Which of the following conditions is the most common complication of radioiodine treatment for Graves' disease?
Q1732
What is the management of choice for a case of Sheehan syndrome presenting with unresponsive hypotension?
Q1733
A 40-year-old woman presents with symptoms of fatigue, weight gain, and cold intolerance, and laboratory tests show elevated TSH and low T4 levels. What is the most likely diagnosis?
Endocrinology Indian Medical PG Practice Questions and MCQs
Question 1731: Which of the following conditions is the most common complication of radioiodine treatment for Graves' disease?
A. Hypothyroidism (Correct Answer)
B. Thyroid cancer
C. Thyroid storm
D. Subacute thyroiditis
Explanation: ***Hypothyroidism***
- **Radioiodine (RAI) therapy** destroys overactive thyroid cells, making it highly effective for Graves' disease but often leading to a permanent state of **hypothyroidism** post-treatment.
- The goal of RAI is to eliminate the source of excess hormone production, and while effective, it frequently necessitates lifelong **thyroid hormone replacement**.
*Thyroid storm*
- **Thyroid storm** is a rare, life-threatening complication, usually seen in untreated or undertreated hyperthyroidism or during acute stress, not typically a direct outcome of effective RAI.
- While a transient increase in thyroid hormones can occur shortly after RAI, a full-blown thyroid storm is infrequent with proper preparation and management.
*Thyroid cancer*
- There is no significant evidence to suggest an increased risk of **thyroid cancer** in adults following therapeutic doses of radioiodine for Graves' disease [1].
- The radiation dose is targeted primarily at the thyroid gland, and studies have shown no clear link to increased malignancy [1].
*Subacute thyroiditis*
- **Subacute thyroiditis** (also known as de Quervain's thyroiditis) is typically a post-viral inflammatory condition of the thyroid, characterized by pain and tenderness in the thyroid gland [2].
- It does not directly result from radioiodine treatment; however, some patients may experience a transient inflammatory response (radiation thyroiditis) after RAI, which is usually mild and self-limiting, not true subacute thyroiditis.
Question 1732: What is the management of choice for a case of Sheehan syndrome presenting with unresponsive hypotension?
A. Hydrocortisone (Correct Answer)
B. Thyroxine
C. Labetalol
D. Epinephrine
Explanation: ***Hydrocortisone***
- **Unresponsive hypotension** in Sheehan syndrome is often due to **adrenal insufficiency** (ACTH deficiency), which requires immediate corticosteroid replacement [1].
- **Hydrocortisone** rapidly replaces cortisol, which is crucial for maintaining vascular tone and preventing hypotensive shock [1].
*Thyroxine*
- While **hypothyroidism** can occur in Sheehan syndrome, **thyroxine** replacement acts slowly and is not an appropriate initial treatment for acute, life-threatening hypotension [1].
- Correcting profound hypotension takes precedence over addressing thyroid hormone deficiencies in an emergency.
*Labetalol*
- **Labetalol** is an **antihypertensive** agent that would worsen hypotension in a patient with Sheehan syndrome and adrenal crisis.
- It would further decrease blood pressure and compromise circulation.
*Epinephrine*
- **Epinephrine** is a potent **vasopressor** and might be considered in extreme shock, but it is not the primary treatment for hypotension due to adrenal insufficiency.
- Without adequate cortisol, the body is less responsive to catecholamines, making steroid replacement essential first.
Question 1733: A 40-year-old woman presents with symptoms of fatigue, weight gain, and cold intolerance, and laboratory tests show elevated TSH and low T4 levels. What is the most likely diagnosis?
A. Graves' disease
B. Subacute thyroiditis
C. Hypothyroidism (Correct Answer)
D. Hyperthyroidism
Explanation: ***Hypothyroidism***
- **Elevated TSH** and **low T4** levels are the hallmark biochemical findings of hypothyroidism, indicating primary thyroid failure [1].
- The patient's symptoms of **fatigue**, **weight gain**, and **cold intolerance** are classic signs of a reduced metabolic rate due to insufficient thyroid hormones [1].
*Graves' disease*
- This is a cause of **hyperthyroidism**, characterized by low TSH and elevated T3/T4 levels, the opposite of the patient's lab results [1].
- Clinical features include **exophthalmos**, pretibial myxedema, and **heat intolerance**, which are not present here [1].
*Subacute thyroiditis*
- Initially, it can cause a **transient hyperthyroid phase** due to the release of preformed thyroid hormones, followed by a hypothyroid phase, but the primary symptoms and lab values directly point to established hypothyroidism.
- It often presents with a **tender thyroid gland** and typically resolves within months, which is not described.
*Hyperthyroidism*
- This condition is characterized by **low TSH** and **elevated free T3/T4**, leading to symptoms like weight loss, heat intolerance, and tachycardia [1].
- The patient's symptoms (weight gain, cold intolerance) and lab results (elevated TSH, low T4) are directly contradictory to hyperthyroidism [1].
