What are the other Names for this Condition? (Also known as/Synonyms)

• Devic Syndrome
• Devic's Neuromyelitis Optica
• NMO (Neuromyelitis Optica)

What is Neuromyelitis Optica? (Definition/Background Information)

• Neuromyelitis Optica is an autoimmune disorder that affects the spinal cord and optic nerves (nerves that carry visual messages to and from the brain)
• In Neuromyelitis Optica, the body's immune system mistakenly attacks healthy cells and a substance called myelin in the spinal cord and eyes
• Symptoms may begin in childhood or adulthood. Spinal cord involvement results in transverse myelitis, which may cause pain, paralysis and abnormal sensations in the spine and limbs
• Bladder and bowel problems may also develop. Symptoms from optic nerve involvement include eye pain and vision loss from optic neuritis. Other symptoms of Neuromyelitis Optica may include episodes of nausea, vomiting, and hiccups
• Some people have episodes of symptoms months or years apart (the relapsing form), while others have a single episode lasting several months (the monophasic form). In either form, people with Neuromyelitis Optica often develop permanent muscle weakness and vision loss
• The cause of the immune system dysfunction leading to Neuromyelitis Optica is not known. It usually occurs in only one person in a family
• There is no cure, but there are therapies to reduce symptoms during episodes and prevent relapses

(Source: Neuromyelitis Optica; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Neuromyelitis Optica? (Age and Sex Distribution)

• Neuromyelitis Optica is a rare congenital disorder. The presentation of symptoms may occur at birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Neuromyelitis Optica? (Predisposing Factors)

• A positive family history may be an important risk factor, since Neuromyelitis Optica can be rarely inherited

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Neuromyelitis Optica? (Etiology)

Neuromyelitis Optica is considered an autoimmune disease in which the immune system mistakenly attacks cells and proteins in the spinal cord and optic nerves. Unfortunately, the reason that the immune system functions abnormally is not known. In rare cases, more than one person in a family may have Neuromyelitis Optica.

• Additionally, many people with Neuromyelitis Optica have another autoimmune disease, or have family members with an autoimmune disease. While this suggests genes play a role in predisposing a person to the disease, no responsible genes have been found
• There have been a few cases of Neuromyelitis Optica occurring in association with certain viruses (e.g., syphilis, HIV, chlamydia, varicella, cytomegalovirus, and Epstein Barr virus). The nature of this link is not clear.
• It is possible that certain infections may trigger Neuromyelitis Optica in people who are predisposed to the condition
• Neuromyelitis Optica usually is not inherited. The disease typically occurs in only one person in a family. However, about 3% of people with Neuromyelitis Optica report having a family member with the disease
• It is possible that some people have a genetic predisposition (or susceptibility) to developing Neuromyelitis Optica. However, it is likely that unknown environmental factors are also involved

(Source: Neuromyelitis Optica; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

What are the Signs and Symptoms of Neuromyelitis Optica?

The signs and symptoms of Neuromyelitis Optica may include: (Based on the frequency of symptoms observed)

Very frequently present symptoms in 80-99% of the cases:

• Dysautonomia
• Sensory impairment

Frequently present symptoms in 30-79% of the cases:

• Abnormal leukocyte count 
• Abnormality of the urinary system physiology
• Autoimmune antibody positivity 
• Hyperproteinemia 
• Spinal cord lesion

Occasionally present symptoms in 5-29% of the cases:

• Abnormality of the cerebrospinal fluid 
• Anxiety
• Cognitive impairment
• Hyperkalemia
• Hyperthyroidism 
• Hypochloremia 
• Increased intracranial pressure 
• Nausea and vomiting
• Seizures
• Visual loss

(Source: Neuromyelitis Optica; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Neuromyelitis Optica Diagnosed?

A diagnosis of Neuromyelitis Optica is based upon the presence of characteristic symptoms, imaging studies of the brain, spinal cord and eyes, as well as results of laboratory tests.

• Additionally, other more common conditions (particularly multiple sclerosis) must be ruled out
• Imaging studies may include magnetic resonance imaging (MRI scan) of the brain, spinal cord and orbits (eyes), and optical coherence tomography (specialized pictures of the retina)
• Laboratory tests include:
  • A blood test for aquaporin-4 (also known as NMO-IgG) - this test detects the aquaporin-4 antibody, which specifically indicates the diagnosis when characteristic symptoms are present. It also helps to distinguish the disease from multiple sclerosis (in which this antibody is not present). However, the absence of this antibody does not mean that a person does not have Neuromyelitis Optica
  • Examination of the cerebrospinal fluid - this may show high levels of white blood cells and proteins

(Source: Neuromyelitis Optica; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Neuromyelitis Optica?

The complications of Neuromyelitis Optica may include:

• Neurological impairment
• Loss of vision

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Neuromyelitis Optica Treated?

There is no cure for Neuromyelitis Optica, but there are therapies aimed at treating episodes in progress, reducing symptoms, and preventing relapses.

• Sudden episodes and relapses are usually treated with intravenous corticosteroids. If this does not relieve symptoms, plasma exchange may be effective
• Low doses of carbamazepine may be used to control painful muscle spasms during an episode. Muscle relaxants may be used for spasticity that develops in those with permanent muscle dysfunction
• For prevention of recurrent episodes, the main treatment is long-term use of medication that suppresses the immune system (systemic immunosuppressive therapy)
• There are no controlled trials evaluating this treatment, so recommendations are generally based on data from observational studies and by the experience of experts who have treated the disease
• People with severe, permanent symptoms may benefit from collaborating with occupational therapists, physical therapists, and social services professionals to address their rehabilitation needs.

(Source: Neuromyelitis Optica; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How can Neuromyelitis Optica be Prevented?

Currently, Neuromyelitis Optica may not be preventable.

• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Neuromyelitis Optica? (Outcomes/Resolutions)

The severity of impairment and life expectancy may depend on the severity of the first (or only) episode, the number of relapses within the first two years, and a person's age when the disease begins.

• In general, the outlook (prognosis) of Neuromyelitis Optica is thought to be worse for people who have severe symptoms during the first episode, have many relapses within a shorter amount of time, and/or are older when the disease begins
• For people with the relapsing form (90% of those with the disease), each episode causes more damage to the nervous system
• Often this eventually leads to permanent muscle weakness, paralysis, and/or vision loss within 5 years
• People with the monophasic form (those who experience one episode) can also have lasting impairment of muscle function and vision
• The disease reportedly may ultimately be fatal in 25-50% of people, with loss of life most commonly due to respiratory failure. However, the life expectancy varies from person to person

(Source: Neuromyelitis Optica; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Additional and Relevant Useful Information for Neuromyelitis Optica:

Neuromyelitis Optica is also known by the following terms:

• Devic Disease
• NMO Spectrum Disorder

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/