Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a 21-year-old man with agammaglobulinemia and chronic progressive encephalopathy. The patient was diagnosed as having X-linked agammaglobulinemia at 6 months of age, and gamma globulin supplementation was initiated. He exhibited normal development until he was 11 years old, when he showed a decline in school performance and a personality change. Computed tomography images at that time disclosed diffuse cerebral atrophy. Several generalized tonic-clonic convulsions, myoclonus and spasticity appeared at the age of 13 years. He lost his ability to walk and speak at the age of 17 years old. He is currently 21 years old and displays severe mental deterioration and spastic tetraplegia. Magnetic resonance imaging showed progressive diffuse cerebral atrophy with no change in intensity. The cerebellum and the brain stem were relatively well maintained. Viral isolations were negative and serum antibody titers for rubella, measles, and human immune deficiency virus were not elevated. Our patient's symptoms resemble those previously reported as chronic progressive encephalopathy without viral isolation. This condition may be a complication of agammaglobulinemia. It is possible that the encephalopathy of our patient has the same etiology as that described in the other reports. Further attempts to identify the etiology of the encephalopathy using molecular techniques are necessary.
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PMID:[A case of agammaglobulinemia with chronic progressive encephalopathy]. 795 27

An abnormality of serotonergic neurotransmission has been hypothesized in p,p'-DDT intoxication to explain myoclonus and the antimyoclonic properties of 5-hydroxytryptophan (5-HTP). To study the role of serotonin (5-HT) receptors in myoclonus induced by p,p'-DDT in the rat, we performed time-course and dose-response studies of the effects of p,p'-DDT on behavior and regional 5-HT1 and 5-HT2 binding sites. At a time when low dose (80 mg/kg) p,p'-DDT elicited stimulus-sensitive and spontaneous myoclonus, there were no significant changes in Bmax or Kd of 5-HT1A, 5-HT1B, 5-HT1C sites in cortex, striatum, brainstem or spinal cord, agonist- or antagonist-labelled 5-HT2 sites in cortex, or 5-HT uptake sites. High dose p,p'-DDT (1000 but not 500 mg/kg), which also induced convulsions, only slightly increased 5-HT1 (unsubtyped) binding sites in cortex but not in brainstem or spinal cord and had no effect on antagonist-labelled 5-HT2 sites. In naive frontal cortex in vitro, 1 microM p,p'-DDT displaced neither [3H]5-HT or [3H]ketanserin specific binding. Lesions of central indoleamine neurons made with 5,7-dihydroxytryptamine significantly prolonged the latency and attenuated the severity of p,p'-DDT behavioral abnormalities, increasing the dose of p,p'-DDT which induced myoclonus (MD50) or convulsions (CD50) in 50 percent of the rats. This is the first report of 5,7-DHT-induced attenuation in the p,p'-DDT myoclonic model.
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PMID:p,p'-DDT myoclonic/epileptic model: serotonin receptor binding and behavioral studies in the rat. 799 Dec 14

Meperidine neurotoxicity, characterized by recurrent convulsions, myoclonus, and asterixis, was diagnosed in an organ transplant recipient. Aside from cyclosporine toxicity, the literature regarding neurologic complications of transplantation contains limited reference to the neurotoxicity of therapy. The case reported illustrates how pharmacokinetic factors might render transplant patients particularly vulnerable to the neurotoxic side effects of certain medications, such as meperidine.
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PMID:Meperidine neurotoxicity after organ transplantation. 800 42

A boy, born after normal pregnancy and delivery, began to have fits at 3 days. The seizures were composed of tonic or tonic-clonic convulsions at the upper extremities but myoclonus was absent. These attacks were not easy to control. There was gross developmental delay. Laboratory investigations were almost normal except for cerebrospinal fluid: pleocytosis and high protein content. EEG showed "suppression-burst" and MRI revealed high signal intensity in the left temporo-occipital region on T2 weighted image. At three and a half months of age, EEG changed into hypsarrhythmia. The child died at 5 months of age. At post mortem neuropathological examination, the cortical ribbon in the bilateral parieto-occipital regions appeared thick, as if there were pachygyria. Microscopically polymicrogyria was noted in these areas as well as in the insular cortex. This lesion showed a symmetrical distribution. The cytoarchitectonic features of the polymicrogyric cortex did not consist of 4 layers. The other structures of the central nervous system were almost devoid of lesion. The number of clinico-pathological reports on Ohtahara's syndrome is very limited and the etiopathogenesis of polymicrogyria is discussed.
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PMID:[Early infantile epileptic encephalopathy (Ohtahara syndrome) with poly-microgyria]. 802 66

Juvenile myoclonic epilepsy does not seem to be recognized as often as it should be, accounting as it does for about one in 10 of those with epilepsy. In addition to the myoclonus, absence seizures and tonic-clonic fits can occur. The interictal EEG shows polyspike and wave discharges, and during the myoclonus, medium to high amplitude 16 Hz spikes. Patients may not be seen by a doctor until a major seizure occurs, and if a history of myoclonus is not obtained, inappropriate treatment may be given. The myoclonus may attributed to clumsiness. The inheritance of the condition is most probably polygenic, although it is claimed that juvenile myoclonic epilepsy may be determined by a single autosomal recessive gene. The most effective treatment is with sodium valproate, and this may have to be life-long. In the presence of major seizures carbamazapine should be used with caution as it may exacerbate minor attacks.
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PMID:Review: juvenile myoclonic epilepsy. 803 30

A range of D1 receptor agonists were tested for their ability to facilitate limbic motor seizures induced by a subthreshold dose of the chemoconvulsant pilocarpine (100 mg/kg IP) in mice. ED50 values (mumol/kg) were calculated from log dose-probit analyses, giving relative proconvulsant potencies of SKF 82958 > CY 208-243 > SKF 77434 = SKF 75670 = SKF 80723 > SKF 38393. The compound SKF 82526, which poorly crosses the blood-brain barrier, did not lower the seizure threshold. Convulsions consisted of rearing and forepaw myoclonus, leading to status epilepticus at higher doses of the D1 agonists. No deaths were recorded. A maximum seizure incidence of 50% was obtained with SKF 75670, compared to 100% for the other compounds. Apart from SKF 82526, the D1 agonists all elicited behavioural signs of central D1 receptor stimulation, including motor restlessness, grooming and sniffing. There was no obvious relationship between the abilities of these D1 agonist drugs to promote epilepsy and their effects on unconditioned motor behaviour, or their affinities and efficacies at the striatal D1 receptor. It is concluded that a reduction of the seizure threshold is an inevitable consequence of central D1 receptor stimulation with existing D1 agonists.
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PMID:Seizure promotion by D1 agonists does not correlate with other dopaminergic properties. 810 96

A 73-year-old woman (patient 1) developed progressive mental deterioration at age 63, and seizures at age 70. On examination, she showed severe dementia, tonic clonic convulsion, hypotonia and muscular wasting. There was neither myoclonus nor cerebellar ataxia. Brain CT revealed a low density area in the right occipital lobe. A 44-year-old man (son of the patient 1) developed unsteady gait at age 15, muscle twitching at age 18 and then noticed speech disturbance at age 35. He had no history of convulsive seizure. Neurological examination showed cerebellar ataxia, myoclonus in the extremities and mild muscular weakness. His intelligence was normal. Brain CT showed moderate atrophy of the pons and the cerebellum. Both cases showed the same mitochondrial DNA mutation as reported previously in patients with MERRF. However, the clinical features, the age of onset and the brain CT findings were totally different between these 2 cases. In the progress of mitochondrial genetic analysis, atypical forms in MERRF like the patient 1 would increase in number, and the wide variation of clinical symptoms should be considered.
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PMID:[Two cases of MERRF (myoclonus epilepsy associated with ragged red fibers) showing different clinical features in the same family]. 812 82

A patient with subacute sclerosing panencephalitis (SSPE) was treated with an intraventricular alpha interferon (IFN-alpha) through an Ommaya reservoir. A 17-year-old boy, who had a history of measles exposure at age 1, showed forgetfulness, difficulties in calculation, reading and writing. Two months later he developed generalized convulsions and myoclonic spasms. He was admitted to the National Saigata Hospital in May 20, 1992. On admission, anti-measles antibody titer in the CSF was 1:16 by complement-fixation method. His EEG revealed a periodic synchronous discharge. Therefore, the diagnosis of SSPE was confirmed. An Ommaya reservoir was implanted on July 7, 1992, and an intraventricular administration of INF-alpha was begun after two weeks. The dose of INF-alpha was gradually increased from 1.0 x 10(6) IU/m2 to 2.0 x 10(6) IU/m2 twice a week. Fever, vomiting and anorexia were developed when the INF-alpha injection was first started. When he received a total dose of 8.0 x 10(6) IU, he became bed ridden for remarkable lethargy. The lethargy was continued for about 10 days despite the therapy was interrupted, and then he gradually became alert. The frequency of myoclonus became more frequent and mentality got worse, so the treatment with INF-alpha was tried again in decreasing the dose to 1.0 x 10(6) IU/m2 twice a week. However, be became drowsy again after he received a total of 7.5 x 10(6) IU. With intramuscular or intravenous administrations of the high doses of INF-alpha (> or = 1.0 x 10(7) IU), significant neurological abnormalities were reported to occur.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A case of subacute sclerosing panencephalitis treated with intraventricular interferon--the side effects of interferon-alpha to the central nervous system]. 815 18

Two instances of successful treatment of the rare ocular dyskinesia, opsoclonus, with chlormethiazole are reported. A 65-year-old woman had the opsoclonus-myoclonus syndrome associated with carcinoma of the breast; her myoclonia and opsoclonus did not respond to intravenous diazepam or phenytoin. Treatment with intravenous chlormethiazole resulted in rapid control of her myoclonic attacks, followed by slower but complete resolution of the opsoclonus. Following control of the acute symptoms the patient was transferred to an oral chlormethiazole maintenance dose which was further reduced and subsequently discontinued after 5 months, when the patient's overall clinical status had improved. A 53-year-old man with opsoclonia, myoclonia, ataxia and encephalopathy, not associated with neoplasia, was given immunosuppressor drugs to establish basal control, and oral chlormethiazole for symptomatic treatment. Almost immediately after the initial dose of chlormethiazole the patient became more orientated; he was sedated and the agitation and myoclonic fits were brought under control quite quickly. The opsoclonus responded progressively and was completely resolved after a few days. The initial oral dose of chlormethiazole was gradually reduced and was discontinued after 5-6 months. Chlormethiazole was well tolerated; it may have an important role in the management of the rare opsoclonus-myoclonus syndrome.
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PMID:Chlormethiazole in the management of the opsoclonus-myoclonus syndrome. 818 45

The chromosomal loci for seven epilepsy genes have been identified in chromosomes 1q, 6p, 8q, 16p, 20q, 21q, and 22q. In 1987, the first epilepsy locus was mapped in a common benign idiopathic generalized epilepsy syndrome, juvenile myoclonic epilepsy (JME). Properdin factor or Bf, human leukocyte antigen (HLA), and DNA markers in the HLA-DQ region were genetically linked to JME and the locus, named EJM1, was assigned to the short arm of chromosome 6. Our latest studies, as well as those by Whitehouse et al., show that not all families with JME have their genetic locus in chromosome 6p, and that childhood absence epilepsy does not map to the same EJM1 locus. Recent results, therefore, favor genetic heterogeneity for JME and for the common idiopathic generalized epilepsies. Heterogeneity also exists in benign familial neonatal convulsions, a rare form of idiopathic generalized epilepsy. Two loci are now recognized; one in chromosome 20q (EBN1) and another in chromosome 8q. Heterogeneity also exists for the broad group of debilitating and often fatal progressive myoclonus epilepsies (PME). The gene locus (EPM1) for both the Baltic and Mediterranean types of PME or Unverricht-Lundborg disease is the same and is located in the long arm of chromosome 21. Lafora type of PME does not map to the same EPM1 locus in chromosome 21. PME can be caused by the juvenile type of Gaucher's disease, which maps to chromosome 1q, by the juvenile type of neuronal ceroid lipofuscinoses (CLN3), which maps to chromosome 16p, and by the "cherry-red-spot-myoclonus" syndrome of Guazzi or sialidosis type I, which has been localized to chromosome 10. A point mutation in the mitochondrial tRNA(Lys) coding gene can also cause PME in children and adults (MERFF).
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PMID:Progress in mapping human epilepsy genes. 829 22


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