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Understanding Dementia

Lewy body dementia

Quick answer

Lewy body dementia combines cognitive change with visual hallucinations, fluctuating alertness, movement changes, and sleep disturbance.

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

Lewy body dementia is caused by abnormal alpha-synuclein deposits. Attention and alertness often vary substantially from hour to hour, which families sometimes mistake for inconsistency or effort.

Common symptoms

  • Well-formed visual hallucinations
  • Marked fluctuation in alertness and attention
  • Slowness, stiffness, shuffling, or falls
  • Acting out dreams during sleep
  • Sensitivity to antipsychotic medications
  • Blood pressure drops on standing

How it progresses

Cognitive, motor, and behavioral symptoms tend to advance together. Falls and fluctuations often drive care needs earlier than memory loss does.

How it is diagnosed

Diagnosis is clinical, supported by history of dream enactment, hallucinations, and parkinsonism. Imaging studies may support the diagnosis in unclear cases.

Treatment

Cholinesterase inhibitors often help. Certain antipsychotics can cause severe reactions and are generally avoided. Blood pressure, sleep, and fall risk need active management.

What families should know

  • Tell every clinician about antipsychotic sensitivity
  • Fluctuation is part of the disease, not lack of effort
  • Hallucinations that are not distressing may not need medication

Questions to ask your doctor

  • Which medications should be avoided?
  • How should we manage hallucinations at home?
  • What can be done about falls and blood pressure drops?

Related resources

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

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