management of hyperthyroidism

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  1. 1. Zelalem semegnew
  2. 2. Outline Physiology of thyroid gland Causes of thyrotoxicosis Clinical features of hyperthyroidism Diagnosis Management Thyroid storm References
  3. 3. Thyroid gland Wt 20-25g parts Pyramidal lobe in 50% Rt &Lt. lobe Isthmus Blood supply aa Sup. thyroid aa Inf. thyroid aa (thyrocervical trunk) Ima aa in 3% veins Sup. thyroid vv Middle thyroid vv Inf. thyroid vv
  4. 4. Thyroid hormone Characteristics Anabolic hormone Secreted in two forms : T3 and T4 Ratio to T4 to T3 : 20 to 1 T3 is more active than T4
  5. 5. Thyroid hormone synthesis Begins with iodide Iodide enters the thyroid follicular cells by active transport Thyroperoxidase catalyzes oxidation of iodide to iodine Peroxidase catalyzes iodination of thyroglobulin Iodination of thyroglobulin s tyrosine residue yields 2 products Monoiodotyrosine (MIT) Diiodotyrosine (DIT) Peroxidase also catalyzes coupling 2 DIT molecules= =T4 MIT +DIT + T3
  6. 6. Thyroid hormone regulation Steps Hypothalamus secretes TRH in to the portal system Pituitary thyrotrophs secrete TSH Thyroid gland secretes T4 and T3 Thyroid hormones act as a negative feedback to inhibit further secretion of TRH and TSH
  7. 7. Thyroid hormone Thyroid hormone function ( 4 Bs) Brain maturation Bone growth Beta adrenergic effects BMR
  8. 8. Hyperthyroidism Thyrotoxicosis symptom complex due to raised levels of thyroid hormones Hyperthyroidism Reserved for disorders that result from sustained overproduction and release of hormone by the thyroid itself. 8/22/2015managment of hyperthyroidism
  9. 9. Causes of Thyrotoxicosis
  10. 10. Graves Disease (Basedows disease) Characteristics The most common cause of thyrotoxicosis (60-80 %) auto-immune disease The most important autoantibody is Thyroid Stimulating Immunoglobulin (TSI) or TSA Others - (anti-TPO) (anti-TG) Symetrical enlargement of the thyroid Hyper secretion of thyroid hormones Patients tend to be young women
  11. 11. Toxic Multinodular Goiter(TMG) (Plummer ds) Characteristics TMG is the next most common cause of hyperthyroidism - 20% Caused by focal regions of hyper functioning follicular cells ( independent of TSH) Due to mutation of the TSH receptor Can be the result of chronic iodine deficiency Excessive TSH stimulation induces Focal hyperplasia Subsequent necrosis and hemorrhage Nodule formation Cardiovascular manifestations tend to predominate
  12. 12. Toxic Single Adenoma (TSA) (Goetschs ds) Characteristics TSA is a single hyper functioning follicular thyroid adenoma. Benign monoclonal tumor that usually is larger than 2.5 cm It is the cause in 5% of patients who are thyrotoxic Nuclear Scintigraphy scan shows only a single hot nodule TSH is suppressed by excess of thyroxines So the rest of the thyroid gland is suppressed
  13. 13. Clinical Features of hyperthyroidism It is eight times more common in females. Sex M : F ratio Graves Disease 1: 5 to 1:10 Toxic MNG 1: 2 to 1: 4 Occurs in any age group. Age Graves disease 20 to 40 Toxic MNG > 50 yrs Toxic Single Adenoma 35 to 50. Clinical features can be grouped those related to hyperthyroidism Those that are specific to Graves disease
  14. 14. those related to hyperthyroidism
  15. 15. Specific to Graves Disease 1. Diffuse painless and firm enlargement of thyroid gland 2. Ophthalmopathy Eye manifestations 50% of cases Classification of Eye Changes in Graves' Disease 0) No signs or symptoms. 1) Only signs, no symptoms. (Signs limited to upper lid retraction, stare, lid lag.) 2) Soft tissue involvement (symptoms and signs). 3) Proptosis (measured with Hertel exophthalmometer) 4) Extraocular muscle involvement. 5) Corneal involvement. 6 Sight loss (optic nerve involvement).
  16. 16. Eye Signs in Toxic Goitre In early stages, may be unilateral but later may become bilateral. Order of appearance of signs Stellwag's sign : Absence of normal blinkingso staring look. Von Graefe`s sign : Upper eye lid lags behind the eye ball as the patient is asked to look downwards. Dalrymphe's sign : Upper sclera is visible due to retraction of upper eye lid. Joffroy's sign : Absence wrinkling in the forehead on looking upwards with the face inclined downwards. Moebius sign : Inability or failure to converge the eye balls Gifford's sign: Difficulty in eversion of the upper lid.
  17. 17. Specific to Graves Disease.. 3. Thyroid dermopathy consists of thickening of the skin, particularly over the lower tibia, due to accumulation of glycosaminoglycans (pre tibial myxedema) Is usually bilateral 4. Thyroid Acropachy Thyroid acropachy is clubbing of fingers and toes in primary thyrotoxicosis.
  18. 18. diagnosis Examinations, symptoms Thyroid blood tests Thyroid function tests TSH , T4,T3 Thyrroid antibodies TSI, ANTI TPO, ANTI Tg Other nonspecific laboratory findings. low serum total, LDL, and (HDL) cholesterol concentrations normochromic, normocytic anemia Serum alkaline phosphatase
  19. 19. Diagnosis. Thyroid imaging Radionuclide imaging Size, shape & function of gland assessed Increased uptake=hot", less risk of malignancy,