What is the first sign of increased intracranial pressure?

• A. Seizure
• B. Decreased LOC
• C. Pupillary dilation
• D. Fever

Answer: (B)

Rising pressure inside the skull first disrupts the brain’s ability to stay awake and alert, because the reticular activating system in the brainstem is very sensitive to changes in perfusion and pressure. This makes the earliest and most reliable sign a change in mental status: the person becomes lethargic, confused, or otherwise less responsive than normal. As ICP continues to climb, this decrease in level of consciousness progresses and may be followed by other signs.

Seizures can occur with elevated ICP, but they’re not typically the initial sign. Pupillary dilation and other brainstem signs tend to appear later, especially with herniation or direct brainstem involvement. Fever is not a direct sign of increased ICP and usually points to infection or another process.