A case of Down's syndrome with diffuse Lewy body disease and Alzheimer's disease

Almost all Down9s syndrome (DS) patients over the age of 35 to 40 years have histologic features of Alzheimer9s disease (AD). However, the presence of extrapyramidal features in up to 364 of these patients has no satisfactory pathologic explanation. We report an older patient with DS, dementia, and parkinsonian signs who showed pathologic changes of Parkinson9s disease and cortical Lewy bodies in addition to AD. These parkinsonian changes may be related to chromosome 21 abnormalities.