In this condition, protein deposits of Alpha-synuclein called lewy bodies develop in nerve cells in brain regions involved in memory, reasoning, perception, thinking, behavior and movement. Many people with DLB experience movement symptoms such as hunched posture, rigid muscles, shuffling walk and trouble initiating movement. Lewy body dementia is the second most common kind of dementia after Alzheimer’s disease that gradually causes decline in mental ability. It may sometimes causes visual hallucination and unusual behaviors such as having conversations with deceased loved ones. It sometimes exists in pure form, or with other brain changes, including those commonly observed in Alzheimer's and Parkinson's diseases.
In a study of diagnostics of Creutzfeldt-Jakob disease (CJD) and other prion diseases in the Netherlands over a period of 11 years (1997-2007), autopsies were carried out on 280 patients with probable or possible CJD at the Dutch Surveillance Center for Prion Diseases in Utrecht. Lewy body dementia was observed in 8% of the patients.