Congenital hypothyroidism is one of the commonest preventable causes of mental retardation is also the most common congenital endocrine disorder of childhood. The subtlety of clinical features and protective effect of the maternal hormone on fetal brain after crossing the placenta mask the clinical features. The incidence varies from 1 in 4000 to 1 in 1000 in newborn infants in various parts of world and is increasing worldwide. Thyroid agenesis remains the most common etiology of CH and other causes are dyshormonogenesis, defects in peripheral thyroid hormone transport, metabolism, or action. CH is usually diagnosed after neonatal screening tests and if treatment started with in few weeks of birth neurodevelopmental outcome is usually normal. Levothyroxine (T4) remains the treatment of choice as most brain T3 is derived from local monodeiodination of T4 and studies have shown normal serum level of T3 in infant treated with T4 alone.
Part of the book: Thyroid Disorders
Multinodular goiter (MNG) is the most common disorder of the thyroid gland. It is highly endemic in iodine-deficient areas; MNG can be seen in almost all individuals with severe iodine-deficient areas. It starts as a diffuse enlargement of the thyroid gland and ends in a nodular enlarged thyroid. Though MNG can be sporadic, there is a strong correlation between occurrence of MNG and iodine deficiency. The characteristic feature of MNG is its functional and structural heterogeneity. The MNG usually presents as neck swelling; rarely it may produce pressure symptoms, i.e., dyspnea, hoarseness of voice, and dysphagia. It can also present with symptoms of hyperthyroidism particularly in long-standing goiter. Imaging particularly ultrasound is very useful to define characteristic of MNG and surrounding structure. The incidence of malignancy in MNG is 4–14%, and risk factors are family history of thyroid carcinoma, history of neck radiation, prior surgery, and presence of cervical lymphadenopathies. Management of MNG can be done by drugs, surgery, and radioiodine (I-131) depending on results of diagnostic evaluation and associated complications.
Part of the book: Goiter
Graves’ disease (GD) is an autoimmune disorder characterized by presence of TSH receptor autoantibody. It is most common cause of hyperthyroidism worldwide. Though GD can occur any age but peak incidence is seen during adulthood in between 20 to 50 years of age. GD is more commonly seen in female. GD is primarily disease of thyroid gland but affects multi organ system i.e. heart, liver, muscle, eye and skin. Symptoms and signs are result from hyperthyroidism or a consequence of underlying autoimmunity. Weight loss, fatigue, heat intolerance, tremor, and palpitations are the most common symptoms. Diffuse goiter presents in most of younger patients with thyrotoxicosis but less common in older patients. Graves’ ophthalmopathy and pretibial myxedema are extrathyroidal manifestations of GD which results from action of TSHR autoantibodies on TSHR present onfibroblast, adipocyte and T cells in extrathyroidal tissue. Treatment of GD remains in between antithyroid drugs, radioiodine or surgery. In this review we discuss the diagnosis and management of GD.
Part of the book: Graves' Disease