Dementia With Lewy Bodies - Classification

Classification

Dementia with Lewy bodies overlaps clinically with Alzheimer's disease and Parkinson's disease, but is more associated with the latter. In DLB, loss of cholinergic (acetylcholine-producing) neurons is thought to account for degeneration of cognitive function (similar to Alzheimer's), and loss of dopaminergic (dopamine-producing) neurons for degeneration of motor control (similar to Parkinson's) - in some ways, therefore, it resembles both diseases. The overlap of neuropathologies and presenting symptoms (cognitive, emotional, and motor) can make an accurate differential diagnosis difficult. In fact, it is often confused in its early stages with Alzheimer's disease and/or vascular dementia (multi-infarct dementia), although, where Alzheimer’s disease usually begins quite gradually, DLB often has a rapid or acute onset, with especially rapid decline in the first few months. DLB tends to progress more quickly than Alzheimer’s disease. Despite the difficulty, a prompt diagnosis of DLB is important because of the risks of sensitivity to neuroleptic drugs and because appropriate treatment of symptoms can improve life for both the person with DLB and their caregivers.

DLB is distinguished from the dementia that sometimes occurs in Parkinson's disease by the time frame in which dementia symptoms appear relative to Parkinson symptoms. Parkinson's disease with dementia (PDD) would be the diagnosis when dementia onset is more than a year after the onset of Parkinson's. DLB is diagnosed when cognitive symptoms begin at the same time or within a year of Parkinson symptoms.