摘要:

Summary:Metaphit [an analogue of phencyclidine (PCP) with an acylating isothiocyanate group] induced audiogenie clonic to clonic‐tonic seizures in mice exposed to audio stimulation 24 h after metaphit administration. The incidence of seizures was reduced by treatment 30 min before audio stimulation with specific PCP‐like compounds [5‐methyl‐10, ll‐dihydro‐5H‐dibenzo(a, d)cyclohepten‐5,10‐imine maleate (MK‐801), and PCP itself], competitiveN‐methyl‐d‐aspartate antagonists 2‐amino‐5‐ phosphonopentanoic acid (AP‐5 and NPC‐12626), antiepileptic drugs [phenobarbital (PB), phenytoin (PHT)], and γ‐aminobutyric acid (GABA) agonists (muscimol and diazepam). In contrast, when given in conjunction with metaphit, most of these drugs were ineffective in protecting animals from audiogenic seizures 24 h later. Only compounds with long half‐lives (t½) such as MK‐801, PB, and PHT had a protective effect. High‐performance liquid chromatography (HPLC) determination of [3H]MK‐801 showed its long‐term presence in the brain after intraperitoneal (i.p.) administration of [3H]MK‐801. Audiogenic seizures observed 24 h after metaphit administration were potentiated by administration of the GABA antagonist picrotoxin 15 min before audio stimulation, and picrotoxin‐induced spontaneous seizures were enhanced by pretreatment (24 h earlier) with a dose of metaphit that in itself did not produce spontaneous seizures at the time of the picrotoxin test. Similar observations were made withN‐methyld‐aspartic acid (NMDA) instead of picrotoxin. Thus, an interplay exists between excitatory glutaminergic and inhib

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02400.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Summary:We previously demonstrated that metaphit (a phencyclidine analogue with an acylating isothiocyanate group) induces occurrence of audiogenic seizures in mice exposed to audio stimulation 24 h after metaphit administration. We have studied various receptor systems associated with excitatory and inhibitory networks: sites for competitive and noncompetitive antagonists of theN‐methyld‐aspartic acid (NMDA) receptor complex, for [3H]muscimol on the ‐γ‐aminobutyric acid (GABA) receptor complex, and for [3H]batrachotoxinin A20‐a‐benzoate on the voltage‐dependent sodium channel. Mice were examined for neurochemical changes at 24 h after pretreatment with metaphit, when susceptibility to audiogenic seizures is greatest. Ex vivo receptor binding studies detected no changes; in vivo labeling of the phencyclidine site in the NMDA receptor complex was reduced by 20% in cortical and midbrain regions. A separate group of experiments was aimed at measuring brain levels of metaphit. One minute after retroorbital administration of [3H]metaphit at a dose sufficient to produce susceptibility to audiogenic seizures 24 h later, the brain level of [3H]metaphit (determined by high‐performance liquid chromatography, HPLC) was 49 pmol/mg tissue; at 1, 4, and 24 h, the level was 12, 6, and 1.4 pmol/mg tissue or μMif metaphit was evenly distributed throughout the brain. Although the observed metaphit concentrations during the first 4 h are high enough to acylate receptors, no firm evidence for acylation was found for most of the examined receptors. Finally, the time course of the brain level of metaphit showing a continuous decrease is entirely different from that of development of the seizure susceptibility, which

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02401.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Summary:Epilepsy was induced in female rats by the injection of tetanus toxin (5 mouse LD50) unilaterally into the ventral hippocampus under anesthesia. During the 2–4 weeks that the rats exhibited intermittent spontaneous convulsions, daily vaginal smear tests showed that their estrous cycle was interrupted. In control rats such interruption only occurred for just a few days after the operation. Investigation of mating behavior, on the first night of proestrus, which occurred after 7 weeks from the operation, showed that there were fewer mounts, intromissions or ejaculations from the males, which were caged with previously epileptic animals. These females produced slighly smaller litters than their controls and there was a marked failure of their young to thrive in comparison with those of the control females. This failure appeared to be related to relatively high “stress” levels in the general laboratory environment. The impairment of reproductive success only lasted about 3 months after the original induction of epilepsy since subsequent litters to the same animals thrived nor

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02402.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Summary:The effects of 5Ø‐pregnan‐3Ø‐ol‐20‐one (3Ø‐OH‐DHP) and phenobarbital (PB) on synaptic excitation and inhibition in rat hippocampal slices in vitro were compared. Stimulations were made orthodromically and antidromically while we recorded extracellularly from the dendritic and the somatic layer of the CA1 region. Perfusion with 5 μg/ml of 3Ø‐OH‐DHP for 30 min significantly increased the recurrent inhibition evoked by antidromic stimulation. The effect was most pronounced at short interstimulus intervals. The duration of the recurrent inhibition also was prolonged. There was no effect on the conditioned population spike after orthodromic paired‐pulse stimulation. Furthermore, no effect was observed on the amplitude of the orthodromic fiber volley, the rate of increase in the field excitatory postsynaptic potential (EPSP) and the latency and amplitude of the CA1 population spike. Qualitative and quantitative similar findings were observed during perfusion with PB 0.1 mg/ml, (i.e., a concentration 20 times higher than that of 3Ø‐OH‐DHP). Higher concentrations of PB also affected synaptic excitation. The findings suggest a similar effect of 3Ø‐OH‐DHP and PB on recurrent GABA‐ergic inhibition; however, 3Ø

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02403.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Summary:The previously reported diminished incidence of neuronal activity recorded from areas ipsilateral to a seizure focus may result from either cell loss or pathophysiologic changes in hippocampus and related structures. We examined records of single‐cell discharge from 471 electrode bundles in 62 patients who later had cell counts taken from samples of resected tissue. Analysis of variance showed that amygdala and parahippocampal gyrus had more activity than hippocampus and the subicular complex and that the resected side had less activity overall. Only the posterior subicular complex showed more high‐amplitude (>50 μV) activity on the epileptogenic side; all other areas showed more activity contralaterally. Activity between 25 and 50 μV did not differ across sides or structures. Percentage of maximal cell count was correlated with the number of electrodes with high‐amplitude activity only in the subicular complex. Low‐amplitude activity in nonresected hippocampus, however, was strongly negatively correlated with cell counts on the resected side, perhaps owing to compensatory mechanisms. Cell counts in hippocampus correlated negatively with high‐amplitude unit activity in resected amygdala, suggesting reciprocity between these areas. These results suggest that the amount of cell activity recorded from mesiotemporal structures involves bilateral factors more complex than simpl

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02404.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Summary:Etiologic, pathologic, and clinical features of possible prognostic significance were studied in 118 children who underwent frontal or temporal lobe epilepsy surgery at the Montreal Neurological Institute (MNI) between 1940 and 1980 (excluding tumor cases). Mean age of seizure onset was 5.1 years (range 0–12 years), mean age at operation was 11.7 years (range 0.6–15 years), and median duration of follow‐up was 15 years (range 2–31 years). Thirteen of 45 frontal surgery patients and 43 of 73 temporal surgery patients had an excellent outcome. In the frontal surgery group, this was restricted almost entirely to patients with an established etiology, particularly if this included a circumscribed resectable structural abnormality. In the temporal surgery group, a history of early, prolonged febrile seizures was usually associated with good outcome, unless there was additional evidence of extratemporal epilepsy. In the entire series, the presence of a nonresectable structural lesion or secondarily generalized seizures was associated with a poor

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02405.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Summary:To address the question of whether complete seizure relief has a positive effect on psychosocial functioning in patients with temporal lobe epilepsy, a follow‐up study was conducted at the Montreal Neurological Institute. The approach was one of “before‐after” study, with focus on the successfully operated patients, those in whom complete seizure relief was obtained. The Washington Psychosocial Seizure Inventory, specifically developed and validated for use with epilepsy patients, was used for psychosocial assessments. Of 30 surgically treated patients screened for the study, 15 gained complete relief from seizures. At 1‐year postoperative followup, they showed reductions in their problem scores on all but one of eight psychosocial scales; the average reduction ranged from 24% in Vocational Adjustment to 60% in Adjustment to Seizures. In the areas of Emotional Adjustment and Interpersonal Adjustment reductions were 37 and 48%, respectively. Among the component items, improvement was greatest in ability to concentrate and make decisions, confidence in interpersonal skills, ability to express personal opinions, and perception by others. No appreciable changes occurred in the 15 patients who did not gain complete relief of seizures; indeed, on six of the eight scales they showed a modest increase in their problem scores. This study provides evidence that complete relief from seizures leads to appreciable improvements in psychosocial well‐being, manifest as early as 1‐year postoperatively, in young a

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02406.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Summary:We measured lumbar cerebrospinal fluid (CSF) levels of somatostatin, cholecystokinin, neurotensin, atrial natriuretic factor, vasoactive inhibitory peptide, neuropeptide Y, adrenocorticotrophic hormone, corticotropin releasing hormone, β‐endorphin, metenkephalin, cortisol, alanine, glycine, aspartate, glutamate, taurine, and γ‐aminobutyric acid in 25 inpatients with epilepsy at known interictal and postictal times and in 11 neurologically normal volunteers. There were no significant differences between interictal or postictal complex partial seizures (CPS), postictal generalized tonic‐clonic seizures (GTC), and control CSF neuropeptide, cortisol, and amino acid (AA) levels. However, there were nonsignificant trends for CSF levels of several neuropeptides to be increased after CPS and GTC as compared with interictal baseline levels. There were significant correlations between levels of certain CSF neuropeptides or (AAs) and serum antiepileptic drug (AED) levels. Several correlations were noted between CSF levels of AAs, including a correlation between the excitatory neurotransmitters aspartate and glutamate identified only af

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02407.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Summary:A study was performed of EEG‐magnetic resonance imaging (MRI) abnormalities in 7 Lennox‐Gastaut syndrome (LGS) children and 3 epilepsia partialis continua (EPC) children with intractable generalized and partial motor seizures, respectively. In 4 children with LGS and 3 children with EPC, depth electrodes were implanted in the centromedian thalamic nuclei (CM) for seizure control. In all children with LGS, hyperdense, T2‐weighted MRI signals were observed at the mesencephalic level of the brainstem, whereas none of the 3 children with EPC had this finding. Patients with idiopathic LGS without cerebral hemisphere MRI abnormalities showed generalized bilateral and symmetrical spike‐wave EEG activity. Patients with symptomatic LGS with unilateral hemispheric MRI abnormalities demonstrated asymmetrical EEG activity with higher amplitude spike‐and‐wave over the normal hemisphere. Patients with EPC with unilateral hemispheric lesions had lateralized higher amplitude spike‐wave over the damaged hemisphere. These data suggest that abnormal mesencephalic MRIs are a sign of bad prognosis in patients with LGS but not with EPC. Maximal amplitude paroxysmal EEG activities may indicate the abnormal hemisphere in patients with EPC or the normal hemisphere in t

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02408.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Summary:Clinical and electrographic features were retrospectively studied in 57 patients with midline (Fz, Cz, Pz) spikes as the only epileptiform activity in their EEG to determine possible predictors of outcome. Our study confirmed previous reports of early age of onset, activation by sleep, and Cz as the most frequent spike location. In contrast to previous studies with smaller numbers of patients, midline spikes were more common in males and most often associated with partial complex seizures and were not activated by sleep at an older age. Of the 29 patients who were followed for 6 months to 9 years, only 15 (52%) achieved good seizure control. Although a tendency toward a poor outcome was noted with several independent variables (positive family history of epilepsy, later age of seizure onset, abnormal EEG background activities, abnormal neuroimaging, abnormal neurologic examination), none was of statistical significance. This study suggests that epilepsy with midline spikes is not necessarily benign and that future studies with larger patient groups may be necessary to identify factors that influence prognosis.

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1993.tb02409.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY