Neuro: IntraCranial Pressure (ICP) – Answers

1) What is ICP?

It’s exactly what it sounds like, just think about what each word (or word part) in the name means.

Intra-: Inside

-Cranial: Skull

Pressure: an applied force

So…ICP is: An applied force inside the skull. In other words, there’s pressure on the brain. And that’s usually a bad thing.


2) What are the 3 things inside the skull that affect ICP?

  1. Brain
  2. Blood
  3. CerebroSpinal Fluid (CSF)


3) If one or more of those things increase and the body can’t compensate by reducing one of the others, then the ICP will increase. Identify some causes of ICP.

  1. 3 types of Cerebral Edema (brain swelling)
    • Bleeding in the brain. Something happens that causes the blood-brain barrier to break down, and allows fluids such as blood to leave the capillaries and enter the brain space.
    • Brain cell death. We’re not just talking 1 or 2 neurons here, but an area of cell death that might be caused by something like trauma or hypoxia (lack of oxygen). And whenever cells die, your body sends the clean-up crew (remember those white blood cells (WBCs)??), and they cause inflammation and swelling in the brain just like they would anywhere else in the body.
    • Increased fluid in the brain. This is usually going to be due to an increase in CSF. One possible cause is the ventricles in the brain are blocked, and so excess CSF can’t move down into the spinal column (ever heard of a VP Shunt? This is why that do that…)



4) Almost everyone knows that dilated and fixed pupils are a sign of ICP. This means that the pupils are big, and stay big even when you shine a light into them. But did you know that this is a very late sign of ICP? As a nurse, if you’re only noticing s/sx of ICP at that point, then either the ICP progressed very rapidly, or you’d better have some good malpractice insurance! Most test questions are going to want you to know how to catch ICP early. So what are some earlier signs of ICP that you should be assessing for?

    • Early signs of ICP

·        Changes in vision (increased blind spot, blurred vision)

·        Unilateral pupil dilation (one pupil is dilated, the other responds normally…for now)

    • Variable signs of ICP (sometimes early, sometimes late, sometimes never!)

·        Headache (and it will be a BAD one…Tylenol won’t help this pain!)

·        Vomiting (because ICP is putting pressure on the areas of the brain that control your autonomic nervous system)

·        Seizures

·        Alteration in level of consciousness (LOC)

    • Late signs of ICP

·        Decorticate (flexion positioning) -> progressing to -> Decerebrate (extension positioning)

1.      What are they? A picture’s worth a thousand words, and a video’s even better. Don’t try to follow everything he’s narrating, but focus on what these positions look like:

2.      I’ve always had trouble remembering which was which. Here’s a few ways, tell me what works best for you!

a.       DeCORticate = arms are flexed towards the CORE

i.      Since decorticate means you are still ‘protecting’ your core, that is a good thing…because it is better than decerebrate, where you’re not…

b.      If you love to decorate, then decorticate sounds similar, just imagine yourself shopping at a decorating store and pulling in all those good deals!

c.       Decorticate sounds like ‘courting,’ which was the old fashion style of dating. Anybody want a hug?

·        Oh, yeah, and death’s a pretty late sign, too.