Topography of the quantitative electroencephalogram in dementia of the Alzheimer type: relation to severity of dementia.

Conventional electroencephalographic (EEG) frequency bands and peak frequency were investigated in patients with probable dementia of the Alzheimer type (DAT). Measures of EEG topography and activity were also related to the severity of dementia, as assessed by neuropsychological tests. EEG activity measured in conventional frequency bands proved to be the most sensitive parameter for the quantitative differentiation of DAT, whereas the topography of peak frequency was the better qualitative discriminator between healthy subjects and DAT patients.