Diagnosing cerebral palsy

- [Voiceover] So, in this video we're going to talk about how we go about diagnosing cerebral palsy. And let's just quickly remind ourselves about what cerebral palsy is. So, when we say cerebral palsy, what we're talking about are a group of disorders that effect a person's ability to move properly. And these movement impairments, they occur because some parts of the brain that control our movements have been damaged or impaired in some way. Maybe by an infection, or lack of oxygen that occurred during really critical periods of development, like during pregnancy, or the actual birth process, or shortly after birth, within the first few years of life. So, let's say that this little boy here is a couple months old, let's say he's nine months old, and he's come in for a routine checkup. So we ask his parents how everything seems to be going, and they express some concern about his motor development. He doesn't really seem to be able to roll over onto his side while he's lying down, and he doesn't seem to be able to sit upright without support, without mom or dad holding onto him. And he also doesn't really seem to be able to grasp his toys very well. So, each of these developmental milestones: rolling over, sitting without support, and grasping objects, these are motor skills that a kid should develop around a particular known age. So at nine months old, our kid here should be able to do all of these things. So the fact that he hasn't reached these developmental milestones yet, will this suggest to us that his motor development is delayed for some reason? And it turns out that this sort of scenario, where it's the parents that first notice that their child isn't meeting some key motor milestones, and then bring it up at a doctor's visit, well, this is often how cerebral palsy is first clued in on. Now, unfortunately we don't really have a specific test that we can use to definitively diagnose cerebral palsy, so instead, to diagnose cerebral palsy, we have to rely on asking the parents questions about the child's movements, do some physical exams on the child, and do some imaging of the child's brain, often an MRI or an ultrasound because they allow us to see any potential areas of damage the best. So, let's do that. So, once we've double-checked that our child here indeed isn't rolling over, or sitting up, or grasping objects like he should be doing at his age, it's then really important that we check with his parents to see if he was ever able to do these things. So, in other words, we want to find out if our kid lost these motor skills, or if he just never developed them in the first place. And the reason that's so important to know is because cerebral palsy is not a progressive disorder. It does not worsen over time. So we wouldn't expect for someone with cerebral palsy to lose skills that they had already acquired, so it's really important that we confirm that our boy here never developed these motor skills before we can continue to consider cerebral palsy as a possible explanation for his delays in motor development. And that point is so important, so let me write it down in the corner here. Cerebral palsy is not progressive. Now you might remember that there are actually quite a few things that can cause cerebral palsy. Let's actually bring out this little timeline here that shows us some examples of things that can happen during these critical periods of development. So, these are just some examples, but that's quite a few different possible causes of cerebral palsy, right? So, one thing that we'll want to do is check to see if mom or our kid here experienced any of these events during pregnancy, birth, or shortly after birth. Did mom have one of these infections while she was pregnant? Was our kid here born prematurely? Or maybe, did he have an infection, like bacterial meningitis, just after he was born? We know that these sorts of events can cause cerebral palsy, so we'd want to find out if any of them had occurred, to make us more or, maybe less suspicious of cerebral palsy. So let's say that we find out that our kid here actually was born prematurely. We'll arbitrarily say that he was born at 31 weeks, instead of at 40 week gestation, like normal. So since prematurity increases the chance of a baby developing cerebral palsy, we're definitely going to consider cerebral palsy as one of the possible explanations for our kid's delayed motor development. But we also know that not all kids who were born prematurely have cerebral palsy, so we can't be too certain just yet. We'll need to look for some more signs of cerebral palsy before we can figure out if it's the right diagnosis. So if we wanted to look for more signs of cerebral palsy, what could we look for? Well, you might remember that, while there are a few different types of cerebral palsy, the most common type is spastic cerebral palsy. And one of the main things that we see in someone with spastic cerebral palsy is really stiff muscles, and the stiffness comes about because of increased muscle tone. So, one thing that we can do to check to see if our kid's muscles are really stiff is we can push and pull on his arms and his legs to see if we feel more resistance than normal. Imagine if you were trying to pull down on your friend's arm while they were flexing their big bicep muscles. Well, this would make it harder for you to move their arm, right? Their arm would feel kind of stiff, and you'd feel more resistance than you would if your friend just relaxed their muscles. Well, this is kind of what it feels like when you try to move the effected muscles in someone with spastic cerebral palsy. It's kind of like the muscles are permanently on, and resisting your efforts to move them. So on our boy here, we can move his arms and his legs and see if we feel any of that extra resistance that would indicate stiffness from increased muscle tone. Now, you might also remember that for someone with another type of cerebral palsy, dyskinetic cerebral palsy, the muscle tone can actually fluctuate. So sometimes the muscle tone ends up being really high and the muscles end up being really stiff, like what we're looking for here. But at other times, the muscle tone can actually be really low, and the muscles can actually feel really floppy. So if we were doing this muscle tone examination here and noticed that the muscles were actually really floppy instead of stiff, we might consider dyskinetic cerebral palsy as a possible cause of our kid's delayed motor development, but because dyskinetic cerebral palsy isn't nearly as common as spastic cerebral palsy, and because there are quite a few other causes of decreased muscle tone or floppy muscles, like muscular dystrophy, or Down's syndrome, or certain infections, we would likely want to rule out some of these other possible causes first, before we set our sites on a diagnosis of cerebral palsy. So while we're here doing some physical exams, there's actually something else we can check for. So when a baby is born, it turns out that they actually have these reflexes that actually disappear. They go away at some point during development. So for example, you know how, if you put your finger on a baby's palm, they wrap their little fingers and thumb really tightly around your finger when they feel it? Well, this is actually a reflex that the baby develops in the uterus, and they are actually supposed to lose this particular reflex when they're about six months old. So this is an example of what we call primitive reflexes: reflexes that a baby is supposed to lose at a certain point in development. And the interesting thing is, as the baby's brain continues to develop after birth, these reflexes get replaced by the baby's new, voluntary motor skills. So, what's interesting is that, when the movement centers in the brain are damaged or impaired, like they are in cerebral palsy, sometimes some of these primitive reflexes either don't develop at all, or sometimes they actually stick around longer than they're supposed to, because the motor impairments are preventing voluntary motor skills from replacing the primitive reflexes. So what we can actually do when we're looking for signs of cerebral palsy, is we can take a look to see if our kid here is maybe missing the primitive reflexes that he's supposed to have for someone his age, and we can also check to see if he still has any primitive reflexes that he should've lost by now. Both of these would suggest to us that something is going on in the movement centers of his brain, and both can be signs of cerebral palsy. Now at this point, we're considering cerebral palsy as the possible diagnosis for our kid's delays in motor development. So our next step would be to take a look at his brain, usually using an MRI or an ultrasound to see if we can find a lesion, a bit of damage that is consistent with cerebral palsy. And we'll look at an example in a sec here, but if we find a lesion, this can help us confirm our cerebral palsy diagnosis. And, what's more, it also might be able to help us figure out exactly what went wrong when the event took place, and how bad the damage is, which can help us figure out what sort of long-term consequences our child might end up with. So, let's look at an example of what we might find. So with our kid, he was born prematurely and is showing signs of cerebral palsy. So one of our concerns is that he has what's called periventricular leukomalacia, which is damage to the white matter around the ventricles, and a cause of cerebral palsy. It doesn't have to be this. There are other causes, too. But let's use periventricular leukomalacia as our example. So let's pull up an example here of an MRI that shows a brain with periventricular leukomalacia. So even if we did find a lesion like we're seeing here, when we looked at the brain and we were really confident with our diagnosis of cerebral palsy, we'd still need to have our kid come back regularly for follow-up visits while he's growing up, because again, even though the damage resulting in cerebral palsy is not progressive, new motor limitations might crop up as he develops and his brain is challenged in new ways. Things might seem one way now, but what about when he wants to start running upstairs or climbing trees? So this is another reason why it can be really difficult to figure out which particular type of cerebral palsy a kid has at a young age like this. So we'll likely need to keep seeing him over the next few months, or maybe years, before we can start to see more of a pattern to his movement abilities and limitations. And that way, we can make a more precise diagnosis.