Neuropathological features of cognitive decline in Lewy body dementia

Parkinson's disease (PD) is associated with mild cognitive impairment and dementia. The causes of cognitive impairment in PD are diverse, and some remain unclear. Cognitive impairment in PD is thought to be caused by abnormal protein accumulation, neurotransmitter circuit dysfunction, synaptic dysfunction, neuroinflammation, mitochondrial dysfunction, and/or changes in microglia and astroglia. PD with dementia (PDD) and dementia with Lewy bodies (DLB) are defined as dementia syndromes that have many overlapping clinical features and underlying genetics. As such, it is difficult to distinguish between PDD and DLB neuropathologically. In this paper, we will use the term "Lewy body dementia" to refer to the dementia syndromes of both diseases. Furthermore, we will describe the cognitive impairment that accompanies PDD and DLB from a neuropathological perspective according to recent research.