Master the Mayhem: 2025 ATLS Practice Exam – Be the Trauma Hero!

Pupil size asymmetry is indicative of potential brain herniation, particularly when one pupil is dilated and the other is constricted. This phenomenon, known as anisocoria, can occur if increased intracranial pressure causes herniation of brain structures, which may compromise the oculomotor nerve (cranial nerve III). This nerve is responsible for constricting the pupil and moving the eye, so any pressure on it can lead to changes in pupil size and reactivity.

Rhinorrhea, or a runny nose, can occur due to various conditions including infections or allergies and does not typically indicate brain herniation. Similarly, missing teeth are not associated with intracranial pressure or brain herniation and are generally related to dental health issues. Otorrhea, which is drainage from the ear, could indicate an ear infection or even a cerebrospinal fluid leak, but it does not directly suggest brain herniation as clearly as pupil size asymmetry does. Thus, pupil size asymmetry serves as a notable sign of neurological compromise that should prompt further evaluation for underlying intracranial issues.