High-intensity alternating current therapy (hi-tACS) for insomnia in neuroimmune disorders

Inclusion Criteria:

1. Patients with idiopathic inflammatory demyelinating disorders (IIDDs) meeting the diagnostic criteria, including neuromyelitis optica spectrum disorders (NMOSD) \[based on the Chinese Guidelines for Diagnosis and Treatment of Neuromyelitis Optica Spectrum Disorders (2016 Edition)\] and multiple sclerosis (MS) \[based on the Chinese Guidelines for Diagnosis and Treatment of Multiple Sclerosis (2023 Edition)\], and accompanied by insomnia.

   * Aged between 18 and 65 years, regardless of gender.
   * Experiencing difficulty falling asleep, difficulty maintaining sleep, or early morning awakening on at least 3 nights per week for more than 3 months.
   * Severe daytime functional impairment (Chinese version of the Pittsburgh Sleep Quality Index, item 7 \[daytime dysfunction\] ≥2).
   * Having not taken hypnotics or insomnia treatment medication for at least 4 months.
   * Female participants aged 18-50 years who agree to use effective contraception throughout the study period.
   * Agreeing to refrain from receiving medication or other non-pharmacological treatments during the study period.
   * Agree to participate and sign the informed consent.
2. Patients diagnosed with chronic primary insomnia according to 《The Diagnostic and Statistical Manual of Mental Disorders》(Text Revision) (DSM-IV-TR) or 《International Classification of Diseases Tenth Revision》(ICD-10):

   * Aged between 18 and 65 years, regardless of gender.
   * Experiencing difficulty falling asleep, difficulty maintaining sleep, or early morning awakening on at least 3 nights per week for more than 3 months.
   * Severe daytime functional impairment (Chinese version of the Pittsburgh Sleep Quality Index, item 7 \[daytime dysfunction\] ≥2).
   * Having not taken hypnotics or insomnia treatment medication for at least 4 months.
   * Female aged 18\~50 years agreeing to adopt birth control measures during the study period.
   * Agreeing to refrain from receiving medication or other non-pharmacological treatments during the study period.
   * Agree to participate and sign the informed consent.

Exclusion Criteria:

* History of relapse within the past 1 month.
* Drug adjustment within the past 1 month, or receipt of modified electroconvulsive therapy, transcranial magnetic stimulation therapy, or other neuralcontroltechnology therapy.
* Participation in any other clinical studies within 1 month prior to enrollment or currently.
* Presence of cochlear implant system, cardiac-pacemaker, or intracerebral implanted stimulators.
* Impaired skin integrity at the electrode placement site, or allergy to electrode gel or adhesive.
* History of organic brain diseases such as epilepsy, hydrocephalus, tumor of central nervous system, craniocerebral injury, or intracranial infection.
* Pregnant or lactating women, or those intending pregnancy soon;
* A score of ≥3 on the suicide item of the Hamilton Depression Scale, or coexisting severe mental disorders;
* Presence of severe or unstable organic diseases;
* Work night shifts;
* Presence of other sleep disorders;
* Poor patient compliance preventing cooperation with treatment, follow-up, or clinical, electroencephalographic (EEG), or imaging data collection;
* Other circumstances deemed by the investigator as inappropriate for study participation.