Critical Care Medicine-Endocrine Disorders>>>>>Thyroid
Question 4#

A 78 year-old female is admitted to the ICU with a 6 month history of generalized fatigue and muscle cramps, which are worsened with exercise. Her symptoms have been progressively worsening and now she is unable to ambulate. On physical examination, pressure stimulus on the muscles of the arm leads to formation of a palpable, painless ridge around the site of the stimulus, which subsides gradually returning the muscle contour to normal in a few seconds. She is also noted to have delayed deep tendon reflexes and anasarca. Her laboratory studies are within normal limits, except for an elevated TSH level.

Which of the following is most likely the cause of her symptoms?

A. Recent influenza vaccine
B. Recent CVA
C. Multiple sclerosis
D. Muscular dystrophy
E. Chronic hypothyroidism

Correct Answer is E


Correct Answer: E

Hypothyroid myopathy is a complication of untreated or uncontrolled hypothyroidism. Although most cases are not clinically significant, severe cases can lead to muscle disease and functional limitations. The exact mechanism is not understood; however, it is believed to be related to intracellular changes secondary to decreased T4 levels. T4 deficiency leads to reduced mitochondrial oxidative capacity, abnormal glycogenolysis, and an insulin-resistant state of the cell causing selective atrophy of type 2 muscle fibers (fast-twitching type), which leads to slowing of muscle contraction seen clinically in patients with hypothyroidism.

“Myoedema” is characteristic of hypothyroid myopathy. It is demonstrated by percussion or a pressure stimulus on the muscles of the arm, which causes the muscle to form a palpable, painless ridge around the site of the stimulus. The swelling subsides gradually returning the muscle contour to normal in a few seconds. This is believed to be caused by prolonged muscle contraction due to delay in calcium reuptake by the sarcoplasmic reticulum after the stimulus causes local calcium release. This sign if elicited can help differentiate hypothyroid myopathy from other types of myopathies. 

Four main types of myopathies are associated with hypothyroidism: Myasthenic syndrome, Atrophic form, Kocher-Debre-Semelaigne, and Hoffman syndrome. Hoffmann syndrome is usually seen in adults and characterized by pseudohypertrophy, painful spasms, proximal muscle weakness, and stiffness. Management of hypothyroidism is the mainstay of treating hypothyroid myopathy. It is reversible with timely diagnosis and prompt treatment.


  1. Fariduddin MM, Bansal N. Thyroid, hypothyroid myopathy. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; January 2018. Updated August 15, 2018. Available from
  2. Bloise FF. Oliveira TS, Cordeiro A, Ortiga-Carvalho TM. Thyroid hormones play role in sarcopenia and myopathies. Front Physiol. 2018;9:560.