statement Neuromyelitis optica spectrum disorder (NMOSD) is a rare Emodin autoimmune disease of the central nervous system that primarily attacks the optic nerves and spinal cord leading to blindness and paralysis. cord leading to blindness and paralysis . NMO was first described and coined in the late 1800s but only recognized to be an entity distinct from multiple sclerosis (MS) over the past 10 years with the discovery of a unique biomarker antibody that identifies the disease in up to 72 % of NMOSD patients with >99 % specificity . NMOSD accounts for approximately 1.5 % of demyelinating diseases in Caucasian populations extrapolating to a prevalence of 0.52 to 4.4 per 100 0 . Although the incidence of demyelinating disease is lower in non-Caucasian countries the percentage of demyelinating diseases made up by NMOSD is higher . Although rare throughout the world NMOSD has received widespread attention because of the progress made in understanding the pathogenesis of disease and the identification of druggable Emodin targets for therapy. In 2005 the target of the NMO antibody was confirmed to be the aquaporin-4 water channel (AQP4) expressed on the end feet of astrocytes in the central nervous system . The coordinated immunological attack against AQP4 is mediated by B and T cells innate cells including neutrophils and eosinophils the complement system as well as pathogenic antibodies each of which has been Emodin successfully targeted for therapy in NMO. Human treatment studies published to date are mostly retrospective with a handful of prospective open-label series that provide an insight into the feasibility and potential efficacy of certain treatments. These small studies laid the foundation for investment Emodin in three worldwide blinded placebo-controlled pivotal trials competing to be the first approved medication for NMOSD. This review will include analysis of the aforementioned retrospective and prospective studies as KIT well as a discussion about the direction of the field of NMOSD treatment. Treatment of NMOSD is divided into two goals: suppression of acute inflammatory relapse and prevention of future relapses. For the purposes of this review we will review the data on these two treatment goals separately. Acute treatment NMOSD is a relapsing disease with repeated attacks leading to accumulating neurological damage and disability . At the time of an acute relapse neurological symptoms and signs localize to the acute NMOSD lesion where Emodin dysfunction occurs as a result of direct CNS damage as well as edema and secondary inflammation. The goals of acute treatment are to suppress the acute inflammatory attack minimize CNS damage and improve long-term neurological function. Building on decades of experience using corticosteroids to treat inflammatory attacks in multiple sclerosis and other inflammatory conditions high-dose intravenous methylprednisolone was widely Emodin adopted as a first-line agent to broadly suppress inflammation in acute NMOSD relapses. Data supporting the use of high-dose corticosteroids in MS have recently been challenged by the observation that they do not provide meaningful long-term improvement in neurological function because spontaneous healing and remyelination in MS may be equally effective . This particular concern does not apply to NMOSD where studies have shown that permanent damage from relapses leads to cumulative disability. Therefore the consensus among experts in NMOSD is that every relapse needs to be treated and high-dose corticosteroids are good starting agents because they are widely available are simple to administer and may provide some benefits in suppressing the acute inflammatory response . The typical starting dose for treatment of NMOSD is 1000 mg of methylprednisolone intravenously for 5 days commonly followed by an oral steroid taper for 2–8 weeks depending on the severity of the attack . Equivalent doses of other corticosteroids are likely equally effective as are other routes of administration given that bioavailability of intravenous versus oral corticosteroids are approximately the same . The initial goal for corticosteroid use in acute NMOSD relapses is to reduce the edema and secondary inflammation in the lesion. This may have the immediate effect of mild to modest improvement in neurological function. For long lesions or severely inflamed attacks additional steroid doses may be.