Graves' Disease

Graves' Disease

1. Anatomy of thyroid gland

   • 3 surfaces
     • Anterolateral
     • Posterior
     • Medial
   • Anterior relations
     • Skin
     • Venous arch
     • Sterohyoid and sterothyroid muscles
   • Medial relations
     • Larynx and tracheal
     • Pharynx
     • esophagus
     • cricothyroid muscle
     • superior laryngeal nerve
     • Recurrent laryngreal nerve
   • Posterior relations
     • Parathyroid glands
     • carotid sheath
     • Ansa cervicalis
     • sympathetic chain
   • Aterial supply
     • Superior thyroid
     • inferior thyroid
     • Thyroidea ima
   • Venous drainage
     • Superior thyroid
       • Internal jugular
     • Middle thyroid
       • Internal jugular
     • Inferior thyroid
       • L Brachiocephalic

2. Causes of unintentional weight loss

   • Addison's disease (adrenal insufficiency)
   • cancer
   • A disease of the gut, such as a stomach ulcer, inflammatory bowel disease (IBD) or coeliac disease
   • Depression
   • Diabetes
   • Hyperthyroidism

3. Thyroid hormone

   • Synthesis
   • Transport
     • Free
       • Produce effect
     • bound to protein
       • TBG
       • Albumin
       • Transthyretin
   • Regulation
     • The chief stimulator of thyroid hormone synthesis is thyroid-stimulating hormone from the anterior pituitary.
       • thyroid-releasing hormone (TRH) from the hypothalamus stimulates TSH from the pituitary, which stimulates thyroid hormone release.
   • Action

4. Hyperthyroidism

   • types
     • Associated with hyperthyroidism
       • Primary
         • Graves' disease
         • Toxic multinodular goiter
         • Hyperfunctional (toxic) adenoma
       • Secondary
         • Thyroid-stimulating hormone (TSH) adenoma of the pituitary gland
       • tertiary
         • Hypothalamic disease
     • not associated with hyperthyroidism
       • Subacute granulomatous thyroiditis
   • Symptoms
   • Causes

5. Pathogenesis

   • Defect in suppressor T cell function > emergence of CD4+ cells targeted to TSH receptors
     • Intolerant CD4+ T cells stimulate B cells-->release Thyroid-Stimulating Immunoglobulin (TSI)
       • Immunoglobulin (TSI) TSI binds and activates TSH receptors on thyroid> hyperactive thyroid gland

6. Immunology of Graves disease

   • Polymorphisms in CTLA4 that result in reduced in activity will have less inhibition of the CTLs and overstimulation that can result in them becoming autoreactive

7. Histologic findings

   • Lymphatic infiltrates and follicular hypertrophy, with little colloid present

8. Prognosis

   • Most patients become hypothyroid and require replacement
   • On occasion, hyperthyroidism returns because of persisting thyroid tissue
     • Surgery or radioactive iodine ablation

9. Investigations

   • Blood sample
     • increased serum fT3 and fT4
     • decreased TSH
   • Radioactive iodine uptake
   • Ultrasound

10. Treatment

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