Increased cortical excitability after selective REM sleep deprivation in healthy humans: A transcranial magnetic stimulation study

• Published in: Sleep medicine Vol. 14; no. 3; pp. 288 - 292
• Main Authors: Placidi, Fabio, Zannino, Silvana, Albanese, Maria, Romigi, Andrea, Izzi, Francesca, Marciani, Maria G, Palmieri, Maria G
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2013
• Subjects: Adult; Cerebral Cortex - physiology; Cortical excitability; Cortical silent period; Evoked Potentials, Motor - physiology; Female; Humans; Intracortical inhibition (ICI); Male; Neural Inhibition - physiology; Neurology; Reference Values; REM sleep deprivation; Sleep Deprivation - physiopathology; Sleep Medicine; Sleep, REM - physiology; Transcranial Magnetic Stimulation; Young Adult; Cortical excitability; REM sleep deprivation; Cortical silent period; Intracortical inhibition (ICI); Transcranial magnetic stimulation
• ISSN: 1389-9457; 1878-5506
• DOI: 10.1016/j.sleep.2012.11.020

Abstract Background REM sleep has antiepileptogenic properties whereas, its loss is known to have a proconvulsive role. However, the mechanisms underlying the proepileptogenic effects of REM sleep deprivation are yet not fully understood. The aim of our study was to evaluate the effects of selective REM sleep deprivation (SRD) on cortical excitability in healthy subjects by means of transcranial magnetic stimulation (TMS). Methods Ten normal subjects underwent three TMS sessions: (1) in baseline condition (BL), (2) after SRD by awakening them at each REM sleep onset and (3) after non-rapid eye movement sleep awakenings (NREM-A) as control for potential non-specific effects of interruptions. The TMS investigation included two protocols: (a) the evaluation of motor evoked potentials (MEPs) and silent period (SP) parameters, recorded in response to single pulse magnetic stimulation; (b) the evaluation of the time course of intracortical motor activity tested with paired-pulse TMS applied at inter-stimulus intervals of 1–10 ms. Results After SRD the principal finding observed using single pulse TMS was a significant reduction in the duration of SP whereas, a reduction of intracortical inhibition was found, using the paired-pulse TMS. TMS parameters did not show significant changes after NREM-A with respect to BL. Conclusions SRD may influence cortical excitability with a reduction of inhibitory intracortical mechanisms, thus supporting the proconvulsant role of REM loss.