[An autopsy case of dementia with Lewy bodies who showed the typical parkinsonism in the initial five years].

A 76-year-old man with parkinsonism and dementia was reported. He developed resting tremor at age 69 followed by hypokinesia, rigidity and small step gait. L-dopa ameliorated his symptoms with no hallucinations for the initial 5 years. His mental level did not decrease during that period. He was admitted to our hospital because of dehydration and fever at age 74. Subsequently, his cognitive function deteriorated, with visual hallucination. Serial brain CT studies displayed a progressive cerebral cortical atrophy without focal lesions. He died of respiratory distress syndrome and disseminated coagulopathy resulting from pneumonia, dehydration and syndrome malin. Postmortem examination revealed a marked bilateral loss of melanin-containing neurons with Lewy bodies in the substantia nigra and locus ceruleus. Lewy bodies were also in the basal nucleus of Meynert, with moderate neuronal cell loss. The distribution of Lewy bodies was widespread in the cerebral cortical areas, corresponding to the neocortical subtype according to the consensus guideline for the pathologic diagnosis of dementia with Lewy bodies. According to the criteria of the Consortium to Establish a Registry for Alzheimer's Disease, the age-related plaque score in the present case suggested Alzheimer's disease, although cortical neurofibrillary changes corresponded to stage II by the criteria of Braak and Braak. These pathological findings established the diagnosis of dementia with Lewy bodies from the quantitative and distributional viewpoints. Based on recent neuropathological evidence, a spectral theory, which presents idiopathic Alzheimer's disease and Parkinson's disease as the two extremes of a spectrum of neurodegeneration, has been proposed. Dementia with Lewy bodies is located in the middle of this spectrum. Pathological evaluation based on quantitative consensus guidelines is important to establish the diagnosis in patients with parkinsonism and dementia, since neuropathological changes of Alzheimer's disease, Parkinson's disease and dementia with Lewy bodies are often observed in a mixed manner in these patients.