Parkinson’s disease (PD) is a chronic and progressive disease of the nervous systemthat can affect thepatient’s mobility and their ability to perform daily tasks.
People with Parkinson’s have a lack of chemical called dopamine because specific nerve cells inside their brain have died. Why these cells die is not known.
Lack of dopamine makes a person slow in their movements and it takes them longer to do things, which makes everyday tasks, such as getting dressed, eating, or using a phone or computer, difficult or frustrating.
The cause of the disease is unknown, and although there is presently no cure, symptoms can be managed by available treatment options such as medication and surgery.
The most common symptoms of Parkinson’s disease are trembling of the hands, arms, jaw, and face; stiffness of the trunk and limbs; slowness of movement; and loss of balance and coordination.
Parkinson’s disease dementia is caused by Lewy bodies, a protein known as alpha-synuclein building up in the brain.
The dementia affects the mind as well as the body.
What are the symptoms of Parkinson’s disease dementia?
Symptoms may include:
- Visual hallucinations
- Difficulty sleeping well
- Memory changes
- Difficulty speaking clearly
- Difficulty taking in what is seen and interpreting it
- Excessive daytime sleepiness and rapid eye movements
Causes and risk factors
Most causes of Parkinson’s disease are idiopathic, meaning thephysician does not know why a person has the condition. However, according to Johns Hopkins Medicine, early-onset Parkinson’s disease is most commonly attributed to genetic defects, possibly those inherited from a parent.
According to scientists, early-onset Parkinson’s disease could be associated with genetic flaws passed on from a parent. They have identified several factors that may cause a Parkinson’s disease patient to experience dementia. The risk factors are:
- Advanced age at time of diagnosis
- Excessive daytime sleepiness
- Hallucinations before onset of other symptoms of dementia
- Mild thought impairment history
- Having a specific Parkinson’s symptom, which causes a person to have difficulty attempting to take a step or who may halt mid-step when walking
- More severe movement impairment symptoms than most people with Parkinson’s disease
However, it is still unknown why some individual with Parkinson’s disease experience nerve damage that affects thinking as well as movement problems.
How does Parkinson’s disease progress over time?
Around 50 to 80% of patients with Parkinson’s disease will experience Parkinson’s disease dementia, according to Alzheimer’s Association. After diagnosis of Parkinson’s it takes about 10 years for the condition to progress to dementia.
This type of dementia leaves a person unable to live by themselves.
Most often a person is diagnosed with PD before start of any dementia symptoms. This is because mobility problems are more likely to occur before any cognitive impairment.
A person should see a doctor if they experience any of the following symptoms:
- Difficulty thinking clearly
- Memory loss
- Sleep disturbances
Although some of these symptoms can be side effects of Parkinson’s disease medicines, a person should notify their doctor if he or she experiences any of these symptoms.
It may be very difficult to diagnose dementia because there isn’t one test that can undoubtedly say anindividual has dementia or a specific dementia type.
The first step for a doctor will be to consider the person’s overall health. They can also note any changes to movement, health, and behaviour over time. Sometimes family members or caregivers may help with providing this information, as the person may not recall or be aware of all changes.
If a Parkinson’s disease patient starts to experience dementia symptoms one year or longer after their diagnosis, the condition may be diagnosed as Parkinson’s disease dementia.
At this point, a doctor will also recommend magnetic resonance imaging (MRI) scan, which can pinpoint any brain changes that may be responsible for the symptoms. For example, a tumour in the brain or restricted blood flow to the brain. [ Read more How low-fat dairy could increase your Parkinson’s disease risk]
How to treat and prevent Parkinson’s disease dementia?
There is no cure for Parkinson’s dementia. Treatments, including medications are focused on lowering symptoms associated with dementia.
Antidepressants. Selective Serotonin reuptake inhibitors (SSRIs) such as Prozac, Lexapro, Celexa, or Zoloft to reduce depression.
Cholinesterase inhibitor. These drugs are aimed at reducing the effects of cognitive decline in those with dementia.
Clonazepam. This drug helps improve sleep quality.
L-dopa. This medicine is intended to reduce Parkinson’s disease-affected movement but can worsen dementia symptoms.
Antipsychotic drugs may also be prescribed but must be done with caution. This is because the side effects may decrease psychotic episodes but increase Parkinson’s symptoms. These medications may also trigger increased confusion and changes in consciousness.
Pimavanserin, or Nuplazid – a new drug recently approved by the US Food and Drug Administration – has been shown to effectively treat hallucinations, without causing the side effects of some other antipsychotic drugs.
A combination of these medications may be prescribed as a means to reduce symptoms. Doctors should discuss both benefits and side effects when considering treatments.
Physical, occupational, and speech therapy may also be applied in order to enhance movement and communication abilities.
Preventing Parkinson’s dementia
As of yet, scientists do not know how to prevent Parkinson’s disease. Although some patients may have a genetic predisposition toward the condition, no specific gene has been identified.
Genetic tests will not work, as most people are not affected by Parkinson’s until later in life. This may mean that a person will not know they are affected until he or she has grand children.
Parkinson’s in the UK
- In the UK, every hour someone is told they have Parkinson’s.
- One person in every 500 has Parkinson’s. That’s about 127,000 people.
- Most people with Parkinson’s are aged 50 or over but younger people can get it too.