What structures are affected with Transtentorial herniation?
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 uncal herniation produce ipsilateral hemiparesis?
The cardinal signs of uncal herniation are an acute loss of consciousness associated with ipsilateral pupillary dilation and contralateral hemiparesis. These symptoms are due to compression or displacement of ascending arousal pathways, the oculomotor nerve (CN III), and the corticospinal tract.
What is the 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.
How does herniation cause death?
Because herniation puts extreme pressure on parts of the brain and thereby cuts off the blood supply to various parts of the brain, it is often fatal.
What is brain hernia?
Brain herniation occurs when something inside the skull produces pressure that moves brain tissues. This is most often the result of brain swelling or bleeding from a head injury, stroke, or brain tumor. Brain herniation can be a side effect of tumors in the brain, including: Metastatic brain tumor.
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). This is recognized at autopsy as Kernohan’s notch.
What is ipsilateral pupil dilation?
A unilateral, ipsilateral (on the same side as the lesion), fixed dilated pupil is the initial focal sign, followed by bilateralfixed dilated pupils, occurring anything from minutes to hours later.
Which of the following are signs of brainstem herniation?
Signs and symptoms may include:
- 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)
Can a transtentorial herniation be reversed with hemiplegia?
Transtentorial herniation classically presents with a dilated pupil ipsilateral to the compressive lesion (ipsilateral CNIII damage) with contralateral hemiplegia (ipsilateral cerebral peduncle compression causing contralateral motor findings). However, either component can be reversed.
What happens to the brain with trans tentorial herniation?
Trans-tentorial uncal herniation leads to compression of the third nerve against the tentorial edge, resulting in a constriction followed by dilatation of the ipsilateral pupil. There may be infarction within the temporal or occipital lobe owing to compression of the calcarine branch of the posterior cerebral artery as well.
Which is herniation of the ipsilateral cingulate gyrus?
Subfalcine Herniation In subfalcine herniation, the ipsilateral cingulate gyrus gets migrated beneath the anterior falx, resulting in infarction along with the distal territory of the anterior cerebral artery. 2. Transalar (transsphenoidal) Herniation
Which is a symptom of ascending transtentorial herniation?
Patients may exhibit characteristic triple components of Cushing triad constituting of hypertension, bradycardia, and irregular respirations. Ascending transtentorial herniation can compression posterior cerebral or superior cerebellar arteries against the tentorium. 5. Cerebellar Tonsillar Herniation
