I did some research on dementia not too long ago and I love how they are trying to be Gentle. Instead of saying 50 to 80% of people with Parkinson's will develop dementia. They say 30%. Of people with Parkinson's will not. Develop. Dementia. Lol. And terrifying at the same time.
Parkinson’s Dementia
Parkinson’s is often thought of as a disease that only involves movement. Yet many people with Parkinson’s complain of slowness in thinking, loss of memory, decreased attention span and difficulty finding words. Dementia refers to problems in memory and thinking that are advanced, interfering with daily activities and quality of life.
Parkinson’s dementia is diagnosed if the onset of dementia occurs a year or more after the onset of motor symptoms. If symptoms of dementia appear before or at the same time as symptoms of Parkinson’s, it is called dementia with Lewy bodies.
What causes Parkinson’s disease dementia?
Memory and thinking problems in Parkinson’s are caused by changes in the structure and chemistry of the brain. Dementia describes a set of symptoms that are caused by a significant loss in brain function. Researchers are still studying exactly how the brain becomes damaged, leading to dementia.
How is Parkinson’s dementia different from Alzheimer’s disease?
Dementia is a hallmark of Alzheimer’s, whereas dementia may or may not occur in people with Parkinson’s. However, dementia produces a greater impact on social and occupational functioning in people with Parkinson’s than in people with Alzheimer’s due to the combination of motor AND cognitive impairments.
There are some overlapping symptoms, but in general, Alzheimer’s affects language and memory, while Parkinson’s affects problem solving (executive function), speed of thinking, memory and other cognitive functions, as well as mood.
At the level of the brain, Parkinson’s dementia is thought to be related to Lewy bodies (sticky clumps of protein found in nerve cells of people with Parkinson’s). Most people with Parkinson’s develop dementia as a progression of their Parkinson’s disease, rather than having both Parkinson’s and Alzheimer’s.
What are the risk factors for dementia?
None of the following risk factors directly cause dementia, but the more of these factors that are present, the higher the likelihood of developing dementia:
Increasing age, Longer duration of disease (advanced stage), Being male, Older age at onset of Parkinson’s, Having visual, Family history of dementia
hallucinations, More severe motor symptoms

How many people with Parkinson’s develop dementia?
The vast majority of people with Parkinson’s may experience some form of cognitive impairment over time. Though it is unique to each person, the development of dementia depends on how long you have Parkinson’s and the stage of disease. In general, about 30% of people with Parkinson’s do NOT develop dementia as part of their progression.
Symptoms of dementia
Difficulty concentrating
Memory problems
Difficulty learning new material » Difficulty problem solving
Disorientation/confusion Treatment of dementia
Mood changes (for example, irritability, impatience, aggression)
Hallucinations (hearing/seeing things others do not) » Paranoia (feeling suspicious or distrustful of others) » Delusions (false, unrealistic or strange beliefs)
The first step is to discuss concerns with a doctor, preferably a neurologist or movement disorders specialist. Although there is no way to stop progression of Parkinson’s or dementia, there are many ways a doctor can help to manage the symptoms, including medication (particularly a drug called rivastigmine), counseling and other therapies.
Tips for caregivers
As dementia progresses, fact and fantasy can become confused, and behavior changes can be particularly hard for caregivers. The person with Parkinson’s may become disoriented and unable to be left alone. They may show signs of agitation, delusions, mood fluctuations and increased impulsivity. In addition to helping the person with Parkinson’s, adopting strategies to help manage dementia can alleviate the caregiver’s stress and emotional pain, too. Try these tips to calm the person with Parkinson’s:
People with dementia are more like to become acutely confused after any operation. Watch out for sensitivity to medication.
Stick to a routine or a structured schedule.
Simplify the décor of the living area to help with distractibility or confusion.
Use a nightlight to reduce visual misperceptions at night.
Keep calm and still while talking with your loved one.
Demonstrate your care and affection for the person with dementia.
Keep in mind that paranoid attacks and false accusations are a product of the disease, not your loved one. www.parkinson.org

Thank you so much for all of your research. I'm sure with PD there are things we do not want to think about possibly developing. I'm usually Better when I know more about something. The more I know, the Better I can handle whatever comes down the road. Thank you for your work in researching PD dementia. It has definitely helped to prepare me Better for the possibility.
Glenn

Same for me. My birth mother had dementia and lived to be 93 yrs old.

No, some do, some don’t. No way of knowing when you are first diagnosed whether you will or not.