ALZHEIMER'S PRESENILE DEMENTIA, SENILE DEMENTIA OF ALZHEIMER TYPE AND DOWN'S SYNDROME IN MIDDLE AGE FORM AN AGE RELATED CONTINUUM OF PATHOLOGICAL CHANGES

Abstract

A loss of nerve cells from the nucleus basalis of Meynert and the locus caeruleus together with a reduction in nucleolar volume in surviving cells was measured in 22 patients with Alzheimer''s disease who ranged in age from 48-92 yr, and in 6 patients > 50 yr of age with Down''s syndrome who also showed extensive formation of senile plaques and neurofibrillary tangles within their cerebral cortex. When compared with age matched controls the severity of these changes was greatest in the younger paients with Alzheimer''s disease, but this fell with age such that by 80 yr the level of change in Alzheimer''s disease approached that in old age alone. There were only slight differences in the extent of these pathological changes in those patients with Alzheimer''s disease. The presenile dementia of Alzheimer''s disease, the senile dementia of Alzheimer type and Down''s syndrome in middle age all form an age-related continuum of pathological change.