If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content
Current time:0:00Total duration:8:54

Video transcript

you may have heard of Parkinson's disease before maybe when you heard of someone raising money for the Michael J Fox foundation or maybe you've listened to Muhammad Ali speaking about the disease well both of these guys actually have Parkinson's disease and they've done a really good job at raising money for and awareness of the disease but what exactly is Parkinson's disease Parkinson's disease is a progressive neurodegenerative disease we call it a progressive disease because it progresses it worsens over time and we say that it's a neurodegenerative disease because during the disease there's actually a loss a degeneration of neurons in the brain now in Parkinson's disease we actually see a loss of a particular kind of neuron and these neurons are called dopamine neurons and dopamine neurons make a little signaling chemical called dopamine which is really important for allowing us to make normal movements and a lot of these dopamine neurons live in an area of the brain called the substantia [ __ ] and the substantia [ __ ] we can see here and it sits here in the brain above the spinal cord in a part of the brain called the midbrain and when these neurons are lost there's a reduction in the amount of dopamine in the brain and again that's because these neurons they used to make a lot of our dopamine and now they're not here anymore and this is the really important part because when there's this reduction in dopamine that's when we start to see the main movement signs of Parkinson's disease so let's talk about these signs one of these signs is shakiness which can often be in the form of a tremor maybe in the hand or the finger a second sign is stiffness and that stiffness is felt when the person bends part of their body maybe the arm or the leg or the wrist so when they're bending that body part let's say it's the arm the movement just isn't very smooth it doesn't feel very fluid anymore and instead it actually feels really rigid a third sign is slowed down movements and this happens because it actually takes the person longer to complete a movement a good way to think about this is to imagine the last time you're in water maybe you went to the pool or you went to the beach to go swim in the ocean so you can probably remember trying to do a somersault underwater or maybe running away from your friends and if you think back you can remember that it actually took you a lot longer to do these things in water than it would have if you were on the land well that's kind of what it's like for someone with these slow down movements they can do them it just takes a lot longer for them to do them and the fourth main sign is problems with balance feeling really and steady or really unstable when standing or walking around now not all patients with Parkinson's disease will have all of these problems but most will have them at some point during the course of the disease now this last one that we talked about the problems with balance that usually crops up later on once the person has had the disease for quite a few years so it's actually these first three that are normally used to decide whether or not someone has Parkinson's disease and all these main movement signs together actually form a symptom complex called parkinsonism or parkinsonian syndrome so that means that Parkinson's is actually a disease that causes parkinsonism and there are a few other neurodegenerative diseases that can cause parkinsonism this symptom complex that we're talking about but Parkinson's disease is the most common so because of this we often call parkinsonism caused by Parkinson's disease primary parkinsonism and then we often call parkinsonism cause by other neurodegenerative diseases secondary parkinsonism now Parkinson's disease doesn't just cause parkinsonism remember that this is a disease of the brain and when things break down in our brain our master control center there's often more than one kind of symptom people with Parkinson's disease can also experience psychiatric problems such as depression cognitive problems such as memory loss and trouble with concentration and lots of other non movement symptoms this can include problems with their sense of smell and problems with their sleeping patterns and the causes of Parkinson's disease are actually largely not known for the majority of cases we actually don't know what triggered the disease so we call these cases idiopathic idiopathic meaning that the cause is unknown and while in the vast majority of cases there is no family history of the disease about 15 percent of people actually do have a family history and for these people their Parkinson's appears to be caused by a mutation in one of a few different genes and depending on which gene is the culprit a mutation can either cause Parkinson's disease or it can increase a person's chance of getting Parkinson's disease so if someone has a problem with one of the genes that can actually cause the disease they'll definitely develop it but if they have a problem with one of the genes that can increase the chance of getting Parkinson's disease they may or may not develop a disease but they are more likely to then someone who doesn't have the mutated gene so genetics are the culprit once in a while but again most of the time we don't know what caused Parkinson's disease but despite this there are some risk factors associated with developing the disease and a risk factor is something that increases your chances of developing a disease so you could say that having a certain gene mutation is a major risk factor for Parkinson's but there are some other non genetic risk factors as well for example exposure to certain pesticides and some cleaning chemicals older age so once you get to about sixty years old your risk of developing Parkinson's disease increases and it continues to go up with each passing year so as well we have a history of concussions as a risk factor of Parkinson's disease and gender so for some reason we're not entirely sure yet men are a bit more likely than women to develop the disease and another risk factor is regularly breathing in heavy metal particles like copper or manganese or lead so maybe if you've lived in an industrial area where those might be found in the air so again these are risk factors for Parkinson's disease which means that they're associated with a higher chance of developing the disease so the treatment of Parkinson's disease will normally involve medication to help deal with the movement symptoms and to do that the way that many of these medications work is by replacing or increasing dopamine levels in the brain because remember our dopamine-producing neurons have degenerated during the disease and for some patients the medication works great it may be all that they need to minimize their symptoms but for most patients after they've had the disease for several years their medication just doesn't really cut it anymore so when this happens they may have surgery to help deal with their symptoms and the goal of surgery is to inactivate areas in the brain that are causing their movement problems like that shakiness or stiffness that we talked about earlier so this brings us the long-term outlook for someone with Parkinson's disease well unfortunately Parkinson's disease is a progressive disease so the disease will continue to develop over the years after diagnosis is made while none of our current methods are able to stop the disease medication and surgery can be really helpful for managing symptoms and making sure the person with Parkinson's disease has a high quality of life for as long as possible I just want to mention a common misconception that can crop up when we hear about Parkinson's disease which is that Parkinson's disease only occurs in older people so while it is true that the average age of this is around sixty to sixty-five about five to ten percent of patients are diagnosed before the age of 50 so this is often referred to as young or early onset Parkinson's disease for patients with young Parkinson's disease those gene mutations we talked about earlier seem to be the cause more often than they are for patients diagnosed in that average 60 to 65 year old range