Movement signs and symptoms of Parkinson's disease
- [Voiceover] Just before we jump into the movement-related signs and symptoms of Parkinson's disease, let's remind ourselves of what Parkinson's disease is. And that's a progressive brain disease. And this progressive disease, it ends up causing a reduction in the amount of a signalling chemical called dopamine. And when dopamine levels are lowered, what we really see are a bunch of problems with movement. So there are four main movement signs that we talk about when we're talking about Parkinson's disease. And we call them the main signs because they're usually the ones that we look for if someone actually has the disease. Not everyone with Parkinson's disease will develop all of these signs, but most people will at some point in the disease. And as the disease worsens over the years that the person has it, because remember, it's a progressive disease, these signs and symptoms usually worsen as well. The first main sign that we'll talk about is a tremor. And this tremor usually starts off in the hand or maybe in the finger. A tremor is involuntary shaking. And it actually happens because of lots and lots of relaxations and contractions in our muscles. You've probably noticed before that your hands can get a little shaky when you do certain things, maybe doing something like threading a needle. People are always making fun of me for having rips in my jeans, so I'm always patching them up, and I find that my hands get super-shaky when I'm threading a needle. Or maybe you've noticed it when you've done something like putting eye drops in your eyes. But the kind of tremor that someone with Parkinson's disease has, it's a lot worse than this. It's more frequent, and it's more debilitating. And we actually have a name for it. It's a particular kind of tremor called a resting tremor. A resting tremor happens when the body part is as it sounds, at rest. And the tremor actually stops when the body part is not at rest. So a good way to think about when a tremor would and wouldn't be around, is to imagine that you're about to go and grab a pen. If you had a resting tremor, your hand would be shaking before you went to grab for the pen, when it was just resting on the table. And this is because the hand would've been at rest. You wouldn't have been using it. But once you actually started to move your hand, your hand and the muscles in your hand wouldn't be at rest anymore, you'd be using them. And so the tremor would actually stop. So this sounds okay, you may be thinking, "Okay, I'll just make sure I'm always moving my hand." But it's not that easy. For a lot of people with Parkinson's disease, they actually still have trouble writing because the tremor can return again once they've finished grabbing the pen, and they're just holding their hand ready to write. So resting tremors are just one of the types of tremors that are out there, and there are lots of other different types that you may see in different conditions or even in just normal healthy people. But it's these resting tremors that are the kind that we see in someone with Parkinson's disease. The next main movement sign that we'll talk about is rigidity. Rigidity basically feels like really, really stiff muscles. When someone with rigidity goes to bend their arm, say they were gonna pick up some food from their plate and put it in their mouth, the movement between the plate and their mouth wouldn't be one smooth movement like it normally is. Instead, it's kind of like that movement happens in a few jerky movements, rather than that one smooth movement. We actually have a name for this series of jerky movements as someone with Parkinson's disease has. And it's called cogwheel rigidity. We call it cogwheel rigidity because this movement, in this case, bending the arm, it kind of looks like cogwheels moving together in that clunky sort of way. You know, like the cogwheels that you would see in a grandfather clock, for example. This rigidity, this feeling of stiffness that causes these clunky movements, it's not just a feeling for the person with Parkinson's disease. Their arm actually is more rigid. So it's not just something that's in their head. A third main movement sign is these really slow movements, and we actually call these slow movements bradykinesia, where the word brady means slow, and the word kinesia means movement. So for the person with bradykinesia, it can feel like a few different things. It can feel like weakness, or maybe fatigue, or even just this kind of general feeling like they can't move the body part that is affected. And there are actually lots of parts of the body that can be affected. This bradykinesia could happen just in one limb, or it can even happen to one whole side of the body, and it can even happen to the whole body. This bradykinesia, this slowing down of movements, actually makes it really hard for the person to complete movements at a normal pace. So to picture what this is like, imagine the last time you were in a swimming pool. Maybe you were just trying to walk around from one point to another, or maybe you were running in the water because you were trying to catch your friend who stole your ball. You can probably remember that walking or running in the water was really slow. It takes you a lot longer to do those movements when you're in the water compared to when you're on land. And that's kind of what bradykinesia is like. So the person can do the movements, but they just feel like they're a lot slower. So this is quite a bit different than the rigidity that we talked about earlier. I often find it a little confusing to think about stiff versus slow muscles, they sound kind of similar. So the way I like to think about it, is I think about our muscles responding to the messages that we send them. You know how you tell your arm to move? Well, with rigidity, we send the message to our muscles telling them to move, and our muscles receive that message and they start to move right away. But because of that extra resistance, the movements are just really jerky. But with bradykinesia, we send the message to our muscles telling them to move, maybe we're telling our leg to kick a ball or arm to reach for an apple. And our muscles do receive that message, but it takes them a while to actually respond to the message, to kick that ball or reach for that apple. And it's this delay between us saying to our muscles, "Hey, time to move," and them actually responding is what makes the movements feel really, really slow. Alright, so the fourth main movement sign of Parkinson's disease is postural instability, being really unstable, really unbalanced when standing or trying to move around. We call it postural instability because it's our postural reflexes, which are these reflexes that normally help us stay nice and balanced. It's those that actually stop working. And when these stop working properly, that's when someone with Parkinson's disease starts to get really unbalanced and unstable on their feet. Postural instability is actually one of the signs that crops up later on in the disease, once the person has had it for quite a few years. And it's actually one of the most debilitating movement problems that someone with Parkinson's disease can have. This is because that instability that they feel on their feet can make it a lot more likely for them to have a fall, and makes it really hard for them to stay independent and walk around. So those are the four main movement signs of Parkinson's disease. Other than postural instability, they normally start early in the disease. And over time, they can get a lot worse. And that's because the disease, as we talked about before, is a progressive disease. It worsens over the years the person has it. And not only can these get worse, but they can actually cause a lot of the other movement problems that we see in someone with Parkinson's disease. For example, the tremor, it can be really subtle earlier in the disease. The person may not even notice it themselves. But as the disease gets worse over the months and the years that the person has it, the tremor can actually get a lot worse, and it can even spread to other parts of the body. So if started in the hand or the finger which is really common, it can move to the legs, even the lips or the tongue, so that's something that can happen over time with the tremor. And rigidity can eventually affect a person's posture. They can actually start to bend over all the time into this stooped posture, and this happens because of all the stiffness that they're feeling in the muscles that would otherwise keep them upright. This stooped posture can cause problems as well. With the person being bent over all the time, this can increase their chances of falling and hurting themselves. Because rigidity affects all sorts of muscles in the body, rigidity can also cause other problems. So, later on, the person can actually lose their ability to make facial expressions. They have trouble smiling or frowning, or even showing you how they feel. And it's not because they don't feel anything. It's actually because of all the stiffness that they're feeling in their facial muscles. It makes it really hard for them to move their mouth or their eyes. So those are some of the problems that rigidity can cause over time. And bradykinesia can also cause problems. One thing that can happen is the person can actually change the way that they walk. The person will start to shorten their stride, and they'll start shuffling their feet. The reason this happens is because those slowed-down movements just make it hard for the person to step up so high or step out as far as they used to. One thing that can happen because of bradykinesia much later on, after quite a few years, is they'll be walking around and everything seems totally fine, but then all of a sudden, they'll just stop in place, and they won't be able to even move themselves. And this can last for quite a few seconds. This is because, after quite a few years, those muscle responses have just become so slow. There's actually a name for this, and it's called freezing. We call it freezing because just as it sounds, the person actually feels like they're frozen in place, like they can't even move. And that postural instability that we talked about, that can also cause more problems later on. What can often happen, is the person's balance kind of gets worse and worse over time. And as this happens, they can eventually lose their ability to walk. So they may start off just feeling a little unbalanced. Maybe they can't walk for as long as they normally could, or maybe they just need a little help when they're tired. But after a while, as things get worse, their balance is just so bad that they don't feel safe being upright, and they actually may fall quite a bit.