How does uncal herniation cause death?
Brain herniation can progress from a subtle finding of pupillary asymmetry (uncal herniation) to an altered level of consciousness (compression of the reticular activating system), then progressing to the moribund stage of abnormal posturing (compression of the diencephalon and the brainstem), and finally death …
Is uncal herniation the same as Transtentorial?
Uncal herniation is a subtype of descending transtentorial herniation that involves the uncus, caused by increased intracranial pressure.
What does an uncal herniation compress?
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 are clinical symptoms of central 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 Monro Kellie hypothesis?
What finally came to be known as the Monro–Kellie doctrine, or hypothesis, is that the sum of volumes of brain, CSF, and intracranial blood is constant. An increase in one should cause a decrease in one or both of the remaining two.
Why is an uncal herniation associated with a dilated pupil?
Uncal herniation The uncus can squeeze the oculomotor nerve (a.k.a. CN III), which may affect the parasympathetic input to the eye on the side of the affected nerve, causing the pupil of the affected eye to dilate and fail to constrict in response to light as it should.
What is a uncal herniation?
Uncal herniation occurs when rising intracranial pressure causes portions of the brain to move from one intracranial compartment to another. It is a life-threatening neurological emergency and indicates the failure of all adaptive mechanisms for intracranial compliance.
What are the cardinal signs of uncal herniation?
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 differential diagnosis for uncal herniation?
Since uncal herniation occurs after a significant elevation in intracranial pressure, the differential diagnosis would include any conditions with symptoms of a headache, nausea, vomiting, or altered mental status. Some possible differentials for uncal herniation could include:
What is the pathophysiology of uncal hernia?
In uncal herniation, there is usually some supratentorial driving force occurring with a raised intracranial pressure (ICP) causing the uncus to slide over the supratentorial notch. [2] Epidemiology The actual incidence of uncal herniation is poorly understood.
How do you treat an uncal herniation?
When symptoms of Uncal herniation start to become visible, then doctors should immediately act to reduce the intracranial pressure by adjusting the volume of anyone structure of the intracranial chamber that could be a brain, cerebrospinal fluid, or blood. To achieve this strategy, the physician should do the following things: