A Preliminary Study of Model-driven Individualized Transcranial Electrical Stimulation for Insomnia

This study is designed to evaluate the efficacy and to explore the best individualized stimulus paradigm of transcranial Electrical Stimulation for insomnia patients.

Twelve insomnia patients in Shanghai Mental Health Center who met the inclusion criteria will be recruited for transcranial electrical stimulation intervention. According to the patients' magnetic resonance structure and high density eeg parameters, personalized modeling was carried out to determine the specific stimulus parameter scheme.The stimulation will be performed for 2 weeks, once a night on weekdays, 10 times in total, and each stimulation will last for 20 minutes. Sleep rhythms will be recorded using a wearable device. Symptom assessment, magnetic resonance and high-density eeg data will be taken after the stimulation, and again 1 week after the stimulation.If the treatment is effective or clinical remission is achieved, the next cycle of stimulation will not be performed; If the treatment does not work, the patients choose to end the study or conduct modeling again to adjust the parameters and continue the next cycle of stimulation according to their wishes. For patients who choose to continue stimulation, the stimulation time of each cycle is still 2 weeks, once every night on weekdays, 10 times in total for each cycle, lasting 20 minutes each time. Each patient received up to four cycles of stimulation.

The stimulation type is cathode direct current stimulation and alternating current stimulation. The maximum stimulation current of a single channel is not more than 3mA. The frequency of electrical stimulation was 0-10Hz; DLPFC was preferentially selected for electrical stimulation, and other candidate brain regions were: orbitofrontal cortex premotor cortex, motor cortex, sensorimotor cortex, auditory cortex, posterior parietal cortex, and cerebellar cortex. The brain state changes caused by each stimulus parameter combination were compared with sleep state to determine the optimal stimulus parameters. Each cycle of stimulation was 2 weeks, once a night on weekdays, a total of 10 times

According to the results of structural phase magnetic resonance and electroencephalogram, four optimal stimulation parameters will be determined.Transcranial electrical stimulation devices (Sorterix)will be used for intervention.In each cycle, the stimulation will be performed every night during weekdays,a total of 10 times.A maximum of four cycles of intervention will be performed for each patient, depending on the efficacy and the their wishes.

Sleep latency is the time it takes a person to fall asleep after turning the lights out. This parameter can be measured by the sleep diary and the Sleep bracelet.

The total amount of time the participants actually fall asleep to wake up. This parameter can be measured by the sleep diary and the Sleep bracelet.

Sleep efficiency (SE) is the ratio between the time a person spends asleep, and the total time dedicated to sleep (i.e. both sleeping and attempting to fall asleep or fall back asleep). It is given as a percentage. SE of 80% or more is considered normal/healthy with most young healthy adults displaying SE above 90%.This parameter can be calculated according to the sleep diary.

Treatment effectiveness was defined as 50% reduction of PSQI after treatment from baseline, clinical remission was defined as PSQI score less than 5, reduction rate = (pre-treatment score - post-treatment score)/pre-treatment score x100%, and total effective cases/total cases ×100% was the total effective rate

The Insomnia Severity Index (ISI) is a brief instrument that was designed to assess the severity of both nighttime and daytime components of insomnia. It is increasingly used as a metric of treatment response in clinical research.

The ESS is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3), their usual chances of dozing off or falling asleep while engaged in eight different activities.

It is a nine-item self-report instrument that tests the likelihood that an individual will get sleep disturbances following various stressful events.

It consists of 21 items and uses a 0 to 3 severity scale. Total scores range from 0 to 63, with higher scores indicating more severe depression symptoms.

It is an inventory of anxiety symptoms with 18 items that are rated on a 5-point Likert scale(0 to 4). Total scores range from 0 to 72, with higher scores indicating more severe anxiety symptoms.

It consists of 10-item and uses 0 to 3 severity scale to rate the intensity of side effects. Total scores range from 0 to 30, with higher scores indicating more severe side-effect. It also assesses the relation between side-effect and the effects of tDCS using 0 to 4 scale. Total scores range from 0 to 40, with higher score indicating the greater relation.

Inclusion Criteria: Between 18 and 50 years old; The patients were diagnosed as insomnia according to the diagnostic and Statistical Manual of Mental Disorders (DSM-5) and Mini-International Neuropsychiatric Interview (M.I.N.I.) . No psychiatric drugs were taken within 8 weeks before enrollment; ④ Junior high school education or above. Exclusion Criteria: Past or current DSM-5 diagnoses other than insomnia, anxiety disorder and depressive disorder Severe anxiety or depression (HAMD-17 > 23 points or HAMA > 30 points) Patients with obstructive sleep apnea syndrome; Participants with claustrophobic, heart pacemaker, mechanical heart valve, mechanical implant such as an aneurysm clip, hip replacement, or any other pieces of metal that have accidentally entered their body. Previous history of neurological diseases (such as epilepsy, cerebrovascular accidents, etc.) or brain trauma, brain surgery; ⑥Have received ECT, rTMS, tES, or cognitive behavioral therapy for insomnia; ⑦Any current significant medical condition. ⑧Women who are pregnant or planning to become pregnant recently