EEG and computed tomography in the investigation of patients with senile dementia.

Fifty-six patients with senile dementia of Alzheimer type and 84 normal elderly people were examined by EEG and computed tomography. In discriminant function analysis of the computed tomography indexes the highest discriminant function coefficient was for width of the third ventricle. Using computed tomography, the groups were correctly classified for 84% of the subjects. In discriminant function analysis of the EEG variables the highest discriminant function coefficient was for dominant occipital rhythm; the groups were correctly classified for 86% of the subjects. In discriminant function analysis of the width of the third ventricle, an index of cortical atrophy, the dominant occipital rhythm, age and sex, the width of the third ventricle had the highest discriminant function coefficient; the groups were correctly classified for 90% of the subjects.