title: Slow oscillating transcranial direct current stimulation during sleep has a sleep-stabilizing effect in chronic insomnia: a pilot study.
abstract: Recent evidence suggests that lack of slow-wave activity may play a fundamental role in the pathogenesis of insomnia. Pharmacological approaches and brain stimulation techniques have recently offered solutions for increasing slow-wave activity during sleep. We used slow (0.75 Hz) oscillatory transcranial direct current stimulation during stage 2 of non-rapid eye movement sleeping insomnia patients for resonating their brain waves to the frequency of sleep slow-wave. Six patients diagnosed with either sleep maintenance or non-restorative sleep insomnia entered the study. After 1 night of adaptation and 1 night of baseline polysomnography, patients randomly received sham or real stimulation on the third and fourth night of the experiment. Our preliminary results show that after termination of stimulations (sham or real), slow oscillatory transcranial direct current stimulation increased the duration of stage 3 of non-rapid eye movement sleep by 33 ± 26 min (P = 0.026), and decreased stage 1 of non-rapid eye movement sleep duration by 22 ± 17.7 min (P = 0.028), compared with sham. Slow oscillatory transcranial direct current stimulation decreased stage 1 of non-rapid eye movement sleep and wake time after sleep-onset durations, together, by 55.4 ± 51 min (P = 0.045). Slow oscillatory transcranial direct current stimulation also increased sleep efficiency by 9 ± 7% (P = 0.026), and probability of transition from stage 2 to stage 3 of non-rapid eye movement sleep by 20 ± 17.8% (P = 0.04). Meanwhile, slow oscillatory transcranial direct current stimulation decreased transitions from stage 2 of non-rapid eye movement sleep to wake by 12 ± 6.7% (P = 0.007). Our preliminary results suggest a sleep-stabilizing role for the intervention, which may mimic the effect of sleep slow-wave-enhancing drugs.
authors.affiliation: School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Saebipour
authors.affiliation: School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran.|Cellular and Molecular Medical Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad T
authors.initials: MT
authors.lastname: Joghataei
authors.affiliation: School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.|National Brain Mapping Centre, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Yoonessi
authors.affiliation: Occupational Sleep Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Khosro
authors.initials: K
authors.lastname: Sadeghniiat-Haghighi
authors.affiliation: Institute of Cognitive Neuroscience, University College London, London, UK.
authors.forename: Nima
authors.initials: N
authors.lastname: Khalighinejad
authors.affiliation: School of Physics, Sharif University of Technology, Tehran, Iran.
authors.forename: Soroush
authors.initials: S
authors.lastname: Khademi
mesh_terms: D000328:Adult; D058256:Brain Waves / Q000502:physiology; D002908:Chronic Disease / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D010865:Pilot Projects; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D007319:Sleep Initiation and Maintenance Disorders / Q000503:physiopathology* / Q000628:therapy*; D065908:Transcranial Direct Current Stimulation
keywords: brain stimulation; brain wave entrainment; sleep stabilization; slow-wave sleep enhancement