NREMT Paramedic Practice

What sign is typically associated with increased intracranial pressure (ICP) when the lower brain or medulla is involved?

1. Flaccid extremities

2. Bradycardia

3. Blown pupil

4. Central neurogenic hyperventilation

The correct answer is: Blown pupil

Increased intracranial pressure (ICP) can lead to a variety of neurological signs and symptoms, depending on the extent and location of the pressure. When the lower brain or medulla, which controls many vital functions, is affected, one of the hallmark signs is the presence of a blown pupil. A blown pupil, or dilated pupil, typically indicates a dysfunction in the brain’s tentorial region or pressure on cranial nerves, particularly the oculomotor nerve (CN III). This can occur due to herniation, where the brain is displaced and puts pressure on surrounding structures. As ICP rises, it can result in compromised blood flow and oxygenation to the areas controlling pupillary response. Therefore, the presence of a blown pupil suggests critical brain involvement and is a clear indicator of significant neurological compromise related to increased ICP. In contrast, while flaccid extremities, bradycardia, and central neurogenic hyperventilation can all occur in scenarios involving increased ICP, they are often associated with broader or alternate brain injury processes rather than being classic presentations specifically linked to lower brain or medullary involvement. Flaccid extremities indicate extreme autonomic dysfunction, bradycardia may occur due to vagal stimulation or brain