People living with Parkinson’s Disease (PD) may be affected by thinking and memory problems. These cognitive issues can have a significant impact on a person’s quality of life and interfere with their daily function.
To some degree, cognitive impairment affects many people with PD. The same brain changes that lead to motor symptoms can also result in slowness in memory and thinking. Stress, medication and depression can also contribute to these changes. There are two levels of cognitive impairment.
Mild Cognitive Impairment (MCI)
Approximately 25 percent of people with PD experience “mild cognitive impairment (MCI)”. People with MCI experience a change in their thinking or memory that is more than expected with normal aging but is not enough to interfere with a person’s daily activities. The condition could stay the same, get better or become worse over time. In some people, MCI gradually progresses to dementia. Unfortunately, there are no U.S. Food and Drug Administration (FDA)-approved medications to treat mild cognitive impairment currently, but research in this area is ongoing.
Symptoms of MCI may include experiencing feelings of distraction or disorganization. It may be harder to focus in situations that divide the attention of a person with MCI, like a group conversation. When facing a task or situation on their own, a person with PD may feel overwhelmed by having to make choices. They may also have difficulty remembering information or have trouble finding the right words when speaking. These changes can range from being annoying to interfering with managing household affairs.
Although treatment is based on the individual, doctors generally recommend that patients:
- Keep the brain active.
- Work with an occupational, speech therapist and/or a cognitive rehabilitation specialist.
Doctors also check for and treat medical conditions that can potentially increase MCI conditions, including:
- Urinary tract infections.
- Depression.
- Sleep problems
Parkinson’s Disease Dementia (PDD)
Approximately 40 percent of people with Parkinson’s have PDD, and small studies suggest this number may be higher in people who have had Parkinson’s for 20 years or more. A PDD diagnosis is considered different than dementia and is determined by the order of onset of the symptoms.
Parkinson’s disease dementia shares symptoms and brain changes (alpha-synuclein protein clumps called Lewy bodies) with a related disease called dementia with Lewy bodies (DLB). These two diseases—PDD and DLB—are grouped under the umbrella term Lewy body dementia. To diagnose Parkinson’s disease dementia, the motor and movement symptoms, including rigidity, weakness, and tremors, should be present at least one year before cognitive declines develop. Dementia with Lewy bodies is diagnosed if the symptoms in mobility and muscle weakness occur at the same time as a cognitive decline, if the cognitive symptoms occur before the motor symptoms, or if a cognitive decline develops less than one year after the motor symptoms begin.
People with PDD experience many of the same symptoms as those with mild cognitive impairment, but to a more considerable degree and may also suffer from movement problems, mood and behavior changes and hallucinations and delusions.
Regardless of the level of cognitive changes, the biggest impact is attention and executive function, rather than memory. People with Parkinson’s most commonly notice difficulty with:
- Paying attention or concentrating
- Multitasking and problem solving (executive function)
- Seeing information three dimensionally (visuospatial skills)
Although no specific cause has been identified, researchers are working out exactly why and how Parkinson’s causes thinking and memory problems. Researchers believe both brain chemical and brain cells changes play a role. Parkinson’s affects several brain chemicals, including dopamine, acetylcholine, serotonin and norepinephrine, which are important for cognition. In brain cells that are responsible for cognition, the protein alpha-synuclein misfolds and clumps into clusters called Lewy bodies, which researchers believe causes cell damage or death.
If you or your loved one notice thinking or memory changes, tell your doctor. No brain imaging or blood tests can diagnose Parkinson’s cognitive changes. Doctors may also check for depression, anxiety, low thyroid, sleep problems or apathy (lack of motivation)—all common in Parkinson’s—which can impact cognition. The doctor also may review prescriptions and over-the-counter medications to ensure none are contributing to cognitive changes. Parkinson’s medications such as Artane (trihexyphenidyl), for example, can sometimes cause confusion.
To date, no medication or activity has yet been proven to prevent or slow cognitive changes. There are medications that can ease symptoms and improve quality of life, but none has yet been proven to slow or stop disease progression. A healthy body likely promotes a healthy brain, so the following activities are recommended:
- Exercise regularly.
- Eat a healthy diet.
- Drink alcohol in moderation.
- Don’t smoke tobacco.
- Be socially active.
- Train your brain.
- Reduce stress.
- Sleep well.
- Take care of medical conditions.
- Review medications.
If you or your loved one suffer from PDD you can learn more about service and care from our specialty trained staff.