Powered By
Most people know Parkinson’s disease as a movement disorder because its first symptoms typically come from the loss of muscle control. As Parkinson’s disease progresses, its impact on the brain can expand to include memory loss and trouble with thinking and reasoning. These thinking and memory issues lead to what’s called Parkinson’s disease dementia, and it affects roughly one-third of people living with Parkinson’s disease. Recent research looked at the risk of dementia in relation to disease duration, finding rates as high as 70 percent to 80 percent in people who’d had Parkinson’s for more than 20 years.
Caregivers of people with Parkinson’s disease might wonder how they can recognize signs of dementia early and what steps they can take to support their loved one. In this article, we’ll talk about how Parkinson’s disease can lead to cognitive decline, signs to watch out for, and treatment options for people who have Parkinson’s disease dementia.
Parkinson’s disease can cause dementia because of how Parkinson’s damages cells in the brain.
Parkinson’s disease dementia develops in the same way as a type of dementia called Lewy body dementia or dementia with Lewy bodies (DLB). Some researchers consider Parkinson’s disease dementia and DLB to be the same, but the two conditions start in different parts of the brain. Parkinson’s disease causes movement symptoms first, with possible cognitive symptoms later, whereas DLB causes cognitive symptoms first, followed by possible movement symptoms as it progresses.
Both conditions develop when alpha-synuclein proteins build up in the brain and form Lewy bodies, which can damage neurons (nerve cells). In Parkinson’s, Lewy bodies first form in the brainstem and in a part of the brain called the basal ganglia. This is the part of the brain that controls body movement. Lewy bodies can eventually spread to other parts of the brain that control memory function, reasoning, and other thought processes. When this happens, Parkinson’s disease dementia can be the result.
One study found a possible link between anticholinergic medications, which are sometimes used to treat symptoms of Parkinson’s disease, and a slight increase in dementia risk. However, more research is needed to confirm if there’s a connection between these medications and an increased risk of dementia.
Talk to your loved one’s doctor if you have any questions about medications and their impact on dementia risk.
Many people with Parkinson’s disease show signs of mild cognitive impairment (MCI), but it doesn’t always progress to dementia. MCI can appear as problems with thinking and memory, but they’re not significant enough to affect a person’s day-to-day functioning. MCI doesn’t only happen to people with Parkinson’s disease — it affects up to 19 percent of the older adult population.
When people with Parkinson’s develop dementia, it usually appears at least one year after their initial diagnosis. For many people, it takes years to develop Parkinson’s disease dementia. The average time between the initial movement problems and the diagnosis of Parkinson’s disease dementia is 10 years.
MyParkinsonsTeam members often talk about changes in their loved ones that might indicate Parkinson’s disease dementia. “My wife received a confirmed diagnosis of Parkinson’s three months ago from her neurologist … Since then, her recent memory has gone, she sees people who are not there, and has become paranoid as well as developing delusions,” one member wrote.
Another member mentioned dementia symptoms they’ve noticed affecting their father. “There are days when he can remember what you just asked or were talking about. Then, some days, he can’t even remember what he just ate. He gets angry when he can’t remember.”
Parkinson’s disease dementia causes symptoms similar to Lewy body dementia, and these symptoms can change often. Unlike MCI and normal aging, these symptoms are significant enough to affect a person’s ability to function and impact their quality of life. Here are some of the common symptoms.
People with Parkinson’s disease dementia may have a hard time making plans, concentrating, and completing tasks. They often have noticeable memory problems, including short-term memory problems and forgetfulness.
Some people with Parkinson’s disease dementia develop speech problems, like muffled speech that other people have trouble understanding. They may frequently forget the names of objects or call people by the wrong names.
They might also have comprehension problems, such as difficulty following and understanding long or complex sentences.
Parkinson’s disease dementia can make it difficult for a person to get consistent sleep because of challenges involving the sleep-wake cycle. In other words, they might be awake all night and struggle to stay awake during the day.
People with Parkinson’s disease dementia might also act out their dreams while they’re asleep. This is called rapid eye movement (REM) behavior disorder, and it affects up to 46 percent of people with Parkinson’s disease. REM behavior disorder early in Parkinson’s disease is a risk factor for Parkinson’s disease dementia later in the condition’s progression.
Hallucinations and delusions are two types of psychosis that people with Parkinson’s disease dementia might experience.
If a person with Parkinson’s disease dementia sees something that isn’t there, it’s called a visual hallucination. Visual hallucinations are more common in Parkinson’s disease dementia than auditory hallucinations, which involve hearing sounds that don’t exist.
Delusions are beliefs that aren’t based in reality or evidence. A person with Parkinson’s disease dementia might experience a type of delusion called paranoid thinking, which involves a lot of suspicion and distrust of their loved ones and people around them.
Extreme mood, mental health, and motivation changes are common in people with Parkinson’s disease dementia. They can change from day to day or hour to hour. They can include:
There isn’t just one specific test to diagnose dementia in people with Parkinson’s disease. Healthcare providers start by discussing the person’s medical history, reviewing their symptoms, and reviewing the medications they currently take.
Your loved one’s doctor might recommend neuropsychological testing to evaluate their mental state. These tests help doctors get a better idea of a person’s brain function and thought processes. They may also use laboratory tests and brain imaging scans to evaluate brain function or rule out other possible causes of cognitive symptoms.
No treatment can cure Parkinson’s disease dementia or slow its progression, but some medications and lifestyle changes can help manage the symptoms and improve a person’s quality of life.
Medications can improve specific symptoms of dementia like hallucinations, delusions, and mood changes. For example, selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed as antidepressants or to improve symptoms of anxiety.
Cholinesterase inhibitors might help reduce visual hallucinations and minimize some behavior changes that come with Parkinson’s disease dementia. Although antipsychotic medications are commonly prescribed to treat psychosis symptoms like hallucinations and delusions, most of them are not recommended for people with Parkinson’s disease dementia.
Your loved one’s doctor might change the dosages of certain medications they already take for Parkinson’s disease, which can make delusions and hallucinations worse.
Specific forms of therapy can add a sense of routine while improving symptoms of dementia in people with Parkinson’s disease. Speech therapy may help with speech and communication challenges, while psychotherapy, including cognitive behavioral therapy (CBT), might lead to some improvement in mood and behavioral symptoms.
If you care for someone with Parkinson’s disease dementia, there are steps you can take to provide more support as their condition progresses. A structured routine can help someone with Parkinson’s disease dementia feel more comfortable, so try to stick to a consistent schedule.
Caregivers can also help a person living with Parkinson’s disease dementia by:
On MyParkinsonsTeam, people share their experiences with Parkinson’s disease, get advice, and find support from others who understand.
Is your loved one with Parkinson’s showing signs of dementia? Let others know in the comments below.
Get updates directly to your inbox.
Continue with Facebook
Sign up with your email
Become a member to get even more
Join
We'd love to hear from you! Please share your name and email to post and read comments.
You'll also get the latest articles directly to your inbox.