What is a potential neurological consequence of severe hyponatremia?

Severe hyponatremia, which is a significantly low concentration of sodium in the blood, can lead to a variety of neurological complications due to shifts in fluid balance across cell membranes. One of the most critical and life-threatening consequences is cerebral edema, which occurs when excess water enters brain cells.

When sodium levels drop, water moves into the brain cells to balance the osmotic gradient, causing these cells to swell. If this edema becomes severe enough, it can lead to increased intracranial pressure and potentially result in brain herniation, where brain tissue is displaced from its normal position. This herniation can compress vital structures within the brain, leading to serious neurological deficits or even death.

A few other options presented in this question are related to bodily functions that do not directly connect to the severe effects of hyponatremia on the brain. Increased heart rate, respiratory failure, and reduced muscle tone, while potentially affected by electrolyte imbalances, do not specifically relate to the neurological consequences attributed to severe hyponatremia as clearly as cerebral edema does.