Impact of deep brain stimulation on sleep-wake cycle in parkinson's disease and correlations between subcortical local field potentials and electrophysiological activity: a longitudinal study

Background: sleep disturbances in Parkinson’s Disease (PD) worsen motor and non-motor symptoms, but the impact of Deep Brain Stimulation (DBS) on sleep-wake cycles and subcortical sleep-related neurophysiology remains insufficiently explored. Objectives: we investigated DBS’s effects on sleep architecture, circadian rhythm, and subcortical electrophysiological control in PD, with a focus on potential neurophysiological mechanisms for sleep modulation. Methods: in our longitudinal study, 38 PD patients (9 females) undergoing DBS implants were evaluated with a thorough clinical evaluation, a 7-days actigraphy and video-polysomnography (vPSG) pre- and 6 months post-surgery. Patients implanted with a sensing enabled device performed synchronized local field potentials (LFPs) recording with actigraphy and vPSG. Repeated measures and linear mixed-effects models were used for statistical evaluation. Results: following DBS, excessive daytime sleepiness levels decreased, significant increase in slow wave sleep with reduction of REM sleep motor events were observed. Actigraphy revealed increased nocturnal sleep consolidation with reduction of napping, and no modification of sleep fragmentation or circadian rhythms. Chronic evaluation of LFPs showed moderate correlations with motor activity and distinguished between diurnal wake and nocturnal sleep. LFPs also showed distinct subcortical oscillatory patterns across sleep phases: delta and theta oscillations reliably marked NREM stages, while beta and gamma patterns better defined REM. Specific frequency patterns were also found during arousals and distinguished REM sleep with and without atonia from actual REM sleep behavior disorder episodes, going beyond the predominance of beta band. Conclusions: these findings underscore foundational neurophysiological insights that may inform future adaptive DBS (aDBS) interventions for sleep-related PD symptoms, emphasizing the need solidify this knowledge to fully develop DBS’s therapeutic potential in sleep regulation.