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Thyroid storm rare condition, with a mortality of 10%, is a rapid deterioration of hyperthyroidism with hyperpyrexia, severe tachycardia and extreme restlessness. Thyroid storm is usually precipitated by stress, infection, surgery in an unprepared patient, or radioiodine therapy.
With careful management it should no longer occur and most cases referred as 'crisis' are simply severe but uncomplicated thyrotoxicosis.
Treatment of Thyroid storm
Treatment is urgent. Propranolol in full doses is started immediately together with potassium iodide, antithyroid drugs, corticosteroids (which suppress many of the manifestations of hyperthyroidism) and full supportive measures.
Hyperthyroidism
Thyroid hormone resistance
Thyroid hormone resistance is an inherited condition caused by an abnormality of the thyroid hormone receptor. Mutations to the receptor result in the need for higher levels of thyroid hormones to achieve the same intracellular effect.
As a result, the normal feedback control mechanisms result in high blood levels of thyroxine with a normal TSH in order to maintain a euthyroid state. This has two consequences:
- First, thyroid function tests appear abnormal even when the patient is euthyroid and requires no treatment; this is not a particular problem as free T 4 and TSH levels are measured.
- Second, different tissues contain different thyroid hormone receptors and, in some families, receptors in certain tissues may have normal activity.
In this case the level of thyroid hormones to maintain euthyroidism at pituitary and hypothalamic levels (which controls secretion of TSH) may be higher than that required in other tissues such as heart and bone, so that these tissues may exhibit 'thyrotoxic' effects in spite of a normal serum TSH. This 'partial thyroid hormone resistance' can be very difficult to manage effectively.
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