About Dementia & Parkinson’s Disease
Parkinson’s disease (PD) has long been considered predominantly a motor disorder. However, its frequent association with dementia, which contributes significantly to the morbidity and mortality of the condition, is gaining increasing recognition. Parkinson’s disease dementia is a decline in thinking and reasoning that develops in many people living with Parkinson’s at least a year after diagnosis.
Parkinson’s disease is a fairly common neurological disorder in older adults, estimated to affect nearly 2 percent of those over age 65. Recent studies following people with Parkinson’s over the entire course of their illness estimate that 50 to 80 percent of those with the disease may experience dementia.
Certain factors at the time of Parkinson’s diagnosis may increase future dementia risk, including older age, greater severity of motor symptoms and having mild cognitive impairment (MCI).
Additional risk factors may include:
- Hallucinations in a person who doesn’t yet have other dementia symptoms.
- Excessive daytime sleepiness.
- Parkinson’s symptom pattern known as postural instability and gait disturbance (PIGD), which includes “freezing” in mid-step, difficulty initiating movement, shuffling, problems with balance and falling.
Commonly reported symptoms of Parkinson’s disease dementia include:
- Changes in memory, concentration and judgment.
- Trouble interpreting visual information.
- Muffled speech.
- Visual hallucinations.
- Delusions, especially paranoid ideas.
- Irritability and anxiety.
- Sleep disturbances, including excessive daytime drowsiness and rapid eye movement (REM) sleep disorder.