Now moving on to the famous cranial nerves here. Yes. Starting with one and two. So one and two are special because they are in the anterior brain.
They're the only two in the anterior brain, so the front of the brain, which means that they are sensory only. Cranial nerve one is the nose, so that's going to be your sense of smell. So to test this, you're going to have the client close their eyes, and you could either test this one at a time, or you can do both, depending on if there's any impairment noted. So I'm going to say, client, can you please tell me what this smells like? Perfume.
Wonderful, so that was perfume. So then cranial nerve one is intact and you want to use non-irritating identifiable smells so something like coffee, peppermint, cinnamon are always great things to utilize. Not tequila?
Not, oh yes, yes. So then cranial nerve 2 is visual acuity, so vision only. To test far away vision, oftentimes we can use the Snellen eye chart if there's one available on the unit.
And remember, the patient always stands 20 feet away for that. Also, if there's not one available, you can ask the patient to identify, can you read that exit sign over there? So identify reading something far away. For up close vision, you can test their ability to read a newspaper, to read discharge instructions, or to read that Jaeger chart. But if it's not available, a newspaper or discharge instructions works just as well.
And then what we talked about in the eye video is you can also test the pupillary light reflex, and that is the one where you're testing perla. So having the patient look straight ahead and testing one eye and the other, and that's cranial nerve two senses the light, but it's cranial nerve three senses the light. three that moves the pupil in response. Yes.
And that's part of that Perla from the eye video. So one important thing about the pupils is that we like them to have a brisk response to light. If the pupils are slow to respond or if there is no response, remember that the pupils are basically a window to the brain. So if the pupils are fixed or if they say they're blown out or very dilated and don't respond to light, then we get concerned about increased intracranial pressure.
So something could have happened, something is taking space in the brain causing the increased pressure. Either trauma to the brain, a brain tumor, and so some type of swelling or incident, even like a stroke where they could have had some type of bleeding in the brain. So if there is an issue, lots of times they will ask test questions about the pupils where pupils sigh. So if they are slow to respond or have no response, your priority is going to be to do an assessment. especially if it's in the first 24 hours of stroke, you're gonna be watching those pupils for response.
So we're looking at just a full neuro assessment at that point, right? Absolutely. Motor function. I remember working on the ambulance, one of the biggest ones was uneven pupils. If one was blown and one was constricted, it was always like indication of a brain bleed or someone had a trauma, they have a swelling in the brain.
Absolutely. We think stroke, brain injury, brain death, and it is a big cause for concern. Now moving on to cranial nerve three through 20, 12 here. It's all originated inside the brain stem.
So both motor and sensory, just feeling. So starting with cranial nerve three, four, and six, this is our eye movements, correct? Yes.
So that's those cat whiskers. So we have the patient follow the pen light with just their eyes, not moving their head. And we draw three whiskers on one side and we're watching for that smooth, coordinated movement.
So we want smooth, coordinated movement with no nystagmus that involuntary fluttering or dancing of the eye or strabismus, that weak eye, that weak extracular muscles that stray and wander around, which we also talked about in the eye video.