Cranial Nerve XI & XII - Accessory and Hypoglossal Nerve - Ultimate Guide - Dr Gill

For the penultimate cranial nerve, we have cranial nerve 11, the spinal accessory nerve. This provides innervation to the trapezius muscles, over the shoulders, allowing us to shrug, and to the sternocleidomastoid muscles, around the neck, allowing us to turn the head. We start off examining for the accessory nerve by putting our hand against the patient's head and getting them to turn their head toward our hand, thus engaging sternocleidomastoid muscle. We then test the trapezius muscle by getting the patient to shrug their shoulders up against resistance. If there is weakness to the shoulder, then we know that there is a problem with the nerve on the same side, whereas if there is weakness in pushing the head into the hand, then we know that there is an issue on the contralateral side, the opposite side to that affected. And we finish off the cranial nerve examination by getting the patient to show us their tongue. Here we're looking for any signs of vesiculation, any wasting of the tongue, and any problems they may have had during the examination, speaking to us. Now the final bit, if you could stick your tongue out for me please, okay, and there's no problems there, and put the tongue to the side of your mouth, I'm going to push back, and then the other side please. I know we've been having a reasonable conversation throughout, but if you could just finish off by saying A, E, I, O, and U please. A, E, I, O, U. Excellent, so we've had no problems with your cranial nerve, so we can give you a clean bill of health on that. Do you have any questions for me? No. Super, thank you very much for your time. The classic teaching at medical school is that the tongue never lies, and what we mean by this is when the patient sticks their tongue out, if there is a cranial nerve 12 lesion, then the tongue will deviate toward the side of the lesion, because it is weak on that side, and the healthy side of the muscle is trying to push the tongue forwards, but as a result ends up pushing it round to the side. We confirm any such weakness by getting the patient to push their tongue into the side of their cheek, whereupon we will push against it. The weak side of the tongue, i.e. the side toward which the tongue deviated when we asked the patient to put it out, will be weak when they push against the side of their cheek compared to the opposite. Well, I've now got random bits of cranium all over the place. I hope that that has been useful to yourselves about understanding some of the bits of the cranial nerves, but specifically what it is that we're doing during the examinations. So, I've tried to do these a few times now. So, we've done understanding the examination where it's been a straightforward podcast. We've now done understanding the examination whereupon I've been using sort of all the props that we've got here, which has been best for in terms of engagement and understanding what we've been talking about. I'd be really grateful if you could shout out down below in the comments and help us to make these videos better for you guys at home. Okay, well, I'm going to leave you at that and get all of this put away. If this has been useful to you, please give it a like, subscribe, make sure you click the bell icon because I do try and get involved in the community page here, so sticking up bits talking about the latest videos that are coming and also trying to get feedback from you guys on how we can improve and build a better channel here. Okay, well, have a good evening and I'll see you later. Cheerio.