Parkinson Disease and Dementia

What is Parkinson disease?

Parkinson disease is a movement disorder that can cause your muscles to tighten and become rigid, making it difficult to walk and engage in daily activities. People with Parkinson’s disease also experience tremors and may ultimately develop cognitive problems, including memory loss and dementia.

Parkinson disease is most common in people who are older than 50; the average age at which it occurs is 60. But some younger people may also get Parkinson disease. When it affects someone younger than age 50, it's called early-onset Parkinson disease. You may be more likely to develop early-onset Parkinson disease if someone in your family has it. The older you are, the greater your risk of developing Parkinson disease. It's also much more common in men than in women.


Parkinson disease is a chronic and progressive disease. That means that it's a disease that doesn't go away and continues to get worse over time.

What causes Parkinson disease?

Parkinson disease arises from decreased dopamine production in the brain. The absence of dopamine makes it hard for the brain to coordinate muscle movements. Low dopamine also contributes to mood and cognitive disturbances later in the course of the disease. Experts don't know what triggers the development of Parkinson disease most of the time. Early onset Parkinson disease is often inherited and is the result of certain gene mutations.

What are the symptoms of Parkinson disease?

Parkinson disease symptoms usually start out mild, and then progressively get much worse. The first signs are often so subtle that many people may not seek medical attention initially. These are common symptoms of Parkinson disease:

  • Tremors that affect the face and jaw, legs, arms, and hands
  • Slow, stiff walking
  • Difficulty maintaining your balance
  • Problems with coordination
  • A stiff feeling in your arms, legs, and torso area
  • Changes in handwriting

Eventually, Parkinson disease symptoms get worse and include:

  • Depression
  • Gastrointestinal problems (like constipation)
  • Problems with urination
  • Difficulty chewing and swallowing food
  • Memory loss
  • Hallucinations
  • Dementia

How is Parkinson disease diagnosed?

Parkinson disease can be difficult to diagnose, as there isn't one single test that can identify it. It can be easily mistaken for another health condition. A health care provider will usually take a medical history, including a family history to find out if someone else has Parkinson's disease, and do a neurological exam. Sometimes, an MRI or CT scan of the brain can identify other problems or rule out other diseases.


How is Parkinson disease treated?

Parkinson disease can't be cured. But there are different therapies that can help control symptoms. Many of the medications used to treat Parkinson disease help to offset the loss of the chemical dopamine in the brain. Most of these drugs do help to manage symptoms quite successfully.

A procedure called deep brain stimulation may also be used to treat Parkinson disease. It sends electrical impulses into the brain to help control tremors and twitching movements. Some people may need surgery to manage Parkinson disease symptoms. Surgery may involve destroying small areas of brain tissue responsible for the symptoms. However, these surgeries are rarely done since deep brain stimulation is now available.

What are the complications of Parkinson disease?

Initially, Parkinson disease causes physical symptoms. Problems with cognitive function, including forgetfulness and difficulty with concentration, may arise later. As the disease gets worse with time, many people develop dementia, which causes profound memory loss and makes it difficult to maintain relationships with others.

Parkinson disease dementia can cause problems with:

  • Speaking and communicating with others
  • Being able to solve problems
  • Understanding abstract concepts
  • Forgetfulness
  • Difficulty paying attention

If you have Parkinson disease and dementia, eventually you probably won't be able to live by yourself. Dementia affects your ability to care of yourself, even if your Parkinson disease allows you to physically perform daily tasks.

Experts don't understand how or why dementia often occurs with Parkinson disease. It’s clear, though, that dementia and problems with cognitive function are linked to changes in the brain that cause problems with movement. As with Parkinson disease, dementia occurs when nerve cells degenerate, leading to chemical changes in the brain. Parkinson disease dementia may be treated with medications also used to treat Alzheimer's disease, another type of dementia.

Can Parkinson disease be prevented?

Experts don't yet understand how to prevent Parkinson disease. In some instances, there seems to be a genetic predisposition to develop Parkinson disease, but this isn’t always the case. Research is underway to find new ways to treat and prevent the disease.

Living with Parkinson disease

These measures can help you live well with Parkinson disease:

  • An exercise routine can help keep muscles flexible and mobile. Exercise also releases natural brain chemicals that can improve emotional well-being.
  • High protein meals can benefit your brain chemistry
  • Physical, occupational, and speech therapy can help your ability to care for yourself and communicate with others
  • If you or your family has questions about Parkinson disease, want information about treatment, or need to find support, you can contact the American Parkinson Disease Association.

When should I call my health care provider?

Call your health care provider if you or your loved one notices a sudden or significant change in symptoms or if mood changes, increased symptoms of depression or feelings of suicide develop.

Key points

  • Parkinson disease is a movement disorder that can make your muscles tight and rigid.
  • It can make walking and taking care of yourself difficult.
  • It can lead to problems such as depression, hallucinations, and dementia.
  • Parkinson disease will progress but medications can help with some symptoms.

Next steps

Tips to help you get the most from a visit to your health care provider:

  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.

This is Your Hospital

Tell Us Why St. Jude is Your Hospital.

Tell My Story
This is Your Hospital