Centrum semiovale white matter CT changes associated with normal ageing, Alzheimer's disease and late life depression with and without reversible dementia.

A standardized, reliable means of assessing CT attenuation numbers in the centrum semiovale and surrounding grey matter was developed. This was applied to cranial CT scans of 60 normal controls (36 aged greater than 60 years), 25 elderly patients with major depression (14 of whom had the dementia syndrome of depression), and 10 patients with Alzheimer's disease (AD). Subjects received neuropsychological evaluation. Centrum semiovale (CSO) CT attenuation numbers decreased with increasing age for both white and grey matter. White matter attenuation values best discriminated elderly controls from the three patient groups. Both white and grey matter CSO attenuation values correlated with performance on a number of cognitive tasks.