Which of the following is a symptom of uncal herniation?

Uncal herniation refers to a specific type of brain herniation that occurs when the temporal lobe (specifically, the uncus) pushes through the tentorial notch due to increased intracranial pressure. This condition is critical and can lead to various neurological symptoms.

One of the key symptoms is the loss of consciousness, which happens because of the pressure on the brainstem and the reticular activating system that controls wakefulness. As the herniation progresses, it can impair consciousness leading to altered mental states ranging from confusion to complete unresponsiveness.

Bradycardia, or a slowed heart rate, is also associated with uncal herniation. This occurs due to increased pressure on the brainstem, which affects the autonomic centers that regulate heart rate. Therefore, as the herniation presses on these areas, it can lead to a decreased heart rate, a critical sign in a patient with increased intracranial pressure.

Additionally, constriction of the pupils can occur due to the compression of the oculomotor nerve, which controls pupil size among other functions. When the uncus herniates downward, it can put pressure on this nerve, leading to miosis (constricted pupils), especially in the earlier stages