A pathological study of the association between Lewy body disease and Alzheimer's disease.

The possibility of an association between Parkinson's disease and Alzheimer's disease has been examined by studying the age-specific prevalence of Lewy bodies in the substantia nigra in a group of 273 control cases without Parkinson's disease and 121 cases of Alzheimer's disease. The substantia nigra was also studied in 14 cases of Downs syndrome, 13 of which had cortical Alzheimer pathology. No case of Down's syndrome had Lewy bodies. Counts of tangles and plaques in hippocampus, frontal and temporal cortex were lower in cases of Alzheimer's disease with Lewy bodies compared with those without, but cortical choline acetyltransferase (ChAT) activities were similar. The relatively small difference in the prevalence of Lewy bodies between controls and Alzheimer's disease could be explained by the additive effects of Lewy body and tangle pathology causing dementia, rather than a greater than chance association between Parkinson's disease and Alzheimer's disease.

Source: Gibb, W.R., Mountjoy, C.Q., Mann, D.M., & Lees, A.J. A pathological study of the association between Lewy body disease and Alzheimer's disease. Journal of Neurology, Neurosurgery & Psychiatry, 1989, 52, 701-708. http://dx.doi.org/10.1136/jnnp.52.6.701