[2][3][4][5] Parkinson's disease starts as a movement disorder, but progresses in most cases to include dementia and changes in mood and behavior.
[6] The signs, symptoms and cognitive profile of PDD are similar to those of DLB;[2] DLB and PDD are clinically similar after dementia occurs in Parkinson's disease.
[8] Parkinson's disease dementia can only be definitively diagnosed after death with an autopsy of the brain.
[6] The 2017 Fourth Consensus Report established diagnostic criteria for PDD and DLB.
DLB is diagnosed when cognitive symptoms begin before or at the same time as parkinsonism.