Main content
Course: Health and medicine > Unit 8
Lesson 10: Parkinson's disease- What is Parkinson's disease?
- What is Parkinson's disease?
- Movement signs and symptoms of Parkinson's disease
- Non-movement symptoms of Parkinson's disease
- The basal ganglia - The direct pathway
- The basal ganglia - Concepts of the indirect pathway
- The basal ganglia - Details of the indirect pathway
- Putting it all together - Pathophysiology of Parkinson's disease
- Genetics and Parkinson's disease
- Diagnosing Parkinson's disease
- Managing Parkinson's disease with medications
- Managing Parkinson's disease with surgery
© 2024 Khan AcademyTerms of usePrivacy PolicyCookie Notice
What is Parkinson's disease?
Parkinson’s disease
Most of us at one time or another have noticed our hands tremble when we are holding a drink, or our teeth chatter when it is very cold out. This is normal. Sometimes though a small tremor is one of the first signs of Parkinson’s disease.
- Parkinson’s disease is a chronic, progressive, movement disorder that affects muscle control and balance. These symptoms gradually worsen over time, and generally other secondary symptoms start to occur.
How your brain coordinates movement and what can go wrong
Parkinson’s disease is caused by a gradual deterioration in the function of nerve cells, or neurons, located in a specific area of your brain. Your brain contains millions of neurons, which process and transmit information. It receives information via neurons from all parts of your body, processes it, and then sends out instructions to other parts of your body to produce specific actions. The information travels along neurons as electrical impulses. When a nerve impulse reaches the junction between two neurons, a chemical neurotransmitter (think of it as a bike courier carrying information from one building to the next) is released that stimulates the impulse in the next neuron so that it continues on to its destination.
Several different areas of your brain are used to process and transmit the information that controls movement, and a malfunction in any of these can cause a movement disorder. With Parkinson’s, the malfunction occurs within an important movement control centre in the midbrain called the substantia nigra. Normally, the neurons in this region produce a neurotransmitter called dopamine. In Parkinson’s, clumps of protein known as Lewy bodies build up inside the dopamine producing neurons, which steadily degenerate and eventually die. The death of dopamine producing neurons means less dopamine, and without enough dopamine other parts of your brain cannot operate properly. Ultimately, this makes walking, reaching for objects and other basic movements very difficult. Additional loss of dopamine in other regions of your brain and in your intestines, is thought to be at least partly to blame for some of the secondary symptoms of Parkinson’s.
What are the symptoms of Parkinson’s?
The primary symptoms of Parkinson’s are related to movement, and vary from one person to the next. Sometimes at the onset of Parkinson’s, you may not even be aware that you have any symptoms. Gradually though, and usually over a period of years, symptoms do become noticeable, and are often of three distinct types:
- tremors - these will typically start in one hand on one side of your body, but you may also feel them in your arms, legs, jaw and face.
- bradykinesia - this is when your movements become slower, making it very difficult to perform even simple tasks.
- rigidity - this is when your muscles are unable to relax, which can affect your posture and make your movements are more jerky. You may even find yourself freezing like a statue in the middle of what you are doing (akinesia).
As the disease progresses, as well as getting slower, Parkinson’s often causes characteristic changes in the way you walk. As a result, you may find you have difficulty starting to walk, are only able to take small shuffling steps, and then have difficulty stopping walking. This is known as Parkinsonian gait. All of the problems with movement are usually accompanied by muscle stiffness that can occur in any part of your body, limit your range of motion, cause you pain, change your posture and disrupt your balance.
There are also many secondary symptoms of Parkinson’s that are not related to movement. Most of these fall into three major categories, autonomic or involuntary symptoms, cognitive and psychiatric symptoms, and sleep disorders; for example, you may lose your sense of smell, find you are sweating a lot, have signs of depression, or have trouble sleeping. However, because every case is unique, it is impossible to predict which of these you might experience. That said, psychiatric symptoms such as nightmares, hallucinations and dementia often become more problematic in the later stages of the disease.
Why do some people get Parkinson’s and not others?
We don’t know what causes the dopamine producing neurons to die in Parkinson’s disease, or why this happens to some people and not others. We do know though that it is very rare when you are young, usually doesn’t start until middle age or later in life, affects men more than women, and seems to run in families. We also know there is a connection between Parkinson’s and head trauma, as well as exposure to some pesticides and solvents. Overall however, none of these risk factors alter the chances you will get Parkinson’s by very much at all.
How common is Parkinson’s?
Overall, around 300 per 100,000 people have Parkinson’s disease. Most people are diagnosed during their 70s; although 15% of cases occur among people who are under 50 years of age. Recent estimates indicate that the number of people living with Parkinson’s steadily increases with age.
How can you prevent Parkinson’s?
Not knowing why someone gets Parkinson’s disease makes it pretty much impossible to know how to prevent it. That said, there is some evidence that caffeine has a protective effect, as coffee drinkers have been found to be at lower risk.
What treatments are available for Parkinson’s?
There are no tests to diagnose Parkinson’s disease. Usually a neurologist who specializes in the brain and nervous system will review your medical history and signs and symptoms, and perform a neurological and physical examination in order to determine whether or not you have it. You may also need to have a brain scan, blood tests, or x-rays to rule out other diseases.
There is no cure for Parkinson’s, but your symptoms can be managed with medicines that help you with tremor, walking, and movement. Once you have been diagnosed, your doctor will be able to advise you whether or not to start treatment. There are many drugs available, but they don’t necessarily work the same for everyone, which means your medication will need to be fine-tuned to your individual needs. One of the most commonly used medications for Parkinson’s is called levodopa. Levodopa is usually taken in combination with carbidopa, which stops the levodopa from being broken down by the body before it reaches the brain. This means lower doses of levodopa can be given, which reduces the frequency of side effects.
Levodopa/carbidopa is usually effective for about 5 years or longer, but after that the effects may wear off, and higher doses are often not an option as they often cause intolerable nausea and vomiting. When this happens adding another type of drug or switching to a new drug formulation may help you to continue to manage your symptoms. Some of the medications available for treating Parkinson’s are:
| Medication | Effects | |
|---|---|---|
| Levodopa/carbidopa (sinemet) | This drug is converted into dopamine in the brain and replaces the natural dopamine that has been lost. It is usually prescribed in the lowest dose possible so as to avoid unwanted side effects. | |
| Dopamine agonists | These medications mimic dopamine in that they are able to transfer information from one neuron to the next in a similar way. They are generally a bit less effective than levodopa and may cause more side effects. | |
| Enzyme inhibitors | Levodopa is usually given in combination with enzyme inhibitors that prevent the breakdown of dopamine in the brain and prolong its effects. In addition, there are some enzyme inhibitors that can be used alone. | |
| Anticholinergic drugs | These drugs are helpful for maintaining dopamine levels, although they generally have severe side effects in older people. | |
| Other drugs | Amantadine is an example of a drug that is sometimes used to treat Parkinson’s. However, its not clear how or why it works, and it is definitely not the first choice. |
If the medications do not control your tremors and movements, there are surgical procedures that can help. One option is deep brain stimulation, which involves inserting electrodes into your brain at precise locations. They are attached to a “brain pacemaker”, which stimulates brain activity and can greatly improve the problems you may have with movement.
There are many other treatment options available that can help you find relief from Parkinson’s symptoms, and enrich your quality of life, including:
- Physical and exercise therapies such as active music therapy, which involves actively participating in making music with an instrument or your voice, treadmill training, and balance training.
- Alternative therapies like acupuncture, massage, and yoga.
- Occupational therapy for help with strategies that enable you to continue living independently for as long as possible.
- Speech and language therapy.
Finally, in addition to the medicines to treat the movement problems you may be experiencing, there are many different medicines available to treat the secondary symptoms of Parkinson’s, such as depression, anxiety, troubles with sleeping, constipation, etc. Your doctor will carefully select compatible medicines to minimize side effects so that you can have the best quality of life possible.
Consider the following:
- Treatment guidelines for healthcare professionals highlight communication as being extremely important to the well-being of patients with Parkinson’s. Why do you think that might be? Good communication between healthcare professionals and patients with Parkinson’s can help empower them to participate in making choices about their care and can provide comprehensive, realistic information that reduces fear and stigma, and provides good reasons for them to feel optimistic.
- Having access to a healthcare team can be very beneficial for a person living with Parkinson’s disease. Why would that be? A patient with a multifactorial disease such as Parkinson’s can benefit hugely from having access to the expertise of a team of experts who can manage the diverse symptoms and side effects, while maximising quality of life. Ideally, the team should include a movement disorder specialist, a speech language specialist, a physiotherapist, an occupational therapist, and a social worker. Working as a team, these individuals are well positioned to access and integrate additional help from nutritionists, psychologists or psychiatrists, as required.
Want to join the conversation?
Is physiotherapy helpful for parkinsons patients?How?(6 votes)
Yes exercise therapies help patients in better coordination of their body parts and muscles(4 votes)
Why would the body breakdown the levadopa before it reaches the brain consequently necessitating a dose of carbidopa to stop it?(3 votes)- You need levodopa to get to the brain in order to treat Parkinson's. To do that, it must cross the blood-brain barrier. But a certain amount of it will get absorbed by the body before that occurs. For the body to absorb levodopa, an enzyme called dopa decarboxylase (DDC) is required.
Carbidopa inhibits the action of DDC, so that less levodopa is absorbed by the body, allowing more of it to get to the brain. Also, when levodopa gets absorbed by the body, nausea will typically result, so carbidopa also helps to reduce nausea. I should add that the standard 25/100 carbidopa/levodopa ratio does not provide enough carbidopa for some patients to prevent somatic absorption of levodopa; supplemental carbidopa (i.e., carbidopa without levodopa) can help with this. However, drug companies have somehow managed to charge a lot more for supplemental carbidopa relative to the cost of the same amount of carbidopa in a levodopa/carbidopa pill. So if you want to stop nausea by taking additional carbidopa, they insist that you (or your insurer) pay them handsomely for that privilege. Nonetheless, it can be helpful for some patients to take additional carbidopa, if you can find a way to pay for it.
Carbidopa cannot itself cross the blood-brain barrier, and so it stays outside the brain. This is important, because if it got to the brain it would break down levodopa before it could be converted to dopamine there. And getting additional dopamine to the brain is the entire reason for taking levodopa in the first place.(1 vote)
In the "What Treatments are Available for Parkinson's?" section of the text, the other medications subheading listed Amantadine as a possible option to treat Parkinson's. There is no statement how or why it works, as well as no further statement via www.Drugs.com outside of the information that it is an NMDA Receptor Antagonist. Is there any updated information regarding that specific prescription and how it treats Parkinson's disease, or if there is any new information for treatment?(1 vote)- Amantadine is an adjunct med that is typically given in combination with Levodopa, carbidopa, MAO type B inhibitors, and COMT inhibitors. As the article states exercise/physical activity is a very beneficial adjust as well, as long as the gait disturbances don't make it contraindicated. Truly the treatment of PD is an art, each patient is unique and requires an optimization of meds and adjuncts to delay disease progression.(6 votes)
Are the XY chromosomes a factor in men getting parkinson's disease more often then women?(3 votes)
That is certainly a possibility! I don't believe they have a specific conclusion yet. You might like this publication: http://jnnp.bmj.com/content/75/4/637.full(4 votes)
- What happens in the last stages of Parkinson's Disease? It would be nice to understand the stages of progression to death.(2 votes)
That answer, sad to say, is completely inaccurate. You can die from Parkinson's (as the tremors get worse and worse, dyskinesia becomes lack of movement at all, etc).(4 votes)
parkinson's disease is not the same as Addison's disease?(2 votes)- Addison's disease is a hormone disorder having to do with the adrenals and that is a gland disease when Parkinson's deals with neurons they are two different things completely.(2 votes)
- well, if you say that there's not really a cure for the disease, it might just sound sort of weird because I have never really known that there is a disease that can't be cured.(0 votes)
- There are tons of diseases which cannot be cured, their symptoms can only be managed. HIV, AIDS, Asthma, Heart Failure, Angina, Epilepsy, to name a few.(9 votes)
Is there any nervous system disease that has cure without side effects on the medicines prescribed by the neurologist?? almost all nervous system diseases have no cure be it Alzheimer's or Parkinson's or anything?? it really scares me that anybody suffering from these diseases will have to be swallowed by the coils of death. How many people can we protect?:((3 votes)- Dr Joel Wallach of (Youngevity 90Forlife)is an expert in these areas. See the book"Epigenetics."(2 votes)
Was there a person that discovered Parkinson's was there name or last name Parkinson's?(2 votes)
The French physician Jean-Martin Charcot named Parkinson's Disease after the British doctor, James Parkinson, who published the first description of the disease in his book An Essay on the Shaking Palsy, written in 1817.(1 vote)
- Does Stuttering comes under Parkinson's category?(2 votes)