Endocrine myopathies

The most commonly recognized endocrine myopathy occurs as a feature of hypothyroidism it may antedate the diagnosis of hypothyroidism by several months. Symptoms and signs of this entity range from mild aches and pains, muscle cramps, and proximal weakness to apparent muscle hypertrophy and the mounding phenomenon, or myoedema (a transient focal ridging of muscle in response to percussing or pinching the muscle). In the usual form, proximal weakness may be observed,...

Deficiency of enzymes in the glycolytic pathway

Muscle phosphorylase deficiency McArdle disease . This inherited deficiency of skeletal muscle phosphorylase is more common than acid maltase deficiency or PFK deficiency 60 cases have been reported. The female-to-male ratio is 1 4. Childhood symptoms of fatigue are usually overlooked. A characteristic pattern of exercise-induced muscle pains, stiffness, and weakness, which resolves with rest, occurs after puberty. Prolonged exercise results in severe cramps of the exerted muscles....