Which monitoring method directly measures intracranial pressure?

• A. Intraventricular catheter (EVD) or intraparenchymal monitor
• B. CT
• C. EEG
• D. Noninvasive blood pressure

Answer: (A)

Direct intracranial pressure monitoring requires placing a sensor inside the cranial contents, such as an intraventricular catheter with an external drain or a sensor inserted into the brain parenchyma. These devices measure the actual pressure within the skull, providing real-time ICP values that guide management in severe traumatic brain injury. An intraventricular catheter not only measures ICP but can also drain CSF to reduce pressure, which is a key practical advantage.

Imaging like CT only gives a snapshot in time and cannot provide continuous ICP readings. EEG assesses electrical activity, not pressure. Noninvasive blood pressure reflects systemic arterial pressure and does not directly measure intracranial pressure.