“When we think of Parkinson’s disease we might just picture the shakiness, the tremors that someone has, those things that we can see. That is kind of what I used to imagine before I started learning a little bit more about the disease.
Parkinson’s does cause these things. It does cause shakiness and other problems related to movement, but it’s a lot more than just a movement disease.
The reason it’s able to be this, the reason it’s able to do all these things and cause more problems than just movement is because a big part of the disease is this breakdown in these really important neurons in the brain, called dopamine neurons.
This breaking down of these neurons is actually a pretty big deal. It’s a big deal because neurons really rely on each other to send messages, send messages all across the brain to complete the tasks that week we can count on for, like maybe allowing us to remember where we left our keys, or letting us calculate something in our head.
All this communicating kind of I works like that telephone game that you might have played when you’re younger. And that telephone game, it goes a little something like this:
So, we’ve got a bunch of people that kind of are in this sort of network. And the aim of the game is to get the first person to send a message to the last person.
But the trick is that all these people in the middle of these people, in between, tell each other the message and it has to stay the same so that the last person can get the message that the first person said.
Person A will tell person B the message. Maybe the message is instructions on how to get from one part to the city to the other.
We need person B to tell person C the message, and person C will then tell person D and so on and so on until the message reaches our final person, the person that needs to get across the city.
For their correct message, the correct instructions on how to navigate the city, in order for these to get from this first-person to the last person we really need all these people here in this little network, we need them each pass along the correct message.
If even one of them kind of messes it up a little bit, maybe says the wrong street name or the wrong bus number, the whole message will be changed.
This is kind of how neurons talk to each other in the brain. This is kind of how they talk to each other to get things done. The work in this network really relies on each other.
When these neurons breakdown, as they do in Parkinson’s disease, this whole network can be kind of thrown off because the telephone game- it doesn’t work very well without everyone’s help
All these different tasks that these different neurons were involved in- well, when the network is thrown off, these tasks can be thrown off too.
To see what happens when this goes on in Parkinson’s disease lets first head over here, to the nose. So, what can happen in this part of the brain, and this little area here, which we call olfactory bulb?
You can see the olfactory bulb here. This area, it helps us smell things. When neurons in this little area here, when they stop functioning, stop communicating in this way that we just had talked about, the person can actually start to have trouble with their sense of smell.
Maybe they can’t really smell at all, so if you put something in front of them, like a bowl of chicken noodle soup, they might not really be able to tell you what it was if their eyes were closed.
Or instead of not be able to actually smell they might have trouble deciding the difference between two different smells.
These problems with smell are actually really common in Parkinson’s disease. They can actually be one of the first things that goes wrong sometimes before even those movement problems that we think about when we think of this disease.
If we head back over here and we look at these regions in the brain, here we’ve got one of the frontal lobes, and this area here called the limbic system. These areas can work together to help us with our moods, they deal with mood related things.
If neurons in these areas have trouble with their communication, when they break down, what can happen is the person can have trouble with their mood.
Some of these things that happen in Parkinson’s disease can be depression, and they might also start to feel really flat kind of like they’re just they’re not interested in anything at all. They don’t want to go outside for a run like they used to. Or they really don’t want to watch their favorite TV show. We call this kind of flat feeling apathy.
Maybe they actually start to feel really anxious, a lot of anxiety, like they’re really worried about things that would have never bothered them before.
They can even start to feel quite panicky in certain situations, maybe when a lot of people are around or they’re doing something new.
These are some of the mood problems that can arise when these areas in the brain have neurons that just are not really communicating very well.
Maybe because of a combination of these problems with their mood, or some of the other symptoms that they’re having, or because their medication for these neurons mis-communicating, the person can start to have trouble with their sleep. They may find it really hard to even get to sleep.
Or they might have trouble staying asleep. You know how it’s really hard to focus at school or to focus at work, after you’ve only had a few hours of sleep?
The person with Parkinson’s disease can also have this feeling. But it can happen, again and again, day after day, so it can become quite a big problem.
All of this kind of adds up. And it can also make some of their other symptoms worse because they’re lacking all this sleep.
Some of the things that can get worse are things like depression, or their anxiety. And as time goes on and on and more and more these neurons are impaired and lost, the person with Parkinson’s disease may have trouble doing things like multitasking.
They may find it really difficult to maybe be on the phone and write down a number at the same time, while someone else in the room was watching television. These are some of the things that normally wouldn’t distract them but may start to really make it hard for them to accomplish a task.
They also might find that they’re getting a little forgetful. They might maybe be at the grocery store, and they’ll come out to their car and just forget where they parked.
Over time, this can get worse and worse. And it can actually develop into dementia.
Dementia is kind of a general term that we use, to describe people who are having a lot in trouble with these things, like memory and multitasking. And they’re having trouble to the point where really it affects their day-to-day life.
Some other things that can happen, is Parkinson’s disease can affect this really important system that we have that we call the autonomic nervous system.
We call it the autonomic nervous system because the neurons in this system, they control things that we think of as automatic. Like digesting food or controlling our heart rate or even keeping our body at the right temperature.
When neurons stop talking properly, when they are having trouble with the telephone game, the person with Parkinson’s disease may get things like constipation because they’re not digesting very well, or light headedness when they stand up because their heart rate is not really changing to account for them sitting down or standing up.
Maybe they’ll find it there sweating a lot, and that’s because their body isn’t regularly temperature properly. These are just some examples, and there’s so many examples of some of the more common symptoms that are related to movement.
But people with Parkinson’s disease have a really individual experience, so they may find they experience different symptoms than these, and they may find that certain symptoms are a lot worse for them than they are for someone else with the disease.
One thing that can really change between each person with Parkinson’s disease is when all the symptoms start. There are no strict rules or guidelines in the body for when the symptoms start, it is very different from person to person.”
Video transcription taken from video Khan Academy Non-movement Symptoms of Parkinson’s Disease by Emma Giles. Image: Parkinson’s UK