Uncal Herniation: Early Recognition and Emergency Management by Prehospital Care Providers-An Updated Review
TL;DR
The anatomical basis, causes, pathophysiology, clinical manifestations, diagnostic evaluation, treatment approaches, complications, and prognosis of uncal herniation are reviewed.
Abstract
Background: Uncal herniation is a rapidly progressive and potentially fatal neurological emergency caused by displacement of the medial temporal lobe through the tentorial notch as intracranial pressure rises. It may result from traumatic brain injury, intracranial hemorrhage, malignant cerebral edema, tumors, hydrocephalus, and other space-occupying intracranial lesions. Aim: This article reviews the anatomical basis, causes, pathophysiology, clinical manifestations, diagnostic evaluation, treatment approaches, complications, and prognosis of uncal herniation. Methods: A narrative review was undertaken using established neurocritical care concepts and published literature addressing transtentorial herniation, intracranial hypertension, clinical neurological assessment, neuroimaging, emergency management, and neurosurgical intervention. Results: Uncal herniation develops when compensatory intracranial mechanisms fail and pressure gradients force the uncus against the tentorial edge. Compression of the ipsilateral oculomotor nerve can cause a dilated, poorly reactive pupil, while cerebral peduncle compression may produce hemiparesis. Progressive midbrain and brainstem involvement can lead to declining consciousness, abnormal posturing, respiratory failure, coma, and death. Urgent non-contrast computed tomography is essential for identifying hemorrhage, mass effect, cisternal compression, hydrocephalus, and midline shift. Immediate management includes airway protection, optimization of oxygenation and cerebral perfusion, osmotherapy, controlled ventilation when indicated, cerebrospinal fluid diversion in selected cases, and urgent evacuation or decompression of the causative lesion. Conclusion: Uncal herniation requires rapid clinical recognition and coordinated emergency, critical care, radiological, and neurosurgical management. Early treatment is central to reducing mortality and limiting permanent neurological disability.