Which of the following is not an early sign of increased ICP?

• A. Vomiting
• B. Decreasing LOC
• C. Pupil changes
• D. Cushing's triad

Answer: (D)

Understanding how ICP presents helps distinguish early from late signs. Early signs reflect rising pressure affecting higher brain function, while late signs indicate brainstem involvement as pressure becomes severe.

Vomiting is an early sign because increased ICP can stimulate the brain’s vomiting center, signaling rising pressure before the brainstem is overwhelmed. A decreasing level of consciousness is another early cue, showing global cerebral dysfunction from reduced cerebral perfusion as ICP climbs. Pupil changes can also occur early, due to pressure effects on neural pathways controlling the pupils and eye movements, indicating evolving intracranial pressure.

Cushing’s triad, however, is a late sign. It reflects brainstem compression and autonomic instability: escalating blood pressure with a slowing heart rate and irregular breathing. This combination signals that the ICP is dangerously high and herniation may be imminent, rather than an initial response to rising pressure.