Non-pharmacological treatment of primary insomnia using sensorimotor-rhythm neurofeedback

Abstract

INTRODUCTIONA non-pharmacological intervention, namely instrumental conditioning of 12–15Hz oscillations (ISC), for improving sleep quality and memory is introduced. EEG recordings over the sensorimotor cortex show a prominent oscillatory pattern in a frequency range between 12 and 15Hz (sensorimotor rhythm, SMR) under quiet but alert wakefulness. This frequency range is also known to be abundant during light non-rapid eye movement sleep, and is overlapping with the sleep spindle frequency band. Some early findings indicated that ISC of SMR during wakefulness can influence subsequent sleep. In the present study we intend to clarify the nature of these effects and apply neurofeedback (NFT) to insomnia patients.MATERIALS AND METHODSTwenty-four subjects (Mean=34.83; SD=10.60) with clinical symptoms of primary insomnia were tested. A counterbalanced within-subjects design (19 lab visits over the course of 3–6weeks) was adopted. Each patient participated in an ISC–NFT as well as a sham-NFT training block. Polysomnographic sleep recordings were scheduled before and after training blocks.RESULTSData confirm a significant increase of 12–15Hz activity over the course of the ten SMR training sessions which was also positiviely related to overnight memory consolidation changes.Number of awakenings were reduced and slow-wave sleep was increased following ISC but not following sham-NFT. In addition, subjective sleep quality was enhanced over the course of the trainings. Last but not least sleep spindles in slow-wave sleep were found to be exclusively enhanced after SMR training.CONCLUSIONCurrent results indicate that besides healthy individuals also people suffering from primary insomnia can experience subjective as well as objective benefits from ISC–NFT. Replication studies are yet awaited.ACKNOWLEDGEMENTSResearch was supported by a FWF research (P-21154-B18) fund from the Austrian Science Foundation. We would like to thank Barry Sterman, Alexander Kunz, Wiebke Böning, Katharina Engl, Martina Feichtinger, Cornelia von Gamm, Daniela Tschann, Gabriela Werner, and Michaela Wittek for their support with the study.