Alterations in coupling between global brain activity and cerebrospinal fluid flow in patients with insomnia disorder before and after transcranial direct current stimulation: a resting-state functional MRI study

Our results indicate that IDs exhibit impaired glymphatic system function, as reflected by reduced gBOLD-CSF coupling strength. This reduction was correlated with the severity of both insomnia and anxiety symptoms. Moreover, we demonstrated that tDCS can not only improve symptoms of insomnia, anxiety, and depression but also enhance glymphatic activity in IDs.