Which of the following is a sign of herniation in head injury patients?

Herniation in head injury patients refers to the displacement of brain tissue due to increased intracranial pressure, which can lead to serious neurological complications. A key indicator of herniation is unequal pupils, known scientifically as anisocoria. This occurs because the pressure in the cranial cavity can compress the optic nerve or influence the muscles controlling pupil size. When herniation occurs, one pupil may become dilated while the other remains smaller or constricted, reflecting shifts in brain structures or function. This sign is critical during patient assessment, as it can indicate severe brain injury and the need for immediate medical intervention.

In contrast, balanced vital signs may suggest a stable condition, while bradycardia (slow heart rate) can sometimes be a result of increased intracranial pressure but is not as directly indicative of herniation as pupil changes. Lastly, a response to verbal stimuli implies that the patient's level of consciousness has some preservation, which is not typically the case in significant herniation scenarios where brain function may be deteriorating rapidly. Therefore, the presence of unequal pupils is a more direct and critical sign to indicate herniation in head injury patients.