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Understanding Dementia

Parkinson's disease dementia

Quick answer

Parkinson's disease dementia develops in some people years after Parkinson's movement symptoms begin.

Author:
Illinois Dementia Guide editorial team
Medically reviewed by:
Amarish Dave, DO, Board Certified Neurologist
Published:
August 2026
Last medically reviewed:
August 2026
Geographic relevance:
Illinois, United States

Overview

Attention, planning, and visual-spatial ability are usually affected more than pure memory. Hallucinations and sleep problems are common.

Common symptoms

  • Slowed thinking and reduced attention
  • Visual-spatial difficulty
  • Hallucinations
  • Sleep disturbance and daytime drowsiness
  • Worsening balance and falls

How it progresses

Cognitive symptoms typically emerge later in the course of Parkinson's disease and progress gradually alongside motor symptoms.

How it is diagnosed

Established Parkinson's disease plus cognitive testing showing decline affecting daily function, after ruling out medication effects and other contributors.

Treatment

Cholinesterase inhibitors may help. Parkinson's medications sometimes need adjustment when hallucinations occur. Fall prevention and physical therapy are essential.

What families should know

  • Medication timing affects both movement and thinking
  • Falls often drive the need for more help at home
  • Report new hallucinations before adjusting medications on your own

Questions to ask your doctor

  • Could any medication be worsening confusion?
  • Would physical or occupational therapy help now?
  • How do we handle hallucinations safely?

Related resources

Medically reviewed. Last reviewed August 2026. This page is educational information, not individualized medical advice.

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