Parkinson’s disease dementia is a degenerative impairment of thinking and reasoning skills that often affects people who have been diagnosed with Parkinson’s disease.
Parkinson’s disease is a common neurological disorder diagnosed in as much as 2% of adults age 65 and older. As a person’s brain continues to change (as a result of Parkinson’s disease), mental functions such as memory, concentration and judgment become impaired.
A person with Parkinson’s disease often struggles to ascertain the steps needed to complete a specific task or tasks. It is estimated that between 50 and 80% of people with Parkinson’s disease eventually end up with dementia as the disease continues to progress. On average, the timeframe from onset of Parkinson’s symptoms to a dementia diagnosis is 10 years.
Parkinson’s disease dementia is a decline in reasoning (or thinking skills in general) that presents in a person who has previously been diagnosed with Parkinson’s disease.
- Changes in concentration, judgment, and/or memory
- Trouble understanding and interpreting visual cues or information
- Muffled speech
- Delusions, hallucinations, or general paranoia
- Varying degrees of depression
- Increased anxiety or irritability
- Sleep disturbances or disorders
Brain or Physical Changes
In Parkinson’s disease dementia, nerve cells progressively degenerate which leads to irreversible chemical changes in the brain. Within the brain of a person with Parkinson’s disease, abnormal deposits of Lewy bodies are present. Lewy bodies are linked to several brain disorders, such as Lewy body dementia. Because of this, Parkinson’s disease/Parkinson’s disease dementia are often confused with other forms of dementia. As a further complication, people with Parkinson’s disease often present with plaques and tangles in the brain, a common symptom of Alzheimer’s disease.
Causes and/or Risk Factors
Certainly, the greatest risk factor for Parkinson’s disease dementia is having Parkinson’s disease. In addition to that, certain risk factors at the time of a Parkinson’s disease diagnosis increase the likelihood that the person will also end up with a dementia diagnosis.
Those risk factors include (but are not limited to) already having the following:
- Mild cognitive impairment
- Extreme daytime drowsiness
- Gait disturbance (specifically known as PIGD)
- Issues with balance and/or falling
Diagnosis, Treatment, and Care
As is the case with most forms of dementia, no one single test (or even series of tests) exist to confirm Parkinson’s disease dementia. Typically speaking, however, a diagnosis is given when a person who was originally diagnosed with Parkinson’s disease presents with dementia symptoms a year (or more) after diagnosis.