Brain Herniation
OVERVIEW
Brain herniation is the displacement of part of the brain through an opening or across a separating structure into a region that it does not normally occupy.
TYPES
Supratentorial
1. Uncal transtentorial herniation
2. Central tentorial herniation
3. Subfalcine herniation
4. Transcalvarial herniation
Infratentorial
5. Upward transtentorial herniation (“reverse coning”)
6. Foraminal or tonsillar herniation (“coning”)
Brain herniation Types: Image Source
UNCAL TRANSTENTORIAL HERNIATION
- The uncinate process of the temporal lobe herniates into the anterior part of the opening of the tentorium cerebelli
- typically leads to
CT Features:
- Shift of brainstem and distortion of adjacent cisterns
- Dilatation of the contralateral temporal horn
- PCA territory infarct due to compression of the posterior cerebral artery as it crosses the tentorium
CENTRAL TENTORIAL HERNIATION
- symmetrical downward movement of the thalamic region through the opening of the tentorium cerebelli
SUBFALCINE HERNIATION
- Displacement of the cingulate gyrus under the falx and across the midline.
TRANSCALVARIAL HERNIATION
- Aka external herniation
- Displacement of brain through a defect in the skull, such as a fracture site or following craniectomy.
UPWARD HERNIATION
- So-called “reverse coning” can occur if an EVD is inserted for hydrocephalus due to a posterior fossa mass lesion. This leads to upwards transtentorial herniation of posterior fossa contents.
FORAMINAL HERNIATION
- Aka tonsillar herniation
- Downward herniation of the cerebellar tonsils into the foramen magnum
References and Links
CCC Neurocritical Care Series
Emergencies: Brain Herniation, Eclampsia, Elevated ICP, Status Epilepticus, Status Epilepticus in Paeds
DDx: Acute Non-Traumatic Weakness, Bulbar Dysfunction, Coma, Coma-like Syndromes, Delayed Awakening, Hearing Loss in ICU, ICU acquired Weakness, Post-Op Confusion, Pseudocoma, Pupillary Abnormalities
Neurology: Anti-NMDA Encephalitis, Basilar Artery Occlusion, Central Diabetes Insipidus, Cerebral Oedema, Cerebral Venous Sinus Thrombosis, Cervical (Carotid / Vertebral) Artery Dissections, Delirium, GBS vs CIP, GBS vs MG vs MND, Guillain-Barre Syndrome, Horner’s Syndrome, Hypoxic Brain Injury, Intracerebral Haemorrhage (ICH), Myasthenia Gravis, Non-convulsive Status Epilepticus, Post-Hypoxic Myoclonus, PRES, Stroke Thrombolysis, Transverse Myelitis, Watershed Infarcts, Wernicke’s Encephalopathy
Neurosurgery: Cerebral Salt Wasting, Decompressive Craniectomy, Decompressive Craniectomy for Malignant MCA Syndrome, Intracerebral Haemorrhage (ICH)
— SCI: Anatomy and Syndromes, Acute Traumatic Spinal Cord Injury, C-Spine Assessment, C-Spine Fractures, Spinal Cord Infarction, Syndomes,
— SAH: Acute management, Coiling vs Clipping, Complications, Grading Systems, Literature Summaries, ICU Management, Monitoring, Overview, Prognostication, Vasospasm
— TBI: Assessment, Base of skull fracture, Brain Impact Apnoea, Cerebral Perfusion Pressure (CPP), DI in TBI, Elevated ICP, Limitations of CT, Lund Concept, Management, Moderate Head Injury, Monitoring, Overview, Paediatric TBI, Polyuria incl. CSW, Prognosis, Seizures, Temperature
ID in NeuroCrit. Care: Aseptic Meningitis, Bacterial Meningitis, Botulism, Cryptococcosis, Encephalitis, HSV Encephalitis, Meningococcaemia, Spinal Epidural Abscess
Equipment/Investigations: BIS Monitoring, Codman ICP Monitor, Continuous EEG, CSF Analysis, CT Head, CT Head Interpretation, EEG, Extradural ICP Monitors, External Ventricular Drain (EVD), Evoked Potentials, Jugular Bulb Oxygen Saturation, MRI Head, MRI and the Critically Ill, Train of Four (TOF), Transcranial Doppler
Pharmacology: Desmopressin, Hypertonic Saline, Levetiracetam (Keppra), Mannitol, Midazolam, Sedation in ICU, Thiopentone
MISC: Brainstem Rules of 4, Cognitive Impairment in Critically Ill, Eye Movements in Coma, Examination of the Unconscious Patient, Glasgow Coma Scale (GCS), Hiccoughs, Myopathy vs Neuropathy, Neurology Literature Summaries, NSx Literature Summaries, Occulocephalic and occulovestibular reflexes, Prognosis after Cardiac Arrest, SIADH vs Cerebral Salt Wasting, Sleep in ICU
FOAM and web resources
- Radiopaedia.org — Cerebral herniation
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC