How does Parkinson’s Disease get diagnosed?

PD is a complicated disease and diagnosing it is very complex and sometimes challenging, especially in the early stages of the disease. There is not a specific blood test of biological marker that can be used to diagnose the disease. Researchers are working on this now and the hope is that one day there will be a diagnostic test! Stay tuned!

Because there is not a specific test we can use to diagnose the disease, diagnosis must be made by a trained clinician- usually a neurologist. The neurologist takes a thorough medical history and reviews the signs and symptoms to make a differential diagnosis. A differential diagnosis basically means the doctor rules out the possibility that the signs and symptoms could be explained by something else. The doctor rules out the possibility that the presenting symptoms are not caused by another disease process or even by medications a person is taking (it can happen!) Once other explanations are ruled out, the person can start a course of treatment for PD and see if it helps. If it helps, that’s a pretty reliable indicator that the person has PD.

 So what are these signs and symptoms that the doctor uses to make his/her differential diagnosis? Well, remember how PD is largely movement related? So these signs and symptoms used for diagnosis are mostly movement related too. To get the diagnosis of Parkinson’s the person needs to meet a symptom criteria. They must have bradykinesia (slowed movement) and either tremor or rigidity or both. There are more signs and symptoms of PD that are NOT movement related and sometimes they show up before the movement problems. Often they are hard to detect though. This video will help you understand some of the non-movement related symptoms doctors use to diagnose PD:

10 key non-movement symptoms of Parkinson's that everybody ought to know about

Now you know the basics of how a diagnosis of PD is made. It is important to be aware of the subtle indicators and note movement related problems but also the non-movement ones because early detection of PD can help in the treatment course!

Check out more resources here:

http://www.parkinson.org/Parkinson-s-Disease/Diagnosis

http://www.pdf.org/en/diagnosis

http://www.mayoclinic.org/diseases-conditions/parkinsons-disease/basics/tests-diagnosis/con-20028488

References:

Chou, K. (2014). Diagnosis of parkinson's disease. UptoDate. Retrieved from http://www-uptodate-com.offcampus.lib.washington.edu/contents/diagnosis-of-parkinson-disease?source=search_result&search=diagnosis+parkinson%27s+disease&selectedTitle=1~150

Giuffre, K. (2010, December 31). 10 key non-movement symptoms of Parkinson's that everybody ought to know about. Youtube. Retrieved from https://www.youtube.com/watch?v=h78x80xAMEk

Parkinson's Disease- tests and diagnosis. The Mayo Clinic. Retrieved from http://www.mayoclinic.org/diseases-conditions/parkinsons-disease/basics/tests-diagnosis/con-20028488

What Causes Parkinson's Disease? How does it work?

We really don’t know. It’s super frustrating, I know. So let's focus on what we DO know: how the disease works and what causes the symptoms.

Remember most symptoms are movement related- shaking (tremors), stiffness (rigidity), poor balance and a general slowness of all movement. These symptoms gradually progress as the disease does. There are other non-motor symptoms that affect a person’s mood, sleep cycle and even use of the 5 senses. The thinking process can also be affected and may sometimes result in dementia.

Now on to how the disease works. It all stems from a reduction in the amount of the neurotransmitter dopamine. Dopamine is a brain chemical that is essential for many things, among them… you guessed it, movement. In PD, a decrease in dopamine causes the movement related difficulties. The neurons that release dopamine hang out the in basal ganglia of the brain (it’s deep in the middle- check out this picture for help!)

The Basal Ganglia

A collection of small structures make up the basal ganglia but the one we care about the most is the substantia nigra. You can spot the substanta nigra because it is darker in color than the rest of brain tissue. This is because the cells there are pigmented. In a normally functioning brain the substantia nigra receives information from the rest of the body via the cerebral cortex. It processes that information and sends it back out to the cerbreal cortex (especially the motor cortex for our purposes). Once it sends the signal out, it influences the actions carried out by neurons in the motor cortex. Dopamine that is required for this signaling to be successful so as you can imagine, this is where problems arise. In Parkinson’s Disease, the cells of the substantia nigra die and they can no longer produce dopamine. This decrease produces the symptoms that contribute to a diagnosis of PD.

It’s super complicated, right? But wait, there’s more. The cells of the substantia nigra don’t just die and disappear. They actually stay in the brain and end up with these abnormal structures made of protein inside. These structures are called lewy bodies. The protein clumps together inside the neuron and this, as you can imagine, causes many problems.

Lewy bodies exist outside the substantia nigra, too. They can clump inside cells all over the brain and cause even more widespread damage. A lot of cognitive problems come along with this and the problem even has it’s own name. Lewy Body Dementia.  

Parkinson’s disease itself is not fatal. People with PD may be susceptible to other conditions that lead to premature death. Among the most common, dementia and pneumonia. It is important to remember that with proper symptom management and precautions, people with PD can live long and productive lives. The best way to help is to educate yourself and those around you!

Check out this video for a visual summary of the pathophysiology of PD!

For you information:

Easier reads:

http://www-uptodate-com.offcampus.lib.washington.edu/contents/parkinson-disease-the-basics?source=see_link

http://www-uptodate-com.offcampus.lib.washington.edu/contents/parkinson-disease-symptoms-and-diagnosis-beyond-the-basics?source=see_link

Super complex and in-depth:

http://www-uptodate-com.offcampus.lib.washington.edu/contents/etiology-and-pathogenesis-of-parkinson-disease?source=search_result&search=parkinson%27s+disease&selectedTitle=4~150

References:

Bergman, H. Deuschl, G.(2002). Pathophysiology of Parkinson's Disease: from clinical neurology to basic neuroscience and back. Movement Disorders. Vol 17 (3). 

Retrieved from

http://onlinelibrary.wiley.com.offcampus.lib.washington.edu/store/10.1002/mds.10140/asset/10140_ftp.pdf?v=1&t=i54h1xns&s=0431b8dfd982d82cfa7f4cc0cc5b7e780c584f24

Jankovic, J. (2014). Etiology and pathogenesis of Parkinson disease. UptoDate.

Retreived on from

http://www-uptodate-com.offcampus.lib.washington.edu/contents/etiology-and-pathogenesis-of-parkinson-disease?source=search_result&search=parkinson%27s+disease&selectedTitle=4~150

Epidemiology of Parkinson's Disease

So who is Mr. Parkinson? James Parkinson was an English doctor who published the first essay about the symptoms of what we now call Parkinson’s Disease. He published this work in 1817 and ever since there has been extensive research and discovery about the disease. Since the days of James Parkinson, there have been an increasing number of cases of PD.

Right now approximately 1% of people over the age of 60 in industrialized countries is living with Parkinson’s disease (de Lau & Breteler, 2006). It is rare for the disease to emerge before the age of 50 and as a person ages, risk of the getting the disease goes up. In fact, for people aged 60-69, approximately 1 in 200 people has PD but for people aged 70-79, 1 in 100 people have PD. And over 80 years old, 1 in 35 people have PD (Tanner, Brandabur & Dorsey, 2008). Parkinson’s is slightly more common in men than women (Lai & Tsui, 2001). It is also more prevalent in developed countries but trends are starting to change. Check out this graph that shows us the prevalence of PD in 2005 by country and then a projected estimate for the prevalence in 2030 (Tanner, Brandabur & Dorsey, 2008).

Distribution of Individuals with Parkinson’s Disease by Country, 2005 and 2030*

Because Parkinson’s affects the lives of so many, we have to ask what causes the disease? Unfortunately there is no simple answer to that question. There is not one particular cause for the disease and many of the influencing factors are poorly understood at this time. Research is going on as I type and that’s pretty exciting! Right now, here is a list of what the experts are investigating:

·      Parkinson’s is likely caused by a complicated interaction of genes and environment that is currently under research (de Lau & Breteler, 2006).

·      Exposure to environmental toxins (pesticides) is a potential cause that is currently undergoing a lot of research with some success in liking these chemicals to an increased risk of developing Parkinson’s (de Lau & Breteler, 2006).

·      Inheritability is being studied. 10-15% of PD cases are familial, meaning the disease runs in their family and may demonstrate a genetic component (Lai & Tsui, 2001).

·      Diet is under investigation as well as drinking habits (both alcohol and caffeine) (Lai & Tsui, 2001).

A diagnosis of Parkinson’s Disease is not a death sentence. People live with the disease for many years with proper symptom management. PD itself is not fatal but life-expectancy may be reduced. This is likely because many patients (25-40%) with PD will develop dementia. Pneumonia is the most common cause of death for someone with PD. This is because a person might have difficulty swallowing and food or liquid may accidentally settle in their lungs instead of their stomach. This can cause an infection in the lungs and a person will develop Pneumonia (Lai & Tsui, 2001).

Research is continuously going on. My hope is that we will learn more about the causes of the disease in the near future so that we can develop more effective care and screening tools to treat and prevent PD.

References:

deLau, L.M.L, Breteler, M.M.B. (2006). Epidemiology of Parkinson's Disease. The

Lancet Neurology 5 (6). Retrieved from http://www.sciencedirect.com.offcampus.lib.washington.edu/science/article/pii/S1474442206704719

Lai, B.C.L., & Tsui, J.K.C. (2001). Epidemiology of Parkinson's Disease. BC

Medical Journal, 43 (3). Retrieved from  http://www.bcmj.org/article/epidemiology-parkinson%E2%80%99s-disease

Tanner, C.M., Brandabur, M., Dorsey, E.R. (2008). Parkinson Disease: A Global View.

Research Reports. Retrieved from http://www.parkinson.org/NationalParkinsonFoundation/files/84/84233ed6-196b-4f80-85dd-77a5720c0f5a.pdf

Understanding Parkinson’s Disease

Who is Mr. Parkinson and What’s the deal with his disease?

Parkinson’s Disease is a complicated neurologic disorder that affects over 1 million people in the United States today (Parkinson’s Disease Overview, National Parkinson Foundation, 2015).  Because it touches the lives of so many people, my objective for this blog is to break down the complex information into manageable bits so that anyone can better understand the disease.

What is Parkinson's? Infographic

Michael J. Fox.org

Let’s start with a simple definition of the disease. Parkinson’s Disease affects a part of the brain that deals with movement. It destroys cells that produce a neurotransmitter (brain chemical) called Dopamine. We’ll talk about more specifics later but for now the most important part to remember is that Parkinson’s destroys certain cells in your brain that normally help control movement. Because these cells are damaged, a person that has Parkinson’s Disease will have many problems with movements. Think weakness, slow movement, or shaking (tremors). This can make activities such as walking, or even holding a fork, more challenging.

Parkinson’s is a progressive disease, which means over time it gets worse. This sounds like bad news. But the good news is that it happens pretty slowly and people with the disease work with their healthcare team to come up with different ways to manage the symptoms.

(Understanding Parkinson's Disease- the Basics, WebMD,2015).

Think about anyone you know that has been touched by Parkinson’s disease. Keep them with you as you read this blog and try to relate what you learn to your experience with that person. Please do keep in mind that everyone is different though!

If you don’t know anyone with the disease, here are some familiar faces to help you get acquainted:

Ryan Reynolds, Michael J. Fox Team Up Against Parkinson's | Today

Ok so who is this Mr. Parkinson? Well, his first name is James and we’ll have more on his later when we talk about epidemiology. Stay tuned! 

Parkinson’s Disease Overview. National Parkinson Foundation. http://www.parkinson.org/parkinson-s-disease.aspx. Accessed January 9, 2015.

Ryan Reynolds, Michael J. Fox Team Up Against Parkinson’s | TODAY [Video]. Youtube https://www.youtube.com/watch?v=sJTQ9G4eQ2o. Published November 26, 2014. Accessed January 9, 2015.

Understanding Parkinson’s Disease- The Basics. WebMD http://www.webmd.com/parkinsons-disease/guide/understanding-parkinsons-disease-basics. Accessed January 9, 2015.

What is Parkinson’s? The Michael J. Fox Foundation. https://www.michaeljfox.org/page.html?what-is-parkinsons-infographic. Accessed January 9, 2015.