What is one of the earliest signs of increased intracranial pressure (ICP)?

• A. Seizures
• B. Change in responsiveness
• C. Projectile vomiting
• D. Dilated pupils

Answer: (B)

Early signs of rising intracranial pressure are most often seen as changes in brain function and awareness. When ICP starts to increase, cerebral perfusion to the brain tissue drops, and neurons don’t function as efficiently. That subtle shift shows up first as a change in responsiveness—patients may become drowsier, less oriented, slower to respond, or harder to arouse. It reflects the brain’s sensitivity to even small drops in perfusion and the beginning of FRC (functional decline) before more dramatic signs appear.

Seizures can occur with high ICP, but they’re not the initial signal; they indicate focal irritability after dysfunction has progressed. Projectile vomiting can happen with increased ICP but tends to occur later, as pressure affects the brainstem and vomiting centers. Dilated pupils point to third-nerve compression and brainstem involvement, a later, more ominous sign than a simple change in responsiveness.

So, a change in responsiveness is the earliest and most reliable early indicator to watch for, signaling the need for rapid assessment and interventions to lower ICP.