摘要:

Summary:Idiopathic generalized epilepsies, i.e., juvenile myoclonic epilepsy (JME), childhood absence epilepsy, and epilepsy with grand mal [generalized tonic‐clonic seizures (GTCS)], are the most common genetic epilepsies. Linkage studies using Bf, HLA serologic, and DNA markers by three independent investigators, one from Los Angeles and two from Berlin, have localized the JME locus to the short arm of chromosome 6 (6p). Because members of the same JME family have the same JME phenotype of childhood absence epilepsy, epilepsy with grand mal (GTCS) seizures, or early childhood myoclonic epilepsy (ECME), our observations give evidence for a single‐locus etiology in 6p for JME and for at least some of the childhood absence seizures, epilepsy with grand mal (GTCS) seizures, and ECME. Studies should now address whether locus heterogeneity exists within childhood absence epilepsy, epilepsy with grand mal (GTCS) seizures, or ECME. Markers linked to JME (Bf, HLA serologic, and DNA markers in the DQ region) can be used to resolve etiologic heterogeneity. Using such markers, both linked and unlinked forms of phenotypes that are clinically indistinguishable may be detected and provide evidence for etiologic heterogeneity. Studies should also concentrate on narrowing the JME locus to 2 to 3 cm by screening families with recombinant events using RFLPs, candidate genes, and new expressed sequences on chromosom

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05855.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary:The feasibility, safety, and preliminary effects of chronic vagal stimulation were studied in an alumina‐gel monkey model. Pilot studies to perfect the equipment, determine stimulation thresholds, and insure the comfort and safety of the animals preceded this study. Four monkeys were equipped with an indwelling, 2‐electrode cuff (titanium bands spaced 7 mm apart; silicone encased; 1.5 cm total length) in contact around the right vagus nerve; avoidance of the cardiac branch was confirmed by electrocardiograms. After postsurgical recovery, the intact and awake animals received constant‐current stimulation (5 mA; 83 Hz, 143 Hz, or 50–250 Hz randomly; 0.5‐ms pulse width) at the onset of every spontaneous seizure for the duration of the seizure or every 3 h for 40 s if stimulation had not occurred in the preceding hour. Stimulation periods of 2–6 weeks, with differing levels of stimulation, were preceded and followed by at least a 2‐week baseline period of no stimulation. During the stimulation periods, the seizure rate decreased to zero in two monkeys and the interseizure intervals became invariable in the remaining two monkeys. These effects carried over temporarily into the poststimulation baseline periods. Vagal stimulation had no consistent effects on seizure severity or EEG interictal spikes. Histological studies of six vagus nerves were unable to separate electrode cuff damage from any direct effects stimulation may have had on the nerves. Although it appears that chronic vagal stimulation is feasible and that epileptogenic processes are influenced, the safety and efficacy of the procedure are stil

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05844.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary:Learning difficulties in children with epilepsy may be caused by brain damage and should be investigated. In many cases, however, seizures and/or electroencephalographic (EEG) findings are the only signs of pathology. Frequency and type of seizures may be determining factors that should, if necessary, be evaluated by long‐term EEG monitoring, preferably during school performance or in conjunction with neuropsychological assessment. This may prove that subclinical epileptiform discharges in the EEG can adversely affect the child's performance. Secondary psychological problems in epilepsy patients, combined with side effects of antiepileptic drugs, may cause or heighten learning problems. Prophylactic control of seizures with one appropriate drug may alleviate learning problems. Computerized neuropsychological testing with simultaneous EEG recording may reveal the influence of epileptiform discharges on cognitive function and also help to evaluate the effects of antiepileptic drugs. Objective assessment of subclinical epileptiform activity makes it easier to treat the pathology identified by the EEG with optimal dosage of the most appropriate drug. A balance is required because epileptiform discharges and even occasional seizures may be less disabling than side effects from large doses of several drugs. Information to the school and the parents concerning the patient's abilities and limitations may be as important as seizure control. Specialized teaching should be started early, when necessary, with the patient integrated into a normal school if possible. However, good functioning in a special school is preferable to marginal functioning in a normal schoo

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05865.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary:Overall, children with epilepsy have poorer concentration and mental processing and are less alert than age‐matched controls. The relationship between cognitive functioning and epilepsy is complex, however, with widely differing degrees of intellectual impairment–ranging from minimal to severe and progressive–related to diverse types of epileptic seizures, syndromes, and etiological factors. Prolonged and frequently repeated seizures are typically associated with more severe effects on cognitive functioning, particularly if epilepsy is symptomatic, i.e., secondary to a demonstrable brain lesion. A combination of such factors may contribute to the mental deterioration seen in many children suffering from severe epi

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05866.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary:Electrical stimulation of cranial and peripheral nerves has been used to ameliorate a variety of neurologic disease states and neural injuries over the past 20 years. In this review, clinical applications and the histopathologic results of chronic implants in animals and humans are discussed, and the results of neural damage models developed at Huntington Medical Research Institutes are summarized. Chronically implanted electrode arrays may produce neural injury by either mechanical factors or by continuous, high‐frequency electrical stimulation. The margin of safety to avoid electrically induced injury may be increased by minimizing the frequency or total stimulation time, and by the use of an intermittent duty cycle. The protocols presently being used for the stimulation of the vagus nerve to effect inhibition of seizures appear to have an adequate margin of safet

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05845.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary:Age‐specific epilepsy syndromes raise important questions about developmental susceptibility to seizures and epileptogenesis and about the effect of seizures on function. The diagnosis and treatment of these syndromes has been enhanced by the use of modern science and technology. Epidemiologic studies have changed our approach to febrile convulsions. This developmental seizure disorder is benign and self‐limited. We have been forced to think carefully about threshold, therapy, and whether other seizures in childhood may be equally benign. This framework of developmental specificity can also be applied to West syndrome, especially with respect to neurophysiology, neurochemistry, neuroimaging, and epidemiology–the types of seizures, clustering, variations associated with sleep, PET scans, and therapy. Rasmussen's syndrome and other unilateral developmental epilepsies are progressive but remain confined to a single hemisphere. However, they usually are devastating to global neurologic function. They are models for examining the impact of epilepsy in one pathologic hemisphere on the function of the entire brain. Current therapy for this condition is hemispherectomy. Recovery of function after this major surgery is striking and provides clues to brain organization. The analysis of these three syndromes provides windows on the dynamic, changing central nervous system of the child and may lead to better understanding and therapy for other seizure diso

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05857.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary:The neurocybernetic prosthesis (Cyberonics, Inc.) is an implantable, multiprogrammable pulse generator that delivers constant current electrical signals to the vagus nerve for the purpose of reducing the frequency and/or severity of epileptic seizures. The device is implanted in a subcutaneous chest pocket just below the clavicle, similar to cardiac pacemaker placement. The stimulation signal is transmitted from the prosthesis to the vagus nerve through a stimulation lead. The prosthesis can be programmed using any IBM‐compatible personal computer with programming software and a programming wand. The electrodes used in the first group of patients were found to break at an unacceptable rate. Design modifications appear to have resolved this proble

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05846.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary:The value of a range of computer‐aided tests in the neuropsychological assessment was investigated in 94–177 children with epilepsy, aged 8–18 years, compared with 68–161 controls in the same age group. Children from the age of 8 years could cope with rather complex tests in a wide range of functions: reaction time measurements, motor speed, information processing, and memory. The speed of performance tended to increase with age in both groups, with differences in information processing becoming apparent from the age of 12 years. The precise control of stimulus and response required to define the mainly minor differences between the epilepsy and control groups can only be fulfilled by computerized testing, which should undergo further refinement including voice and language recognition, followed by artificial intel

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05868.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary:Primary intraparenchymal tumors of the brain are important etiologic factors in partial or focal epilepsy. Indolent low‐grade gliomas may be associated with a long‐standing seizure disorder refractory to medical treatment. Surgical resection of the neoplasm and the epileptogenic area may render patients seizure‐free. Removal of the tumor alone may also be associated with an excellent survival rate and surgical outcome. Conventional neurosurgical procedures are restricted in patients with tumors that are deep‐seated lesions or involve functional cerebral cortex. Computer‐assisted stereotactic surgical procedures have been developed for biopsy and resection of intra‐axial brain‐mass lesions. Stereotactic tumor resection may allow pathological determination of intracranial lesions and produce a worthwhile reduction in seizure activity in some patients with intractable par

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05858.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary:The surgical technique for the implantation of the neurocybernetic prosthesis is described in detail. This procedure is straightforward and is easily carried out by surgeons familiar with carotid surgery.

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1990.tb05847.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY