Effects of sleep deprivation on cortical excitability: A threshold-tracking TMS study and review of the literature

Magdalena Mroczek; Amedeo de Grado; Hossain Pia; Zahra Nochi; Hatice Tankisi

doi:10.1016/j.cnp.2023.12.001

Effects of sleep deprivation on cortical excitability: A threshold-tracking TMS study and review of the literature

Clin Neurophysiol Pract. 2023 Dec 12:9:13-20. doi: 10.1016/j.cnp.2023.12.001. eCollection 2024.

Authors

Magdalena Mroczek¹, Amedeo de Grado^{1

2}, Hossain Pia¹, Zahra Nochi³, Hatice Tankisi^{1

4}

Affiliations

¹ Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark.
² Neurophysiology Unit, IRCCS Fondazione Istituto Neurologico "Carlo Besta", Università degli Studi di Milano, Milano, Italy.
³ Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
⁴ Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark.

Abstract

Objective: Insufficient sleep is linked to several health problems. Previous studies on the effects of sleep deprivation on cortical excitability using conventional transcranial magnetic stimulation (TMS) included a limited number of modalities, and few inter-stimulus intervals (ISIs) and showed conflicting results. This study aimed to investigate the effects of sleep deprivation on cortical excitability through threshold-tracking TMS, using a wide range of protocols at multiple ISIs.

Methods: Fifteen healthy subjects (mean age ± SD: 36 ± 3.34 years) were included. The following tests were performed before and after 24 h of sleep deprivation using semi-automated threshold-tacking TMS protocols: short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) at 11 ISIs between 1 and 30 ms, short interval intracortical facilitation (SICF) at 14 ISIs between 1 and 4.9 ms, long interval intracortical inhibition (LICI) at 6 ISIs between 50 and 300 ms, and short-latency afferent inhibition (SAI) at 12 ISIs between 16 and 30 ms.

Results: No significant differences were observed between pre- and post-sleep deprivation measurements for SICI, ICF, SICF, or LICI at any ISIs (p < 0.05). As for SAI, we found a difference at 28 ms (p = 0.007) and 30 ms (p = 0.04) but not at other ISIs.

Conclusions: Sleep deprivation does not affect cortical excitability except for SAI.

Significance: This study confirms some of the previous studies while contradicting others.

Keywords: Intracortical facilitation; Long-interval intracortical inhibition; Short-interval intracortical facilitation; Short-interval intracortical inhibition; Short-latency afferent inhibition; Sleep deprivation; Threshold-tracking transcranial magnetic stimulation.