Effects of STN DBS and auditory cueing on the performance of sequential movements and the occurrence of action tremor in Parkinson's disease.

Background: Parkinson's disease (PD) patients show a higher ability to perform repetitive movements when they are cued by external stimuli, suggesting that rhythmic synchronization with an auditory timekeeper can be achieved in the absence of intact basal ganglia function. Deep brain stimulation (DBS) is another therapeutic method that improves movement performance in PD and may suppress or enhance action tremor. However, the combined effect of these therapies on action tremor has not been studied yet.

Power spectral density analysis of physiological, rest and action tremor in Parkinson's disease patients treated with deep brain stimulation.

Background: Observation of the signals recorded from the extremities of Parkinson's disease patients showing rest and/or action tremor reveal a distinct high power resonance peak in the frequency band corresponding to tremor. The aim of the study was to investigate, using quantitative measures, how clinically effective and less effective deep brain stimulation protocols redistribute movement power over the frequency bands associated with movement, pathological and physiological tremor, and whether normal physiological tremor may reappear during those periods that tremor is absent.

Methods: The power spectral density patterns of rest and action tremor were studied in 7 Parkinson's disease patients treated with (bilateral) deep brain stimulation of the subthalamic nucleus.