The treatment protocol consisted of 12 mg/m2 MITO intravenous infusions every 3 months for 2 years. Dosage was adjusted according to side effects. Neurological assessment including the determination of the Expanded Disability Status Scale (EDSS) score and ophthalmologic evaluations were performed every 3 months and during relapses. Flow cytometric analysis, brain and spinal cord MRI was performed at baseline, 6, 12, 18, and 24 months.

Inclusion Criteria:

• Recurrent longitudinal myelitis (>3 segments of spinal cord involvement by MRI) with or without recurrent ON (unilateral or bilateral) but with normal brain MRI and positive serological NMO IgG antibody.
• Recurrent longitudinal myelitis (>3 segments of spinal cord involvement by MRI) with or without spatially limited brain lesion and positive serological NMO IgG antibody.
• NMO, fulfilled Wingerchuk 2006 Criteria for NMO.
• Patient presented at least 2 relapses during the 12 months preceding the start of mitoxantrone therapy, despite immunotherapies using corticosteroid, interferon beta, azathioprine, cyclophosphamide, Cyclosporin A, Mycophenolate Mofetil or a combination of these drugs
• Extended Disability Status Score 3-8.
• Normal range for white-blood-cell count (more than 4×109/L), neutrophil count (more than 2×109/L), and platelet count (more than 100×109/L).

Exclusion Criteria:

• Cardiac risk factors (e.g history of congestive heart failure and left ventricular ejection fraction (LVEF) < 50%
• Systemic diseases such as lupus, Sjogren's syndrome, anti-phospholipid antibody syndrome, sarcoidosis, rheumatoid arthritis, or vitamin B12 deficiency
• Previous treatment with mitoxantrone or anthracyclines
• Pregnant or planning to be pregnant
• Patients with severe liver disorders (WHO grade 4)