Description

Neuromyelitis optica, also known as NMO, is a disorder of the central nervous system that causes inflammation of the nerves of the eye and the spinal cord.

NMO is also called neuromyelitis optica spectrum disorder (NMOSD) and Devic's disease. Occurs when the immune system reacts against the body's own cells. This occurs mainly in the spinal cord and the optic nerves, which connect the retina of the eye to the brain. But sometimes it happens in the brain.

The disease may occur after an infection, or it can be linked with other autoimmune disease. Alteration of antibodies bind to proteins in the central nervous system and cause damage.

Neuromyelitis optica is often misdiagnosed as multiple sclerosis, also known as MS, or is seen as a type of MS . But NMO is a different condition.

Neuromyelitis optica can cause blindness, weakness in the legs or arms, and painful spasms. It can also cause loss of sensation, vomiting, and hiccups, and bladder or bowel symptoms.

The symptoms may get better and worse again, known as a relapse. The treatment to prevent relapse, it is important to help prevent disability. NMO can cause permanent loss of vision and difficulty walking.

Symptoms

The symptoms of neuromyelitis optica are related to the inflammation that occurs in the nerves of the eye and the spinal cord.

Vision changes caused by NMO is called optic neuritis. These may include:

  • Blurred vision or loss of vision in one or both eyes.
  • Not being able to see the color.
  • Pain in the eyes.

Symptoms related to the spinal cord is called transverse myelitis. These may include:

  • The stiffness, weakness, or numbness in the legs and sometimes the arms.
  • The loss of sensitivity in the arms or legs.
  • Not being able to empty the bladder or problems controlling your bladder or bowel function.
  • A sensation of tingling or stabbing pain in the neck, back, or stomach.

Other symptoms of NMO may include:

  • The hiccups.
  • Nausea and vomiting.

The children may have confusion, seizures, or coma. However, these symptoms in children are more common in a condition known as myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

The symptoms may start to improve and then get worse again. When they get worse, it is known as a relapse. Relapses may occur after weeks, months, or years. Over time, relapses can lead to total blindness or loss of sensitivity, known as paralysis.

Causes

Experts do not know exactly what causes neuromyelitis optica. In people who have the disease, the immune system attacks the healthy tissues in the central nervous system. The central nervous system includes the spinal cord, brain and optic nerves, which connect the retina of the eye to the brain. The attack occurs due to alteration of antibodies bind to proteins in the central nervous system and cause damage.

This reaction of the immune system that causes swelling, known as inflammation, and leads to damage of the nerve cells.

Risk factors

Neuromyelitis optica is rare. Some of the factors that can increase the risk of developing NMO include:

  • The sex assigned at birth. Women have NMO more often than men.
  • Age. More often, NMO affects adults. The average age of diagnosis is 40. However, children and older adults also may have neuromyelitis optica.
  • Race or ethnic origin. People of Hispanic, Asian, or African, or Afro-Caribbean descent have NMO at higher rates than people who are white.

Some research suggests that the fact of not having enough vitamin D in the body, smoking, and having few infections early in life may also increase the risk of neuromyelitis optica.

Diagnosis

Diagnosis of neuromyelitis optica consists of a physical exam and tests. Part of the process of diagnosis is to rule out other conditions of the nervous system that have similar symptoms. The health professionals also look for the symptoms and the test results linked to the NMO . The criteria for the diagnosis of neuromyelitis optica spectrum disorder (NMOSD) is proposed in 2015 by the International Panel on the Diagnosis of NMO.

A health care professional to review your medical history and symptoms and do a physical exam. Other tests include:

  • Neurological examination. A neurologist examines the motion, muscle strength, coordination, sensation, memory, thought, vision, and speech. An eye doctor may also be involved in the examination.
  • The magnetic resonance imaging. This imaging test uses a magnetic field and radio waves to create a detailed view of the brain, optic nerves and the spinal cord. The results may show lesions or damaged areas in the brain, the optic nerves or the spinal cord.
  • Blood tests.A healthcare provider may do blood testing for autoantibodies that bind to the proteins and causesNMO. Autoantibodies are called aquaporin-4-immunoglobulin G, also known as AQP4-IgG. The evidence for this autoantibody can help health professionals to distinguish betweenNMOandMSand make an early diagnosis ofNMO. Other biomarkers, such as serum glial fibrillary acidic protein, also called GFAP, and serum neurofilament light chain to help detect relapse. A myelin oligodendrocyte glycoprotein immunoglobulin G antibody test, also called MOG-IgG antibody test, also could be used to look for other inflammatory disorder that mimicsNMO.
  • Lumbar puncture, also known as a spinal tap.During this test, a health care professional inserts a needle into the lower back to remove a small amount of fluid from the spinal cord. This test determines the levels of immune cells, proteins, and antibodies in the liquid. This test could distinguishNMOfromMS. The cerebrospinal fluid may show a very high level of white blood cells duringNMOepisodes. This is higher than the level usually seen nmis, although this symptom is not always the case.
  • The stimuli of the test response.To learn how the brain responds to stimuli, such as sounds, images, or touch, you can have a test called evoked potential or evoked response test. Wires called electrodes attached to the scalp and, sometimes, the lobes of the ears, neck, arms, legs, and back. The computer connected to the electrodes of the records of the brain's responses to stimuli. These tests help to find injuries or damaged areas in the nerves, spinal cord, optic nerve, brain or brainstem.
  • The optical coherence tomography. This test is seen in the nerve fiber layer of the retina and its thickness. Patients with swollen optic nerves of NMO have more-extensive loss of vision of the retina and the nerve thinning that people with EM .

Blood tests. A healthcare provider may do blood test for the antibodies that binds to proteins and causes of the NMO . Autoantibodies are called aquaporin-4-immunoglobulin G, also known as AQP4-IgG. The evidence for this autoantibody can help health professionals to distinguish between NMO and MS and make an early diagnosis of NMO .

Other biomarkers, such as serum glial fibrillary acidic protein, also called GFAP, and serum neurofilament light chain to help detect relapse. A myelin oligodendrocyte glycoprotein immunoglobulin G antibody test, also called MOG-IgG antibody test, also could be used to look for other inflammatory disorder that mimics NMO .

Lumbar puncture, also known as a spinal tap. During this test, a health care professional inserts a needle into the lower back to remove a small amount of fluid from the spinal cord. This test determines the levels of immune cells, proteins, and antibodies in the liquid. This test can distinguish NMO from MS .

The cerebrospinal fluid may show a very high level of white blood cells during the NMO episodes. This is higher than the level that is usually seen in MS , although this symptom is not always the case.

The stimuli of the test response. To learn how the brain responds to stimuli, such as sounds, images, or touch, you can have a test called evoked potential or evoked response test.

Wires called electrodes attached to the scalp and, sometimes, the lobes of the ears, neck, arms, legs, and back. The computer connected to the electrodes of the records of the brain's responses to stimuli. These tests help to find injuries or damaged areas in the nerves, spinal cord, optic nerve, brain or brainstem.

Treatment

Neuromyelitis optica can't be cured. But treatment can sometimes lead to a long period without symptoms, known as remission. NMO treatment consists of therapies to reverse recent symptoms and prevent future attacks.

  • Revert recent symptoms.In the early stage of the anNMOattack, a health professional may give you a medicine corticosteroid such as methylprednisolone (Solu-Medrol). It is administered through a vein in the arm. The medication usually takes about five days, and then tends to decrease slowly over several days. Plasma exchange is often recommended as the first or second treatment, in general, in addition to steroid therapy. In this procedure, blood is removed from the body, and the blood cells are mechanically separated from liquid called plasma. The cells of the blood is mixed with a solution of replacement, and the blood is returned to the body. This process can eliminate the harmful substances and clean the blood. Health professionals can also help control other symptoms, such as pain or muscle problems.
  • The prevention of future attacks. Your health care professional may recommend that you take a lower dose of corticosteroids in time to prevent in the future NMO attacks and relapses.
  • The reduction of relapses.Monoclonal antibodies have been shown in clinical trials to be effective in reducing the risk ofNMOrelapses. These medications include eculizumab (Soliris), satralizumab (Enspryng), inebilizumab (Uplizna), ravulizumab (Ultomiris) and rituximab (Rituxan). Many of these have been approved by the Food and Drug Administration (FDA) for the prevention of relapse in adults. Your healthcare provider may also recommend that you take a medication that suppresses the immune system. This could include azathioprine (Imuran, Azasan), mycophenolate (Cellcept, Myhibbin), methotrexate (Trexall, Xatmep, others), cyclophosphamide, or tocilizumab (Actemra). Intravenous immunoglobulins, also known as antibodies, may decrease the rate of relapse ofNMO.

Revert recent symptoms. In the initial stage of an NMO attack, a health professional may give you a medicine corticosteroid such as methylprednisolone (Solu-Medrol). It is administered through a vein in the arm. The medication usually takes about five days, and then tends to decrease slowly over several days.

Plasma exchange is often recommended as the first or second treatment, in general, in addition to steroid therapy. In this procedure, blood is removed from the body, and the blood cells are mechanically separated from liquid called plasma. The cells of the blood is mixed with a solution of replacement, and the blood is returned to the body. This process can eliminate the harmful substances and clean the blood.

Health professionals can also help control other symptoms, such as pain or muscle problems.

The reduction of relapses. Monoclonal antibodies have been shown in clinical trials to be effective in reducing the risk of NMO relapses. These medications include eculizumab (Soliris), satralizumab (Enspryng), inebilizumab (Uplizna), ravulizumab (Ultomiris) and rituximab (Rituxan). Many of these have been approved by the Food and Drug Administration (FDA) for the prevention of relapse in adults.

Your healthcare provider may also recommend that you take a medication that suppresses the immune system. This could include azathioprine (Imuran, Azasan), mycophenolate (Cellcept, Myhibbin), methotrexate (Trexall, Xatmep, others), cyclophosphamide, or tocilizumab (Actemra).

Intravenous immunoglobulins, also known as antibodies, may decrease the rate of relapse of NMO .

Symptoms and treatment of Neuromyelitis optica