What are the symptoms and treatment of brain herniation?

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Last updated: June 25, 2025View editorial policy

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From the Guidelines

Brain herniation is a life-threatening condition requiring immediate medical attention, and treatment should focus on reducing intracranial pressure through medications like mannitol or hypertonic saline, as well as supportive care to promote venous drainage and maintain proper oxygenation. Symptoms of brain herniation include severe headache, altered consciousness, unequal pupil size, abnormal eye movements, irregular breathing patterns, weakness or paralysis on one side of the body, and seizures. As the condition progresses, patients may develop Cushing's triad (hypertension, bradycardia, and irregular breathing), posturing (abnormal body positioning), and ultimately coma.

Treatment Options

  • Medications:
    • Mannitol (20% solution) or hypertonic saline solution can be used to treat threatened intracranial hypertension or signs of brain herniation, with a recommended dose of 250 mOsm in infusion of 15–20 minutes 1.
    • Mannitol induces osmotic diuresis and requires volume compensation, while hypertonic saline exposes to hypernatremia and hyperchloremia, and monitoring fluid, sodium, and chloride balances is necessary 1.
  • Supportive Care:
    • Positioning the head at 30 degrees to promote venous drainage, as head position may be one of the single most important nursing modalities for controlling increased intracranial pressure 1.
    • Maintaining proper oxygenation and controlling seizures with medications.
    • Avoiding aggressive antihypertensive agents with venodilating effects, such as nitroprusside, which can cause cerebral venodilation and lead to a more elevated intracranial pressure 1.

Key Considerations

  • Rapid intervention is essential for survival, as brain herniation occurs when increased intracranial pressure forces brain tissue to shift across compartments within the skull, compressing vital structures and disrupting blood flow.
  • Treatment should be individualized based on the patient's physiological response to routine care, and frequent neurological assessments must be done to look for potential changes in brain perfusion 1.

From the Research

Symptoms of Brain Herniation

  • Increased intracranial pressure can lead to brain herniation, which is a life-threatening condition 2
  • Symptoms of brain herniation include mydriasis, which is a dilation of the pupils, and can be an indication of severe intracranial hypertension 3
  • Other symptoms may include altered mental status, cranial nerve palsies, and movement disorders 4
  • Brain herniation can occur due to various causes, including traumatic brain injury, intracranial hypertension, and spontaneous intracranial hypotension 2, 4

Treatment of Brain Herniation

  • The treatment of brain herniation typically involves reducing intracranial pressure using hyperosmolar therapies such as mannitol or hypertonic saline solution 5, 6, 3
  • Hypertonic saline solution has been shown to be an effective alternative to mannitol in reducing intracranial pressure 6, 3
  • In some cases, surgical intervention may be necessary to relieve pressure on the brain and prevent further herniation 5
  • The choice of treatment depends on the underlying cause of the brain herniation and the severity of the condition 2

Medical Management

  • Osmotherapy is considered the mainstay of medical therapy for increased intracranial pressure, and should be administered as soon as possible 5
  • The goal of medical management is to maintain or re-establish adequate cerebral blood flow and prevent further herniation 5
  • Monitoring of patients with brain herniation is crucial to ensure prompt detection of any changes in their condition and adjustment of treatment as needed 6, 3

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Brain Herniation and Intracranial Hypertension.

Neurologic clinics, 2021

Research

Comparison of mannitol and hypertonic saline solution for the treatment of suspected brain herniation during prehospital management of traumatic brain injury patients.

European journal of emergency medicine : official journal of the European Society for Emergency Medicine, 2024

Research

Spontaneous intracranial hypotension: key features for a frequently misdiagnosed disorder.

Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology, 2020

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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