Lewy body dementia (LBD) is an umbrella term for two similar and common subtypes of dementia:[1] dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD).[2][3][4][5] Both are characterized by changes in thinking, movement, behavior, and mood.[1] The two conditions have similar features and may have similar causes, and are believed to belong on a spectrum of Lewy body disease[2] that includes Parkinson's disease.[5] As of 2014, they were more often misdiagnosed than any other common dementia.[6]

Reference
Wiki: Lewy body disease