Quantitative EEG during a double-blind trial of THA and lecithin in patients with Alzheimer's disease

Quantitative electroencephalography (EEG) was performed on eight of ten Alzheimer patients in a double-blind, inpatient-outpatient tetrahydroaminoacridine (THA) and lecithin trial. Neuropsychological measures were related to EEG activity. Patient baseline dominant parietal rhythms (DPRs) and power spectral distributions differed significantly from controls. Severity of cognitive impairment was related to the degree of parietal slowing. Inpatient THA treatment resulted in increased DPR frequency in six of eight patients. Four of eight inpatients demonstrated reduced power in the delta and theta bands. During the outpatient long-term treatment phase, six of the patients were able to continue. Three of these improved significantly on tests of cognition. Two of these improved patients demonstrated DPRs with increased frequency. One of these patients also showed a decrease in slow-wave activity. Thus, THA may accelerate DPRs while reducing power in the slower EEG bands. However, there appears to be only a tentative coupling between individual quantitative EEG measures and cognitive performance associated with THA administration.