Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162671 (MELAS)
 587 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of mitochondrial encephalomyopathy (MELAS) with mental disorder is reported. The SPECT study using 123I-iodoamphetamine (IMP) and MRI study revealed abnormality in the left parieto-occipital areas without abnormality in the brain CT or brain scintigram. These findings suggest a localized dysfunction of the brain capillary endothelium in association with the cerebral involvement of mitochondrial encephalomyopathy.
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PMID:Mitochondrial encephalomyopathy (MELAS) with mental disorder. CT, MRI and SPECT findings. 233 39

We report a 26-year-old male who developed aphasia due to an ischemic cerebral infarction caused by MELAS (myoencephalophatic syndrome with lactic acidosis and cerebral ischemia). The most common causes of cerebral infarction in young patients were ruled out by laboratory investigations. The diagnosis of MELAS was suspected on the basis of past history of epilepsy, migraine and progressive sensory deafness, and increased resting blood lactic acid. Cerebral computed tomography showed bilateral caudate-putamen-pallidal calcification and nuclear magnetic resonance scan disclosed a left ischemic parietal-temporal-occipital infarction. The diagnosis was confirmed by muscular biopsy, which was characteristic of mitochondrial myopathy showing "red disarrayed" fibers in the histologic modified trichromic Gomori stain. Our patient showed that MELAS should be considered in young adults with cerebral infarction. The diagnosis should initially be suspected on a clinical basis, and confirmed by the presence of "red disarrayed" fibers with modified trichromic Gomori stain histologic muscle study.
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PMID:[Cerebral infarct in a young adult, as the presenting form of myeloencephalopathic syndrome with lactic acidosis and cerebral ischemia]. 236 6

MELAS syndrome is a distinct clinical entity belonging to a group of mitochondrial encephalomyopathies characterized by the tetrad of myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. Computed tomography (CT) and magnetic resonance (MR) findings are reviewed in a patient with MELAS. Serial CT studies demonstrated multiple "migrating" infarcts in various stages of evolution involving primarily the posterior temporal and occipital regions. MR was more sensitive than CT in demonstrating the number and extent of cortical lesions in this disease entity.
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PMID:Magnetic resonance imaging in MELAS syndrome. 239 45

We reported a case of mitochondrial encephalomyopathy with repeated stroke-like episodes. A 33-year-old single male was admitted to our hospital because of stroke-like episodes with visual field defect, hemiplegia and convulsion repeated seven times for the past seven years. There were no abnormalities on the physical examination. He was hallucinative and perseverative and had mental deficiency. Muscle weakness and atrophy were not prominent, and generalized hyporeflexia were present without pathological reflexes. Myoclonus was not observed. Serum CK and blood gas analysis were normal (pH 7.398). Although blood levels of lactate and pyruvate were almost within normal limit, lactate was elevated by 20WATT-15 minutes exercises. On the contrary, the CSF levels of lactate and pyruvate were elevated markedly. CT of the brain revealed the presence of the low density areas in the right occipital and the left frontal lobes. Cranial 4 vessels studies were unremarkable. EEG showed the diffuse slowness with spike and wave complex. CT of the muscles were normal. A specimen obtained from the left biceps brachii muscle showed ragged-red fibers without obvious myogenic or neurogenic changes, and accumulations of abnormal mitochondria with paracrystalline inclusion bodies were observed by electron microscopy. However, mitochondrial abnormalities were not seen in the vessel walls in the biopsied muscle. Activities of complex I + III, II + III, IV in mitochondria were normal. Clinical features of this case were consistent with MELAS. However, this case showed no muscle weakness, short stature and lactic acidosis which characterize MELAS, and the onset of this case was later than those cases that were reported before.
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PMID:[A case of mitochondrial encephalomyopathy characterized by repeated stroke-like episodes]. 250 53

A 29-year-old man with mitochondrial encephalomyopathy caused by partial deficiency of mitochondrial NADH-ubiquinone oxidoreductase (Complex I) is described. Clinical manifestations were characterized by generalized convulsion, dementia and stroke-like episodes consisting of hemianopsia, Gerstmann's syndrome and visual hallucination. Blood and cerebrospinal fluid lactate and pyruvate levels were elevated. Biochemical studies on a muscle biopsy specimen revealed partial deficiency of Complex I activity, and decreases in the 75-kDa and the 20-kDa subunits of Complex I by immunoblotting analysis. Serial brain CT scans revealed multiple low-density areas with fluctuating densities. Single photon emission tomographic study revealed preservation of blood circulation where CT scans showed diminished density in acute stage, suggesting the presence of abnormal cellular metabolism rather than vascular occlusion as the basic mechanism of his stroke-like episodes. Pathogenesis of neurological manifestations in MELAS is discussed with reference to the possible involvement of free radicals in inducing brain damage.
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PMID:Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes with special reference to the mechanism of cerebral manifestations. 251 13

This study reports a case of MELAS with epileptic seizure, and reviews the characteristics of seizures in patients with this syndrome. They are characterized by: (1) generalized and/or partial seizures, (2) frequent association with visual symptoms and hemiparesis, and (3) posteriorly predominant EEG abnormalities.
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PMID:Epileptic seizures in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and strokelike episodes (MELAS). 251 71

We report a 9 year-old boy with MELAS. High dosed oral thiamine administration and high fat diet induced remarkable neurological and biochemical improvement. His mother had episodic headaches and hemiplegia, probably MELAS. He complained muscle weakness and repeated episodes of vomiting started from 2 years of age. High levels of serum lactate and pyruvate were recognized, but with no metabolic acidosis. He developed generalized muscle weakness, growth retardation, generalized convulsions and stroke-like episodes at 5 years old. Optic nerve atrophy and mental retardation gradually appeared. A muscle biopsy at 5 years old revealed numerous ragged-red fibers with excess accumulation of lipid droplets and glycogen particles. Scattered fibers had no cytochrome c oxidase (CCO) activity representing focal CCO deficiency. An electron microscopy showed markedly increased number of giant mitochondria filled with markedly proliferated complicated cristae. Pyruvate dehydrogenase complex level in the fibroblasts was within normal ranges. Serum carnitine level was normal. With oral administration of thiamine hydrochloride (1000 mg) and high fat diet (60-70%), muscle weakness improved, and lactate and pyruvate levels in the serum reduced to normal ranges, whereas the mental deterioration, muscle atrophy, pes cavus progressed very slowly. He died from cardiac and renal failures at 9 years old. Autopsied muscles showed a marked decrease in cytochrome c oxidase activity (biochemically 12.8% of the normal level), and almost all muscle fibers had no cytochrome c oxidase activity histochemically. The progression of the MELAS was probably in parallel with the decrease in CCO activity.
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PMID:[A case of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) with progressive cytochrome c oxidase deficiency]. 255 13

The case of 12 years-old boy with seizures, headache, severe vomit and focal neurological signs is reported. These episodes had several recurrences and regression with little neurologic deficits. In the investigation it was found: lactic acidosis; stroke like episodes and calcification in the basal ganglia on computerized axial tomography; ragged red fibers on muscle biopsy and decreased of cytochrome C oxidase in the muscle tissue. A revision about mitochondrial disorders with involvement of the central nervous system and muscle is made, with emphasis on diagnosis and recognition of MELAS.
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PMID:[MELAS (mitochondrial encephalopathy, lactic acidosis and stroke-like episodes): report of a case]. 283 Aug 68

Identical twins developed myoclonic epilepsy in their teens. One twin remained mildly affected but the other went on to develop sensorineural deafness and ataxia with lactic acidosis and ragged red fibres leading to a diagnosis of mitochondrial encephalopathy. Multiple stroke-like episodes with hemiparesis followed, indicating progression from a MERRF to a MELAS phenotype. Biochemical studies revealed a severe deficiency of mitochondrial NADH-ubiquinone reductase and a moderate deficiency of cytochrome aa3. Western immunoblotting experiments using polyclonal antibodies raised against human placental cytochrome oxidase identified a similar profile of bands to those seen in controls, supporting the view that cytochrome aa3 deficiency in this case may be a secondary consequence of a failure of assembly related to a severe proximal respiratory chain defect.
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PMID:Progression from MERRF to MELAS phenotype in a patient with combined respiratory complex I and IV deficiencies. 285 17

Muscle biopsy specimens from two patients with MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes) were studied biochemically. 14CO2 production rates from (1-14C)pyruvate, (U-14C)malate, and (1-14C)2-ketoglutarate were all decreased in intact mitochondria in both patients. Rotenone-sensitive NADH cytochrome c reductase activities were decreased to 8% (patient 1) and 6% (patient 2) of control values; succinate cytochrome c reductase and cytochrome c oxidase values were within normal limits. These results indicate that both patients have a defect of NADH-CoQ reductase of the respiratory chain and that MELAS can be brought about by a defect of NADH-CoQ reductase.
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PMID:Two cases of NADH-coenzyme Q reductase deficiency: relationship to MELAS syndrome. 310 Jul 53


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