TY - CHAP M1 - Book, Section TI - Herniation Syndromes A1 - Stark, Christopher L. A2 - Knoop, Kevin J. A2 - Stack, Lawrence B. A2 - Storrow, Alan B. A2 - Thurman, R. Jason Y1 - 2021 N1 - T2 - The Atlas of Emergency Medicine, 5e AB - Severe head injury can result in extra-axial hematoma, cerebral contusion, or diffuse cerebral edema, which, in turn, may cause one of five brain herniation syndromes: uncal, central transtentorial, cerebellotonsillar, subfalcine, and external. Uncal herniation occurs when the uncus of the temporal lobe is displaced inferiorly through the medial edge of the tentorium. Compression of cranial nerve III can cause an ipsilateral dilated pupil. Typically, patients with uncal herniation are unconscious and require intubation. A contusion to the eye may also result in a dilated, nonresponsive pupil and arouse suspicion for uncal herniation, but typically these patients are alert. SN - PB - McGraw-Hill CY - New York, NY Y2 - 2024/03/29 UR - accessemergencymedicine.mhmedical.com/content.aspx?aid=1186300057 ER -