[EEG changes in senile dementia of the Alzheimer type]

Character and extent of changes in EEG in 45 patients with senile dementia of Alzheimer type (SDAT) were reported and the EEG-findings of patients with moderate (18) or severe (27) dementia were compared. The EEG-findings in these patients were compared with a group of 82 patients with multi-infarct dementia (MID). The EEG showed pathological results in 37 patients with predominating general changes (59%). In patients with severe dementia significantly more pathological results especially a significantly slower basic rhythm could be found. The degree of the cerebral atrophy verified by CT did not correspond with character and extent of the changes in EEG. The comparison between patients with SDAT and 82 patients with MID, revealed a significantly more frequent occurrence of unilateral slowing of the basic rhythm but a less frequent occurrence of focal changes. However, there was no significant difference in the number of normal and pathological EEG. The comparison between patients with SDAT and patients with MID without neurological deficit failed to show a significant difference in the number of normal and pathological EEG as well. It could be shown that in patients with severe dementia the EEG revealed significantly more pathological results as well as a significantly slower basic rhythm. However, the EEG could not differentiate between SDAT and MID.