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.
1. Uncal transtentorial herniation
2. Central tentorial herniation
3. Subfalcine herniation
4. Transcalvarial herniation
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
- 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
- Displacement of the cingulate gyrus under the falx and across the midline.
- Aka external herniation
- Displacement of brain through a defect in the skull, such as a fracture site or following craniectomy.
- 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.
- Aka tonsillar herniation
- Downward herniation of the cerebellar tonsils into the foramen magnum
References and Links
FOAM and web resources
- Radiopaedia.org — Cerebral herniation
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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