You’ve probably heard that people living with Parkinson’s disease (PD) can also experience memory problems, or even dementia in more advanced stages. However, Parkinson’s disease usually affects older adults, and ageing itself can also bring about some cognitive changes.
So, how do we know if these changes are a regular part of ageing or are caused by Parkinson’s? What exactly is dementia? And is it the same as Alzheimer’s disease?
In this blog, we’ll explore what cognitive changes are, what’s normal, and what we refer to as mild cognitive impairment and dementia in the context of Parkinson’s disease.
Cognition is the way we think — how we focus, plan, remember, use language, and understand the world around us.
Cognitive changes in Parkinson’s disease are not just about memory. They can affect one or more of the following five areas:
Attention
Staying focused may be harder. Alertness can change during the day — someone might follow a conversation easily in the morning but struggle later in the afternoon.
Executive functions
These help us plan, organise, switch between tasks, and control impulses. In Parkinson’s, these skills can be affected because specific brain networks don’t work as efficiently.
Memory
People may struggle to recall information, but can often recognise the correct answer when presented with options. Reminders or cues can be beneficial.
Language
Language changes are usually mild. Some people find it harder to find specific words or may speak more slowly or less fluently.
Visuospatial skills
These help us judge distance, shapes, and directions. People may misjudge a doorway or get turned around in a familiar place.
Cognitive changes in Parkinson’s usually affect executive and visuospatial functions the most. Memory tends to be less impacted, and language is often preserved.
These changes can significantly impact quality of life, but their effects vary greatly from person to person. They may also be related to sleep patterns, mood, or certain medications. Monitoring them over time is essential — mild changes usually don’t affect independence, but more severe ones can lead to dementia.
Cognitive changes can exist on a spectrum, ranging from normal ageing to mild cognitive impairment (MCI) to dementia.
Studies show that up to 35% of people newly diagnosed with Parkinson’s may have mild cognitive impairment, and about 40% may develop dementia later in the disease.
Let’s look at what makes them different:
Mild Cognitive Impairment (MCI)
In Mild cognitive impairment, thinking abilities are not as sharp as before, but people can still live independently (socially, job and personal care)
A person with Parkinson’s is considered to have MCI if:
- A gradual decline in thinking or movement is noticed by the person, their family, or a doctor.
- Mild cognitive changes are confirmed through cognitive testing (MoCA) or neuropsychological evaluation.
- The person remains independent in daily life.
- Other causes (like infection, depression, medication effects, stroke, or head injury) have been ruled out.
- Other Parkinson’s symptoms (like tremor or anxiety) are not the main reason for the changes.
Parkinson’s Disease Dementia (PDD)
The main difference between MCI and dementia is that dementia affects daily life, such as work, social interactions, or self-care.
It is diagnosed when:
- There’s a decline in at least one cognitive area (attention, executive function, visuospatial skills, or memory).
- There’s an apparent change from how the person used to think before diagnosis.
- The changes interfere with everyday life.
People may also experience behavioural and emotional changes, including apathy, mood swings, hallucinations, delusions, or excessive daytime sleepiness.
It’s important to know that Parkinson’s disease dementia is not the same as Alzheimer’s disease — they are distinct conditions, even if both involve memory and thinking changes. We’ll discuss these differences in more detail in future blogs.
Normal Aging
Normal ageing happens when cognitive changes don’t meet the criteria for mild cognitive impairment or dementia.
Some forgetfulness can be a regular part of ageing, for example, occasionally misplacing objects or taking longer to recall names. It is important to note that they don’t impact your daily living.
However, to clearly distinguish between normal ageing and MCI, doctors often use neuropsychological testing or brief cognitive assessments, such as the Montreal Cognitive Assessment (MoCA).
To answer the question: Is Parkinson a type of dementia? The answer is no. While some individuals with Parkinson’s may experience cognitive changes over time, many do not develop dementia.
If you or a loved one notices differences in memory or thinking, try not to worry — help is available. Each person’s experience with Parkinson’s is different, and cognitive changes are only one part of a much broader picture. You are not alone in this journey.
Consult a movement disorder neurologist team as soon as possible. They can offer practical tips, such as memory aids and strategies for managing daily tasks, as well as emotional support for you and your family. They can also discuss treatment options, including medications and therapies, to help maintain independence and quality of life.
Simple daily habits — such as staying active, maintaining a routine, and engaging your mind — can make a significant difference over time. These habits can empower you to take charge of your cognitive health and instill hope for a better future.