1/183. adult-onset MELAS presenting as herpes encephalitis.OBJECTIVE: To report an unusual presentation of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) manifested in late life with a clinical picture of herpes simplex encephalitis. DESIGN: Case report. SETTING: Clinical neurology department in a tertiary care hospital. CASE DESCRIPTION: A 55-year-old woman developed aphasia and delirium during ophthalmic herpes zoster infection treated with oral prednisone and ophthalmic steroids, which was followed by progressive cognitive decline without acute neurologic events for 5 years. At age 60, the patient presented with new onset of seizures, hemiparesis, and hemianopsia. Subsequently she developed cortical blindness, multiple traumatic soft tissue injuries from falls, acute psychosis, and severe dementia with periods of agitation. She died in a nursing home in March 1997, 6 years after initial presentation. RESULTS: magnetic resonance imaging scan of the brain showed hyperintensity on T2-weighted images involving temporal, parietal, and occipital lobes bilaterally as well as mild atrophy of brainstem and cerebellum. Single photon emission computed tomographic imaging showed hypoperfusion of temporal, parietal, and occipital lobes. Results of video electroencephalographic monitoring showed periodic lateralizing epileptiform discharges in temporal and occipital areas. The serum lactate level was normal in May 1996 and elevated in October 1996. The creatine kinase level was elevated with a 100% MM fraction in August 1991 and normal in March 1996. Results of repeated cerebrospinal fluid analyses indicated elevated protein levels. Analysis of dna was diagnostic of MELAS by mitochondrial dna point mutation at position 3243. The results of autopsy showed moderate cerebral, cerebellar, and brainstem atrophy with signs of infarction in temporal and parietal lobes bilaterally. CONCLUSIONS: The clinical presentation as well as age at onset of MELAS are highly variable. Onset of mitochondrial disorders can be provoked by febrile illness when there is mismatch between energy requirements and availability. In the differential diagnosis of herpes encephalitides, melas syndrome should be considered.- - - - - - - - - - ranking = 1keywords = myopathy (Clic here for more details about this article) |
2/183. Serial electroencephalographic findings in patients with MELAS.To clarify the electroencephalographic characteristics of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS), the medical records and electroencephalograms of six patients with MELAS and two of their relatives with MELA (mitochondrial myopathy, encephalopathy, and lactic acidosis, without strokelike episodes) were retrospectively reviewed. All have a point mutation in the mitochondrial dna at nucleotide position 3243. The electroencephalograms (n = 79) were divided into four groups according to the time relation to the strokelike episode: (1) before the first strokelike episode, (2) within 5 days after the strokelike episode (acute stage), (3) between 6 days and 1 month after the strokelike episode (subacute stage), and (4) more than 1 month after the strokelike episode (chronic stage). In the acute stage, 10 of the 11 electroencephalograms (9 strokelike episodes in four patients) revealed focal high-voltage delta waves with polyspikes (FHDPS), which were recognized as ictal electroencephalogram. Ictal events during FHDPS included focal clonic or myoclonic seizure and migrainous headache. In the subacute and chronic stages, focal spikes or sharp waves and 14- and 6-Hz positive bursts were frequently recorded. The authors' results suggest that FHDPSs present a reliable and accurate indicator of a strokelike episode in patients with MELAS.- - - - - - - - - - ranking = 2keywords = myopathy (Clic here for more details about this article) |
3/183. Effect of coenzyme Q10 in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS): evaluation by noninvasive tissue oximetry.We evaluated the effect of coenzyme Q10 supplementation to two patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) by using noninvasive tissue oximetry with near-infrared spectra of hemoglobin from the quadriceps muscle during bicycle ergometer exercise. patients showed distinct oxygen consumption patterns reflecting the defect in oxidative phosphorylation and the impairment in oxygen utilization during exercise. Based on the oxygen consumption pattern, we considered one patient as having severe mitochondrial disorder and another patient as having mild one. After coenzyme Q10 supplementation, the oxygen consumption pattern of the patient with the severe form shifted to the mild one, while that of the patient with mild form remained unchanged. The shift of the pattern to the mild form correlated well with reduction of the sum of the serum lactate and pyruvate content during exercise. Noninvasive tissue oximetry may be useful to evaluate the effect of coenzyme Q10 supplementation to patients with mitochondrial encephalomyopathy including MELAS.- - - - - - - - - - ranking = 6keywords = myopathy (Clic here for more details about this article) |
4/183. MELAS with prominent white matter gliosis and atrophy of the cerebellar granular layer: a clinical, genetic, and pathological study.This report concerns an autopsy case of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) with unusual neuropathological findings. The patient was a Japanese woman who was 21 years old at the time of death. Her mother is a patient with genetically confirmed MELAS. Her clinical manifestations included convulsions and lactic acidosis in the latter half of the first decade of life, followed by deafness, dementia, muscle weakness in the lower extremities, slight ataxia in the upper and lower extremities, and diabetes mellitus. Muscle biopsy revealed ragged-red fibers, and genetic study showed a point mutation at nucleotide pair 3243 in mitochondrial dna. She died of lactic acidosis. In the clinical course, she did not develop stroke-like episodes. The neuropathological examination revealed not only minute to small necrotic foci in the cerebral cortex, amygdala, hippocampus, and cerebellum, but also prominent white matter gliosis in the central nervous system and cerebellar cortical degeneration of granular cell type. Our neuropathological findings, including prominent white matter gliosis of the central nervous system and cerebellar cortical degeneration of granular cell type, may indicate morphologically widespread cellular dysfunction, not restricted to either neuronal or vascular derangement, in the brain pathology of MELAS.- - - - - - - - - - ranking = 1keywords = myopathy (Clic here for more details about this article) |
5/183. The mitochondrial dna A3243G mutation in portugal: clinical and molecular studies in 5 families.Out of 90 Portuguese patients with mitochondrial cytopathy, six harbored the A3243G mutation in the mtDNA tRNA(Leu(UUR)) gene ('MELAS mutation'). They had heterogeneous clinical features, including myopathy with stroke-like episodes, progressive external ophthalmoparesis, diabetes mellitus, and subacute encephalopathy. Histochemical and biochemical analyses of muscle biopsies showed abundant ragged-red fibers reacting positively with the cytochrome oxidase stain, and decreased respiratory chain enzyme activities. On average, the proportion of mutated mtDNA was 67% (20-88%) in tissues from patients and 21% (0-49%) in blood from 20 maternal relatives. The proportion of mutated mitochondrial genomes in muscle did not correlate with clinical presentation or duration of disease. This study, the first in Portuguese patients, confirms the frequent occurrence of the A3243G mutation in patients with mitochondrial diseases, and emphasises the usefulness of genetic testing in reaching a correct diagnosis.- - - - - - - - - - ranking = 1keywords = myopathy (Clic here for more details about this article) |
6/183. Flow cytometric evaluation of defects of the mitochondrial respiratory chain.Cultured human skin fibroblasts from 12 patients with a variety of mitochondrial respiratory chain defects were examined for their capacity to oxidize dihydrorhodamine-123 to the fluorescent molecule rhodamine-123 using a flow cytometer. We found that cells from patients with functional defects in respiratory chain enzymes were less able to oxidize dihydrorhodamine-123 than those of healthy controls. Ten of the cell strains had reduced activity in at least one of the respiratory chain complexes and also showed significantly reduced fluorescence when compared to the mean of eight normal control cell strains. One patient had mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (with the A3243G mutation) and reduced respiratory chain activities in muscle and liver. Molecular analysis did not show the mutation in cultured skin fibroblasts, and had correspondingly normal fluorescence. The 12th cell strain showed reduced fluorescence but did not reach statistical significance. This strategy could be of use in helping direct further investigations in patients, and in studying the biochemical pathogenesis of mitochondrial dna mutations in cybrid studies.- - - - - - - - - - ranking = 1keywords = myopathy (Clic here for more details about this article) |
7/183. skin manifestations of a patient with mitochondrial encephalomyopathy with lactic acidosis and strokelike episodes (melas syndrome).skin abnormalities in a patient with newly diagnosed melas syndrome are reported. He presented with scaly, pruritic, diffuse erythema with reticular pigmentation on his entire body. Moderate hypertrichosis was also noted on the lower extremities. Thickened arrector muscles with longitudinal and cross sections were seen in the dermis. Analysis of mitochondrial dna in a biopsy specimen from the biceps brachii disclosed the presence of an A-to-G point mutation at nucleotide pair 3243. Electron microscopy revealed marked increase in the number of morphologically abnormal mitochondria in the arrector muscles of the involved skin. This is the first report of a melas syndrome patient with skin manifestations and evidence of morphologically abnormal mitochondria.- - - - - - - - - - ranking = 4keywords = myopathy (Clic here for more details about this article) |
8/183. Renal complications in patients with diabetes mellitus associated with an A to G mutation of mitochondrial dna at the 3243 position of leucine tRNA.The substitution of guanine for adenine at position 3243 of the leucine tRNA gene of mitochondrial dna was originally described in association with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes). diabetes mellitus associated with the mutation (mitochondrial diabetes) is a different phenotype from MELAS. We identified 11 patients with the mutation among 385 Japanese diabetic patients: two had MELAS and nine had mitochondrial diabetes. We present data on a male patient with mitochondrial diabetes who developed the nephrotic syndrome at the age of 23. light microscopy revealed mesangial expansion, PAS-positive deposits and segmental sclerosis in the glomeruli. Scattered mesangial electron-dense deposits and thickening of the basement membrane were found on electron microscopy, suggesting that diabetic glomerulosclerosis accompanied by focal glomerulosclerosis (FGS). Mitochondrial diabetes may pre-dispose patients to renal complications, including forms of glomerulonephritis, such as FGS.- - - - - - - - - - ranking = 1keywords = myopathy (Clic here for more details about this article) |
9/183. Mitochondrial maculopathy: geographic atrophy of the macula in the MELAS associated A to G 3243 mitochondrial dna point mutation.PURPOSE: To report ocular findings in the mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (melas syndrome) in a family with the A to G 3243 mitochondrial (mt) dna point mutation. methods: case reports. Ocular findings are described from four family members with the MELAS associated A to G 3243 mt dna point mutation. RESULTS: Findings included ophthalmoplegia, neurosensory deafness, reduction of photopic and scotopic electroretinogram b-wave amplitudes, and myopathy, as well as macular retinal pigment epithelial atrophy. No family members had nyctalopia, attenuation of retinal blood vessels, or retinal bone spicule pigmentation. CONCLUSION: The finding of slowly progressive macular retinal pigment epithelial atrophy expands the reported phenotypic diversity of patients with A3243G mt dna mutations.- - - - - - - - - - ranking = 2.0603942815596keywords = myopathy, ophthalmoplegia (Clic here for more details about this article) |
10/183. prevalence of macular pattern dystrophy in maternally inherited diabetes and deafness. GEDIAM Group.OBJECTIVE: To evaluate the prevalence of macular pattern dystrophy (MPD) in maternally inherited diabetes and deafness (MIDD), a new subtype of diabetes mellitus that cosegregates with a mutation of mitochondrial dna (i.e., the substitution of guanine for adenine at position 3243 of leucine transfer rna) and to report the clinical characteristics of MPD. DESIGN: Prospective cohort study. PARTICIPANTS: Forty-six patients from 29 families with an adenine-to-guanine mutation of mitochondrial dna were recruited from a French collaborative multicenter study. Thirty-five patients had MIDD, 8 were asymptomatic children of MIDD patients, and 3 had melas syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes). The 33 MIDD patients with diabetes were matched for diabetes duration and gender with 33 patients with "common" type-2 diabetes to compare the prevalence of diabetic retinopathy (DR) in both series. methods: All patients had a full ophthalmologic examination and fundus photographs. MAIN OUTCOME MEASURES: The presence and severity of MPD and DR were assessed in each patient. RESULTS: Thirty MIDD patients (85.7%) of 35 exhibited bilateral MPD characterized by linear pigmentation surrounding the macula and optic disc. In 24 of these 30 patients, visual acuity was 20/25 or more in both eyes. The prevalence of DR was 6% in MIDD patients with diabetes versus 15% for patients with common type-2 diabetes (a difference that was not significant, P = 0.23). The fundus of each of the eight asymptomatic children was normal. MPD was present in one of the three cases of MELAS. CONCLUSION: The prevalence of MPD in MIDD is high. Its detection may be helpful for the diagnosis of this new subtype of diabetes, for which specific treatments may be proposed.- - - - - - - - - - ranking = 1keywords = myopathy (Clic here for more details about this article) |
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