🧠 Brain Herniation Syndromes — Recognition and Management
Match the localising signs of each brain-herniation type to emergency intracranial-pressure reduction. Instant, browser-side.
Clinical takeaway
Osmotherapy: mannitol 0.25–1 g/kg IV push or hypertonic saline (3% 250 mL / 23.4% 30 mL via central line), monitoring sodium/osmolality.
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When to use
Recognise brain-herniation syndromes and apply emergency ICP-lowering measures.
How it works
Uncal: ipsilateral fixed dilated pupil + contralateral hemiparesis. Central: rostral-caudal deterioration. Subfalcine: ACA compression, lower-limb weakness. Tonsillar (foramen magnum): Cushing's triad + respiratory arrest. Upward: aqueductal obstruction. General rescue: head-up 30°, osmotherapy, brief hyperventilation as a bridge, emergency neurosurgical decompression.
Key points
- Osmotherapy: mannitol 0.25–1 g/kg IV push or hypertonic saline (3% 250 mL / 23.4% 30 mL via central line), monitoring sodium/osmolality.
- Brief hyperventilation to PaCO₂ 30–35 is a rescue bridge only — avoid prolonged levels < 30 to prevent rebound ischemia.
- Lumbar puncture is contraindicated in posterior-fossa / obstructive raised pressure (tonsillar herniation).
- Definitive treatment is etiologic: hematoma evacuation, decompressive craniectomy, EVD, plus correction of coagulopathy and control of seizures/fever.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Herniation type | Uncal herniation (transtentorial) |
|---|
→HerniationUncal herniation
- Localising signs：Ipsilateral oculomotor nerve (CN III) compression → ipsilateral fixed dilated pupil and ptosis; contralateral hemiparesis (if the contralateral cerebral peduncle is compressed — Kernohan's notch → ipsilateral hemiparesis, a false localising sign); declining consciousness; may progress to decerebrate posturing
- Emergency management (general)：Head-of-bed elevation 30°, head/neck midline to avoid jugular compression; secure airway/oxygenation, avoid hypotension; analgesia-sedation
- Osmotherapy：Mannitol 0.25–1 g/kg IV push; or hypertonic saline (3% 250 mL or 23.4% 30 mL via central line), monitoring serum sodium/osmolality
| Herniation type | Upward transtentorial herniation (posterior-fossa mass) |
|---|
→HerniationUpward transtentorial herniation
- Localising signs：A posterior-fossa mass drives the cerebellar vermis upward through the tentorium: midbrain compression, aqueductal obstruction causing hydrocephalus, declining consciousness. Posterior-fossa decompression/EVD must be done cautiously to avoid precipitating upward herniation
- Emergency management (general)：Head-of-bed elevation 30°, head/neck midline to avoid jugular compression; secure airway/oxygenation, avoid hypotension; analgesia-sedation
- Osmotherapy：Mannitol 0.25–1 g/kg IV push; or hypertonic saline (3% 250 mL or 23.4% 30 mL via central line), monitoring serum sodium/osmolality
Frequently asked questions
- What is Brain Herniation Syndromes — Recognition and Management?
- Match the localising signs of each brain-herniation type to emergency intracranial-pressure reduction. Instant, browser-side.
- How is Brain Herniation Syndromes — Recognition and Management calculated? What is the core formula?
- Uncal: ipsilateral fixed dilated pupil + contralateral hemiparesis. Central: rostral-caudal deterioration. Subfalcine: ACA compression, lower-limb weakness. Tonsillar (foramen magnum): Cushing's triad + respiratory arrest. Upward: aqueductal obstruction. General rescue: head-up 30°, osmotherapy, brief hyperventilation as a bridge, emergency neurosurgical decompression.
- When is Brain Herniation Syndromes — Recognition and Management used?
- Recognise brain-herniation syndromes and apply emergency ICP-lowering measures.
- What are the key clinical points for Brain Herniation Syndromes — Recognition and Management?
- Osmotherapy: mannitol 0.25–1 g/kg IV push or hypertonic saline (3% 250 mL / 23.4% 30 mL via central line), monitoring sodium/osmolality. Brief hyperventilation to PaCO₂ 30–35 is a rescue bridge only — avoid prolonged levels < 30 to prevent rebound ischemia. Lumbar puncture is contraindicated in posterior-fossa / obstructive raised pressure (tonsillar herniation). Definitive treatment is etiologic: hematoma evacuation, decompressive craniectomy, EVD, plus correction of coagulopathy and control of seizures/fever.
- What are the limits and cautions when using Brain Herniation Syndromes — Recognition and Management?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is Brain Herniation Syndromes — Recognition and Management calculated in practice? Can you show a worked example?
- Inputs: Herniation type Uncal herniation (transtentorial) → Result: Herniation Uncal herniation（Localising signs: Ipsilateral oculomotor nerve (CN III) compression → ipsilateral fixed dilated pupil and ptosis; contralateral hemiparesis (if the contralateral cerebral peduncle is compressed — Kernohan's notch → ipsilateral hemiparesis, a false localising sign); declining consciousness; may progress to decerebrate posturing, Emergency management (general): Head-of-bed elevation 30°, head/neck midline to avoid jugular compression; secure airway/oxygenation, avoid hypotension; analgesia-sedation, Osmotherapy: Mannitol 0.25–1 g/kg IV push; or hypertonic saline (3% 250 mL or 23.4% 30 mL via central line), monitoring serum sodium/osmolality） Inputs: Herniation type Upward transtentorial herniation (posterior-fossa mass) → Result: Herniation Upward transtentorial herniation（Localising signs: A posterior-fossa mass drives the cerebellar vermis upward through the tentorium: midbrain compression, aqueductal obstruction causing hydrocephalus, declining consciousness. Posterior-fossa decompression/EVD must be done cautiously to avoid precipitating upward herniation, Emergency management (general): Head-of-bed elevation 30°, head/neck midline to avoid jugular compression; secure airway/oxygenation, avoid hypotension; analgesia-sedation, Osmotherapy: Mannitol 0.25–1 g/kg IV push; or hypertonic saline (3% 250 mL or 23.4% 30 mL via central line), monitoring serum sodium/osmolality）