From Ask Dr Wiki
Thyrotropic insufficiency, also known as thyrotrophic insufficiency or thyrotropic deficiency, is partial insufficiency of the anterior pituitary or the respective component of total hypopituitarism, where deficient thyrotropin secretion leads to anderstimulation of the thyroid gland with consecutive secondary hypothyroidism.
Depending from severity the following types are differentiated:
- partial thyrotropic insufficiency with residual pituitary function:
- complete thyrotropic insufficiency (TSH and FT4 reduced).
Thyrotropic insufficiency may be caused by the following disorders:
- Pituitary apoplexy
- Pituitary adenoma
- Pickardt-Fahlbusch syndrome
- Hypothalamic damage (with consecutive tertiary hypothyroidism)
- Craniocerebral injury
Treatment relies on substitution with thyroxine. However, the substitution dose is adjusted in dependence from FT4 levels and not (as usual in primary hypothyroidism) from TSH levels.