What is tentorial 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.
Which brain herniation is the most life-threatening?
Central herniation Downward herniation can stretch branches of the basilar artery (pontine arteries), causing them to tear and bleed, known as a Duret hemorrhage. The result is usually fatal.
Why can tonsillar herniation be rapidly fatal?
Cerebellar Tonsillar Herniation Increased pressure in the posterior fossa forces the cerebellar tonsils through the foramen magnum. These will compress the lower part of the brain stem and upper cervical cord, resulting in life-threatening consequences.
What structures are affected with Transtentorial herniation?
Transtentorial herniation The herniating lobe compresses the following structures: Ipsilateral 3rd cranial nerve (often first) and posterior cerebral artery. As herniation progresses, the ipsilateral cerebral peduncle. In about 5% of patients, the contralateral 3rd cranial nerve and cerebral peduncle.
How does tentorial herniation occur?
Descending Transtentorial Hernia. Descending transtentorial hernia (DTH) is the second most common type of cerebral hernia. It occurs when brain tissue is displaced downward through the tentorial notch (9). DTH may be divided into two types: lateral (anterior and posterior) and central hernias.
What is the tentorial opening?
The tentorial notch (also known as the tentorial incisure or incisura tentorii) refers to the anterior opening between the free edge of the cerebellar tentorium and the clivus for the passage of the brainstem.
What causes tentorial herniation?
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.
Can brain herniation reversed?
Brain herniation is potentially reversible with appropriate and timely therapy. Reversal of transtentorial herniation has been observed in 50–75 % of adult patients with either TBI [58] or with supratentorial mass lesions [59].
How is tonsillar herniation treated?
The most common surgery to treat Cerebellar Tonsillar Ectopia is posterior fossa decompression surgery. This procedure relieves pressure and compression on the brainstem by removing small pieces of bone in the posterior skull, and in turn enlarges the foramen magnum.
What is the tentorium of the brain?
The tentorium cerebelli, the second-largest dural reflection, is a crescent-shaped dura fold that extends over the posterior cranial fossa, separating the occipital and temporal cerebral hemisphere from the cerebellum and infratentorial brainstem [1,6].
What is most likely to cause brain herniation through the tentorial notch?
Increased intracranial pressure sometimes causes protrusion (herniation) of brain tissue through one of the rigid intracranial barriers (tentorial notch, falx cerebri, foramen magnum).
How do you fix a brain herniation?
Treating brain herniation
- surgery to remove a tumor, blood clot, or abscess.
- ventriculostomy, a surgery that places a drain through a hole in the skull to get rid of fluids.
- osmotic therapy or diuretics, such as mannitol or hypertonic saline, to pull fluid out of the brain tissue.
- corticosteroids to reduce inflammation.