Gamma synchronization increases during movement and scales with kinematic parameters. Here, disease-specific characteristics of this synchronization and the dopamine-dependence of its scaling in Parkinson's disease are investigated. In 16 patients undergoing deep brain stimulation surgery, movements of different velocities revealed that subthalamic gamma power peaked in the sensorimotor part of the subthalamic nucleus, correlated positively with maximal velocity and negatively with symptom severity. These effects relied on movement-related bursts of transient synchrony in the gamma band. The gamma burst rate highly correlated with averaged power, increased gradually with larger movements and correlated with symptom severity. In the dopamine-depleted state, gamma power and burst rate significantly decreased, particularly when peak velocity was slower than ON medication. Burst amplitude and duration were unaffected by the medication state. We propose that insufficient recruitment of fast gamma bursts during movement may underlie bradykinesia as one of the cardinal symptoms in Parkinson's disease.
- Andrea A Kühn
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Human subjects: All participants provided written informed conset which was approved by the local review boeards of the Charité - Universitätsmedizin Berlin and Hannover Medical School and in accordance with the standards set by the Declaration of Helsinki (EA2/071/08).
- Eilon Vaadia, The Hebrew University of Jerusalem, Israel
© 2018, Lofredi et al.
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