If you were to name the symptoms of Parkinson’s disease, you’d probably start with the visible motor symptoms—tremor, stiffness or slowness. These symptoms emerge as brain cells that produce dopamine stop working or die.
But that lack of dopamine affects more than just movement, so people with Parkinson’s disease often have symptoms others can’t immediately see, including changes in thinking and mood. However, the timing and severity of those symptoms can vary.
“Every person with Parkinson’s disease has a very different experience with all symptoms, including cognition,” says UNC Health movement disorders specialist Daniel Roque, MD.
If you have recently been diagnosed with Parkinson’s, your early symptoms can sometimes provide clues about how cognitive symptoms might progress, Dr. Roque says.
“If you present with tremor as the early symptom, development of cognitive complaints might take decades, rather than just a few years,” he says. “If you instead present with more balance issues and falls, cognitive complaints tend to present earlier, sometimes within five to seven years of earliest symptoms. Still, the experience is different for every person with Parkinson’s.”
Dr. Roque explains what to expect and steps you can take to preserve cognitive function.
Early Cognitive Changes in Parkinson’s Disease
Early in the progression of the disease, people can often expect two cognitive changes, Dr. Roque says.
“The most common concern is difficulty remembering names, even if you can place faces without a problem,” he says. “The other complaint involves visuospatial difficulties, or impaired thinking about where things are in space.”
Early on, visuospatial difficulties may take the form of forgetting where you placed something, such as your keys or a book; while this can happen to everyone occasionally, you may notice it happening more often, particularly if you’re trying to multitask. As these difficulties worsen, it may make it difficult to perform more complex tasks like driving, as you may not be able to adequately judge how much space you have to park your car or pass another driver. While walking around, you may bump into things or have difficulty navigating familiar spaces.
Difficulties with language can begin during the early years of Parkinson’s disease.
“Sometimes, you can think through everything you want to say, but when you go to deliver the information, it doesn’t come out as directly or as eloquently as you planned,” Dr. Roque says. “You may have to use shorter phrases or might naturally replace words you intended to say with other word choices.”
To someone on the other end of the conversation, it may be hard to distinguish whether you’re having trouble finding the words or forming the words because of a speech difficulty or voice problem. Both can occur in Parkinson’s disease, but speech issues have different treatment options than language concerns. Your neurologist can help to determine the difference so that you can get the best support for your issue.
Later Cognitive Changes in Parkinson’s Disease
As the disease progresses, issues with mental processing and memory will become more pronounced.
“Some people experience executive dysfunction with decision-making and prioritizing,” Dr. Roque says. “That means when you try to approach a scenario, your ability to reliably and consistently problem-solve will be impaired.”
To a caregiver, it may appear that you can’t pay attention or follow simple instructions, or completion of tasks will take much longer than they used to.
Difficulties with decision-making can progress so that you behave abnormally or inappropriately. Some patients develop impulse control disorders, in which they may shop or gamble excessively, or do some other negative behavior.
Most people with Parkinson’s disease will eventually develop dementia.
“When we think of other syndromes associated with memory loss, there’s often loss of short-term memory but preservation of long-term memory,” Dr. Roque says. “With Parkinson’s disease, most experience both short-term and long-term memory differences alongside other complaints.”
Mood Disorders in Parkinson’s Disease
Some cognitive symptoms can be caused or worsened by mood disorders such as depression or anxiety. Because these are also common in people with Parkinson’s disease, it’s important to consider the overlap, particularly in early stages of the disease.
“In people with Parkinson’s disease, the rate of mood disorders is higher than the general population,” Dr. Roque says.
Depression or anxiety may be one of the first symptoms a person experiences, before a diagnosis of Parkinson’s disease is made, or they may deal with increased mood changes as the disease progresses.
“It’s a layer we have to consider in regard to cognitive changes,” Dr. Roque says. “We don’t want to discount this as an influencing factor when there are treatment options like cognitive behavioral therapy.”
There is no way to reverse cognitive decline, but your medical team can help you preserve function for as long as possible.
“A healthy lifestyle and cardio exercise help to preserve brain health,” Dr. Roque says. “Staying physically active optimizes and enhances cognition as well as other symptoms of Parkinson’s.”
That’s true whether you have Parkinson’s disease or not: Active adults have lower rates of cognitive decline than those who are inactive. If you do have Parkinson’s disease, exercise can help manage other symptoms and improve mobility and balance.
If you find yourself forgetting people’s names or finding words, it may be tempting to avoid social activities so that you don’t embarrass yourself, but this will make things worse. Seek out supportive friends and activities you enjoy so you stay connected.
“Don’t withdraw,” Dr. Roque says. “Stay socially and mentally engaged. You do have to exercise the brain, alone and with others.”
Solo exercise for the brain might include puzzles, reading books or learning something new. You or your caregiver can work with a therapist to identify supports or strategies to help with remembering or completing daily tasks.
It’s important to see your care team regularly and to let them know when you experience new symptoms, especially when taking medications.
“Unfortunately, some cognitive concerns in the mid-to-late stages of the disease are influenced by the medications that we use for other symptoms,” Dr. Roque says. “For example, the medications we give to address tremor can come at the cost of worsening cognitive complaints. We need to tailor these kinds of medications toward a meaningful balance between cognitive and other symptom control.”
Dr. Roque says medications given to people with Alzheimer’s disease, including rivastigmine, donepezil and memantine, can be considered for early stages of dementia in Parkinson’s as well. Medication may slow progression of dementia for about six to 12 months.
Though benefits may not continue past a year, you often have to continue to take these medications once you’ve started them; after a few months, they change the balance of neurotransmitters in the brain, and once the medication is removed, a person can become combative or disoriented, Dr. Roque says.
He acknowledges these options are less than ideal and can seem daunting if you’re in an early stage of Parkinson’s disease.
“You can’t view Parkinson’s disease in a bubble here, because lots of issues can influence cognition if you live long enough,” Dr. Roque says. “There’s something to be said for knowing that these things will limit your cognition so you can take a proactive approach to protecting it with activities like exercise and social engagement.”
If you’re concerned about your cognitive health, talk to your doctor. If you need a doctor, find one near you.