NMO 101
2017 Patient Day hosted by the Guthy Jackson Charitable Foundation
What is NMO?
Neuromyelitis Optica Spectrum Disorder (NMOSD, commonly shortened to NMO) is an autoimmune disorder that is currently incurable but it is treatable. NMO, originally referred to as Devic’s Disease, was previously thought to be a variant of some sort of the disease Multiple Sclerosis. Due to dedicated and focused research and discoveries especially in the last decade, we now know that NMO is its own distinct disease.
The body’s immune system begins attacking itself, affecting the spinal cord, optic nerves, and brain stem. This can lead to temporary or permanentconditions such as loss of motor functions and/or bladder/bowel control, paralysis, blindness, severe nausea/vomiting/hiccuping. It is not considered a progressive disease, and the disease course will manifest differently in each patient in regards to severity of attack, frequency of attack, and what is permanent damage verses what is regained.
There are different types of medications to either treat an acute, active attack, preventative medications to try and help a patient stay in remission or lesson the severity of an attack, and medications to help manage residual symptoms left from previous attacks. Once diagnosed, the key is finding a preventative medication that works for you to hopefully keep you in long periods of remission.
What causes NMO?
As of this writing (2017), there is no definitive cause of NMO. It is not a disease that can be contracted, and there is no link as of yet that has been found to say what can definitively conclude the onset of the disease course. Experts do believe that that NMO results fromdysfunction in immune intolerance. Basically, one’s immune system loses the ability to determine one’s own cells or proteins from foreign materials.
How common is NMO? I’ve never heard of it.
NMO is an ultra rare autoimmune disorder that afflicts a very minuscule portion of the world’s population. In the United States, a rare disease is defined as rare if it affects less than 200,000 at any given time. As of this writing (2017), currently there are an estimated 6,000 cases in the United States. Worldwide, there is an estimated 250,000 cases.
What is a NMO attack, and what are the symptoms?
An NMO attack, also referred to as a relapse or flare, is when there is active damage and inflammation occurring on either the optic nerves, spinal cord, brain stem, or a combination. Typically, an MRI will be performed with contrasting dye to determine whether new activity is occurring on any of these areas. If it is active, inflammation will highlight on the MRI. Previous damage will also appear on a new MRI.
If the optic nerve is affected, an OPTIC NEURITIS attack is occurring. symptoms of this can be blurred vision in one or both eyes, eye pain, headache, colors or light perception dimming, and eye pain upon movement. Not all symptoms will manifest in each attack.
If the spinal chord is affected, a TRANSVERSE MYELITIS attack, symptoms range from numbness/tingling/burning sensations loss of strength, paralysis, banding (MS hug), sharp pain in the spine, etc. Again, a combination of symptoms may present during an active attack but it may not be all.
With an attack on the brain stem area, prolonged nausea, vomiting, or intractable hiccups will occur. One or more of these symptoms may present during an active attack.
How often do new attacks/relapses occur?
At this point in time, past and current research has not proven a link to indicate an individual patient’s disease course. Some cases will have one attack, while others relapse frequently. Some will have the initial onset attack, be in a period of remission for years, and inexplicably relapse again. The quickness of onset of an attack can occur over a matter of hours to days. The severity of the attack and resulting damage is unpredictable in each attack, as well. Once diagnosed with NMO, preventative medications will be used in hopes of preventing future relapses or mitigating the severity of the attack.
How is NMO diagnosed?
Until recent times, NMO was thought to be a variant of Multiple Sclerosis. The NMO-IgG test, or AQP4 (Aquapourine-4) antibody is what definitivelyseparated NMO from MS. The test for this critical biomarker was developed by theMayo Clinic. If a patient is tested positive for the NMO AQP4 antibody, then their diagnosis is definitively NMO, even if the disease course has only had one attack, or if only one form of attack (Optic Neuritis, Transverse Myelitis, or Brain Stem lesions).
In 2015, the diagnostic criteria was expanded because there are some patients that test negative (sera-negative) for the AQP4 antibody but still display lesions or other episodes that indicate NMO rather than MS.
Update: 12/11/20. The MOG anitoby is currently being included in the diagnosis of NMOSD. Those that test positive for the MOG antibody tend to have more Optic Neuritis attacks, though diligent research and more patients being diagnosed with this antibody are always changing the current data.
What are treatments for NMO?
For an acute, active attack, it is standard protocol to receive a 5 day course of high dose steroids, intravenously (IVSM) totry to halt the attack damage being done. If the patient does not seem to be responding or even have worsening symptoms, a treatment that can be used next is called Plasmapheresis. This is also referred to as plex, or also plasma exchange. It is similar to an oil change for a car as a patients plasma is removed from the patient and new plasma, either synthetic or humanized, is replaced into the patient. The aim of this treatment is to quickly remove the harmful antibodies that are causing the attack.
For maintenance medications, In 2020, Solaris (Eculizumab) was the first FDA approved preventative treatment for NMO patients that are AQP4 positive. The next FDA approved treatment for NMO was the drug Uplizna (Inebilizumab). Shortly following this the medication Ensuring (Satralizumab) was approved for the preventative treatment of NMO. Three additional commonly used drug therapies are Rituximab (Rituxan), an IV infusion therapy, Azathioprine (Imuran), an oral preventative therapy, and Cellcept (Mycophenolate Mofetil), another oral preventative drug therapy. These are not FDA approved for NMO treatment specifically as no clinical trials were performed for NMO, but they have been found effective in helping keep patients stable with years of retrospective data. There are some other drug therapies used, such as Methotrexate, Toculizumabb, IVIG, and maintenance Plasmapheresis. There may be some trial and error in finding the correct maintenance therapy for each patient, but the hope is to find one therapy or combination of therapies that will help keep the patient in remission or lesson the severity of an attack.
For Managing Residual Symptoms left from an Attack: There are a myriad of medications that can be used to manage residual symptoms left from an attack. Antidepressants, oral steroids, pain management medications, among other things. Some common medications are Lyrica, Gabapentin, Cymbalta, and Prednisone. It is always vital to have these medications monitored and prescribed by your doctors.