Graves Disease_Hyperthyroidism

Question 1

Definition

Answer 1

Autoimmune Condition where aitoantibodies act as Thyroid stimulating hormone leading to an excess production of thyroid hormone

Leading cause of Hyperthyroidism (70%)

Question 2

Epidemiology

Answer 2

30 cases per 100,000

Female : Male = 5:1

Typical age range: 20-40years

Question 3

Pathophysiology

Answer 3

• B and T cell-mediated autoimmunity
• Production of stimulating immunoglobulin G (IgG)
• IgG binds to TSH receptor
• Type ii hypersensitivity reaction
• Increased thyroid function
• Increased T3/T4 production negative feedback shuts off physiological production of TSH

Question 4

Etiology/Risk Factors

Answer 4

Etiology:

• Genetic predisposition (50% of patients have family history of an autoimmune condition)
• Autoimmunity (B & T lymphocyte mediated disorder)

Risk Factors/Triggers:

• Pregnancy
• Physical or Physiological Stress
• Infectious agents
• Environmental factors (smoke, irradiation, drugs)

Question 5

Presentation

Answer 5

Signs

• Diffuse Goitre*
• Graves Ophthalmopathy (Eyelid retraction & Anterior Protrusion)*
• Non-pitting Odema & Plaques on Lower Limbs (TSH receptor deposits)
• Hypertension
• High HR
• Irregular Pulse

Symptoms

• Heat Intolerance*
• Weight Loss*
• Anxiety
• Chest Pain

Question 6

Lab Work Up

Answer 6

First Line:
- Undetectable TSH & High T3/T4

Measure Thyroid Antibodies (TRAbs)

Question 7

Imagining

Answer 7

If TRABs are low (mild case) then thyroid scintigraphy:
- Diffuse uptake of radioactive Iodide

If TRABs are low (mild case) and pregnant then Ultrasound
- Enlarged & Hypervascular

Question 8

Complications

Answer 8

Osteoporosis
- Excessive T4 speeds up the work of osteoclasts
- Osteoblasts don’t keep up
Thyrotoxic crisis
- Sudden increase in T3/T4 levels leading to systemic acute illness
Heart Disorders
Pregnancy Issues

Question 9

Differential Diagnosis

Answer 9

Iodine Induced (excessive iodine, more common in iodine different areas)
Toxic Multinodular goiter (over 50)

Question 10

Treatment

Answer 10

Lifestyle
- Avoid foods with a high Iodide content

Pharmacology

• Thionamides (anti-thyroid drugs) - Slowly taper on remission
  * Carbimiazloe
  * Proplythiouracil
• β-blockers (Thyrotoxic crisis & Cardiac complications)

Surgery/Procedures

• Radioiodine
• Surgery

Question 11

Prognosis

Answer 11

50% remission for pharmacological treatment

Generally good when managed correctly

Can be fatal if left untreated (complications)

Question 12

Histology

Answer 12

Macroscopic:
- Diffuse, uniform gland enlargement & beefy red appearance

Microscopic:

• Diffuse hyperplasia of thyroid follicles
• Tall, hyperplastic and hypertrophic follicular cells