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

• Published in: Clinical neurophysiology practice Vol. 9; pp. 13 - 20
• Main Authors: Mroczek, Magdalena, de Grado, Amedeo, Pia, Hossain, Nochi, Zahra, Tankisi, Hatice
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 2024; Elsevier
• Subjects: 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; Threshold-tracking transcranial magnetic stimulation; Short-interval intracortical facilitation; Short-interval intracortical inhibition; Short-latency afferent inhibition; Intracortical facilitation; Long-interval intracortical inhibition; Sleep deprivation
• ISSN: 2467-981X; 2467-981X
• DOI: 10.1016/j.cnp.2023.12.001

•Threshold-tracking transcranial magnetic stimulation (TMS) was performed before and after at least 24 h sleep deprivation.•Short- and long interval intracortical inhibition (SICI, LICI), facilitation (SICF, ICF), and short latency afferent inhibition (SAI) were done.•No effect of sleep deprivation was shown on SICI, LICI, SICF, and ICF while there was a decrease in SAI at 28 ms and 30 ms. 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. 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. 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. Sleep deprivation does not affect cortical excitability except for SAI. This study confirms some of the previous studies while contradicting others.