Parkinson's Disease and Dementia

Parkinson's 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, in some cases, may ultimately develop cognitive problems, including memory loss and dementia.

Parkinson's disease arises from decreased dopamine production in the brain. The absence of dopamine makes it hard for the brain to coordinate muscle movements and contributes to mood and cognitive disturbances later in the course of the disease.

Facts about Parkinson's disease

Parkinson's 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's disease. When it affects someone younger than age 50, it's called early-onset Parkinson's disease. You may develop early-onset Parkinson's disease because someone in your family has it. The older you are, the greater your risk of developing Parkinson's disease. It's also much more common in men than in women.

Parkinson's 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.

Experts don't know what triggers the development of Parkinson's disease most of the time, although some people may inherit it.


Parkinson's disease symptoms usually start out mild, 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's 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's disease symptoms get worse and include:

  • Depression

  • Gastrointestinal problems (like constipation)

  • Problems with urination

  • Difficulty chewing and swallowing food

  • Memory loss

  • Hallucinations

  • Dementia

Dementia from Parkinson's disease

Initially, Parkinson's 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's 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's 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's disease allows you to physically perform daily tasks.

Experts don't understand how or why dementia often occurs with Parkinson's 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's disease, dementia occurs when nerve cells degenerate, leading to chemical changes in the brain. Parkinson's disease dementia may be treated with medications also used to treat Alzheimer's disease, another type of dementia.


Parkinson's 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 doctor will usually take a medical history, including a family history to find out if someone else has Parkinson's disease, and perform a neurological exam. Sometimes, an MRI or CT scan of the brain can identify other problems or rule out other diseases.


Parkinson's disease can't be cured. But there are different therapies that can help control symptoms. Many of the medications used to treat Parkinson’s 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's disease. It sends electrical impulses into the brain to help control tremors and twitching movements. Some people may need surgery to manage Parkinson's disease symptoms, as well.


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

Finding help

If you or your family has questions about Parkinson's disease, want information about treatment, or need to find support, you can contact the American Parkinson Disease Association.