Motor symptoms of Parkinson's disease have been associated with the synchronized oscillatory activity in the cortico-basal ganglia-thalamic circuits. Here we will present our observations of the patterns of synchronized activity obtained through simultaneous intraoperative recordings of spikes and LFP in the basal ganglia and cortical EEG in parkinsonian patients. We discuss the temporal patterning of the observed synchronized patterning. We show how the synchronization of EEG in motor and prefrontal areas (which can be obtained noninvasively) is predictive of the spike-LFP synchrony in subthalamic nucleus. We also consider the observed phenomena within the framework of mathematical models of cortico-basal ganglia circuits.