Effects of rivastigmine on the quantitative EEG in demented Parkinsonian patients

Objectives - Quantitative electroencephalogram (qEEG) can be used to measure the effects of drugs on the brain. We studied the effects of rivastigmine on the qEEG in Parkinson's disease (PD) patients with dementia. Subjects and methods - Demented PD patients (n =19) were treated with rivastigmine in an open label study. Recordings were obtained prior to and following 12 weeks of treatment. Results were analyzed using two-way ANOVA with repeated measures. Results - A significant increase in the relative alpha (P < 0.05) activity was observed after treatment with rivastigmine. This was general rather than localized to specific brain surface areas. An increase in beta activity and decrease in the slower frequencies (delta and theta) were also observed; however, these were not statistically significant. Conclusion - qEEG may serve as an objective tool to monitor the effects of antidementia drug therapy. The changes characterized by increased faster frequencies and decreased slower frequencies that were observed may indicate increased arousal or improvement in the cognitive state of the patients as a consequence of the treatment with rivastigmine.