Neuromuscular disease. Okay, so if you go to Prometrics, and if you see this, run, all right? You're not in the right place. Okay, so you like to know where the lesion is. The last talk was above. So lower motor neuron unit is spinal cord. So it starts here with the anterior horn cell. You get a dorsal root, ventral root. You get a peripheral nerve that's covered with myelin, and then we go down. You get to the end, and then you've got the neuromuscular junction, or the cleft, and then you've got muscle. So I'm going to run us through starting at the anterior horn cells. So what gets patients into trouble with spinal cord injury? They get respiratory failure. So again, you've got this. You can work through it all, but it tells you why. Most important, how do we diagnose it? How do we recognize it? So this is based on an adult, but you look at your vital capacity should be 70 per kilo. Now, there's nothing more annoying than trying to get a seven-year-old to do a vital capacity at two in the morning. Then you get this stat page that you've got to run up, and I'm like, if you do mine right now, it's probably half of what it should be. So you want, but at the end of the day, what you're looking for is they're getting weaker. What's the best way to tell? You want to look at negative inspiratory force, right? So NIF, which unfortunately, it's a negative number. So a man should be able to generate minus 100, a female about minus 75. So as the numbers become more positive or go down, they're getting weaker. Most people would agree between minus 15 and minus 20, it's time to intubate. And this is just to show you what happens as you're losing the vital capacity, why they start to get into trouble. And again, so diseases at the anterior horn cell, just lump them together, polio, West Nile virus, spinal muscle atrophy, they love that one. Because now, if you look at a translational medicine question, we can actually replace the gene that the protein isn't made. So I find it fascinating. You want to take a look at that. And there's much more detail on it in the hour-long session. And then I just want to mention what's new is AFM, acute flaccid myelitis. So I have no idea why, but it's only every other year, even years. You go to the CD website, gone, gone. So I don't know if anybody here has any idea on why that is. Usually associated with enterovirus. Well, the enterovirus is the polio virus is an enterovirus. So again, it causes a problem at the cell body. Then what happens? We've got the myelinated nerve. So we need to be able to stimulate the nerve, and it goes to the muscle, and you move it. So what happens in Guillain-Barre, and they love Guillain-Barre and myasthenia. So what happens is the myelin gets chewed away. And they love it because it describes molecular mimicry. And I just love this concept. Because you always get a kid that's got a viral syndrome or sick two weeks before. It's usually kids coming back from a petting zoo. And so what it is, is because when they're in the petting zoo, it gets gram-negative, like you can, you know, campylobacter. And so they get an infection, they make antibodies to the campylobacter, and it goes away. However, campylobacter, which is here, I can't see. So this is the lipoplasm. So this is gram-negative, this is endotoxin. If you look at that, and you look at the gangliosides, they look alike. So it's an autoimmune phenomenon triggered by, and there's animal models with mycoplasma. It can happen with that, but common things happen commonly. So what they like you to know is if you do a, it's a clinical diagnosis, it's an albino-aminocytotologic. What does that mean? The protein goes up, and the white cells usually aren't above 100. If you tap them early, you're not going to see anything because it hasn't had time for the protein to go up. So when are you going to intubate any neuromuscular disease of these kids? The vital capacity is down to 15 or 20. I showed you the triangle, alveolar hypoventilation. Blood gases are not the way to go because sometimes they're so in you, nobody wants to do them anymore. By the time you do them, the kid cries, hyperventilates, and the CO2 is going to be normal. So it doesn't work. So Guillain-Barre starts at the bottom, works its way up. They love to compare. Botulism starts at the top, works its way down. Botulism releases a toxin that binds with the… prevents the release of acetylcholine. So you think about acetylcholine, I need it to contract and relax my muscle. Now all of a sudden, I can't relax it. What happens? Well, I become flaccid, sort of flaccid paralysis, again, a lower motor neuron disease. So it usually starts up top, so the oculomotor, they usually have difficulty swallowing. It goes this way, Guillain-Barre comes this way, and tick paralysis. So tick paralysis can look the same way. You have to look for the tick. I remember Neuro one day fighting outside a PICU, and I forget what we were fighting about. But anyway, a nurse let out an ungodly scream because this girl had long black hair and she's brushing it and she found the tick. So there's papers out there, like the occurrence of whatever, it's because she had long black hair. If you look at a tick on my head, it's going to be pretty easy to find. So but it's interesting, once you remove the tick and the toxin, everything goes back and it can release the acetylcholine again. So things go back to normal. So you got to watch the tick. Well, some hair is harder than others to find it. Anyway, my daughter laughs that that was a picture of me. You can buy a special device. I see people spend hours, do we turn clockwise or counter-clickwise? So you can buy for eight bucks, tick off, or you just take tweezers, grab it and pull it out. You just got to get it out. It doesn't really mean, you don't want to leave the claws behind. Oh, so tetanus, so they like tetanus because it's 410, you said 415, and you're telling me I'm safe. All right. I'm going to throw the red flag. Okay. So tetanus, the reason I like to show tetanus, if you look at the face, it's called sardonicus. So this is what your heart surgeon looks like when he comes in in the morning and you started an epidrip after the kid's been on bypass for six hours and cross-clammed for two hours. So I used to say, oh, you got rhesus sardonicus. Never knew what it was. So anyway, but the reason they like to test this is the toxin, the tetanotoxin, gets into the inhibitory neurons in the spinal cord. So the inhibitory neurons keep you from doing this. So you block them, and all of a sudden, they do this. The treatment for this is usually benzodiazepines for it. And then with the masseter spasm, the rhesus sardonicus, there's actually, people argue, well, what about if you use Botox, because the botulin toxin will stay there. So it's kind of weird to treat the most lethal disease known to man with the second most lethal toxin. But anyway, it's out there. So I'm only going to do one more, and then I'm going to stop. And I'm still going to be done early. So myasthenia, the reason I put sleepy up there, allegedly, Walt Disney's seven dwarves are named after seven of his friends. One of his friends had myasthenia. So if you don't remember anything, you just remember sleepy, this will kind of help you. So we talk about the eye droops, they get tired, they get weaker at the end of the day. You ask them to do things, and it sort of just slows down. And what happens with myasthenia is that there's antibodies to the receptors in the cleft. And so what happens is everything works normal. You release acetylcholine, there's just not enough receptors so that you can get a response. I told you these are all over the place, you can look at it. So it's immune-mediated neuromuscular block. And so the release of acetylcholine is normal. And so they get the ptosis, the extraocular. So in the old days, we used to test them by giving them a short-acting anticholinesterase. So we know acetylcholine makes things happen. If you don't have enough receptors, the acetylene floats around and the enzyme that's made in the muscle but stored in the cleft breaks it down. So what you do is you block the enzyme, right, which is like what physostigmine does. And then you've got a lot of ACH around. And even though you've got less receptors, you've got enough ACH that you can actually sort of get by. The way to make the diagnosis is an EMG. And if you think about it, the way the EMG is going to look, if I stimulate and put a nerve here and I'm going to be doing this, if you've got myasthenia, what's going to happen is it's going to, and you see like the myasthenic fade, they call it. So myasthenic crisis. You've got to determine, is the patient got a respiratory infection on top of the myasthenia or are we giving them too much anticholinesterase? So clinically, the way to tell is to look at the pupils. In a cholinergic crisis, the pupils should be small. So that's how you can tell the two apart, which is why I say it's so important to understand the autonomic nervous system in our neuro exam. We're going to skip that. Okay, and we're going to do a question on that, so we'll skip that. Last thing, you did ask your muscle disease. What's the more common one? Duchenne's muscular dystrophy. So you see it. This is what happens. Here's normal muscle. They get older. The muscle gets replaced with bad things, with fat, muscle debris, and things of that sort. As time goes by, they develop severe scoliosis. Their functional FRV goes down, functional reserve capacity goes down. So if you're going to operate on them and do anything for scoliosis, sooner rather than later because they lose 10% a year, but that's how a pulmonary question could present from a neurologic disorder. I just wanted to give you that example. And we already did neuromuscular blockers. So we all know what can cause the prolonged weakness. And I'll stop there. Okay, thank you. Thank you.

neuromuscular diseases

spinal cord lesions

respiratory assessment

Guillain-Barre syndrome

autonomic nervous system