Longitudinal EEG findings in dementia related to the parietal brain syndrome and the degree of dementia.

EEG slow-wave activity was correlated with the regional brain syndrome profile in 74 patients with dementia. The EEGs were visually assessed using a semiquantitative rating scale. The intensities of four regional brain syndromes (parietal, frontal, subcortical, global) and the degree of dementia were rated. The patients were examined twice with a 1-year interval. A significant relationship was found between the increase in EEG slow-wave activity and the increase in intensity of the parietal brain syndrome. A somewhat lower significance was found for the relation between increase in slow-wave activity and increase in dementia degree. The results suggest that the EEG deterioration in dementia mainly reflects the gradual decline of parietal brain function.