Abstract

Abstract Background and Objective Memory impairment is a frequent and debilitating symptom in neurodegenerative disorders. The objective of this study was to provide proof‐of‐principle that deep brain stimulation during sleep can modify memory consolidation in people with Parkinson's disease depending on the stimulation frequency that is applied. Methods Twenty‐four patients with Parkinson's disease who were treated with deep brain stimulation of the subthalamic nucleus were included in this single‐blind pilot study. Six patients had to be excluded because of insomnia on the night of testing. Patients were randomized (1:1 ratio) to receiving either low frequency deep brain stimulation (4 Hz) or clinically used high frequency deep brain stimulation (130 Hz) during early non‐rapid eye movement (NREM) sleep. The main outcome measure was overnight memory retention as measured by a validated declarative memory task. Results Patients receiving low frequency deep brain stimulation during early NREM sleep (n = 9, 4 females, mean age 61.1 ± 4.3 years) showed improved overnight memory retention ( z = 2.549, P = 0.011). Patients receiving clinically used high frequency deep brain stimulation (n = 9, 2 females, mean age 62.2 ± 7.1) did not show any improvement ( z = 1.023, P = 0.306) leading to a significant difference between groups ( z = 2.214, P = 0.027). Stronger improvement in memory function was correlated with increased cortical low frequency activity after low frequency deep brain stimulation as measured by electroencephalography (ρ = 0.711, P = 0.037). Conclusion These results provide proof‐of‐principle that memory can be modulated by frequency‐specific deep brain stimulation during sleep. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.