Endocrinology

Question 1

Hypokalemic Periodic Paralysis

Answer 1

Hypokalemic periodic paralysis is a rare disorder of uncertain cause characterized by potentially fatal episodes of muscle weakness or paralysis which can affect the respiratory muscles. Acute attacks, in which the sudden movement of potassium into the cells can lower the plasma potassium concentration to as low as 1.5 to 2.5 meq/L, are often precipitated by rest after exercise, stress, or a carbohydrate meal, events that are often associated with increased release of epinephrine or insulin. The hypokalemia is often accompanied by hypophosphatemia and hypomagnesemia

Hypokalemic periodic paralysis may be familial with autosomal dominant inheritance (in which the penetrance may be only partial) or may be acquired in patients with thyrotoxicosis. Asian males are at particular risk for thyrotoxic periodic paralysis.

Question 2

Pituitary Apoplexy

Answer 2

Sudden hemorrhage into the pituitary gland is called pituitary apoplexy. Hemorrhage often occurs into a pituitary adenoma. In its most dramatic presentation, apoplexy causes the sudden onset of excruciating headache, ophthalmoplegia, diplopia, change in mental status, and hypopituitarism. All pituitary hormonal deficiencies can occur, but the sudden onset of ACTH and therefore cortisol deficiency is the most serious, because it can cause life-threatening hypotension.

Pituitary apoplexy may require emergency surgical intervention; however, sometimes it can be managed more conservatively with medical therapies, particularly corticosteroid replacement if hypopituitarism (and particularly hypotension from adrenal insufficiency) is evident. Patients with evidence of optic chiasm compression or with an acute decrease in level of consciousness are typically considered candidates for emergency surgical resection of the infarcted or hemorrhagic tissue and decompression of structures surrounding the pituitary