Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038220 (status epilepticus)
 7,272 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Continuous myoclonus in a localised area of the body was observed in three patients. In two cases the myocloni sometimes developed into motor Jacksonian convulsions. All three patients had neurological signs on the same side as their continuous twitching indicating a lesion of the contralateral hemisphere. The surface EEG did not show changes which could be directly correlated with continuous convulsions in any of the cases. The cause was found to be a malformation of the hemisphere in one case, a recent encephalomalacia in the second and a severe hyperosomolar diabetic electrolyte imbalance in the third. Epilepsia partialis continua Kozevnikov differs from motor Jacksonian epilepsy in the continuous non-attack character and the absence of a "march of convulsions". Pathophysiologically they are both forms of focal cortical status epilepticus.
 ...
PMID:[Epilepsia partialis continua of Kozevnikov (author's transl)]. 40 31

Pilocarpine administration to lithium chloride-pretreated rats results initially in discrete convulsive seizures, each behaviorally and electroencephalographically terminated, which then progress to convulsive activity with waxing-and-waning behavioral and electrographic severity; finally, a continuous convulsive state ensues, associated electrographically with continuous fast spiking. This stage does not last indefinitely but is followed by a dramatic electrographic change to periodic epileptiform discharges. The purpose of the present study was to determine with the 14C-2-deoxyglucose functional mapping technique what changes occur in the seizure anatomic substrate during and after this transition, in order to enable inferences about underlying mechanisms. Behavior associated with early and late continuous fast spiking consisted of head twitching; corresponding deoxyglucose autoradiographs displayed seizure-induced intense glucose utilization in most forebrain areas; extranigral brainstem was normal. At 2-3 h of status, fast spiking became interrupted by flat periods; periodic complexes soon dominated the electroencephalogram. Behaviorally, convulsive severity increased. Despite this dramatic electrographic evolution, little change in generalized forebrain metabolic hyperactivation occurred, except that the zona incerta/pretectal/superior colliculus complex displayed markedly increased activity. Deoxyglucose studies in late stages of periodic epileptiform discharges established a sequence of further changes. In late periodic discharges with clonic jerks, at 4 h after status entry, generalized forebrain hyperactivation still prevailed, but to a lesser degree than in early periodic discharges with clonic jerks. At a still later stage, late periodic discharges, subtle convulsive, autoradiographs revealed constriction of the seizure-activated anatomic substrate: hyperactivation was lost in most of neocortex and thalamus, and in caudal olfactory structures, cortical amygdala, and entorhinal areas, but retained in deep occipital cortex and many limbic areas. In the last stage, late periodic discharges, electrical, not associated with convulsive behavior, autoradiographs revealed residual activation in only Ammon's horn; in contrast, much of the forebrain displayed below-normal glucose utilization. These results demonstrate that in the later stages of status epilepticus, the transition from fast spiking to periodic complexes is not associated with a reduction in the seizure anatomic substrate. The electrographic entity of periodic epileptiform discharges is not anatomically or behaviorally homogeneous, but proceeds through successive stages characterized initially by a reduction of glucose utilization within generalized seizure-activated forebrain, then a contraction of the seizure anatomic substrate. Possible mechanisms underlying the transition to periodic complexes are discussed.
 ...
PMID:Functional mapping of the late stages of status epilepticus in the lithium-pilocarpine model in rat: a 14C-2-deoxyglucose study. 775 76

Much remains to be learned about mechanisms underlying entry into, and temporal progression of, status epilepticus (SE). This report describes a non-pharmacologic model of generalized convulsive SE in rat. Pulsed trains of suprathreshold electric current, were administered bilaterally to either of four rostral forebrain sites: orbital cortex, medial precentral cortex, deep prepiriform cortex, or rostral caudate-putamen (n = 8 per site). This induction method resulted in 30/32 animals attaining limb-clonic convulsive SE within a mean of 30-35 min for each forebrain site, with no differences between sites. Subsequent SE proceeded without further interventions, permitting observation of the natural course of progression. A stereotyped behavioral/electrographic sequence occurred, characterized by devolution. Behaviorally, animals progressed from predominantly limb clonus to head clonus, then to subtle twitching, and finally to electrical SE before cessation of spikes. The corresponding electrographic progression was from fast and slow spiking to periodic epileptiform discharges (PEDs). In 20 animals surviving to 48 h, pathologic damage affected mainly limbic sites; damage was related to total convulsive time rather than to clonic activity. High-dose phenobarbital but not phenytoin suppressed SE when given during orbital cortex-induced limb-clonic SE. These findings are compatible with human observations and indicate that this model will enable investigations of generalized SE mechanisms and evaluation of new therapeutic agents for refractory SE.
 ...
PMID:A new, non-pharmacologic model of convulsive status epilepticus induced by electrical stimulation: behavioral/electroencephalographic observations and response to phenytoin and phenobarbital. 781 10

Generalised or partial seizures are a common problem with many supratentorial gliomas. Their underlying pathophysiological mechanisms are poorly understood. To investigate this problem clinical and EEG seizure thresholds were investigated in experimental rodent gliomas using the epileptogenic drug pentylenetetrazole (PTZ). Mixed C6/A15A5 malignant gliomas were grown in adult Wistar rats after unilateral stereotactic implantation of a 50:50 cell mix into the caudoputaminal region. Eleven to 14 days later EEG (raw and spectrally analysed) was recorded bilaterally from the frontal and parietal regions under mixed alpha-chloralose and urethane anaesthesia. Baseline EEG (15 minutes), EEG during and after (30 minutes) PTZ infusion (100 microliters/min) and the time to appearance of seizure manifestations after starting PTZ were recorded. Fourteen animals were studied (5 normal, 5 with tumours, 4 sham implants) and mean BP, PaCO2, PaO2 and temperature were similar in the three groups. Baseline raw EEG showed predominate slow wave activity with lower amplitude and less spontaneous activity overlying tumours. Following PTZ infusion a sequence of vibrissal twitching (following a mean of 14.5 mg/kg PTZ in control and sham animals); jaw/nasal twitches (17.5 mg/kg); fore and hind limb jerking (46 mg/kg); myoclonic jerking (47 mg/kg); and status (77.5 mg/kg) was observed. The seizure thresholds for all PTZ induced seizure phenomena were, except for status epilepticus, highest in the tumour bearing animals. The time to 70% seizure activity on the EEG was also significantly longer in the tumour bearing animals. Spectral analysis of the EEG, although showing increased alpha and theta activity after PTZ infusion, did not discriminate between the three experimental groups either before or after PTZ activation. These studies have confirmed that experimental gliomas alter baseline EEG and both the EEG and behavioural response to PTZ. The reasons for the raised seizure threshold in the glioma bearing animals and the relevance of this experimental paradigm to human tumour associated epilepsy are discussed.
 ...
PMID:The effects of malignant glioma on the EEG and seizure thresholds: an experimental study. 873 86

Six patients (4 boys and 2 girls) with hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome are described. They had prolonged seizures, lasting from 30 min to 12 h, at ages 1-4 years. These took the form of hemiconvulsion in three of the children and generalized tonic-clonic seizures in the others, being preceded by hemifacial twitching or head and eye deviation in two. They were followed by hemiplegia, which cleared with time in five patients, apart from subtle pyramidal tract signs. One child had spastic quadriparesis, choreiform movements, contracture deformities and severe mental retardation following repeated status epilepticus. Subsequent epilepsy developed in five patients and was satisfactorily controlled with carbamazepine and/or phenobarbitone. Cerebral hemiatrophy was documented in all patients by cranial computed tomography and/or magnetic resonance imaging. Single photon emission computed tomography (done in 4 patients) showed ipsilateral hypoperfusion (of the damaged hemisphere). Electroencephalography showed ipsilateral slowing and low voltage of background activity. Epileptiform discharges were found on the ipsilateral side in two cases and the contralateral side (the undamaged hemisphere) in one.
 ...
PMID:Hemiconvulsion-hemiplegia-epilepsy syndrome. A clinical, electroencephalographic and neuroradiological study. 922 14

This study reports on a girl with a permanent cerebral lesion and opercular syndrome after status epilepticus (SE). She had previously been healthy and had her first focal motor seizure at 5 years of age, which was controlled with intravenous phenytoin and rectal diazepam. Twenty-four hours later, she developed partial SE consisting of right facial twitching and right-hand clonic movements. These uncontrollable seizures lasted for 5 days, after which the partial SE changed to generalized SE, and the seizures continued for another 5 days. CT performed the day before onset of SE revealed no brain abnormality. Another CT performed a year later disclosed bilateral brain lesions, more severe in the left hemisphere. Follow up at 16 years of age revealed moderate motor sequelae of the right-hand side of the body, anarthria, difficulty chewing, dysphagia, bilateral facial weakness, and drooling, all of which clinically characterize opercular syndrome. An MRI study performed at 14 years of age showed a cerebral parenchymatous lesion which extended between the parietal cortices of both hemispheres, more severe on the left side, and which crossed the corpus callosum, destroying the posterior-middle zone. Evidence from the CT indicates that the lesion was not present before onset of SE. It seems likely that the focal SE caused the focal brain damage, but the possibility that the subsequent generalized SE played a role cannot be excluded.
 ...
PMID:Status epilepticus-induced brain damage and opercular syndrome in childhood. 1087 32

Since the dorsal and ventral hippocampus in the rat may act differently from one another in limbic seizures, we studied effects of orthogonal transection between the dorsal and ventral hippocampus upon kainic acid-induced amygdalar seizures. A total of 26 rats were divided into three groups. Ten rats underwent transection using a modified wire knife (transection group); 16 others were untransection group (n=10) and controls (n=6). All the rats then underwent stereotactic implantation of electrodes in the left amygdala (LA), left dorsal hippocampus (LdH), left ventral hippocampus (LvH), and the left sensorimotor cortex (LCx). A stainless steel cannula also was introduced into the LA. Rats except controls later received 1.0 microg of kainic acid (KA) via the cannula. Controls received phosphate buffer solution alone. In the untransection group, multiple spike discharges in the LA immediately propagated concurrently to the LvH and LdH. Propagation involved the LCx to become status epilepticus 1 to 2 h after KA injection. Seizures, characterized by mastication, salivation, facial twitching, forelimb clonus, and sometimes rearing and falling, lasted 1 to 2 days. Microscopic examination revealed severe neuronal cell damage in the LA, LvH, and LdH. In the transection group, multiple spike discharges initiated from the LA and were propagated to LvH, but LdH as well as LCx involvement was slight. Status epilepticus involved only the LA and LvH 1 to 2 h following KA injection. Seizures subsided within 24 h, showing no ictal manifestations except for aggressiveness. Overall, seizures were weak and transient compared with those in controls. Histologically, hippocampal neuronal damage was slight, but damage to amygdalar neurons was similar to that in untransection group. No electroclinical and histological changes were seen in controls. These results indicated that connections between the dorsal and ventral hippocampus are important for full development of KA-induced amygdalar seizures.
 ...
PMID:Hippocampal transection attenuates kainic acid-induced amygdalar seizures in rats. 1128 62

Nonconvulsive status epilepticus (NCSE) is much more common than is generally appreciated. It is certainly underdiagnosed, but its presentation is protean. Diagnostic criteria and treatment are controversial. Absence status is characterized by confusion or diminished responsiveness, with occasional blinking or twitching, lasting hours to days, with generalized spike and slow wave discharges on the EEG. Complex partial status consists of prolonged or repetitive complex partial seizures (with a presumed focal onset) and produces an "epileptic twilight state" with fluctuating lack of responsiveness or confusion. There is a clear overlapping of syndromes. Other confused, stuporous, or comatose patients with rapid, rhythmic, epileptiform discharges on the EEG may have "electrographic" status and should be considered in the same diagnostic category. NCSE typically occurs following supposedly controlled convulsions or other seizures, but with persistent neurologic dysfunction despite apparently adequate treatment. Confusion in the elderly or among emergency room patients is also a typical setting. The diagnosis of NCSE usually involves an abnormal mental status with diminished responsiveness, a supportive EEG, and often a response to anticonvulsant medication. All patients have clinical neurologic deficits, but the EEG findings and response to seizure medication are variable and are more controversial criteria. The response to drugs can be delayed for up to days. Experimental models and pathologic studies showing neuronal damage from status epilepticus pertain primarily to generalized convulsive status. Most morbidity from NCSE appears due to the underlying illness rather than to the NCSE itself. Some cases of prolonged NCSE or those with concomitant systemic illness, focal lesions, or very rapid epileptiform discharges may suffer more long-lasting damage. Although clinical studies show little evidence of permanent neurologic injury, the prolonged memory dysfunction in several cases and the similarities to convulsive status suggest that NCSE should be treated expeditiously. The diagnosis is important to make because NCSE impairs the patient's health significantly, and it is often a treatable and completely reversible condition.
 ...
PMID:Presentation, evaluation, and treatment of nonconvulsive status epilepticus. 1260 61

The succinic semialdehyde dehydrogenase (SSADH) null mouse represents a viable animal model for human SSADH deficiency and is characterized by markedly elevated levels of both gamma-hydroxybutyric acid (GHB) and gamma-aminobutyric acid (GABA) in brain, blood, and urine. GHB is known to induce absence-like seizures and absence seizures have been reported to occur in children with SSADH deficiency. We tested the hypothesis that the phenotype of the SSADH(-/-) mouse shows absence-like seizures because of the inordinately high levels of GHB in the brain of this mutant animal. Sequential electrocorticographic (ECoG) and prolonged video ECoG recordings from chronically implanted electrodes were done on SSADH(-/-), SSADH(+/-), and SSADH(+/+) mice from postnatal day (P) 10 to (P) 21. Spontaneous, recurrent absence-like seizures appeared in the SSADH(-/-) during the second week of life and evolved into generalized convulsive seizures late in the third week of life that were associated with an explosive onset of status epilepticus which was lethal. The seizures in SSADH null mice were consistent with typical absence seizures in rodent with 7 Hz spike-and-wave discharge (SWD) recorded from thalamocortical circuitry, the onset/offset of which was time-locked with ictal behavior characterized by facial myoclonus, vibrissal twitching and frozen immobility. The absence seizures became progressively more severe from P14 to 18 at which time they evolved into myoclonic and generalized convulsive seizures that progressed into a lethal status epilepticus. The absence seizures in SSADH(-/-) were abolished by ethosuximide (ETX) and the GABA(B)R antagonist CGP 35348. The seizure phenotype in the SSADH(-/-) recapitulates that observed in human SSADH deficiency. Hence, SSADH(-/-) may be used to investigate the molecular mechanisms that underpin the pathogenesis of absence and generalized tonic-clonic seizures associated with SSADH deficiency. As well, the SSADH(-/-) may represent a unique animal model of the transition from absence to myoclonic and generalized convulsive seizures that is observed in up to 80% of patients with juvenile absence epilepsy.
 ...
PMID:Absence seizures in succinic semialdehyde dehydrogenase deficient mice: a model of juvenile absence epilepsy. 1558 27

This report describes the management of three children, ranging in age from 7 to 9 years, who had refractory status epilepticus. This condition was likely the result of viral encephalitis; it manifested initially as generalized tonic-clonic seizure and later frequent subtle eye staring and twitching of mouth or limbs as well as tachycardia and dilatation of pupils. The seizures were not responsive to treatment with conventional doses of intravenous phenobarbital, phenytoin, and midazolam infusion. Very-high-dose phenobarbital was administered at accumulated daily doses up to 80 mg/kg, with a resulting serum level of more than 1000 mumol/L. It was effective in achieving seizure control, with milder adverse effects compared with thiopental infusion.
 ...
PMID:Very-high-dose phenobarbital for childhood refractory status epilepticus. 1637 83


1 2 3 Next >>