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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Myoclonus occurs in a variety of pathological conditions, some inherited. We recently evaluated 3 members of a Louisiana-Texas family with an autosomal dominant disorder manifested by adult-onset, generalized, stimulus-sensitive myoclonus and slowly progressive distal muscle weakness and wasting. The analyses of cerebrospinal fluid homovanillic acid and 5-hydroxyindoleacetic acid before and after probenecid provided some evidence of impaired turnover of central dopamine and serotonin. Treatment with clonazepam resulted in complete and lasting improvement of the myoclonus. A postmortem examination in 1 member of the family revealed chiefly neuronal degeneration of the anterior horn cells, Clark's nucleus, and the lower cranial nerve nuclei. A similar syndrome has not previously been reported.
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PMID:Hereditary myoclonus and progressive distal muscular atrophy. 53 21

A previously undescribed form of complicated hereditary spastic paraplegia with epileptic myoclonus in four affected offspring of consanguineous parents is reported. The disorder was inherited as an autosomal recessive trait. Age at onset varied from the prenatal period to 10 years. The main findings when examined between 26 and 42 years of age were spastic paraplegia, epileptic myoclonus, distal muscle atrophy, mental retardation or dullness, ataxia, hearing loss and a progressive course. The difference in phenotypic expression was striking. One woman had progressive epileptic myoclonus, ataxia and only slight distal wasting and could have been misdiagnosed as a case of Unverricht-Lundborg's disease. Thorough biochemical investigations revealed no cause of the disorder.
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PMID:Hereditary spastic paraplegia with epileptic myoclonus. 195 Apr 52

Myoclonus epilepsy associated with ragged-red fibers (MERRF) is a degenerative disease involving dentate nuclei of the cerebellum, globus pallidus, the posterior columns and spinocerebellar tracts of the spinal cord, and skeletal muscles. Abnormal mitochondria were observed in the cells of the cerebellar cortex and of the dentate nuclei. The main symptoms of this disease include cerebellar ataxia and myoclonus in addition to muscular wasting. Patients with MELAS occasionally have myoclonus, but they never have myoclonus as their initial symptoms. Most of the patients with both clinical features of MERRF and MELAS were regarded as belonging to the category of MELAS.
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PMID:MERRF: a clinicopathological study. Relationships between myoclonus epilepsies and mitochondrial myopathies. 196 54

A case of mitochondrial encephalomyopathy with a partial cytochrome c oxidase deficiency was reported with special reference to electrophysiological studies. A 56-year-old man was readmitted to Himeji Central Hospital due to mental deterioration and character change. At the age of 44 when he was attacked by his first epileptic seizure, he was admitted to Himeji Central Hospital, where EEG abnormalities and cerebral atrophy were found. Anticonvulsants helped to relieve his generalized convulsions but the EEG abnormalities persisted. At age 46, he had the second generalized seizure, so he quit his job as a crane operator. His family began to notice deterioration of his intellectual function and hyperaggressive behavior. His daily activities, intellectual performance and mental condition gradually deteriorated (WAIS FIQ less than 60). Other clinical and laboratory findings are as follows: bilateral impaired hearing, no optic nerve atrophy, no disturbance of extra ocular muscle movements, mild wasting and weakness of his extremities, normal coordination and sensation, no myoclonus or other involuntary movements, normal laboratory data of serum creatinine kinase, lactate dehydrogenase and aldolase, and increased amount of lactate and pyruvate in serum and cerebrospinal fluid (CSF), no abnormal amino acids in urine. A biopsy specimen of right biceps brachii muscle revealed numerous ragged-red fibers in frozen sections stained by the Gomori trichrome method. These fibers did not react to a cytochrome c oxidase staining. An ATPase staining demonstrated an atrophy of type-2 fibers. An electron micrograph showed many mitochondria in the sarcoplasm but few paracrystalline inclusions. A biochemical analysis of the muscle biopsy also revealed a significant decrease in the cytochrome c oxidase activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A mitochondrial encephalomyopathy due to partial cytochrome c oxidase deficiency with giant evoked potentials--a case report]. 217 89

Fasciculations may be generated at any point on a hyperexcitable lower motor neuron. Physiological ('benign') fasciculations often begin suddenly and persist for years without development of muscular wasting or weakness. Fasciculations may be a sign of degeneration of lower motor neurons in which case they may be associated with muscle cramps and neuromyotonia. Both sensory and motor axons are overactive in neuromyotonia, the symptoms of which are relieved by administration of anticonvulsants such as carbamazepine. Spinal muscular atrophy is a feature in some cases of progressive myoclonic epilepsy of the systems degeneration type that may be overlooked because muscular wasting is overshadowed by the dramatic appearance of action myoclonus.
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PMID:Association of lower motor neuron disorders with fasciculation, neuromyotonia and myoclonus. 314 66

We report a family of 4 siblings from a non-consanguineous marriage, presenting with an early onset recessive cerebellar ataxia and progressive distal limb wasting. Ocular or other telangiectasias were absent. There were neither frequent infections nor immunodeficiencies. The two youngest patients exhibited an incapacitating myoclonus which abated markedly after 20 years. Late onset diabetes was demonstrated in 3 patients. Hypogonadism was not a feature and there was a prolonged survival in the 4 patients. The oldest sibling died of a pancreatic adenocarcinoma. alpha-Fetoprotein was elevated with normal carcinoembryonic antigen values in three patients. Cytogenetic analysis and radioresistant DNA synthesis was compatible with the diagnosis of ataxia-telagiectasia. This family probably represents a rare variant of ataxia-telangiectasia.
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PMID:An early-onset recessive cerebellar disorder with distal amyotrophy and, in two patients, gross myoclonia: a probable ataxia telangiectasia variant. 778 63

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

Mitochondrial encephalomyopathy is a genetic disorder for which there is at present no cure. Conventional treatment regimes may not be effective in preventing weight loss and muscle wasting in many patients. Recombinant human GH has been shown to have anabolic effects on protein metabolism and to reduce muscle wasting in various diseases. We have treated a patient known to have myoclonus, epilepsy with ragged red fibres (MERRF) with a high protein diet for 1 month followed by a high protein diet and GH therapy for 1 month. To assess the benefit of these treatments the patient underwent whole body protein turnover, myometric and body composition studies at baseline, following the high protein diet (100 g/day) and following GH therapy. Whole body protein synthesis (and protein breakdown) increased following a high protein intake and was further enhanced by treatment with GH and in a high protein diet. Body composition did not change significantly following treatment with either the high protein diet or GH but there was an improvement in muscle performance following GH treatment. Mitochondrial encephalomyopathy, a wasting disorder, may be a disease in which the known protein anabolic effect of GH may have a therapeutic benefit.
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PMID:Growth hormone therapy may benefit protein metabolism in mitochondrial encephalomyopathy. 930 81

MERRF is an acronym of myoclonus epilepsy associated with ragged-red fibers and was first reported as a new nosological entity belonging to mitochondrial encephalomyopathies in San Remo symposium on "Mitochondrial Pathology" in 1982. MERRF was named Fukuhara disease by Rowland (1983). The first reported patient had been diagnosed as having Ramsay Hunt syndrome associated with Friedreich's ataxia. However, nowadays, the previously reported cases as having Ramsay Hunt syndrome associated with Friedreich's ataxia are regarded as having been suffered from MERRF. The history in establishing the nosological entity of MERRF was described. Patients with MERRF develop myoclonus, epileptic seizures, cerebellar ataxia, dementia, sensorineural hearing disturbance, optic atrophy, muscular wasting, and foot deformities at the advanced stage. Pathological findings show degeneration of the dentate nuclei, globus pallidus, and red nuclei, substantia nigra, inferior olivary nuclei, cerebellar cortex, and spinal cord. The posterior columns, the spinocerebellar tracts, and Clark's columns are degenerating in the spinal cord. The pyramidal tracts never show a severe degeneration as in Friedreich's ataxia. The skeletal muscles show mitochondrial abnormalities histologically and electron microscopically. Clinical features of MERRF are not necessarily uniform in the early stage and muscle biopsy findings are also very mild in some patients with MERRF, necessitating genetic analysis for diagnosis. Most of patients show a point mutation (A --> G) of nt 8344 in mitochondrial DNA.
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PMID:[Fukuhara disease]. 1823 33