Quantitative EEG changes in non‐demented Parkinson's disease patients before and during L‐dopa therapy

Abstract

Nineteen non‐demented Parkinson's disease patients have been studied before and during L‐dopa therapy by quantitative EEG performed at rest with eyes closed (EC) and during attentive (BR) and cognitive (FIX) tasks. The data have been compared by ANOVA analysis with those of 22 age‐matched healthy subjects. In all three conditions a significant increase of the mean δ power as well as a decrease of β1 power was observed in patients before therapy. Abnormal high δ values were observed in 10 out of 19 patients. L‐Dopa therapy did not modify this EEG pattern. After therapy, however, a significant decrease of reactivity to BR and FIX was observed in patients compared to normal subjects. These data confirmed the presence of an EEG synchronization (increase of slow activity and decrease of fast activity) in non‐demented Parkinson's disease patients. This pattern, similar to that of subjects with Alzheimer‐type dementia, might indicate an intellectual impairment at sub‐clinical level. A non‐dopaminergic mechanism could be responsible for this impairment