The Wikipedia article of the day for July 21, 2021 is Dementia with Lewy bodies.
Dementia with Lewy bodies is a common dementia characterized by changes in sleep, behavior, cognition, movement, and automatic bodily functions. Symptoms worsen over time until cognitive decline interferes with normal daily functioning. The core features are REM sleep behavior disorder (in which people act out their dreams), visual hallucinations, marked fluctuations in attention or alertness, and parkinsonism. The exact cause is unknown, but involves deposits of abnormal clumps of protein in the brain, known as Lewy bodies. Gastrointestinal and heart function can be affected. Definitive diagnosis usually requires an autopsy, and a probable diagnosis—based on symptoms and tests—is often missed. Management of the many symptoms is challenging and involves multiple specialties. There is no cure or medication to stop the disease progression. After the suicide of Robin Williams (pictured) in 2014, his autopsy found that diffuse Lewy bodies explained his symptoms.