On the EEG component waves of multi-infarct dementia seniles.

Component waves of EEGs led from the F3-A1, C3-A1, O1-A1, and O2-A2 scalp regions of 24 multi-infarct dementia seniles (MID) patients (ages 58 to 85 years, average 73.3 years) and eight to 19 normal, healthy, adult (NA) subjects were obtained by autoregressive component analysis. Some differences in the component waves were demonstrated between the two groups of subjects. (1) The characteristics of the EEG component waves, including the natural, damping, and resonance frequencies, their power, regularity, etc. were determined, and compared between MID patients and NA subjects. (2) No significant difference was found between male and female patients in the occurrence rate of 11 types of component waves. (3) On the average, the alpha wave frequency was lower in MID patients. (4). Slow alpha waves (7.5 to 9.4 Hz) of MID patients were superior to those of NA subjects, whereas typical alpha waves (9.5 to 11.4 Hz) were inferior to those of NA subjects. (5) The power of alpha waves in the F3-A1 and C3-A1 regions of MID patients was superior to that of NA subjects, whereas the result was reversed in the O1-A1 and O2-A2 regions. However, there was less regularity of alpha waves in all regions among MID patients. (6) The theta wave frequency in all regions was higher in MID patients than in NA subjects. (7) Both the power and regularity of theta waves of MID patients were superior to those of NA subjects in all regions. (8) The average number of delta waves that appeared in the O1-A1 and O2-A2 regions was larger in MID patients than in NA subjects. EEG were led from the F3-A1, C3-A1, O1-A1, and O2-A2 scalp regions of multi-infarct dementia seniles (MID) patients, who had sleep disorders, such as reversed day-time sleep patterns or irregular sleep-wake patterns, frequently accompanied by behavior disorders, such as wandering, violent behavior, and/or delirium. Examination by the method of EEG pattern discrimination revealed some differences in EEG component waves in comparison with normal, healthy, adult (NA) subjects.