Neuromyelitis Optica (NMO)/ Neuromyelitis Optica Spectrum Disorders (NMOSD) is an immune-mediated inflammatory demyelinating disease of the central nervous system mainly involving optic nerve and spinal cord. It is clinically characterized by simultaneous or sequential involvement of the optic nerve and spinal cord, presenting a progressive or remission and relapse course, which can lead to paralysis and blindness.

The objective of this study is to provide evidence regarding treat effects and factors related to prognosis which will help physicians better evaluable risk-benefit in NMOSD management and improve patients' outcome.

Neuromyelitis Optica (NMO)/ Neuromyelitis Optica Spectrum Disorders (NMOSD) is an immune-mediated inflammatory demyelinating disease of the central nervous system mainly involving optic nerve and spinal cord. It is clinically characterized by simultaneous or sequential involvement of the optic nerve and spinal cord, presenting a progressive or remission and relapse course, which can lead to paralysis and blindness.

Globally, there is no solid data available for the diagnosis, treatment and prognosis of patients with acute Neuromyelitis Optica Spectrum Disorders (NMOSD) attack, particularly very rare data from prospective studies. This is a multicenter, prospective, real-world cohort study in patients with acute NMOSD attack in China.

Baseline data for approximately 200 patients with acute NMOSD attack from approximately 4 centers will be collected. Patients with acute NMOSD attack (including first episodes and relapses) whose expansile disability status score (EDSS ) ≥ 2 points at baseline will be eligible to be further included in prospective study cohort for analysis of treatment effects and prognosis.

The objective of this study is to provide evidence regarding treat effects and factors related to prognosis which will help physicians better evaluable risk-benefit in NMOSD management and improve patients' outcome.

1. Inclusion criteria for patients with baseline data collection:

1. The subject can fully understand the content of the study and voluntarily sign the informed consent form;
2. Male or female ≥18 years old;
3. Diagnosed as NMOSD based on 2015 NMOSD diagnostic criteria of International NMO Diagnostic Team (IPND) and currently under acute attack.

2. Inclusion criteria for subjects enrolled in a prospective study cohort should further meet:

1. The subject can fully understand the content of the study and voluntarily sign the informed consent form;
2. Male or female,≥18 years old;
3. Diagnosed as NMOSD based on 2015 NMOSD diagnostic criteria of International NMO Diagnostic Team (IPND) and currently under acute attack.
4. Subjects with acute attack (including first episodes and relapse) should have an EDSS of ≥ 2 at baseline; and for patients with acute relapse, new symptoms or the primary symptoms, being judged by investigator, should have been aggravated for 24 hours or more [11-13];
5. The subject should have typical symptoms of movement, sensation, vision, defecation/urination or nausea/vomiting at attack;
6. Subjects should agree to participate in the study, and to receive AQP4-IgG examination before and after treatment;
7. Subjects should agree to undergo an ophthalmologic examination before and after treatment;
8. Subjects should agree to participate the study and agree to have the collected data analyzed by this study.

3. Exclusion criteria:

1. Subjects treated with study medication in another clinical trial during the last 30 days or 5 half-life periods prior to screening or during the effect period of the drug, whichever is the longest; Note: Subjects who participated in an observational study (ie, the study did not require changes to medication or other interventions) were not excluded.
2. Immediate relatives of the researcher/research center staff directly related to the study, or the researcher/research center staff directly related to the study ("immediate relatives" refer to spouses, parents, children or siblings (Whether it's biological or legal adoption).

Acute episode of Neuromyelitis Optica Spectrum Disorders (NMOSD)