40Hz transcranial alternating current stimulation enhance insomnia treatment efficacy: a pilot study

Insomnia is a prevalent clinical condition characterized by difficulty for patients to initiate and/or stay in sleep along with common comorbidities such as irritability or fatigue during wakefulness [1]. Study found that insomnia patients show declines in cognitive abilities such as working memory and aspects of execution [2]. Currently, pharmacotherapy and cognitive-behavioral therapy for insomnia (CBT-I) are the primary treatment methods in clinical practice, but the effects of drug tolerance, dependence, and side effects, as well as CBT-I in terms of compliance, treatment professionalism, and their efficacy appears to vary among individuals [3]. Therefore, various neuromodulation techniques, such as magnetic stimulation, electrical stimulation, and light stimulation, strive to provide innovative therapeutic alternatives.

Flickering light stimulation is a non-invasive neuromodulation technique that has promising futures in alleviating pathological changes in insomnia [4]. Current research hypothesized that the therapeutic effect of light flickering stands on the fundamentals of brain entrainment, such as repetitive and regular stimulation of light, sound or other electrical and magnetic signals could prompt the brain to produce brain waves in the matching frequency, and 40 Hz light induce the strongest gamma oscillation [5, 6]. Even though studies conducted specifically on light flickering and insomnia is yet limited, we are going to introduce a new study below that demonstrates the specific neurochemical basis for 40 Hz flickering and how its therapeutic effect on insomnia was achieved [7].