Thyroid hormone replacement in central hypothyroidism

Central hypothyroidism (CH) is a defect of thyroid hormone production due to an insufficient stimulation by thyrotropin (TSH) of an otherwise normal thyroid gland. Hypothyroidism is the most prevalent endocrine dysfunction, but CH is rare accounting for a small portion of hypothyroid patients. CH can affect patients of all ages with no sexual preference. The prevalence of CH can be estimated at 1:20,000 in the general population. Large tumors of the sella region represent the major cause of CH. Hypothyroid state is usually mild to moderate and manifestations are frequently masked by concomitant defects of other pituitary hormones. Treatment of CH takes advantage of thyroid hormone replacement. Nevertheless treatment cannot be is easily tuned as in primary hypothyroidism because the evaluation of circulating TSH levels has a very limited value in central defects In this paper, various clinical and pathogenic aspects of central hypothyroidism are critically presented and discussed. A particular emphasis is given to tools and methods for an adequate treatment.