Central Diabetes Insipidus - Clinical Features and Diagnosis

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What is the primary clinical feature of central diabetes insipidus?

Mental status changes

Low serum sodium levels

High urine osmolality

Decreased serum osmolality (correct)

Which condition is characterized by impaired renal response to ADH?

Central diabetes insipidus

Thyroglossal duct cyst

Syndrome of inappropriate ADH secretion (SIADH)

Nephrogenic diabetes insipidus (correct)

What is the recommended treatment for SIADH?

Free water restriction (correct)

Adequate hydration

Desmopressin

Lithium

Which condition leads to hyponatremia and low serum osmolality?

SIADH Signup and view all the answers

What is the characteristic feature of the urine in central diabetes insipidus?

Low osmolality Signup and view all the answers

Which medication can cause nephrogenic diabetes insipidus?

Lithium Signup and view all the answers

What is the effect of a water deprivation test in diagnosing central diabetes insipidus?

Has no effect on urine osmolality Signup and view all the answers

What is the pathophysiology behind the clinical features of SIADH?

Retention of free water leading to cerebral edema Signup and view all the answers

What is the most common cause of congenital adrenal hyperplasia?

21-hydroxylase deficiency Signup and view all the answers

What is the typical treatment for a patient with an ectopic source of ACTH?

Resection of ectopic source with hormone replacement Signup and view all the answers

Which scenario can lead to enlargement of a pituitary adenoma, resulting in hyperpigmentation, headaches, and bitemporal hemianopsia?

Bilateral adrenalectomy in refractory cases Signup and view all the answers

What is a characteristic feature of Nelson syndrome?

Hyperpigmentation Signup and view all the answers

Why might mineralocorticoids and androgens be increased or decreased in congenital adrenal hyperplasia?

Enzymatic defects in cortisol production Signup and view all the answers

In which condition would a patient likely require bilateral resection of hyperplasia with hormone replacement?

Congenital adrenal hyperplasia Signup and view all the answers

What is a potential treatment option if surgical resection is not possible for a patient with androgen excess due to elevated ACTH?

Ketoconazole or metyrapone therapy Signup and view all the answers

What symptom may indicate enlargement of a pituitary adenoma due to bilateral adrenalectomy in refractory cases?

Hyperpigmentation Signup and view all the answers

Which of the following is a complication of diabetes?

All of the above Signup and view all the answers

What is the primary function of the glomerulosa layer of the adrenal cortex?

Produce mineralocorticoids Signup and view all the answers

Which of the following is a characteristic of insulinomas?

Presents as episodic hypoglycemia with mental status changes Signup and view all the answers

Which of the following hormones are derived from cholesterol in the adrenal cortex?

Cortisol Signup and view all the answers

What is the leading cause of blindness in the developed world?

Diabetes Signup and view all the answers

Which of the following is a characteristic of gastrinomas?

Presents as treatment-resistant peptic ulcers Signup and view all the answers

What is the mechanism by which aldose reductase contributes to diabetic complications?

Converts glucose to sorbitol, resulting in osmotic damage Signup and view all the answers

Which layer of the adrenal cortex produces weak androgens?

Reticularis Signup and view all the answers

Which of the following is a symptom associated with high cortisol levels in Cushing's syndrome?

Muscle weakness with thin extremities Signup and view all the answers

Which of the following physical features is associated with Cushing's syndrome?

Moon facies and truncal obesity Signup and view all the answers

What is the likely cause of abdominal striae (stretch marks) in Cushing's syndrome?

Impaired collagen synthesis Signup and view all the answers

Which of the following is a common feature of hypertension in Cushing's syndrome?

Hypokalemia and metabolic alkalosis Signup and view all the answers

What is the initial diagnostic test for Cushing's syndrome?

24-hour urine cortisol level or late night salivary cortisol level Signup and view all the answers

What is the purpose of the low-dose dexamethasone suppression test in the diagnosis of Cushing's syndrome?

To suppress cortisol production in normal individuals but not in Cushing's syndrome Signup and view all the answers

What is the next step after determining that Cushing's syndrome is ACTH-independent?

Perform a CT scan of the adrenal glands Signup and view all the answers

What is the purpose of the high-dose dexamethasone suppression test in the diagnosis of Cushing's syndrome?

To differentiate between pituitary and ectopic ACTH sources Signup and view all the answers

What causes the buildup of glycosaminoglycans, inflammation, fibrosis, and edema leading to exophthalmos and pretibial myxedema in Graves' disease?

TSH activation of fibroblasts behind the orbit and overlying the shin Signup and view all the answers

Which of the following is NOT a typical laboratory finding in Graves' disease?

Decreased total and free T4 levels Signup and view all the answers

What is the primary mechanism of action of propylthiouracil (PTU) in the treatment of Graves' disease?

Inhibiting the peroxidase-mediated steps of thyroid hormone synthesis Signup and view all the answers

What is the primary cause of multinodular goiter?

Relative iodine deficiency Signup and view all the answers

What is the characteristic microscopic appearance of Graves' disease?

Irregular follicles with scalloped colloid and chronic inflammation Signup and view all the answers

Which of the following is NOT a potential complication of Graves' disease?

Thyroid lymphoma Signup and view all the answers

What is the treatment for thyroid storm, a potentially fatal complication of Graves' disease?

Propylthiouracil, β-blockers, and steroids Signup and view all the answers

What is the primary cause of toxic multinodular goiter?

TSH-independent hormone production by nodules in a multinodular goiter Signup and view all the answers