What is a 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.
When does Transtentorial herniation occur?
Upward transtentorial herniation can occur when an infratentorial mass (eg, tumor in the posterior fossa, cerebellar hemorrhage) compresses the brain stem, kinking it and causing patchy brain stem ischemia. The posterior 3rd ventricle becomes compressed.
What are signs of herniation?
Symptoms
- High blood pressure.
- Irregular or slow pulse.
- Severe headache.
- Weakness.
- Cardiac arrest (no pulse)
- Loss of consciousness, coma.
- Loss of all brainstem reflexes (blinking, gagging, and pupils reacting to light)
- Respiratory arrest (no breathing)
What is a Subfalcine herniation?
Subfalcine hernia, also known as midline shift or cingulate hernia, is the most common type of cerebral hernia. It is generally caused by unilateral frontal, parietal, or temporal lobe disease that creates a mass effect with medial direction, pushing the ipsilateral cingulate gyrus down and under the falx cerebri.
What is Duret hemorrhage?
Duret hemorrhage is a small hemorrhage (or multiple hemorrhages) seen in the medulla or pons of patients who are rapidly developing brain herniation, especially central herniation.
How is brain herniation diagnosed?
Computed tomography or magnetic resonance imaging is done to diagnose brain herniation. Doctors treat causes if possible and take measures to support breathing (such as mechanical ventilation) and to reduce the increased pressure within the skull.
What is a transtentorial herniation?
The midbrain passes through this opening and is continuous with the diencephalon.[2][3] A transtentorial herniation is any parenchymal herniation through the tentorial notch; of which there are three kinds: Brain herniation is the movement of brain parenchyma from one cranial compartment to another.[1]
What is the difference between ascending and descending transtentorial hernia?
Transtentorial herniation is a type of cerebral herniation. There are two types: descending transtentorial herniation, more frequently known as uncal herniation. ascending transtentorial herniation, which is less common than uncal herniation.
What is the imaging spectrum for cerebral hernia?
Cerebral herniation is a potentially life-threatening condition that needs to be diagnosed promptly. The imaging spectrum can range from subtle changes to clear displacement of brain structures. The radiologist should be able to identify the main imaging features of the brain herniation subtypes.
What should a radiologist know about cerebral herniation syndromes?
Having a thorough understanding of cerebral herniation syndromes and their imaging spectrum is essential. The radiologist should keep in mind that many of these patterns of herniation may overlap and that common complications include compression of cranial nerves, CSF spaces, and blood vessels.