Comparisons of transcranial alternating current stimulation and repetitive transcranial magnetic stimulation treatment therapy for insomnia:a pilot study

To the editor:Insomnia disorder has a serious and widespread detrimental effect on humans with comorbidity with other mental or physical health problems.In recent years,noninvasive brain stimulation(NIBS)techniques,especially transcranial magnetic stimulation(TMS)and transcranial electrical stimulation,have been increasingly used for the treatment of brain diseases,including insomnia disorder.

Electroencephalography microstates as novel functional biomarkers for insomnia disorder

Background Insomnia disorder(ID)is one of the most common mental disorders.Research on ID focuses on exploring its mechanism of disease,novel treatments and treatment outcome prediction.An emerging technique in this field is the use of electroencephalography(EEG)microstates,which offer a new method of EEG feature extraction that incorporates information from both temporal and 6/spatial dimensions.Aims To explore the electrophysiological mechanisms of repetitive transcranial magnetic stimulation(rTMS)for ID treatment and use baseline microstate metrics for the prediction of its efficacy.Methods This study included 60 patients with ID and 40 age-matched and gender-matched good sleep controls(GSC).Their resting-state EEG microstates were analysed,and the Pittsburgh Sleep Quality Index(PSQI)and polysomnography(PSG)were collected to assess sleep quality.The 60 patients with ID were equally divided into active and sham groups to receive rTMS for 20 days to test whether rTMS had a moderating effect on abnormal microstates in patients with ID.Furthermore,in an independent group of 90 patients with ID who received rTMS treatment,patients were divided into optimal and suboptimal groups based on their median PSQI reduction rate.Baseline EEG microstates were used to build a machine-learning predictive model for the effects of rTMS treatment.Results The class D microstate was less frequent and contribute in patients with ID,and these abnormalities were associated with sleep onset latency as measured by PSG.Additinally,the abnormalities were partially reversed to the levels observed in the GSC group following rTMS treatment.The baseline microstate characteristics could predict the therapeutic effect of ID after 20 days of rTMS,with an accuracy of 80.13%.Conclusions Our study highlights the value of EEG microstates as functional biomarkers of ID and provides a new perspective for studying the neurophysiological mechanisms of ID.In addition,we predicted the therapeutic effect of rTMS on ID based on the baseline microstates of patients with ID.This finding carries great practical significance for the selection of therapeutic options for patients with ID.

Dual roles of the amygdala-hippocampus circuit in the regulation of rapid eye movement sleep and depression symptoms by repetitive transcranial magnetic stimulation in patients with insomnia

To the editor:It is commonly reported that people with insomnia often experience comorbid emotional disorders,such as mood and anxiety disorders.12 A study found that fragmented rapid eye movement(REM)sleep in individuals with insomnia is associated with higher Beck Depression Inventory(BDI)scores.3 REM sleep architecture disruption is a typical symptom of insomnia.