Dementia Japan 31:280-287, 2017

Neuropathologic substrate of dementia with Lewy bodies

Koichi Wakabayashi

Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine

The histopathological hallmark of Parkinson's disease (PD) and dementia with Lewy bodies (DLB) is the presence of fibrillar aggregates referred to as Lewy bodies, in which α-synuclein is a major constituent.  Dementia in PD and DLB relates to subcortical neuronal degeneration and resultant neurochemical dysfunction of cholinergic, dopaminergic, noradrenergic and serotonergic projection systems.  Although cortical Lewy body pathology is the main substrate driving the progression of cognitive impairment in PD and DLB, Alzheimer disease pathology (amyloid plaques and neurofibrillary tangles) is commonly found in these brains.  It has become apparent that there is a strong interaction between α-synuclein, β-amyloid and tau at a molecular level.  Further studies are needed to examine the interactions of these pathogenic proteins in producing dementia in PD and DLB.

Address correspondence to Dr. Koichi Wakabayashi, Department of Neuropathology, Hirosaki University Graduate School of Medicine (5 Zaifu-cho, Hirosaki 036-8562, Japan)