Saccade-Related beta-Band Desynchronization in the Subthalamic Nucleus of Parkinson Disease Patients during Successful Antisaccades and Error Trials (P01.196)

Abstract

Objective: To investigate the saccade-related beta-band desynchronization (beta-SRD) recorded from deep brain stimulation (DBS) electrodes implanted in the subthalamic nucleus (STN) of Parkinson disease (PD) patients during successful antisaccades and error trials. Background The basal ganglia including the STN are involved in response selection by exerting or removing tonic inhibition in the thalamocortical loops and in the brainstem motor circuits. Beta-SRDs are thought to play a role in inhibition of unwanted movements and in execution of movements. Antisaccades require a strong inhibition of reflexive saccades towards the visual cue and a strong driving signal for voluntary saccades away from the visual cue. Whether beta-SRDs in the STN during successful antisaccades are different from those during error trials has not been studied. Design/Methods: Eighteen PD patients performed an antisaccade task 1 to 3 days after DBS surgery when the leads were externalized. Local field potentials were recorded from DBS electrodes implanted in the STN and electrooculography was used to measure saccades. We analyzed the power spectrum in each DBS contact pair using Morlet wavelets averaged on saccade onset. The incidence, latency, and duration of beta-SRDs during successful antisaccades were compared with those during errors trials. Results: The averaged incidence of errors was 36.3%. Mean latencies of saccades were longer during antisaccades (432.6 ± 170.6 ms (mean ± SD)) than during errors (309.5 ± 146.1 ms). Beta-SRDs were observed more often during antisaccades (24 of 31 STN) than during errors (7 of 31 STN; p Conclusions: Beta-SRDs were observed more frequently and were sustained for longer during successful antisaccades than during error trials. Those results suggest that beta-SRDs played a role in the suppression of unwanted saccades and in the successful execution of antisaccades. Disclosure: Dr. Yugeta has nothing to disclose. Dr. Hutchison has received personal compensation for activities with Medtronic Inc. as a speaker. Dr. Hutchison has received research support from Medtronic Inc. Dr. Chen has received personal compensation for activities with Allergan, Inc., Medtronic, Inc., Biovail, EMD Serono, Merz Pharma, the American Academy of Neurology, the Douglas Mental Health University Institute, Movement Disorders Society, the University of Pittsburg, Merz, CHIR, the Michael J. Fox Foundation for Parkinson9s Research, the Dystonia Medical Research Foundation, and has provided expert testimony and affidavit in welding related litigations. Dr. Chen has received research support from Medtronic, Inc.