Parkinson’s Disease and Dementia

Feb 14, 2020 | Signs, Symptoms and Science of Dementia

Parkinson’s disease is typically thought of as a disease that only affects movement. With a very early diagnosis of the disease the obvious physical symptoms, which may be sporadic, include tremors, slow movement, impaired posture, and muscle rigidity. 

As time goes on, studies suggest that 50 to 80% of people with Parkinson’s disease (PD) experience a decline in thinking and other symptoms, such as memory loss, that may lead to a diagnosis of Parkinson’s disease dementia (PDD). 

If your loved one is diagnosed with Parkinson’s disease dementia, you may wonder how Parkinson’s disease progressed to the diagnosis of dementia. 

What causes Parkinson’s disease dementia? 

Parkinson’s disease changes the structure and chemistry of the brain. The progression of PD destroys and eliminates dopamine, a naturally occurring substance in the brain, which leads to cognitive decline and impairments and the diagnosis of dementia. 

What are the risk factors for Parkinson’s disease dementia?

Not every person diagnosed with Parkinson’s disease develops dementia, but many people in advanced stages of the disease show some form of cognitive impairment. Studies indicate that the average time from onset of PD to a diagnosis of dementia is about 10 years, however, several factors increase the risk of developing Parkinson’s disease dementia. These risk factors include:

  • Age of patient (advancing age and an older PD diagnosis age)
  • Male (2 to 1 male to female ratio at any age)
  • Family history of dementia (close relative with dementia may increase the risk factor up to 30%)
  • Visual hallucinations (early identifier of dementia)
  • Severe motor symptoms (tremor, rigidity, impaired/unstable balance, slow movement)

How is Parkinson’s disease dementia diagnosed? 

There are no core tests that specifically determine if someone has Parkinson’s disease dementia.

Guidelines for assessing and diagnosing PDD begin with a person who has been diagnosed with Parkinson’s and:

  • Began showing symptoms of dementia such as memory loss, communication difficulties, inability to focus, poor judgment and decision making, and vision changes, at least a year or more following the Parkinson’s diagnosis.
  • Began showing symptoms of Lewy body dementia (LBD) before, or present with, the motor symptoms of Parkinson’s disease, or LBD symptoms that occurred within one year after the movement symptoms began. 

LBD is a disease that gets its name from deposits of a protein called alpha-synuclein in the brain. These deposits are called Lewy bodies. Lewy bodies affect chemicals in the brain which lead to impaired thinking, and problems with movement similar to those diagnosed with Parkinson’s, such as tremors, stiffness, slowness, difficulty walking, as well as visual hallucinations, sleep disorders, behavioral and mood symptoms, and changes in body functions, such as blood pressure control, temperature regulation, and bladder and bowel function. 

What are the treatment options?

There is no cure to stop the brain cell damage in any form of dementia, including Parkinson’s disease dementia. Doctors focus on relieving the symptoms of dementia as well as Parkinson’s disease through medication. 

Management of Parkinson’s disease dementia can be tricky as the main treatment for Parkinson’s disease increases dopamine levels in the brain through a combination of the medicines carbidopa and levodopa, however, this treatment often worsens dementia and mental symptoms. 

Depression is common in people with Parkinson’s disease dementia, which is typically treated with antidepressants such as selective serotonin reuptake inhibitors (SSRIs). 

Sleep disturbances are common as well, which is often treated with clonazepam, a drug that can help with REM sleep dysfunction as well as reduce anxiety. Melatonin, an over-the-counter supplement, is also used to restore healthy circadian rhythms. 

Doctors must use caution when treating Parkinson’s disease dementia as people with PDD are particularly sensitive to medications. New medications, or a combination of medications, may aggravate hallucinations and confusion.

What can we do for our loved one?

If your loved one has symptoms of Parkinson’s disease dementia, whether they have been diagnosed but you believe symptoms are worsening, or if they have not yet been diagnosed, take notes and discuss your concerns and observances with a doctor. 

Show support to your loved one. This may help them with depression. Develop routines and schedules and avoid major environmental changes to counteract confusion. 

Decrease risk factors for dementia through proper diet, exercise, and sleep. This is a two-fold approach. Your own proper diet, exercise, and sleep help to boost your personal wellness and your ability to be a great caretaker. 

If you are a caregiver and would like to talk about the best options for the future, give us a call at 512-399-5089. We can help you through every step of the way.