[Hypothyroid hypertrophic myopathy in adults related to chronic lymphocytic thyroiditis. A case].

The authors report a case of hypothyroid hypertrophic myopathy which reveal chronic lymphocytic thyroiditis. This entity est uncommon, can be the most important sign of hypothyroidism and cure after the institution of thyroid hormone replacement therapy. The E. M. G. is usually myopathic and serum muscle markers (myoglobin and enzymes) increased. Pathologic studies of muscle show caracteritic but non specific and inconstant abnormalities. Hypothyroid myopathy could be caused by a mitochondrial oxidative phosphorylation deficiency or changes in muscle contractile properties (both in fibre type proportion and in the properties of the muscle contractile proteins).