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Approach to myopathy. Dr omid yaghini. MUSCLES DISORDERS. Definition: Diseases involving the muscle fibers (myogenic) Unlike: neuronopathies : secondary to LMN Heterogenous etiology, genotype, phenotype… No specific treatment for most of them.
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Approach to myopathy Dromidyaghini
MUSCLES DISORDERS Definition: • Diseases involving the muscle fibers (myogenic) • Unlike: neuronopathies: secondary to LMN • Heterogenous etiology, genotype, phenotype… • No specific treatment for most of them
ETIOLOGY / CLASSIFICATION • Inherited myopathies • Muscular dystrophies • Congenital myopathies • Inherited channelopathies • Periodic paralysis • Inherited metabolic myopathies Disorders of glycolysis Disorders of oxidative metabolism Lipid myopathies Mitochondrial myopathies
Acquired myopathies Inflammatory myopathies Acquired metabolic myopathies Toxic myopathies
Weakness • Constant fluctuation • Longlife acquired MG periodic P • metabolic • Progressive static • Dystrophy congenital
muscular dystrophy • are inherited myopathy characterized by progressive muscles weakness °eneration &subsequent replacement by fibrous & fatty connective tissue • Historically were categorized by their: • Age onset /distribution of weakness& pattern of inheritance • The genetic mutation &abnormal gene product were defined for many of them
Congenital myopathy • Are distinguished from dystrophy in threerespect: • Characteristic morphologic alteration • At birth • Non progressive • However there are exception to all these generalization • Inheritance: are variable
c/p: hypotonia with subsequent developmental delay • Reduce muscles bulk, slender body build &long narrow face • Skeletal abnormalities: high arched palate ,pectus exacavitum, kyphscliosis, dislocated hip, pes cavus) • Absent or reduced muscle stretch reflex • Weakness: limb girdle mostly, but distal weakness exist • CK &EMG may be normal • Muscle biopsy: the diagnostic method
Metabolic myopathy • Glucose/glycogen metabolism • Fattay acid metabolism • mitochondrial
Gowers' Sign “Climbing up himself”
Gowers’ sign always denotes proximal muscle weakness
Common Features: Clinical: Muscle weakness: main feature Gower’s sign (proximaly dominating deficit) Contractures +/- severe: advanced stages Pain: in inflamm. Disorders only Atrophy (+/- pseudohypertrophy in X-linked) Deformity: advanced disease DTR: normal, diminished or absent Tone: slightly or normal Other systems may be involved
Common Features: Laboratory Investigations: • CBC, LFT.. Normal • ESR: high in inflammatory only • U&E: abnormalities in some endocrinopathies and periodic paralysis • C.K & aldolase: generaly: raised (normal in few sittings: metabolic, endocrine…) • Lactic acid • Genetic study: location & type of chromozomal abnormalities:
Common Features: Neurophysiology • NCS: normal • EMG: • Spontaneous activities +/- in inflammatory disorders • Interferential tracing • MUPs: small A Short D • polyphsics