Abrupt withdrawal of endogenous cortisol after brain surgery may lead to which condition?

• A. Hyperglycemia
• B. Hypocortisolism
• C. Hypercalcemia
• D. Hypokalemia

Answer: (B)

Abrupt withdrawal of cortisol after brain surgery can cause adrenal insufficiency because the hypothalamic–pituitary–adrenal axis may be damaged or suppressed, leaving the body unable to produce adequate cortisol during stress. Cortisol is essential for maintaining blood pressure and vascular responsiveness, regulating glucose, and supporting the stress response. When cortisol suddenly drops, the body can develop an adrenal crisis with symptoms such as low blood pressure, fatigue, weakness, nausea, vomiting, and headaches. In this situation, mineralocorticoid function (which helps regulate potassium and sodium) is usually preserved, so potassium levels aren’t typically elevated, and hyperkalemia is not expected. Hyperglycemia would be more characteristic of cortisol excess, not its withdrawal, and the other electrolyte patterns listed are not typical of secondary adrenal insufficiency.