LAUSR

patient at home (36% improvement in stim-on/meds-off at enrollment visit). During the study, the patient continued the home medication regimen and took 1 pill of fast-acting oral levodopa/benserazide 100/25 mg on 2 occasions. Levodopa improved parkinsonian symptoms by 5 points on the MDSUPDRS part III score, without adverse events (i.e., dyskinesias). No adverse events or complaints by the patient were reported. The Ethical Committee approved the study, and all patients gave written informed consent. Our results prove the feasibility of prolonged recordings (up to 24 hours) in freely moving, chronically stimulated patients. They further corroborate the hypothesis that oscillations in the β-frequency range might be used as a levodoparelated biomarker for adaptive DBS paradigms, as they are present during active stimulation and years after surgery. We also provide for the first time preliminary evidence that interhemispheric subthalamic coupling changes between wakefulness and sleep can be monitored and possibly serve as an additional behavior-specific biomarker. These findings pave the way for testing different adaptive stimulation paradigms for STN-DBS and prompt a more accurate definition of symptom-related and behavior-specific biomarkers in PD.