Case-control study of late onset "probable Alzheimer's disease".

A case-control study was conducted on 64 cases of "probable Alzheimer's disease" with late onset of illness (after age 70 years) and 64 controls matched by age (+/- 3 years), race, and sex. Information was obtained on birth order, lifetime medical and surgical history, personal characteristics, exposure to toxins and animals, and a family history of various illnesses. None of the variables studied, including family history of dementia, reached statistical significance. An antecedent history of head trauma with loss of consciousness, though not statistically significant, was more frequently found in cases than in controls.