Summary

• A neurodegenerative disorder with parkinsonism, progressive cognitive decline, prominent executive dysfunction, and visuospatial impairment.
• Core features include at least 2 of the following: recurrent visual hallucinations, cognitive fluctuations, or spontaneous extrapyramidal signs.
• Suggestive features include rapid eye movement (REM) sleep behaviour disorder and severe antipsychotic sensitivity.
• Diagnosis is made clinically and can only be confirmed pathologically by the presence of Lewy bodies. Many patients have concomitant Alzheimer's disease (AD)-type pathology.
• Pharmacological treatment is off-label use of cholinesterase inhibitors for both the cognitive and neurobehavioural symptoms. Memantine may be of some value in treatment of dementia and behavioural symptoms.
• The use of antipsychotic medication must be minimised due to the increased sensitivity to these medicines' adverse effects, including increased mortality.
• Levodopa/carbidopa can be used for the extrapyramidal symptoms, though adverse effects may be restrictive and response limited; clonazepam is effective for REM sleep behavioural disorder.