EEG and reaction time in patients with Parkinsonism before and duringl-dopa therapy

Abstract

Electroencephalograms were performed on 58 of 100 patients treated with/-dopa for Parkinsonism. Half the electroencephalograms were abnormal and, with few exceptions, showed slowing of normal background activity and increased generalized theta activity. The degree of electroencephalographic abnormality paralleled the degree of clinical disability. In twelve patients mean energy content of the electroencephalogram, coefficient of variation and reaction time were studied before and during treatment with l-dopa. Mean energy content of the electroencephalogram did not change during therapy. Coefficient of variation was markedly reduced before and during treatment. Reaction time shortened with/-dopa therapy in patients who improved clinically. It is suggested that reaction time can be used as an objective measure to assess efficacy of treatment in Parkinsonism.