Clinical and pathological features of diffuse cortical Lewy body disease (Lewy body dementia).

Four patients with severe dementia and a parkinsonian syndrome are described. Dysphasia, dyscalculia, dyspraxia, visual and verbal memory disturbance and psychosis, usually of depressive type, occurred early in the course of the illness. Pathologically they were characterized by the presence of numerous Lewy bodies throughout both the cerebral cortex and brainstem. Three cases also had severe neurofibrillary tangle change or senile plaques in the neocortex, compatible with Alzheimer's disease, but the cortical tangle distribution did not always match that of the Lewy bodies. This disorder may form part of the spectrum of pathology in Parkinson's disease, where it may be one possible cause of dementia.