ABSTRACT
Objective To study the clinical, laboratorial, histopathological, imaging features of two cases of hypothyroid myopathy. Method Clinical manifestations, thyroid function, electromyography, muscle MRI, muscle biopsy and follow-up results were collected, and analyzed with the literature. Result These two patients were middle-age to old age and the onset of disease was insidious. Their common clinical manifestations included subacute progressive weakness in the proximal muscles,myalgia after sports and reduction in tendon reflex.The blood test showed an increase in serum concentration of CK and TSH, and a decrease in FT3 and FT4. The electromyography showed suspicious myogenic damage.Muscle histopathological findings were largely nonspecific,such as type I fiber predominance and type 2 atrophy. The MRI revealed extensive muscular dystrophy and fatty filtration in the posterior group of thighs. Treatment of replacement therapy with L-T4 relieved the myopathic symptoms quickly. Conclusion When a patient presents with a subacute progressive weakness in the proximal muscles, the hypothyroidism should be consideration. Muscle histopathological findings may be nonspecific. The muscle MRI have a value of differential diagnosis and lesion assessment.