The cause of NMOSD is not well understood, and there is no cure. Treatment aims at relieving symptoms (called palliative treatment) and preventing relapses.
The immune system functions typically to attack only foreign cells (such as viruses). But when a person has an autoimmune disorder, the immune system suddenly begins attacking the body’s organs and tissues (such as the nerve cells)—the damage resulting from this immune system attack results in the signs and symptoms of NMOSD.
Frequent Symptoms
Most of the symptoms of NMOSD are caused by transverse myelitis, optic neuritis and brain stem inflammation.
The optic nerve involvement results in symptoms of optic neuritis. Symptoms that commonly result from this inflammation of the optic nerve include:
Eye pain (that may worsen after a week, then resolves in several days)Blurring of visionLoss of vision (in one or both eyes)Loss of the ability to perceive color
Transverse myelitis often adversely affects three vertebral segments (portions of the spine that protect the spinal cord), or more, and can leave a person very debilitated. Symptoms that commonly result from inflammation of the spinal cord (transverse myelitis) include:
Loss of sensation/numbness and tinglingA feeling of coldness or burning sensationParaparesis or quadriparesis (weakness or heaviness in one or more limbs, this may eventually lead to total paralysis)Paralysis of one or more limbsConstipationUrinary retention (the inability to empty the bladder)Other changes in urination (such as difficulty urinating or more frequent urination)Loss of bladder or bowel controlSpasticity (increase in muscle stiffness or tone) in the extremitiesFatigue
Brain stem involvement, particularly a lesion in the postrema area of the brain (located in the medulla oblongata of the brain stem), is the underlying cause of common symptoms such as:
NauseaUncontrollable hiccoughingIntractable vomiting (vomiting that is difficult to control; it does not get better in time or with treatment. It’s a sensation of constantly feeling as though a person needs to vomit).
Two Forms of NMOSD
There are two different types of NMOSD, including:
The relapsing form of NMOSD is the most common type of NMOSD. It involves flare-ups, which can occur over a time span of months or even years apart, with periods of recovery between episodes. However, most people with NMOSD develop permanent muscle weakness and vision impairment, which continues even during the periods of recovery. Women are much more likely to have relapsing NMOSD. In fact, according to Genetics Home Reference, “For unknown reasons, approximately nine times more women than men have the relapsing form. ” It is not yet well understood exactly what triggers these attacks, but medical experts suspect that it may be linked to a viral infection in the body. The monophasic form of NMO is characterized by one single episode that can last up to several months. Those who have the monophasic form of NMOSD do not have relapses. Once the symptoms go away, the condition does not recur. This form of NMOSD is much less common than the relapsing form; it affects women and men equally.
Progression of Symptoms
Progression of Transverse Myelitis
The inflammation caused by transverse myelitis causes a lesion extending the length of three or more spinal bones called vertebrae. These lesions damage the spinal cord. The protective covering that surrounds the nerve fibers (called myelin) in the brain and spinal cord is also damaged; this process is called demyelination.
Healthy myelin is needed for normal nerve transmission, so that the brain can get messages to travel through the spinal cord, to the intended parts of the body. An example of this normal nerve transmission is when the brain needs to get a signal to the muscles to contract.
Transverse myelitis may develop in people with NMOSD over a period of several hours, or up to several days. It causes pain in the spine or extremities (arms or legs); it may also cause paralysis in the limbs, abnormal sensations in the lower extremities (such as numbness or tingling) and possible loss of bowel or bladder control. In some people with NMOSD, muscle spasms occur in the upper extremities or the upper body. Full paralysis, inhibiting a person from being able to walk, may occur. Breathing problems could be present, depending on which area of the spinal column is involved.
Progression of Optic Neuritis
In NMOSD, optic neuritis often occurs suddenly; it causes pain (that tends to worsen with movement) and various levels of vision loss (from blurred vision to blindness). Usually, just one eye is affected, but in some people, optic neuritis affects both eyes at once.
Symptoms of NMOSD vs. Multiple Sclerosis
When a person initially begins to have symptoms of NMOSD, it may be difficult to distinguish between signs of NMOSD and multiple sclerosis (MS). Differentiating signs and symptoms often include:
Symptoms of optic neuritis and myelitis that are more severe in NMOSDBrain MRI results are usually normal in NMOSDThere is a lack of the biomarker called oligoclonal bands in NMOSD. Oligoclonal bands are commonly seen in those with MS.
A biomarker is a measurable substance in which, when detected, indicates the presence of a disease.
There are also newer tests which are positive in neuromyelitis optica such as anti-AQO4, anti-MOG, and anti-NF.
Rare Symptoms
Rarely, those with NMOSD have other classic (but uncommon) symptoms. These include:
ConfusionComa
The cause of confusion and coma is cerebral edema (swelling of the brain). Children with NMOSD are more likely to have symptoms that occur as a result of cerebral edema than adults.
Endocrine disordersSleep disorders (such as narcolepsy)
The cause of endocrine and sleep disorders is the involvement of the hypothalamus of the brain.
Complications/Sub-Group Indications
There are many complications that can occur as a result of NMOSD, these include:
Blindness or visual impairment Depression Long-term mobility impairment (caused by damage to nerves when relapses occur) Sexual dysfunction (such as erectile dysfunction). Osteoporosis (softening and weakness of the bones from long-term steroid treatment) Breathing problems (from weakness in muscles needed to breathe normally)
Some people may need artificial ventilation because breathing problems become so severe. In fact, respiratory failure (which can be fatal) occurs in approximately 25% to 50% of those with relapsing NMOSD).
Those with relapsing NMOSD usually end up getting permanent vision loss, paralysis, and permanent muscle weakness within five years after diagnosis.
Co-occurring Immune Disorders
In approximately a fourth of those with NMOSD, additional autoimmune disorders occur, including myasthenia gravis, lupus erythematosus or Sjogren syndrome. These co-occurring (when two diseases occur at the same time) autoimmune disorders can cause an array of additional symptoms for those with NMOSD.
When to See a Doctor/Go to the Hospital
A person who experiences any of the initial signs and symptoms of NMOSD (such as vision problems, eye pain, numbness or paralysis of the limbs) must seek emergency care immediately.
Anytime a person diagnosed with NMOSD notices a sudden change in symptoms, abruptly requires more help than usual, or has a change in mood (or other signs and symptoms of depression, including suicide thoughts), it’s time to seek immediate medical attention.
A Word from Verywell
Neuromyelitis optica spectrum disorder is a chronic (long-term) condition with severe, debilitating symptoms. Any type of debilitating condition usually requires that a person learn an entirely new set of coping skills. Developing positive coping skills can have a major impact on a person’s psychological outlook and functioning, as well as act as a driving force in the overall quality of one’s life.
If you are diagnosed with NMOSD, it’s vital to work towards building a support system of friends, family members, professionals and others going through similar experiences (having a debilitating disease).
Online support programs, such as the live helpline offered by the Siegel Rare Neuroimmune Association, are available. Other supportive services that may be needed include social services (to help with needs such as finding a handicapped equipped living environment), an occupational therapist, (to help a person adapt to functioning at his or her highest level after suffering from a disability), a physical therapist, and more.
Muscle weaknessDifficulty walkingNumbnessPainful spasmsUncontrollable nausea, vomiting, or hiccupsBladder or bowel problems
