Changes of Quantitative EEG after Donepezil Treatment in Alzheimer's Disease

Kwak, Yong Tae; Han, Il Woo; Bang, Oh Young

Abstract

BACKGROUND: Though symptomatic improvements after treatment of donepezil is well documented in Alzheimer's disease (AD), the electrophysiological change have not yet been elucidated. Among the parameters of quantitative electroen-cephalography (q-EEG), high frequency activity, especially gamma rhythm, may play a role in normal cognitive function including the integration of sensory processing, association, coupling or selective attention, which are characteristically impaired in AD.
METHODS
In order to define the profile of q-EEG changes including gamma rhythm after donepezil treatment, we followed 17 AD patients for 12 weeks. We analyzed the spectra power taken from 16 derivations by averaging twenty-2-sec epoch in normal controls and AD patients. After logarithmic transformation of spectra power, statistical test was done and the effect of donepezil treatment on q-EEG profile was analyzed during follow up period.
RESULTS
Before medication of donepezil, AD patients had a significantly lower alpha spectra power as well as a significant higher delta spectra power, compared with normal control. After medication of donepezil in AD patients, compared to base-line q-EEG, gamma spectra power was significantly increased, whereas delta spectra power was significantly reduced. Compared to absolute power, relative power was more sensitive in detecting change of EEG after donepezil treatment.
CONCLUSIONS
This study suggests that donepezil significantly change delta and gamma spectra power in q-EEG, and the increase in gamma rhythm may be correlated with the clinical improvements after donepezil treatment. (J Korean Neurol Assoc 19(3):245~250, 2001)