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

We describe a young man with a progressive neurological disorder including myoclonus, mental retardation, muscle weakness and a mitochondrial myopathy (myoclonus epilepsy and ragged red fibres--MERRF). Multiple abnormalities of the mitochondrial respiratory chain in skeletal muscle are shown by direct measurement of the flux through the individual complexes, low-temperature redox spectroscopy and decreased immunodetectable subunits of complexes I and IV by immunoblotting. No abnormality of mitochondrial DNA was found. This is the first report of combined defects of complexes I, III and IV as a cause of this clinical syndrome. However, we propose that the occurrence of multiple respiratory chain defects may be more common than previously recognised and that this particular combination of defects, involving complexes I, III and IV, may be the predominant biochemical abnormality in MERRF.
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PMID:Multiple defects of the mitochondrial respiratory chain in a mitochondrial encephalopathy (MERRF): a clinical, biochemical and molecular study. 164 12

Of 85 consecutive patients with mitochondrial myopathy, 29 had clinically significant central nervous system involvement. Nine of these had movement disorders that included dystonia, chorea, parkinsonism, and myoclonus. Autopsy studies of one patient with ataxia, dementia, and parkinsonism followed by dystonia showed the features of olivopontocerebellar atrophy with additional degenerative changes in the basal ganglia. Postmortem in a further case with myoclonus, deafness, muscle weakness, retinopathy, and ataxia showed symmetrical mineralisation of the striatopallidodentatal system.
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PMID:Movement disorders in mitochondrial myopathies. A study of nine cases with two autopsy studies. 232 72

A 41-year-old female of mitochondrial myopathy characterized by recurrent paralytic ileus and atonic bladder with the evidence of peripheral nerve involvement was described. This patient was admitted to our hospital because of the episode of paralytic ileus and atonic bladder at the age of 40 and 41 (1987). She had noticed sporadic headache from 1967, constipation from 1977, tinnitus and hearing disturbance from 1984. One month after her second admission in 1987, her symptoms of paralytic ileus and atonic bladder gradually disappeared. She was then transferred to the department of neurology for the evaluation of underlining neurological disorders. Neurological examination revealed dementia, oro-lingual dyskinesia, and proximal muscular weakness. However, none of the following signs or symptoms were observed; Ophthalmoplegia, blepharoptosis, retinitis pigmentosa, myoclonus, cerebellar ataxia, sensory disturbance, and orthostatic hypotension. Deep tendon reflexes were normal. Planter responses were flexor. Pyruvate and lactate were elevated in both serum and cerebrospinal fluid. Brain CT scan displayed moderate cerebral atrophy and basal ganglia calcifications. EMG was normal except for the external anal sphincter muscles which showed a denervation pattern. Motor nerve conduction velocity was normal in the right median and the right peroneal nerves. Sensory nerve conduction velocity was also normal in the right median and the right sural nerves. However, the amplitude of sensory potential was low in both these nerves. Atonic type of neurogenic bladder was noted on cystometry. There was a lack of voiding desire. The number of active sweat glands iontophoretically stimulated by pilocarpine was reduced. The most prominent feature of the muscle biopsy (the left biceps brachii) was myopathic changes with ragged-red fibers.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Paralytic ileus and atonic bladder in a case of mitochondrial encephalomyopathy--electrophysiological, chemical and pathological study with evidence of the peripheral nerve involvement]. 255 55

The CNS diseases that are associated with mitochondrial myopathy have been reviewed in this chapter. The disorders causing myoclonus have been compared to those in which myoclonus has been reported. Both groups have been associated with lactate and pyruvate accumulation, and both have a wide spectrum of clinical and pathologic findings. Deficiency of components of the respiratory chain has been offered as an explanation for the mitochondrial accumulation in the muscles of these patients. Skeletal muscle respiratory-chain components may be deficient, and there is experimental evidence that indicates that mitochondria will proliferate in muscle and other tissues when vital nutrients are withheld. There are two features of these patients that separate them from other patients with myoclonus. The first is the elevation of serum lactate and pyruvate due to deficient oxidative phosphorylation. The second is a pedigree that indicates maternal inheritance.
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PMID:Myoclonus and mitochondrial myopathy. 308 Aug 47

A 19-year-old woman with long-standing sensorineural deafness, bilateral cataracts and mild clumsiness, presented with acute focal edema in the left temperoparieto-occipital area which required surgical decompression as a life-saving measure. Investigation revealed a persistent lactic acidemia and evidence of many ragged red fibres in a skeletal muscle biopsy specimen, suggesting a diagnosis of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome. The patient developed two further stroke-like episodes over a short period. One sibling died at the age of 14 years with a progressive neurological illness characterised by seizures, bilateral optic atrophy, ataxia, myoclonus and progressive dementia. The diagnosis of MELAS syndrome should be considered in young people presenting with stroke-like episodes that fail to conform to a given vascular territory, particularly if they have long-standing minor neurological abnormalities or a family history of obscure early onset neurological disease. The different clinical pictures in the two affected siblings in this family suggest that MELAS syndrome is part of a spectrum of inherited mitochondrial cytopathies rather than a discrete disease entity.
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PMID:Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS): adolescent onset with severe cerebral edema. 339 2

A family is described with familial myoclonic epilepsy associated with mitochondrial myopathy. The disorder follows a maternal inheritance pattern consistent with a mitochondrial DNA (mtDNA) mutation. The large kindred permitted exclusion of autosomal dominant, recessive, and X-linked patterns of transmission. Several characteristics of the inheritance and variability of expression within the pedigree are consistent with recently acquired knowledge about the genetics of human mtDNA. The clinical spectrum of disease is compatible with a proportionality model of mutant and wild-type mtDNAs. Muscle biopsies of affected patients showed an increased number of abnormal muscle mitochondria. Serum levels of pyruvate or pyruvate and lactate were elevated. The most severely affected patient had constant myoclonic jerking, dementia, ataxia, spasticity, hearing loss, and hypoventilation. Cerebral dysfunction in patients with mild involvement was marked by prominent photic driving seen on electroencephalograms and high-amplitude visual and somatosensory evoked responses but no myoclonus, ataxia, or dementia. The individual clinical features of the disease worsen over time for all patients; however, mildly affected patients have not become moderately affected and moderately affected patients have not become severely affected.
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PMID:Maternally inherited mitochondrial myopathy and myoclonic epilepsy. 392 81

A 50-year-old Japanese woman with action myoclonus, cerebellar signs, neuropathy with axonal degeneration and onion-bulb formation, muscle atrophy with mitochondrial abnormalities, and isolated ACTH deficiency was reported. Her daughter had myoclonus epilepsy and cerebellar ataxia. Neuropathologic findings included atrophy of the dentate and inferior olivary nuclei, Purkinje's cell loss, and demyelination of the posterior columns and spinocerebellar and pyramidal tracts of the spinal cord, besides severe respirator changes. Lafora's bodies were absent. The present case should be included in the entity "myoclonus epilepsy associated with mitochondrial myopathy."
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PMID:Myoclonus, cerebellar disorder, neuropathy, mitochondrial myopathy, and ACTH deficiency. 631 Apr 38

We describe three patients with mitochondrial myopathy, dementia, loss of vision and hearing, seizure disorder with myoclonus, intermittent headaches of a vascular type, visual hallucinations, cerebellar dysfunction, and lactic acidosis. Muscle biopsies in all patients and liver biopsy in one revealed abnormal mitochondria. The disorder may be due to a deficiency of mitochondrial NADH-CoQ dehydrogenase.
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PMID:Mitochondrial myopathy and encephalopathy: three cases--a deficiency of NADH-CoQ dehydrogenase? 641 59

A report is given of an association of dyssynergia cerebellaris myoclonica associated with Friedreich's ataxia and mitochondrial myopathy in 2 patients. They had suffered from gradually increasing bursts of myoclonus since the wage of 14 and childhood, respectively. The other striking clinical features included generalized convulsions, mental deterioration, intention tremor, ataxia, muscular atrophy and deformity of feet. Muscle biopsies revealed ragged-red fibres in both cases. On electron microscopy these fibres contained subsarcolemnal aggregations of abundant abnormal mitochondria with proliferation of inner membranes or paracrystalline inclusions. One of these patients showed elevated blood lactate and pyruvate with an increased lactate/pyruvate ration, apparently of primary origin. These 2 cases resemble those reported briefly by Tsairis et al. (1974). An association of dyssynergia cerebellaris myoclonica associated with Friedreich's ataxia and mitochondrial myopathy in these 2 patients is unlikely to be coincidental but may represent one nosological entity. This myoclonus epilepsy syndrome associated with ragged-red fibres is compared with other possibly related mitochondrial encephalomyopathies.
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PMID:Myoclonus epilepsy associated with ragged-red fibres (mitochondrial abnormalities ): disease entity or a syndrome? Light-and electron-microscopic studies of two cases and review of literature. 677 61

A 23-year-old man presented with a history characterized by a myoclonic syndrome developing over a period of seven years. Predominant symptoms were intention and activity myoclonus, generalized epileptic seizures occurring infrequently from the age of 20, a slowly progressive cerebellar syndrome first apparent at 19 years, and the sudden onset of loss of visual acuity at 19, which then partially regressed; optic atrophy and clinical and campimetric signs were suggestive of Leber's disease. Intellectual ability was not affected. E.E.G. records showed generalized spike-waves with photosensitivity, progressive reduction in basal rhythm, and sleep organization disturbances with focal abnormalities. Obvious clinical signs of muscle disease were lacking but muscle biopsy confirmed the presence of a mitochondrial myopathy (ragged-red fibers). An indefinite history of familial neurological disease was obtained. Diagnosis was established as myoclonic cerebellar dyssynergy with spastic hereditary ataxia and Leber's disease. Their association with a mitochondrial myopathy has been previously reported by Tsairis et al, Fukuhara et al, Fitzimons et al (familial case), and Niedermeyer et al (sporadic case). In spite of the non-specific nature of associated mitochondrial abnormalities, all these cases would appear to correspond to a single nosological entity.
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PMID:[Spinocerebellar degeneration, optic atrophy, epilepsy, myoclonus and mitochondrial myopathy: a case report (author's transl)]. 681 Apr 37


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