ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<227::AID-MRDD1>3.0.CO;2-2

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY

摘要:

AbstractThe determination of the developmental consequences of seizure syndromes in the neonate is based upon a number of factors which include: understanding of the clinical and electroencephalographic (EEG) features of neonatal seizures; current theories of the mechanisms by which neonatal seizures are generated; a current classification of neonatal seizures; potential etiologic and risk factors for seizures; and therapies. In addition, different seizure types, mechanisms of generation and etiologies of cerebral dysfunction may vary with conceptional age of the infant. There are a few distinct neonatal epileptic syndromes, which are rare, have been well described: benign neonatal convulsions; benign neonatal familial convulsions; early myoclonic encephalopathy and early infantile epileptic encephalopathy. The prognosis for the first two is relatively good while the outcome for the other two with encephalopathy is catastrophic. However, the majority of neonatal seizures occur as acute, reactive events in association with a wide range of etiologic factors. These etiologic factors, as well as those of the more traditionally defined syndromes, are the main determinants of eventual developmental outcome of neonates who experience seizures. Although experimental data suggests that some epileptic seizures eventually may have physiological, histological, metabolic, or behavioral consequences, there is yet direct evidence in humans to suggest that the occurrence of seizures themselves in the neonate is the main determinant of long‐term outcome. MRDD Research Reviews 2000;6:229–241. © 2000 Wiley‐Lis

ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<229::AID-MRDD2>3.0.CO;2-Y

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY

摘要:

AbstractSeizures 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. MRDD Research Reviews 2000;6:242–252. © 2000 Wiley‐L

ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<242::AID-MRDD3>3.0.CO;2-W

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY

摘要:

AbstractThe 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. MRDD Research Reviews 2000;6:253–257. © 2000 Wiley‐Lis

ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<253::AID-MRDD4>3.0.CO;2-P

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY

摘要:

AbstractThe nervous system has an enhanced capacity to generate seizures during a restricted phase of postnatal development. Studies in animals and particularly in in vitro brain slices from hippocampus and neocortex have been instrumental in furthering an understanding of the underlying processes. Developmental alterations in glutaminergic excitatory synaptic transmission appear to play a key role in the enhanced seizure susceptible of rodents during the second and third week of life. Prior to this period, the number of excitatory synapses is relatively low. The scarcity of connections and the inability of the existing synapses to release glutamate when activated at high frequencies likely contribute importantly to the resistance of neonates to seizures. However, at the beginning of week 2, a dramatic outgrowth of excitatory synapses occurs, and these synapses are able to faithfully follow activation at high frequencies. These changes, coupled with the prolonged nature of synaptic potentials in early life, likely contribute to the ease of seizure generation. After this time, seizure susceptibility declines, patterns of local synaptic connectivity remodel, and some synapses are pruned. Concurrently, the duration of excitatory postsynaptic potentials shortens due at least in part to a switch in the subunit composition of postsynaptic receptors. Other studies have examined the mechanisms underlying chronic epilepsy initiated in early life. Models of both cortical dysplasia and recurrent early‐life seizures suggest that alterations in the normal development of excitatory synaptic transmission can contribute importantly to chronic epileptic conditions. In the recurrent early‐life seizure model, abnormal use‐dependent selection of subpopulations of excitatory synapses may play a role. In experimental cortical dysplasia, alterations in the molecular composition of postsynaptic receptor are observed that favor subunit combinations characteristic of infancy. MRDD Research Reviews 2000;6:258–267. © 2000 Wiley

ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<258::AID-MRDD5>3.0.CO;2-H

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY

摘要:

AbstractBrain malformations, resulting from aberrant patterns of brain development, are highly correlated with childhood seizure syndromes, as well as with cognitive disabilities and other neurological disorders. The structural malformations, often referred to as cortical dysplasia, are extremely varied, reflecting diverse underlying processes and critical timing of the developmental aberration. Recent studies have revealed a genetic basis for many forms of dysplasia. Gene mutations responsible for such common forms of dysplasia as lissencephaly and tuberous sclerosis have been identified, and investigators are beginning to understand how these gene mutations interrupt and/or misdirect the normal developmental pattern. Laboratory investigations, using animal models of cortical dysplasia, are beginning to elucidate how these structural malformations give rise to epilepsy and other functional pathologies. MRDD Research Reviews 2000;6:268–280. © 2000 Wiley‐Liss,

ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<268::AID-MRDD6>3.0.CO;2-B

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY

摘要:

AbstractOur understanding of the genetic basis of epilepsy is progressing at a rapid pace. Gene mutations causing several of the inherited epilepsies have been mapped, and several more are likely to be added in coming years. In this review, we summarize the available information on the genetic basis of human epilepsies and epilepsy syndromes, emphasizing how genetic defects may correlate with the pathophysiological mechanisms of brain hyperexcitability. Mutations leading to epilepsy have been identified in genes encoding voltage‐ and ligand‐gated ion channels (benign familial neonatal convulsions, autosomal dominant nocturnal frontal lobe epilepsy, generalized epilepsy with febrile seizures “plus”), neurotransmitter receptors (Angelman syndrome), the molecular cascade of cellular energy production (myoclonic epilepsy with ragged red fibers), and proteins without a known role in neuronal excitability (Unverricht‐Lundborg disease). Gene defects can lead to epilepsy by altering multiple and diverse aspects of neuronal function. MRDD Research Reviews 2000;6:281–292. © 2000 Wil

ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<281::AID-MRDD7>3.0.CO;2-9

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY

摘要:

AbstractEpilepsy and mental retardation, two relatively common childhood conditions, are both associated with a wide range of behavioral disorders. This article reviews the behavioral disturbances found in children with epilepsy, mental retardation, and both conditions. The behavioral disturbances found in children with epilepsy are associated with seizure‐related, cognitive, developmental, and psychosocial factors. Although children with mental retardation also demonstrate a broad spectrum of behavioral disturbances, children with specific mental retardation syndromes have better‐defined patterns of psychopathology. The presence of epilepsy and mental retardation seems to increase the severity of psychopathology. Further studies are needed, however, to define better the interaction of these two conditions and how they impact the behavior of children. MRDD Research Reviews 2000;6:293–299. © 2000 Wiley‐L

ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<293::AID-MRDD8>3.0.CO;2-1

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY

摘要:

AbstractThe relationship between epilepsy, language, behavior, and cognition is not well understood. Developmental and acquired disabilities such as autistic spectrum disorders, Landau‐Kleffner Syndrome, electrical status epilepticus in sleep, and developmental dysphasias have been associated with epileptiform abnormalities. These disorders share many common features and raise important questions regarding this intricate relationship. This article reviews these disorders and discusses the proposed interaction between epileptiform abnormalities and cognitive dysfunciton. Diagnostic and treatment issues will also be reviewed. MRDD Research Reviews 2000;6:300–308. © 2000 Wiley‐Lis

ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<300::AID-MRDD9>3.0.CO;2-R

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY

摘要:

AbstractThe medical management of epilepsy in the multi‐handicapped patient requires careful evaluation, classification, and pharmacologic treatment. It is estimated that 20–40% of patients with mental retardation and cerebral palsy have epilepsy. This review reports the clinical trial data and personal experience related to the use of newer AEDs in the chronic management of epilepsy syndromes in children and adults, as well as information available on the treatment of seizures in individuals with mental retardation and associated handicaps. Furthermore, clusters of seizures, prolonged seizures and status epilepticus are more commonly seen in the multiply handicapped and mentally retarded population and require special attention. The new antiepileptic drugs felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, vigabatrin and zonisamide show specific advantage in some multiply handicapped patients, be it for seizure control or medication tolerance. Furthermore, new modalities of treatment for prolonged seizures allow better efficacy both outside of hospital and within hospital facilities. The treatment of epilepsy in multi‐handicapped and retarded adults and children has significantly advanced in the past few years, and much of this improvement can be attributed to improved knowledge and monitoring of new antiepileptic drugs. Conventional anticonvulsants remain first line therapy for most clinicians, but newer AEDs must broaden the therapeutic option and do allow improved therapy for some multiply handicapped patients. MRDD Research Reviews 2000;6:309–323. © 2000 Wiley

ISSN:1080-4013    

DOI:10.1002/1098-2779(2000)6:4<309::AID-MRDD10>3.0.CO;2-I

出版商:John Wiley&Sons, Inc.    

年代:2000

数据来源: WILEY