What is Transtentorial herniation?
By Isabella Harris
What is Transtentorial herniation?
A transtentorial herniation is the movement of brain tissue from one intracranial compartment to another. This includes uncal, central, and upward herniation. These are life-threatening and time-critical pathologies that may be reversible with emergent surgical intervention and medical management.
Is Transtentorial herniation the same as uncal herniation?
Uncal herniation is a subtype of transtentorial downward brain herniation that involves the uncus, usually related to cerebral mass effect increasing the intracranial pressure.
What does the Uncus do?
Functionally, the uncus is involved in olfaction, emotions, and forming new memories mainly due to its connectivity with multiple nuclei and cortices related to these functions. Uncal herniation syndrome and uncinate fits of mesiotemporal epilepsy are the main neurological abnormalities associated with this structure.
Can you survive brain herniation?
The outlook varies, depending on where in the brain the herniation occurs. Without treatment, death is likely. There can be damage to parts of the brain that control breathing and blood flow. This can rapidly lead to death or brain death.
Why does uncal herniation cause contralateral hemiparesis?
The mass lesion causing the uncal herniation usually causes a contralateral hemiparesis, but as the pressure increases, the opposite cerebral peduncle is compressed against the tentorium, which causes an ipsilateral hemiparesis (Kernohan’s sign).
What are the types of herniation?
Brain herniation is classified as follows:
- Subfalcine herniation.
- Transalar (transsphenoidal) herniation.
- Transtentorial uncal herniation.
- Central (trans-tentorial) herniation (descending and ascending)
- Cerebellar tonsillar herniation.
- Transcalvarial herniation.
What causes tonsillar herniation?
Usually, tonsillar herniation is caused by an expanding infratentorial mass (eg, cerebellar hemorrhage). The cerebellar tonsils, forced through the foramen magnum, compress the brain stem and obstruct cerebrospinal fluid (CSF) flow. Brain herniation is a complication of a disorder that causes increased intracranial pressure (ICP).
What is brain herniation?
A brain herniation, or cerebral herniation, occurs when brain tissue, blood, and cerebrospinal fluid (CSF) shifts from their normal position inside the skull. The condition is usually caused by swelling from a head injury, stroke, bleeding, or brain tumor. A brain herniation is a medical emergency and requires immediate medical attention.
