Hydrocephalus can influence metabolism by which mechanism?

• A. Interrupts the hypothalamic pituitary axis -> abnormal leptin secretion (increases risk of obesity)
• B. Decreases leptin production causing reduced appetite
• C. Directly improves energy expenditure
• D. Causes immediate loss of motor function

Answer: (A)

Hydrocephalus can influence metabolism by disturbing brain regions that regulate energy balance. When intracranial pressure from hydrocephalus affects the hypothalamic-pituitary axis, it can disrupt how the body handles signals that control appetite and body weight. Leptin, a hormone produced by fat tissue, informs the hypothalamus about energy stores and helps regulate hunger and energy expenditure. If the hypothalamic-pituitary axis is compromised, leptin signaling can become abnormal, which can increase the risk of obesity because the normal cues that tell the brain to stop eating or to burn energy may be blunted or misinterpreted.

This mechanism aligns with the idea that disruption of central regulatory systems—not direct changes in leptin production by fat or immediate changes in motor function—drives the metabolic effects in hydrocephalus. The other options don’t fit this regulatory context: a simple decrease in leptin would predict reduced appetite rather than obesity risk; direct improvement of energy expenditure is not a typical outcome of hydrocephalus, and immediate loss of motor function describes neurological deficits rather than a metabolic mechanism.