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Query: UMLS:C0027121 (myositis)
 4,538 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The notion of a "myopathic" or "neuropathic" electromyogram (EMG) is usually based on qualitative visual and acoustical impressions. Conventional quantification defines abnormality but not diagnosis, which requires interpretation of patterns of change. Discriminant analysis is a model for this multivariate decision. It tells how probable it is that a motor unit potential (MUP) comes from a normal, myopathic, or neuropathic muscle. Accumulation of single MUP information by a sequential Bayesian algorithm produced diagnostic probabilities above 0.95 in 91% of all muscles (223 biceps brachii muscles from 80 patients with motoneuron disorders, 56 patients with neuropathies, 71 patients with myopathies, and 34 controls). Two muscles from patients with neurogenic disorders were misclassified as "myopathic." Misclassification was more frequent only in myositis (4 of 28 muscles) and in oculopharyngeal muscular dystrophy (2 of 4 muscles). MUP discriminant classification was as sensitive as, and more specific than, conventional quantitative EMG, which discriminated between myopathic and neuropathic in only 22% of the muscles. This rate was 59% for discriminant analysis. As a knowledge-based expert system, MUP discriminant analysis successfully distinguishes between myopathic, neuropathic, and unclassifiable MUP samples. It discloses more information than conventional quantitative MUP analysis.
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PMID:The diagnostic power of motor unit potential analysis: an objective bayesian approach. 1033 57

Hypertrophy of the cricopharyngeal muscle is a serious clinical condition that can cause severe dysphagic symptoms, including prolonged deglutition and postdeglutitive aspiration. Although the therapeutical concepts are well established, the pathogenic mechanism of cricopharyngeal hypertrophy remains unclear. We present a patient with a ten-year history of progressive dysphagia. The neurological and MRI findings were normal. However, videocineradiography showed severe hypertrophy of the cricopharyngeal muscle. This condition was first treated by injections of botulinum toxin, which did not alleviate the symptoms. Next, myotomy and muscle biopsy were performed. Histological evaluation disclosed lymphoplasmacellular florid myositis, single-fiber atrophy, and muscle fiber necrosis with phagocytosis. There were no signs of inclusion body myositis or oculopharyngeal muscular dystrophy. Our finding of severe cricopharyngeal muscle hypertrophy associated with myositis has been published previously (n = 34). The study presented here shows cricopharyngeal dysphagia associated with various systemic diseases, including motor neuron disease, general granulomatous disease, dermatomyositis, or inclusion body myositis. Isolated changes of the cricopharyngeal muscle were described in 65% of the cases.
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PMID:Cricopharyngeal muscle hypertrophy associated with florid myositis. 1172 Mar 99

The diagnosis of mitochondrial myopathy depends upon a constellation of findings, family history, type of muscle involvement, specific laboratory abnormalities, and the results of histological, pathobiochemical and genetic analysis. In the present paper, the authors describe the diagnostic approach to mitochondrial myopathies manifesting as extraocular muscle disease. The most common ocular manifestation of mitochondrial myopathy is progressive external ophthalmoplegia (PEO). To exclude myasthenia gravis, ocular myositis, thyroid associated orbitopathy, oculopharyngeal muscular dystrophy, and congenital fibrosis of the extraocular muscles in patients with an early onset or long-lasting very slowly progressive ptosis and external ophthalmoplegia, almost without any diplopia, and normal to mildly elevated serum creatine kinase and lactate, electromyography, nerve conduction studies and MRI of the orbits should be performed. A PEO phenotype forces one to look comprehensively for other multisystemic mitochondrial features (e.g., exercise induced weakness, encephalopathy, polyneuropathy, diabetes, heart disease). Thereafter, and presently even in familiar PEO, a diagnostic muscle biopsy should be taken. Histological and ultrastructural hallmarks are mitochondrial proliferations and structural abnormalities, lipid storage, ragged-red fibers, or cytochrome-C negative myofibers. In addition, Southern blotting may reveal the common deletion, or molecular analysis may verify specific mutations of distinct mitochondrial or nuclear genes.
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PMID:Extraocular mitochondrial myopathies and their differential diagnoses. 1676 Jan 17