Myopathy

B9402040 許瑜真

Myopathy

• Inflammatory disorders• Endocrine disorders• Electrolyte disorders• Metabolic myopathies• Drugs and toxins• Infections • Rhabdomyolysis

Myositis (Inflammatory disorders)

• 會出現 systemic rheumatic disease的症狀– scleroderma– systemic lupus erythematosus

• Muscle biopsy • “Myositis specific" antigens– Ex. anti-histidyl-t-RNA synthase [anti-Jo-1]

Endocrinopathy (Endocrine disorders)

• Hypothyroidism• Cushing's syndrome (or exogenous steroid

administration)

Electrolyte disorders

• Hypokalemia• Hypophosphatemia• Hypocalcemia• Hypernatremia or hyponatremia

Metabolic myopathy

• Recurrent episodes of exertion-related pigmenturia and weakness

• Slowly progressive rather than episodic course• Muscle biopsy – Special stains can demonstrate enzyme

deficiencies and abnormal accumulations of glycogen or lipid

Drug-induced myopathy

• Medication, alcohol, or substance-abuse

Infections

• Viral– influenza, parainfluenza, Coxsachie, HIV,

cytomegalovirus, echovirus, adenovirus, Epstein Barr virus

• Bacterial– pyomyositis, lyme myositis

• Fungal• Parasitic– trichinosis, toxoplasmosis

Rhabdomyolysis

• Serum muscle enzymes– creatine kinase >100,000 IU/L– aldolase, lactate dehydrogenase, and the

aminotransferases• Myoglobinuria– urine blood (+)– RBCs in the sediment (-)

• Electrolyte abnormalities• Acute renal failure