What Is Neuromyelitis Optica Or Devic’s Disease?

Neuromyelitis optica is a severe and chronic autoimmune disease that involves demyelination of the optic nerve and spinal cord. It can be confused with multiple sclerosis.

Autoimmune diseases are a group of pathologies in which the cells responsible for defending the body attack their own organs. Neuromyelitis optica (NMO) is a condition that fits into this group and is characterized by demyelination of certain areas of the central nervous system (CNS).

The entire CNS is covered in a substance called myelin , which is involved in the correct transmission of nerve impulses. In neuromyelitis optica, specific antibodies attack proteins located in the spinal cord and optic nerve: aquaporins 4, altering their correct functioning.

This pathology is also known as Devic’s disease and has a recurrent presentation with relapses in 70% of cases. The most frequent symptoms are changes that are related to inflammation of the optic nerve and spinal cord.

Similarities and differences between NMO and multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease that also attacks the central nervous system, so it can be confused with NMO. In fact, neuromyelitis optica has been considered a type of multiple sclerosis for many years.

The two pathologies in question affect the structures that make up the central nervous system, causing demyelination. Both diseases affect the spinal cord, but MS is capable of altering several brain structures, while NMO is limited to the optic nerve.

The symptoms presented by the patients are very similar, as both have recurrent and unique presentations. On the other hand, people with multiple sclerosis also have optic neuritis and myelitis, so they often have eye and sensory problems as well.

The main difference between the two pathologies is the humoral alteration in neuromyelitis optica. Studies have shown that most patients with NMO have anti-aquaporin 4 antibodies, which are very rare in people with MS.

Multiple sclerosis is more general and less localized, and can lead to loss of the ability to walk.

Symptoms of Neuromyelitis Optica

As already mentioned, the clinic presented by people with NMO will be related to optic neuritis and transverse myelitis. It may be bilateral or unilateral, in addition to changing a structure called the optic nerve chiasm optical. Among the most relevant ophthalmological symptoms, the following stand out:

Decrease in visual acuity.
Loss of vision.
Pain in the eyes.
Tired eyes.
Oculomotor dysfunction.

On the other hand, the spinal cord will also be affected by an inflammatory process in at least 3 segments, which is why neurological symptoms may appear. In this regard, the main changes include the following:

Inability to move one or more members.
Changes in sensitivity.
Loss of sphincter control.
Muscle spasms.
Nausea and vomiting.

People diagnosed can relapse between 2 and 3 years after the initial episode. Neuromyelitis optica is more common in women aged 39 and over. Studies show that motor impairment in women is generally worse than in men.

How is neuromyelitis optica diagnosed?

Making an accurate diagnosis of this pathology can be a complex task for specialists, so a number of different tests will be needed. In this sense, the physician must differentiate symptoms from other neurological pathologies.

Anti-Aquaporin 4 Antibodies

One of the main results that guide the diagnosis of neuromyelitis optica is the presence of anti-aquaporin 4 antibodies in the bloodstream. We find these antibodies in more than 70% of patients with the disease, so they are a clear way to confirm the pathology.

These molecules are responsible for the destruction of aquaporins 4 in the CNS and subsequent demyelination. Despite being a recent discovery, it has been useful to make an early diagnosis.

Image Studies

Magnetic resonance imaging is the imaging exam of choice used in this case. The exam uses magnets and radio waves to create a detailed image of CNS structures. Doctors can detect some damage to the brain or spinal cord.

Patients with neuromyelitis optica will have an obvious spinal cord injury, usually at the level of the second thoracic vertebra, which will recur in 3 consecutive spinal segments. In addition, the exam determines that the only brain structure affected is the optic nerve.

Cerebrospinal fluid (CSF) studies

Experts can remove a small amount of CSF for analysis. The fluid in question has a high amount of proteins and white blood cells when neuritis occurs, which is greater than that found in patients with multiple sclerosis.

Presence of diagnostic criteria

Since 1999, a series of criteria have been established that are present in all patients with neuromyelitis optica. In 2006 these paradigms were modified. In total, there are 3 definitive criteria that indicate the presence of the disease:

Optic neuritis.
Acute myelitis.
Absence of clinical disease outside the spinal cord and optic nerves.

The possibility of causing blindness is a serious consequence of the pathology, difficult to prevent and prevent.

Neuromyelitis Optica Treatment

The symptoms of the disease are caused by an inflammatory process, so the use of corticosteroids helps to lessen the impact of the signs. Furthermore, this type of medication prevents future relapses.

When corticosteroids do not improve symptoms, a plasma exchange may be necessary. This procedure involves removing blood from the body, which is then separated from the cell’s plasma or fluid and replaced with a synthetic analogue.

Plasma exchange is a process that can take hours and must be performed several times. Finally, the doctor prescribes immunosuppressive medications. They decrease the activity of the immune system, thus reducing damage to CNS structures.

Recommendations for the diet of a person with NMO

All patients diagnosed with NMO should make a shift towards a healthier lifestyle in order to prevent or delay disease progression. In this sense, it is advisable to make changes in the diet.

It is important that the patient consults a nutritionist to follow an adequate plan according to the pathology he/she presents. Among the following recommendations, the following stand out:

Increase your intake of vegetables : fruits, cereals and grains.
Cut down on foods high in saturated fat and carbohydrates.
Drink between 5 and 8 glasses of water or sugar-free liquids.
Eliminate alcohol and coffee consumption.

NMO: a difficult disease to diagnose

Neuromyelitis optica is a degenerative autoimmune disease with ocular and neurological symptoms. It is common to confuse this pathology with others in the CNS. Fortunately, diagnostic methods have come a long way.

There is no specific treatment for this disease, but corticosteroids and immunosuppressants help improve symptoms. It is important for people with NMO to make lifestyle changes to prevent disease progression and relapse.