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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Health care providers who care for patients with seizure disorders should be able to recognize progressive myoclonus epilepsy. Progressive myoclonus epilepsy is a syndrome confused with myoclonic seizures and other epilepsies. The main symptom is myoclonus, a brief involuntary muscle jerk of varying intensity that can throw a patient against a wall or to the ground. This article describes major types of progressive myoclonus epilepsy, a typical case presentation and two clinical drug trials available for these patients. The focus of clinical drug trials is to identify a drug that controls the myoclonus and improves the quality of life for the affected individual. There is no cure for patients with progressive myoclonus epilepsy. 5-hydroxy-L-tryptophan and piracetam are two drugs available through clinical-research protocols to patients with progressive myoclonus epilepsy.
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PMID:The clinical challenge of progressive myoclonus epilepsy. 835 98

We describe a 42-year-old woman with overlapping syndrome of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) and MERRF (myoclonus epilepsy and ragged-red fibers). Clinically, she had episodic headache, stroke-like episode with left hemiparesis and lactic acidosis commonly found in MELAS syndrome. However, myoclonus seizure, and ataxia with dyssynergic gait characteristic of MERRF were also noted. Computed tomographic scans showed a right temporo-parietal hypodense lesion. The lesion disappeared 20 months later, even magnetic resonance images also failed to reveal this abnormality. A molecular analysis of mitochondrial DNA was conducted by using restriction endonucleases ApaI and NaeI. A transition from A to G was found at the nucleotide position 3243, but not found at the 8344th nucleotide pair. In this report, we document the fluctuating CT changes and emphasize the importance of molecular analysis in patients with overlapping syndrome of mitochondrial encephalomyopathies.
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PMID:Overlapping syndrome of MERRF and MELAS: molecular and neuroradiological studies. 835 81

One hundred-sixteen patients with epilepsy over 50 years old were investigated to explore the clinical characteristics of epilepsy in elderly persons. Eighty-four patients having seizures within the last 3 years (residual group) were compared with 32 patients having no seizures within the last 3 years (disappeared group). Regarding the epilepsy type, there were 87 partial epilepsies (64 in the residual group and 23 in the disappeared group) which were approximately 70 percent of the total patients. Generalized epilepsies were comparatively rare in the both groups. Eleven patients with progressive myoclonus epilepsy were observed in the residual group. Regarding the seizure type, generalized convulsive seizures (GCS) were more likely to disappear than partial seizures regardless of number of seizures the patient had. Thirty-eight patients (29 in the residual group and 9 in the disappeared group) had histories of psychiatric problems. Paranoid states were most commonly seen in 12 patients in the residual group and 5 patients in the disappeared group. Intellectual disturbance was seen more frequently in the residual group.
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PMID:[Clinical research of patients with epilepsy over age 50 years--a retrospective study of early onset case]. 836 46

The 1981 International Classification of Epileptic Seizures (ICES) was used to study the distribution of seizure types in 1,250 patients attending an Epilepsy Clinic in Sri Lanka. Based on seizure symptomatology 94.6% of the cases could be classified, and by adding the routine interictal EEG findings the percentage of classifiable seizures increased to 97%. Partial seizures (73.8% cases) were three times as common as generalized seizures (23.3% cases). Of the partial seizures, simple partial seizures (SPS) accounted for only 0.4% cases, and complex partial seizures (CPS) for 8.8%, whereas partial seizures secondarily generalized (PSGS) accounted for 64.6%. PSGS had simple onset in 12.5% and complex onset in 34.8% of cases. Myoclonic seizures were the commonest of the generalized seizures, accounting for 14.6% of all cases. Tonic-clonic seizures accounted for 7.4% of cases; absence seizures accounted for only 1.3%. The study showed the 1981 ICES to be relevant and applicable in a clinical setting with limited investigatory facilities. Difficulties encountered with regard to certain subcategories could be overcome with minor modifications which made the classification operative. Routine EEG confirmed the diagnosis in a significant number of cases but changed the diagnosis in only a few, confirming that a good standardized questionnaire is the key instrument for classifying epileptic seizures.
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PMID:Classification of epileptic seizures: a hospital-based study of 1,250 patients in a developing country. 840 30

Four syndromes comprise the absence epilepsies. Each is classically associated with the absence seizure, although other syndromes also have absence attacks as part of their repertoire. The most common syndrome is childhood absence epilepsy; it usually occurs in the age range of 6-7 years. The absence seizures may occur many times daily, and the electroencephalographic (EEG) characteristics are the most typical of the absence epilepsies. The second form of absence epilepsies is juvenile absence epilepsy; it begins near puberty and may represent a continuum from the childhood form. Myoclonic seizures are more common than in the childhood form, and the spike-wave discharges in the EEG are often faster than that seen in childhood absence epilepsy. The third form of absence epilepsy is juvenile myoclonic epilepsy, characterized especially by myoclonic jerks in the morning; these attacks occasionally progress to generalized tonic-clonic seizures. The final form of absence epilepsy is epilepsy with myoclonic absences, a rare disorder with a specific form of absence seizures. The absence seizure itself is observed to a greater or lesser extent in all of these syndromes. This seizure is a curious event, and its causes are poorly explained by current knowledge of the fundamental mechanisms of the epilepsies. Although the etiology of the absence seizure at a biochemical level is unknown, some studies suggest that certain low-threshold calcium ion currents (T currents), which are partially controlled by GABA-B mechanisms, may activate burst firing of thalamic neurons, initiating an absence seizure. The evidence of a genetic predisposition for the absence epilepsies is overwhelming.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The absence epilepsies. 850 Apr 32

This man with myoclonus epilepsy and ragged red fibres (MERRF) syndrome due to the tRNA(Lys) A-->G(8344) mutation of mitochondrial DNA (mtDNA) died of bronchopneumonia at 18 years of age. He had progressive clinical symptoms from 6 months of age manifesting as ataxia, myoclonic seizures, and muscle weakness. A post-mortem examination revealed 91-99% mutated mtDNA in all 32 examined tissue samples, including various organs and different brain regions. The brain appeared without macroscopic changes, but microscopic examination showed degeneration with loss of nerve cells and gliosis affecting the globus pallidus, substantia nigra, red nucleus, dentate nucleus, inferior olivary nucleus, cerebellar cortex, and the spinal cord. Skeletal muscle showed cytochrome c oxidase deficient muscle fibres with proliferation of mitochondria. In addition to pathological changes of muscle and brain there were few morphological changes that could be attributed to his mitochondrial disease. These data support the concept that in patients with the tRNA(Lys) A-->G(8344) mutation who are manifesting disease there are high levels of mutated mtDNA in all tissues, but only some tissues and brain regions are vulnerable.
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PMID:Tissue distribution and disease manifestations of the tRNA(Lys) A-->G(8344) mitochondrial DNA mutation in a case of myoclonus epilepsy and ragged red fibres. 852 9

Ten patients, two men and eight women with mitochondrial encephalomyopathy, had an A-G mutation at nucleotide pair 8,344 in the mitochondrial DNA, the most common genetic defect in myoclonus epilepsy with ragged-red fibers (MERRF). Eight patients had the clinical and pathologic characteristics of MERRF including myoclonus, seizures, cerebellar ataxia and myopathy with ragged-red fibers. Two patients had atypical symptoms such as early onset of fatal cardiac failure and late onset of rapid mental deterioration, respectively. The striking feature in our patients with the 8,344 mutation cardiac involvement and two developed progressive heart failure. In the typical MERRF patients, the proportion of mutant mitochondrial DNA in their skeletal muscles, quantified by a single strand conformation polymorphism analysis, was above 85%. However, there was no significant correlation between clinical severity, histopathological findings and the proportion of mutant mtDNA in muscle biopsy samples, suggesting that non-ragged-red fibers play an important role in the phenotype expression of the mutants.
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PMID:The 8,344 mutation in mitochondrial DNA: a comparison between the proportion of mutant DNA and clinico-pathologic findings. 858 Jul 30

Jittery (ji) is a recessive mouse mutation on Chromosome 10 characterized by progressive ataxic gait, dystonic movements, spontaneus seizures, and death by dehydration/starvation before fertility. Recently, a viable neurological recessive mutation, hesitant, was discovered. It is characterized by hesitant, unco-ordinated movements, exaggerated stepping of the hind limbs, and reduced fertility in males. In a complementation test and by genetic mapping we have shown here that hesitant and jittery are allelic. Using several large intersubspecific backcrosses and intercrosses we have genetically mapped ji near the marker Amh and microsatellite markers D10Mit7, D10Mit21, and D10Mit23. The linked region of mouse Chromosome 10 is homologous to human 19p13.3, to which several human ataxia loci have recently been mapped. By excluding genes that map to human 21q22.3 (Pfkl) and 12q23 (Nfyb), we conclude that jittery is not likely to be a genetic mouse model for human Unverricht-Lundborg progressive myoclonus epilepsy (EPM1) on 21q22.3 nor for spinocerebellar ataxia II (SCA2) on 12q22-q24. The closely linked markers presented here will facilitate positional cloning of the ji gene.
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PMID:The neurological mouse mutations jittery and hesitant are allelic and map to the region of mouse chromosome 10 homologous to 19p13.3. 881 88

The sensory-motor portion of the inferior collicular cortex is capable of seizure genesis that is characterized initially by coincident wild running behaviors and localized electrographic afterdischarge. With repeated stimulations, this seizure activity spreads into the forebrain, producing generalized tonic-clonic or myoclonic seizure activity. In order to characterize the neural network subserving this caudal-rostral seizure generalization, three mapping techniques were used: 2-deoxyglucose (2-DG) utilization, c-fos expression and local anesthetic microinjection. Kindled seizure generalization from the inferior collicular cortex produced a global increase in 2-DG accumulation, while relative 2-DG increases were found in the inferior collicular cortex, dorsal lateral lemniscus, dorsal central gray, peripeduncular nucleus, medial geniculate nucleus, substantia nigra, entopeduncular nucleus, ventroposterior and centromedian thalamus and tenia tectum, as well as the perirhinal, somatosensory and frontal cortices. Kindled seizure generalization also increased c-fos-like immunoreactivity (FLI) in the inferior collicular cortex, cuneiform nucleus, dorsal lateral nucleus of the lateral lemniscus, peripeduncular nucleus, caudal central gray, dentate gyrus of the hippocampus, rhinal fissure area of the perirhinal cortex and the frontal cortex. Microinjections of procaine into the amygdala, perirhinal cortex, entopeduncular nucleus, substantia nigra, peripeduncular nucleus, dorsal central gray, and pontine reticular nucleus all prevented generalized seizure behaviors, but had no effect on the wild running seizures. Conversely, procaine microinjection into the area of the cuneiform nucleus/pedunculopontine tegmental nucleus prevented the wild running seizure but did not block the generalized seizure activity. Neither wild running, nor generalized seizures were altered following procaine microinjections into the anterior thalamus, sub-thalamus, lateral hypothalamus, hippocampus or deep superior colliculus. Thus, specific forebrain sites form a widespread neural network that mediates the generalization of seizure activity from the inferior collicular cortex into the forebrain.
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PMID:Metabolic and functional mapping of the neural network subserving inferior collicular seizure generalization. 892 73

Clozapine is an 'atypical' neuroleptic that improves symptoms of many patients with schizophrenia whose illness is resistant to treatment with other neuroleptics. Unlike the 'typical neuroleptics (chlorpromazine, haloperidol), clozapine does not induce extrapyramidal symptoms such as Parkinsonism and tardive dyskinesia in humans or catalepsy in the rat. However, clozapine frequently causes epileptiform EEG changes and causes seizures in 3-5% of patients treated with this drug in therapeutic doses. Clozapine also induces dose dependent myoclonus in the partially restrained rat. In the experiments reported here, partially restrained rats were administered repeated alternate day or weekly low, fixed doses of clozapine (1 mg/kg). This dose initially caused no behavioral change. Following the third and subsequent administrations, the same dose elicited an increasing number of myoclonic seizure-like jerks reaching 140/h following the 15th injection in rats receiving the same low dose of clozapine on alternate days and 160/h following the 9th injection in animals that received the same dose once weekly. These effects are consistent with kindling, i.e. a progressive increase of brain excitability following repeated administration of a fixed subconvulsive dose of an excitatory agent. Clozapine kindled animals exhibited a significantly different pattern of early gene expression in ventral tegmental area, origin of the mesolimbic-mesocortical dopamine system and in the anterior thalamic nuclei, compared with saline treated controls subjected to exactly the same recording conditions. The evidence of central nervous system excitation with clozapine may be important to the unique therapeutic effect of this atypical antipsychotic in the treatment of symptoms, especially the deficit symptoms, of schizophrenia.
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PMID:Kindling with clozapine: behavioral and molecular consequences. 898 8


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