Layman’s Guide to NMO

Layman Guide NMO

Thanks for visiting this page! If you are here because you have received a diagnosis of NMO or you want to learn more about this condition that affects a friend or relative, you are at the right place. NMO, while a rare disease, is the specialty of many neurologists in the United States and around the world. Also, many renowned scientists are dedicating their careers to find better treatments for NMO.

Below, you will find a list of important questions and answers with the goal of informing you and your loved ones about this condition. This guide covers important information about diagnosis, symptoms and available treatments. Please be aware that the questions below are answered with general information about NMO and may not fit your individual situation.

Please remember that the best source of individualized and the most up-to-date information is your neurologist and NMO specialist. If you are still looking for more information on the internet, we recommend that you visit the Guthy Jackson Charitable foundation, the National Multiple Sclerosis society, and the Transverse Myelitis Association.

What is NMO?

Neuromyelitis optica (NMO), Devic’s disease or neuromyelitis optica spectrum disorders (NMOSD) are different names for the same condition. NMO is an autoimmune disease that causes inflammation in different locations in the central nervous system. The disease manifests itself through relapses (also called exacerbations or attacks) and the most common relapses are of optic neuritis (inflammation of the optic nerve), myelitis (inflammation of the spinal cord) or syndrome of the area postrema (inflammation of the an small area in the brain that causes nausea, vomiting and hiccups)

What is the cause of NMO?

While we know how NMO happens, nobody knows why. As in other autoimmune diseases (eg. Type 1 Diabetes, Lupus, Chron’s disease), the person’s own immune defense system attacks normal proteins in the body. In most NMO patients, blood tests reveal antibodies that attack a protein called Aquaporin-4 or AQP4 for short.

What is AQP4? Why is it so important?

AQP4 is the most important water channel in the central nervous system. It functions like a gate, allowing water to come in and out of the cells. Most AQP4 is located in a cell called astrocyte. The presence of AQP4 is larger in optic nerves and spinal cord, reason why the attacks of inflammation on those locations. The inflammation may lead to nervous tissue abnormalities and in most severe cases destruction (necrosis).

How is NMO Diagnosed?

NMO is usually diagnosed by a neurologist or neuro-ophtalomologist. These physicians use a combination of history information (symptoms), physical exam (neurological and ophtalmological), blood tests (AQP4 and other antibody tests) and imaging (MRI of the brain, orbits and spinal cord).

What is a typical history for an NMO attack?

Most often a NMO attack takes hours or day to reach the most neurological disability. NMO specialists consider it an urgency since patients who get treatment more promptly have better chances of recovery. The history may be about symptoms from the eyes or difficulty with strengh, sensation or bladder control. As mentioned before, some patient with NMO may also have attacks of severe nausea or vomitting.

Why doctors request MRIs?

An MRI is a very important test in the diagnosis of NMO. Advanced machines create a magnetic fields that are used to obtain detailed images of the optic nerves, brain and spinal cord. The person lies in a long tube and the MRI scan takes approximately 30 to 45 minutes. In most cases, there is also need to use an intravenous contrast, called Gadolineum. Using the contrast helps identify which areas of the brain have active inflammation. MRIs are painless. The person needs to lie still so high-quality images can be obtained. Your doctor will determine which MRIs you should have and whether you need intravenous contrast.

What does an MRI of the spine may show?

If a patient with NMO has symptoms related to weakness, sensation, or bladder control, the MRI of the spine most often shows inflammation of long segments of the spinal cord. Such lesions occur either on the cervical (neck) and/or thoracic areas (chest). To compare, in multiple sclerosis (MS), a disease that also may cause inflammation in the spinal cord, the lesions tend to be shorter.

What does the MRI of the brain may show?

A brain MRI is done to look for inflammation of the optic nerves and other sites in the brain. While up to 60% of patients may have areas of inflammation in the brain, most of these areas do not lead to symptoms or disability.

What is the Aquaporin 4 antibody test?

This is test that can be performed both in blood and spinal fluid (the liquid that surrounds the brain and spinal cord). It is usually more helpful to test the blood since this is where the AQP4 antibodies are produced. This is a very important test, because the presence of Aquaporin 4 antibodies is very specific to a diagnosis of NMO. This antibody is found in approximately 80% of patients with NMO and along the course of your treatment, your doctor may need to repeat the test. Sometimes after immunosuppressant treatment is started, the antibody test may become negative.

What is a Lumbar Puncture?

Cerebrospinal Fluid (CSF) is the clear liquid that surrounds and protects the brain and spinal cord. A lumbar puncture (LP) is the procedure that allows a small amount of CSF to be drawn from the spinal cord with a needle. This only takes a few minutes and is normally done under a local anesthetic. Some people can get a headache after the procedure which can generally be avoided by lying flat for a few hours after the test and having plenty of water or beverages with caffeine.

What kind of tests are performed by Ophthalmologists?

An ophthalmologist is trained to identify even the smallest changes in a patient’s vision.
Ophthalmoscopy (looking at the back of the eye) may show swelling of the optic disc. In a Visual Evoked Potential (VEP), electrodes are placed on the back of the head to measure the speed of nerve messages along the optic nerve from the eye to the brain. Damage to the optic nerve shows slower response time. The Visual Field Tests show whether there are any areas of vision missing (central or peripheral). Optical Coherence Tomography (OCT) is a scan that can measure the thickness of the nerve fibers in the optic nerve.

What is a relapse? Why do relapses happen?

A relapse or an ‘attack’ of NMO occurs when there is new inflammation within the nervous system. The inflammation causes people to experience new symptoms. It is not yet understood what causes or triggers a relapse. The timing is also unpredictable. The good news is that treatment with drugs to suppress part of the immune system may be very effective preventing relapses. There are many options for treatment and you and your doctor will work to find the best option for you.

How to identify a relapse of NMO?

In people with NMO, relapses usually affect either the optic nerve or the spinal cord.When relapses affect the optic nerves they cause problems with vision. Symptoms normally come on over a period of hours or days, or people may wake up one morning with visual symptoms. Some people notice that it is painful when they look around, or have pain behind the eye. Optic neuritis can also cause colors to look faded or ‘washed out’ or grayish.

When people with NMO experience a relapse affecting the spinal cord, they may experience symptoms related to strength and sensation in the arms, legs and trunk, and problems with bladder or bowel control. Below are examples of what inflammation in the spinal cord may cause many different symptoms including:

  • Weakness in the arms and/or legs (either in one or both sides of the body).
  • Tingling, numbness or abnormal sensations in the arms, legs, groin or trunk.
  • A band-like sensation around the trunk, like being squeezed or tight hug.
  • Problems with the bladder such as difficulty or inability to pass urine, feeling of incomplete bladder emptying, or incontinence of urine.
  • Constipation or loss of control of bowel movement.
What is not a new attack?

If a patient with NMO had an attack of optic nerve in the past, they may find that their vision varies from day to day. For example, vision may vary if they are tired or when they have an infection such as a urinary tract infection. This is not a new attack.

What should I do if I think I’m having a relapse?

It is important to remember that relapses of NMO need to be assessed and treated promptly. Please follow the guidelines below. If you feel that you are experiencing any of the symptoms described, please contact your NMO doctor/nurse. If you are not getting a prompt response, you should go to the nearest emergency room and have the doctors there contact your neurologist for expert advice on how to investigate further.

How is a relapse is treated?

Every patient, and every relapse are different and the treatment will depend upon your individual needs. It is important that you are assessed quickly during a relapse, as early treatment may prevent long term damage.The most common treatments are steroids (a powerful anti inflammatory) and in more severe cases, plasma exchange (a procedure that separates the blood to remove antibodies).

What happens after a relapse?

The time taken to recover and degree of improvement after a relapse can be affected by many factors and vary from person to person. In many cases, rehabilitation will also help.

What is the current treatment options for NMO?

At the present there is no cure for NMO, the treatment is directed to different goals, including treating acute attacks/relapses, preventing relapses, and treating the residual symptoms after a relapse. Below you will find the options for each of these goals.

For Relapses: A high dose steroid, Methylprednisolone (Solu-Medrol) is usually given during a relapse. Steroids work to reduce inflammation. If steroids don’t help, Plasma Exchange is most frequently used or sometimes Intravenous Immunoglobulins may be given. Plasma Exchange is a procedure in which the blood is drawn out of the body and the plasma (which contains the antibodies) is separated. The blood is then returned back into the body without the plasma that had the antibodies.

For Preventing Relapses: Immunotherapies are medicines that diminish the the activity of the body’s immune system may be used. Drugs such as Prednisone, Azathioprine, Methotrexate, Mycophenolate and Rituximab are used to allow reduction of steroids. All of these treatments increase the risk of serious infections. Therefore, blood will be monitored for full blood count, kidney and liver function.

What are the medications commonly used in NMO?

Oral Prednisone tablets
Steroids are good immunosuppressants. Long-term treatment side effects include; weight gain, acne, indigestion, cataracts, osteoporosis (thinning of the bones), deterioration of the head of the thigh bone and diabetes. To reduce the side effects, other medications are taken such as an antacid Omeprazole or Lansoprazole, tablets for bone protection.

Azathioprine, Methotrexate and Mycophenolate are all considered to be good at suppressing the immune system. They all have side effects that are well understood, but need to be explained to you before you take the medication.


This is an intravenous medication, given in a course of two infusions two weeks apart, followed by a six month break until the next course. It is from a family of drugs called “monoclonal antibodies” which are capable of reducing B-cells that are responsible for producing NMO antibodies.