Which three symptoms are characteristic of Cushing triad associated with increased ICP?
A.
Bradycardia, hypertension, and widening pulse pressure
B.
Widening pulse pressure, headache, and seizure
C.
Hypertension, tachycardia, and headache
D.
Hypotension, tachycardia, and narrowing pulse pressure
The correct answer and Explanation is :
The correct answer is:
A. Bradycardia, hypertension, and widening pulse pressure
Explanation:
Cushing triad refers to a set of three classic clinical signs that are indicative of increased intracranial pressure (ICP). These signs reflect a life-threatening situation and are caused by the brain’s attempt to maintain perfusion in the face of elevated pressure.
- Bradycardia (Slow Heart Rate):
As the ICP rises, it puts pressure on the brainstem, particularly affecting the vagus nerve (cranial nerve X), which controls heart rate. The increased pressure triggers the parasympathetic nervous system, leading to a slower heart rate. - Hypertension (High Blood Pressure):
The body responds to increased ICP by attempting to maintain cerebral perfusion pressure (CPP), which is the net pressure gradient that drives oxygen delivery to the brain tissue. To do so, systemic blood pressure rises to overcome the elevated pressure in the skull and push blood into the brain, ensuring that it remains oxygenated. This is part of the body’s compensatory mechanism known as the Cushing reflex. - Widening Pulse Pressure:
This refers to the difference between systolic and diastolic blood pressures. As systolic blood pressure increases due to the body’s effort to maintain cerebral blood flow, and diastolic pressure either remains stable or falls, the pulse pressure widens. This widening of pulse pressure is a hallmark of advanced increased ICP.
The development of Cushing triad is a sign of brainstem compression and impending herniation, which can be fatal if not treated rapidly. It represents the body’s last-ditch effort to protect the brain by increasing blood pressure, slowing the heart rate, and widening pulse pressure to preserve cerebral perfusion.
Other symptoms of increased ICP, such as headache or seizures, are also common but not specific to Cushing triad. The triad’s combination of bradycardia, hypertension, and widening pulse pressure is distinctive for severe ICP elevation.