Application of Transcranial Direct Current Stimulation in Sleep Disturbances

Abstract

Sleep disturbances are common across all age groups, and they encompass a broad range of impairments of daytime functioning and comorbid various clinical conditions. However, current treatment methods for sleep disturbances have several limitations. As the ‘top-down’ pathway is known to play an important role in sleep-wake regulation, and as neuronal activity abnormalities have been reported as a potential pathological mechanism of sleep disturbances, the use of non-invasive brain stimulation—such as transcranial direct current stimulation (tDCS) in treating sleep disturbances—has emerged. In the present review, we first explain the mechanism of tDCS, and we also introduce recent studies that have applied tDCS to sleep disorders, along with other sleep-related tDCS studies. In conclusion, many studies have achieved improvements in sleep state, although some of these studies have reported inconsistent effects of tDCS according to the protocol and the conditions used. Further studies are needed to explore the optimal protocols to use when applying tDCS in each sleep disturbance and to enhance the evidence on the clinical efficacy of tDCS.

A Meta-Analysis of the Effectiveness of Transcranial Magnetic Stimulation and Transcranial Direct Current Stimulation as Therapy of Insomnia

“…This heterogeneity can be caused by differences in the location, frequency, motor threshold of TMS stimulation, and the total session duration of TMS between the two studies. Additionally, the data used in the meta-analysis were not raw data from these two studies [23]. Consistent with the meta-analysis conducted by Zheng et al [14], it was found that TMS is most effective when administered for an extended period of up to 4 weeks.…”

“…The mechanism of action of tDCS on DLPFC region involves modulating cortical stimulation, affect the top-down pathway that targets the corticothalamic pathway in regulating sleep-wake cycles. This modulation helps reduce hyperarousal and hyperactivity in the DMN and SN regions, leading to a decrease in sleep onset latency (SOL) and an increase in total sleep time (TST) [18,23]. It also triggers sleep waves and sleep spindles, especially in N2, and reduces the likelihood of transitioning from N2 sleep to wakefulness while increasing the transition from N2 to N3 [24,25].…”