DISORDERS OF THE THYROID GLAND · 2019-03-20 · DISORDERS OF THE THYROID GLAND HYPOTHYROIDISM &...
Transcript of DISORDERS OF THE THYROID GLAND · 2019-03-20 · DISORDERS OF THE THYROID GLAND HYPOTHYROIDISM &...
DISORDERS
OF THE THYROID
GLANDHYPOTHYROIDISM
& THYROTOXICOSIS
PHYSIOLOGY
• NORMAL DAILY INTAKE FOR IODINE150 – 200 μg
• Incorporation of iodide into tyrosine1 m. J → 3-monoiodotyrosine – MIT2 m. J → 3,5-diiodotyrosine – DIT
• Coupling reactions: MIT + DIT = T3
DIT + DIT = T4
• T3 and T4 are binded to thyroglobulin (Tg)
• In bloodstream T3 and T4 are also binded to albumins (1:1000), active are only free forms fT3 i fT4
• Regulation by TSH and TRF
HYPOTHYROIDISMHYPOTHYREOSIS
•
THYREOGENIC (PRIMARY)
the most frequent
PITUARY (SECONDARY)
consequence of insufficiency of pituary gland
• Prevalence –inborn1:5000 of newborns
• Etiology : lack of the gland, dysplasia of the
gland, defect of synthesis or secretion
HYPOTHYREOSISsymptoms in adults
• Reduced energy level, tiredness, weakness, apathy,
• Cold intolerance
• Dry skin, brittle hair, loss of hair, nonpitting odema of the skin
• Deeping of the voice
• Inotropic and chronotropic effect on heart
• Accerelation of development of atherosclerosis (CAD) - hypercholesterolemia
• In elder patients – symptoms are milder
LABORATORY DIAGNOSTICS
• ↑ TSH > 4 m.U./ l
• ↓T4
• antibodies against thyreoglobulins – in
autommune thyroiditis
• scyntygraphy – reduced uptake of
radioisotope by thyroid gland
Myxedema
Examination
of thyroid gland
TREATMENT
• Substitution L-T4
• Gradually: increase of the dose for 25 μg
every 1 – 2 weeks
• TSH – regular control during the treatment
THYROTOXICOSIS
HYPERTHYREOSIS
-autoimmune disorder: thyroid gland stimulating factors (immunoglobulins) Graves’ Disease
-single functionating nodule(s) is/are autonomous Plummer’s Disease
-Hashimoto’s thyroiditis
-iatrogenic
HYPERTHYREOSIS – signs & symptoms
• goiter (90%pts)
• Ophtalmopathy
• Increased contractility of heart, rapid HR, AF
• Nervousness, irritability, problems with concentration
• Sleeplessness
• Tremor
• Weight loss & increased apetite
• Soft, smooth, atrophic, warm skin
• Sweating, hypertermia
• Loose stools / mild diarrhoe
HYPERTHYREOSIS
– diagnostics
• fT3 ↑↑↑ (~100%)
• fT4 ↑↑↑ (~90%)
• TSH ↓
• Ultrasonography
• Scintigraphy
Thyroid gland in sonographyA-normo-B-hyper- & hypo-C-hypo-D-hypo-echogenic areaswith calcifications
Scintygraphy of thyroid gland
HYPERTHYREOSIS – treatment
• Pharmacological: methimazole,
propylotiouracyl Side effects: agranulocytosis,
cholestasis
• Surgical
• Radioactive iodine