Diagnosis and management of MELAS

Department of Neurology, Institute of Psychiatry, King's College London, UK.
Expert Review of Molecular Diagnostics (Impact Factor: 4.27). 09/2004; 4(5):631-44. DOI: 10.1586/14737159.4.5.631
Source: PubMed

ABSTRACT Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is the most common maternally inherited mitochondrial disease. An A-->G mutation in the transfer RNA(Leu(UUR)) gene at position 3243 of the mitochondrial DNA accounts for most MELAS cases. The transient nature of the stroke-like episodes is reflected in abnormalities on neuroimaging. The cardinal laboratory abnormalities include elevated serum lactate during the acute episodes and respiratory enzyme defects in skeletal muscle. Muscle biopsy also helps confirm the diagnosis by identifying abnormal proliferation of mitochondria. Although current treatment options for MELAS are largely supportive, several therapeutic approaches have been attempted with limited success. Genetic counseling is an important component of patient management in MELAS. Newer reproductive technologies hold promise for reducing the recurrence of MELAS in subsequent generations. Advances in research into gene therapy offer hope of treatment for the future.

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    • "mmol/L), CSF lactate of 4.6 mmol/L (normal: 1.1– 2.8 mmol/L) and CSF pyruvate of 3.5 mmol/L (Normal: 0.5–1.7 mmol/L). Genetic testing confirmed the presence of the A-to-G point mutation at the 3243 position in the mitochondrial DNA, which is diagnostic for MELAS [1]. "
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    ABSTRACT: Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a rare but important cause of stroke-like symptoms which can often be missed Thambisetty and Newman 2004. We describe a case of a young male presenting with stroke-like episodes, later diagnosed with MELAS in an attempt to improve the understanding about diagnosing MELAS in the appropriate clinical context.
    07/2011; 2011:140630. DOI:10.4061/2011/140630
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    • "Stroke-like events may be reversible or permanent both from clinical and radiological points of view. These lesions may be small or large, single or multiple, usually asymmetric and their distribution does not correspond to vascular supply areas (Pavlakis et al. 1984; Hirano et al. 1992; Thambisetty and Newman 2004). In the acute stage the lesions are swollen. "
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    ABSTRACT: Brain MR imaging techniques are important ancillary tests in the diagnosis of a suspected mitochondrial encephalopathy since they provide details on brain structural and metabolic abnormalities. This is particularly true in children where non-specific neurologic symptoms are common, biochemical findings can be marginal and genetic defects may be not discovered. MR imaging modalities include conventional, or structural, imaging (MRI) and functional, or ultrastructural, imaging (spectroscopy, MRS; diffusion, DWI-ADC; perfusion, DSCI--ASL). Among them MRI and MRS are the main tools for diagnosis and work up of MD, and this review will focus mainly on them. The MRI findings of MD are very heterogeneous, as they depend on the metabolic brain defects, age of the patient, stage and severity of the disease. No correlation has been found between genetic defects and neuroimaging picture; however, some relationships between MR findings and clinical phenotypes may be identified. Different combinations of MRI signal abnormalities are often encountered but the most common findings may be summarized into three main MR patterns: (i) non-specific; (ii) specific; (iii) leukodystrophic-like. Regarding the functional MR techniques, only proton MRS plays an important role in demonstrating an oxidative metabolism impairment in the brain since it can show the accumulation of lactate, present as a doublet peak at 1.33 ppm. Assessment of lactate should be always performed on brain tissue and on the ventricular cerebral spinal fluid. As for MRI, metabolic MRS abnormalities can be of different types, and two distinct patterns can be recognized: non-specific and specific. The specific metabolic profiles, although not frequent to find, are highly pathognomonic of MD. The un-specific metabolic profiles add value to structural images in allowing to define the lesion load and to monitor the response to therapy trials.
    Bioscience Reports 07/2007; 27(1-3):69-85. DOI:10.1007/s10540-007-9046-z · 2.85 Impact Factor
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