摘要:

Summary:The rate and pattern of development of seizures induced by penicillin injected intraperitoneally were determined in rats that had been depleted of brain norepinephrine (NE) by bilateral injections of the neurotoxin 6‐OH dopamine into the locus ceruleus. Behavioral observations and scalp electrographic recordings were made after injection and the efficacy of NE depletion was determined by high performance liquid chromatography measurement of cortical levels of NE and its metabolites. We found that in comparison to sham‐operated control rats, NE‐depleted rats had a significantly shorter latency to first observable myoclonic jerk, the first epileptic discharge, the first convulsion with sustained epileptic discharges, and a longer duration of convulsions. We observed a similar electrographic pattern of multifocal spikes with bilateral synchrony in both groups. However, more of the control rats (six of 12) had convulsions as compared to the lesioned rats (four of 12). These findings are consistent with previous evidence that depletion of neocortical NE facilitates the development of epileptiform activity in the CNS; however, a convulsive state was not induced by NE depl

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04697.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Summary:Peptides DBI 42–50 (DRPGLLDLK) and DBI 43–50 (RPGLLDLK) are synthetic fragments of an 18 amino acid peptide called octadecaneuropeptide (QATV‐GDVNTDRPGLLDLK), a brain derivative of diazepam‐binding inhibitor (DBI). The two peptides were unilaterally injected into the dorsal hippocampus (granule cells of dentate gyrus) of freely moving adult rats. The electroen‐cephalographic (EEG) pattern was continuously recorded from bilateral hippocampal and cortical electrodes, and the animals' behavior was observed throughout the experiment. A dose of 100 nmol peptide 42–50 was required to reliably cause EEG alterations (seizures and spiking). EEG changes, defined as seizures, were characterized by discrete repetitive periods of high‐frequency and/or mul‐tispike complexes and/or high‐voltage synchronized spike or wave activity. EEG seizures were often associated with a frozen appearance of the animal and “wet dog shakes.” Tonic‐clonic convulsions were not observed. EEG seizures induced by peptide 42–50 were prevented by 90 mg/kg PK 11195, a selective antagonist of a novel GABAAreceptor‐linked subtype of a benzodiazepine (BDZ) receptor, but were unaffected by flumazenil, an agonist of the “central” type of BDZ receptor and by D(‐)2‐amino‐7‐phosphonoheptanoic acid, a selective antagonist of the N‐methyl‐D‐aspartate subtype of excitatory amino acid receptors. Light microscopy showed no neuropathological changes in the injected hippocampus. The data show that these DBI‐derived peptide fragments induce a typical pattern of limbic seizures in rats. DBI and/or its natural processing products may

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04698.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Summary:The acute effects of the organophosphorous cholinesterase inhibitor soman include hypersecretions, convulsions, and death. The purpose of this study was to evaluate the anticholinergic compounds aprophen, atropine sulfate, azaprophen, benactyzine, benztropine, bi‐periden, scopolamine HBr, and trihexyphenidyl for their efficacy in preventing soman‐induced hypersecretions and convulsions. Male rats were injected with the oxime HI‐6 (125 mg/kg, i.p.), to increase survival time, along with various intramuscular doses of the anticholinergics 30 min prior to a dose of soman (180 μg/kg, s.c; equivalent to 1.6 × the median lethal dose) that produced 100% convulsions. Signs of intoxication as well as the time‐to‐onset of convulsions were observed. The calculated anticonvulsant median effective dose values were 0.18, 0.33, 0.36, 0.55, 2.17, 2.30, 2.45, and 31.09 μmol/kg for scopolamine HBr, biperiden, trihexyphenidyl, benactyzine, benztropine, azaprophen, aprophen, and atropine sulfate, respectively. The same rank order of potency for inhibition of hypersecretions among these compounds was observed. Parallel studies with quaternary analogs of atropine sulfate and scopolamine HBr demonstrated, however, that these charged compounds afford no protection against soman‐induced hypersecretions and convulsions. The results indicate that tertiary anticholinergic compounds afford protection against soman‐induced convulsions and hypersecretions and that the beneficial anticonvulsant effects are mediated through the central cholinergic system. Excitatory amino acid neurotransmitter systems may be involved in the effectiveness of

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04699.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Summary:Twenty epileptic patients (10 male and 10 female) were polygraphically recorded during nocturnal sleep. Ten subjects, with a wide age range, were affected by focal lesional epilepsy, and 10 were children affected by benign epilepsy with rolandic spikes (BERS). In five cases a bihemispheric expression of the focal lesional bursts emerged occasionally during the night recordings. The behavior of interictal electroencephalographic (EEG) paroxysms were analyzed with respect to the two arousal states of non‐rapid‐eye‐movement (REM) sleep: (a) the cyclic alternating pattern (CAP), expressed by biphasic EEG periodic activities and related to long‐lasting fluctuations between greater (phase A) and lesser (phase B) arousal levels; and (b) the non‐CAP (NCAP), manifested by EEG stationarities that reflect a sustained relative stability of arousal. The CAP/NCAP modality affected the spiking activity and distribution of the focal lesional EEG paroxysms, which appeared enhanced during CAP and which were mostly collected in phase A. The even more powerful influence of CAP and especially phase A on the secondary bisynchronous bursts suggests a crucial integration among thalamocortical circuits, arousal modulation, and epileptic generalization mechanisms. Conversely, in the BERS recordings no significant differences emerged throughout CAP and NCAP. The intense activity of the rolandic foci induced by sleep as such could be explained on the basis of the greater dependence of these functional cortical EEG abnormalities on the degree of synchronization dur

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04700.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Summary:Auditory oddball scalp and limbic P3s were recorded from 18 patients with unilateral temporal lobe epilepsy (TLE) prior to seizure surgery. Limbic P3s were unilaterally absent ipsilateral to the seizure focus and were present in the nonepileptogenic temporal lobe in all 18 cases studied. Scalp P3s, recorded from C3and C4, on the other hand, were elicited bilaterally and there was no significant difference in amplitude or latency between the epileptogenic and nonepileptogenic sides. These data concur with studies of scalp P3 performed following surgery and suggest that the assessment of the contribution of limbic P3 to scalp P3 may be masked by volume conduction effects and other generators of P3. We conclude that the P3 recorded from central scalp sites, unlike its limbic counterpart, offers little clinical information in the presurgical assessment of patients with TLE.

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04701.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Summary:We report magnetoencephalographic localization of subdural electrode dipoles placed at the basal and mesial surfaces of the temporal lobe in a patient with temporal lobe epilepsy. The locations of the three dipoles were predicted from their magnetic fields with a computer model of the head as a conducting sphere. The predicted locations were within 1,3, and 4 mm of the actual locations. These results, obtained in an area of the brain from which epileptiform discharges are frequently recorded, strongly support the capability of magnetoencepha lography to accurately localize electrical events in this brain region.

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04702.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Summary:We examined the seizure records of 13 patients (nine men and four women, ages 27–50 years) with intractable partial epilepsy, maintained with steady anti‐epileptic drug dosages. Patients recorded daily seizure frequency on calendars. Periods of outpatient observation ranged from 99 to 1,710 days and the number of observed seizures ranged from 18 to over 400, with daily seizure rates of 0.1–4.3 per day. We used the quasi‐likelihood regression model to examine the following four departures of the daily seizure counts from a Poisson (random) model: (1) linear increasing or decreasing time trends in expected seizure rates; (2) clustering, where the expected seizure rate on a given day depends on the number of seizures observed on the immediate prior days; (3) monthly cyclicity; and (4) increased variability (overdis‐persion). Linear time trends were seen in six patients (four increasing and two decreasing), clustering was seen in 10 patients, and a near‐monthly cycle appeared in four patients (two of nine men and two of four women). A significant amount of extra variation (overdispersion) relative to a Poisson distribution was observed in all but one of the 13 patients. Departures from a Poisson (random) model appear more common in this population of patients with medically intractable epilepsy than is commonly recognized, and have clinical importance as well as implications for the design of clini

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04703.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Summary:A 27‐year‐old man had a 5‐year history of a peculiar state characterized by clouded consciousness provoked by ingestion of alcohol. The episode was identified electroclinically as nonconvulsive status epilepticus and was activated by ingestion of alcohol. Single‐photon emission computed tomography (SPECT) examination during the nonconvulsive status epilepticus showed increased regional cerebral perfusion in the right frontal region. This finding, along with the EEG expressions, supports a cortical origin of the nonconvulsive status epilepticus and a diagnosis of complex partial status epilepticus (CPSE). To our knowledge, this is the first report of a documented case of CPSE during intoxication provoked by alcohol ingestion and also of a SPECT examination duri

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04704.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Summary:Cerebrotendinous xanthomatosis (CTX) is a rare hereditary disease characterized by xanthomata of tendons, osteoporosis, cataracts, cerebellar ataxia, spastic paresis, and dementia. Though electroencephalo‐graphic (EEG) abnormalities are frequent in CTX, epileptic seizures have not been recognized as a major feature. A CTX patient is reported who presented with a generalized epileptic seizure and was evaluated with EEG and neuropsychological testing. Epilepsy should be considered a feature of CTX, and CTX considered as a possible, though rare, cause of symptomatic seizure

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04705.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Summary:We reviewed EEGs from children whose history and clinical course was compatible with benign partial epilepsy of childhood with centrotemporal spikes. In 21% of patients with a single EEG focus, the discharge was outside the centrotemporal area. In 37.5% of patients with more than one focus, one was in the centrotemporal area while the other was not. We suggest that the typical EEG features of this syndrome are the normal background, the stereotypic morphology of the sharp waves, and their activation by drowsiness and sleep, not their exclusive location in the centrotemporal regions. Insistence on a centrotemporal location for the EEG discharges in this syndrome may lead to a misclassification of the type of epilepsy in some children with implications for therapeutic decisions and prognostic statements.

ISSN:0013-9580    

DOI:10.1111/j.1528-1157.1991.tb04706.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY