What is NMO?

Neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorder (NMOSD) occur when the immune system mistakes normal tissues of the central nervous system as being foreign. As a result, the immune system attacks these tissues, making proteins (called antibodies) and recruiting immune system cells that can harm otherwise healthy parts of the central nervous system.

Often, because CNS tissues are rich in a protein called aquaporin-4 (AQP4), the initial attack targets the nerves of the eyes and other parts of the central nervous system, which include the brain and spinal cord.

Once thought to be a type of multiple sclerosis (MS), NMO and NMOSD are variants of a distinctive but rare autoimmune disease. NMO is not MS. Click here to learn more.

Dr. Sean Pittock of the Mayo Clinic explores the causes behind NMO.

What Are The Symptoms of NMO?

The symptoms of NMO can vary from person to person in disability, duration and severity. However, NMO is most commonly characterized by optic neuritis (ON) that affects eye function, and/or transverse myelitis (TM) that affects limb function.

Generally, NMO symptoms begin rapidly. After the initial attack, NMO follows an unpredictable course, and time to remission can vary. Recurring episodes of optic neuritis and/or transverse myelitis can be weeks to months in duration, and in some very unusual cases can last years. However, much more often these symptoms are temporary and resolve fully or partially, usually after a course of treatment.

Symptoms Explained

NMO symptoms may develop quickly — even within a few hours — increase over the course of a few days and then plateau. Symptoms may improve over weeks and months with treatment.

Dr. Jeffrey Bennett, University of Colorado, Denver, explores the symptoms of NMO.


What Treatment Options are Available?

A key mission of the GJCF is to catalyze the discovery or development of treatments that advance to be proven safe and effective in NMO through clinical trials. While just a few years ago there were none, the good news is that there are multiple now clinical trials in progress testing therapies in NMO. There is great hope that these clinical trials will progress such that one or more drugs may soon be approved to treat NMO.

We encourage you to explore our resources below, including our list of expert doctors, information on available clinical trials, and more.

More Resources


Answers to some of the most frequently asked questions about neuromyelitis optica (NMO), featuring video interviews with leading scientists.

Patient Guide

Our full-text NMO Patient Resource Guide offers help and information to those who have been affected by NMO. Topics include education, treatment, and awareness.


After more than 100 years with no approved treatment, today there are three therapeutics for NMOSD which have been regulatory approved in the U.S. and other regions of the world. 

Find A Doctor

Explore our map with locations of NMO clinicians. Thus far, over 200 clinicians have been mapped all over the world and our list continues to grow.


Multiple Sclerosis and Neuromyelitis Optica are treated in different ways and early detection and treatment help ensure best outcomes.


Browse over 1000 research publications related to neuromyelitis optica, including some of the groundbreaking research sponsored by the foundation.

Video Library

Explore our massive library of personal and scientific videos, examining everything from patient care, research, and the work of the foundation.

Clinical Trials

Find access to information, FAQs, and video resources about ongoing clinical trials in Neuromyelitis Optica Spectrum Disorder.

Pioneering a New Scientific Research Model

Reese Witherspoon explores the history of the foundation and our revolutionary approach to solving Neuromyelitis Optica.