Associate Professor of Neurosurgery University of Nebraska Medical Center Omaha, Nebraska, United States
Disclosure(s):
Stephen V. Gliske, PhD: Natus Neurology: Royalty Recipient (Ongoing)
Introduction: Sleep is highly disrupted in patients with Parkinson’s disease (PD). Mounting evidence suggests that subthalamic (STN) deep brain stimulation (DBS) ameliorates certain aspects of sleep dysfunction. However, the interaction between sleep, PD severity and progression, and DBS is unknown. Our objective was to clarify these interactions, by using local-field potential (LFP) beta-power (12-30 Hz) recorded within STN in a sleep lab setting.
Methods: Three nights of simultaneous polysomnograms (PSG) and STN LFP recordings were obtained from 13 PD subjects, including at least one baseline night and one night with intermittent sub-threshold stimulation (30 seconds every 5 minutes; 70% of therapeutic mA) through a percutaneous extension cable connected to a unilateral DBS lead. Sleep scoring was based on consensus of three expert raters. Power in the beta frequency band was computed for each 30-second epoch. Due paucity of sleep stages other than NREM2, we pooled sleep scores into just sleep and wake states.
Results: Beta-power was lower during sleep than during bouts of wake after sleep onset (WASO) (p=0.01 baseline nights, p=0.05 stimulation nights). Beta-power was similar between WASO and the 30-minutes prior to sleep onset (p=0.68 baseline, p=0.50 stimulation). Beta-power decreased during the first 15 minutes of sleep bouts (p=2e-27 baseline, p=3e-24 stimulation), though the decrease at sleep bout onsets was less steep on nights with stimulation (p=2e-5). At baseline, beta-power returns to higher levels in the one minute prior to bouts of WASO (p=8e-5) but not on stimulation nights (p=0.85). Among 9/13 subjects with lower beta-power on stimulation nights in the 30 minutes prior to sleep onset, beta-power was also decreased during sleep and WASO (p=0.01 sleep, p=0.01 WASO).
Conclusion : Both sleep and stimulation impact beta-power. The association of beta-band power with WASO and its increase prior to WASO might serve as a target for improving sleep.
