inhibit N -methyl-D-aspartate (NMDA) receptor channels and voltage-operated calcium and sodium channels with different potencies. The inhibition of the NMDA receptor is believed to be the predominant mechanism of action responsible for the anticonvulsant and neuroprotective properties of the compounds.