Inclusion Criteria:

• - 1.

No requirement for age and sex.

• - 2.

Need to meet the diagnosis of at least one IDD (clinically isolated syndrome (CIS)/multiple sclerosis (MS)/neuromyelitis optica spectrum disorder (NMOSD)/MOG antibody-associated disease (MOGAD)/acute disseminated encephalomyelitis (ADEM).

• - 3.

Signed informed consent form.

Exclusion Criteria:

• - Those with severe mental disease unable to cooperate with the examination and/or follow-up.

• - Any patient (or the patient's legal representative) who is unable or refuses to sign informed consent.

Large prospective cohort studies allow long-term observation and analysis of the clinical status and disease activity of IDD patient population, and are the best way to understand IDD's natural course, clinical outcome, and drug efficacy in specific populations. Globally, several large prospective follow-up cohort studies have been conducted, providing important information on the disease characteristics of IDD patients. However, there is no large nationwide registry study of CNS IDD in China, and therefore there is a relative lack of data on the natural course of disease and drug efficacy in the Chinese IDD patient population, as well as a lack of standardized follow-up management of Chinese IDD patients. This study will establish a large prospective cohort study database of Chinese IDD, which will record detailed electronic information on IDD patients. We aim to establish a national (multicenter) disease registry for central nervous system idiopathic inflammatory demyelinating diseases in China, and to establish a unified standardized follow-up management process and treatment guidelines for patients with IDD in China; To provide real world data on the disease status of Chinese IDD patients; To understand the disease progression characteristics of IDD in China; To search for biological and imaging markers that predict the relapse, progression, and prognosis of IDD; to investigate the efficacy, safety, compliance and switch of different disease-modifying drugs (DMDs) in the long-term treatment of Chinese patients with IDD. The study is a prospective observational (non-interventional) national multicenter cohort study to collect clinical data from IDD patients who have signed informed consent, to routinely and regularly follow up IDD patients on multiple clinical indicators, and to assess clinical outcomes. All information is to be completed prospectively from the time point the patient visited the hospital (except for Basic patient information and information about previous disease that are required at enrollment follow-up).Once the project started, the study sites are not allowed to discontinue the study on their own until the end of study is announced. In addition, to ensure the continuity of the data, each site needs to appoint designated clinical data collectors to collect data from qualified inpatient clinical cases consecutively, so as to ensure the consecutive registration of each inpatient case who meets the inclusion and exclusion criteria. As the purpose of this study is to establish a national multicenter disease registry to provide disease-related information on patients with IDD in China, and the primary and secondary endpoints of the study being descriptive endpoints, therefore no formal calculation of sample size is needed. 10000 IDD patients are planned to be recruited.

Arms

: MS/CIS

Diagnosis of MS and CIS based on the 2017 McDonald MS diagnostic criteria.

: ADEM

Diagnosis of ADEM based on the 2012 IPMSSG diagnostic criteria for ADEM

: MOGAD

Diagnosis of MOGAD based on the 2020 Chinese Expert Consensus.

: NMOSD

diagnosis of NMOSD according to 2015 International Panel for Neuromyelitis Optica Diagnosis criteria.

Interventions

Drug: - Intravenous steroid

This study does not limit treatment methods. Patients commonly use high-dose intravenous steroid therapy (HD-S) during acute stage. Immunomodulatory therapies are necessary for the remission stage. All drugs are used in accordance with relevant guidelines.