Analysis of Movement-Related Beta Oscillations in the Off-Medication State During Subthalamic Nucleus Deep Brain Stimulation Surgery.

PURPOSE: Local field potential recordings from deep brain stimulation (DBS) leads provide insight into the pathophysiology of Parkinson disease (PD). We recorded local field potential activity from DBS leads within the subthalamic nucleus in patients with PD undergoing DBS surgery to identify reproducible pathophysiological signatures of the disease.

METHODS: Local field potentials were recorded in 11 hemispheres from patients with PD undergoing subthalamic nucleus-DBS. Bipolar recordings were performed off medication for 2 minutes at rest and another 2 minutes with continuous repetitive opening-closing of the contralateral hand. Spectral analysis and bicoherence were performed and compared between the two testing conditions.

RESULTS: In all hemispheres, predominance of the beta band frequency (13-30 Hz) was observed at rest and during movement. Beta peak energy was significantly (P < 0.05) increased during movement compared with rest in 6 of 10 hemispheres. Significant beta bicoherence was observed at rest and during movement in 5 of 10 hemispheres. The most robust local field potential recordings were observed at the DBS contact(s) independently chosen for programming in 9 of the 10 hemispheres.

CONCLUSIONS: In patients with PD, beta activity that increases with repetitive movement may be a signature of the "off" medication state. These findings provide new data on beta oscillatory activity during the Parkinsonian "off" state that may help further define the local field potential signatures of PD.