The Role of Basal Ganglia Theta Oscillations in Predicting the Onset of Levodopa‐Induced Dyskinesias

Background Levodopa‐induced dyskinesias (LIDs) are an important burden for patients with Parkinson's disease (PD), yet their mechanisms remain incompletely understood. Objective The objective of this study was to investigate the temporal and spatial relationship between local field potential (LFP) changes and dyskinesia development in PD. Methods We recorded bilateral subthalamic LFPs, electromyography, and accelerometry in patients with PD with peak‐dose LIDs undergoing deep brain stimulation (DBS) surgery. Apomorphine was administered to induce dyskinesias, and recordings continued for 200 seconds postonset. Spectral power changes were analyzed over time and mapped to the DBS “sweet spot.” A machine‐learning algorithm detected dyskinetic movements. Results In 9 of 36 patients, dyskinesias were preceded by a bilateral beta power decrease ( P < 0.001) and contralateral theta increase ( P = 0.02), followed by gamma elevation ( P = 0.03). These changes peaked in the DBS sweet spot. Conclusions Our results provide insights into the sequential nature of beta, theta, and gamma oscillatory changes. Theta activity may serve as a key biomarker for adaptive DBS.