Devic’s disease: symptoms, causes and treatment

This disease, also called neuromyelitis optica (NMO), can cause blindness.

Autoimmune diseases are diseases in which the body attacks itself. One of the best known is multiple sclerosis. In this article, however, we will talk about another one, which is related to it: Devic's disease or neuromyelitis optica (NMO)..

This disease is inflammatory and demyelinating; it affects the nerve fibers of the central nervous system, especially those of the optic nerve and the spinal cord. In this article we will know what it consists of, its fundamental characteristics, its symptoms, causes and treatment.

What is Devic's disease?

Devic's disease, also called neuromyelitis optica (NMO) (or spectrum of NMO disorders), is a neurological disorder considered rare, affecting between 1 and 9 people per 100,000. It is an autoimmune an autoimmune and demyelinating inflammatory disease, which mainly affects the myelin of the optic nerve and the spinal cord..

Myelin is a coating that protects the axons of nerve cells, and has the function of increasing the speed of nerve impulse transmission.

Features

The main affectation in Devic's disease is a demyelination of the nerve fibers of the Central Nervous System (CNS), which includes the optic nerve (this becomes inflamed) and produces axonal degeneration. On the other hand, spinal symptoms also appear due to inflammation of the spinal cord. (motor and sensory alterations in the extremities).

In relation to its course, this can vary from one person to another; in women, for example, there is usually a course of recurrent attacks. However, although more rarely, a monophasic course may also occur, with episodes of optic neuritis (ON) (inflammation of the optic nerve) and myelitis isolated in time, but simultaneous (more on this later).

This second type of course appears more typically in young people, in both males and females.. In terms of gender distribution, 90% of people affected by Devic's disease are women. The average age of onset is around 50-55 years, although it can appear at any age.

Symptoms

The main symptoms of Devic's disease are as follows:

Optic neuritis (ON) attacks 2.

Optic neuritis is an inflammation of the optic nerve. These attacks can be unilateral or bilateral. Basically, in these episodes the cells of our immune system attack the structures of the organism; in this case, the myelin sheaths of the optic nerve(s). of the optic nerve(s). This symptom is also typical of multiple sclerosis.

2. Acute myelitis

Also called acute transverse myelitis, this is an inflammation of the white and gray matter of the CNS, in one or more adjacent spinal cord segments. Generally the thoracic segments are inflamed. Myelitis can occur as a result of Devic's disease, but also as a result of multiple sclerosis, infections, certain drugs, etc.

3. Attacks of blindness

These attacks are usually acute and very severe. It is usual that they appear separated in time (every "X" months or even years). After them, the patient presents a partial recovery of them. of the same.

Attacks of blindness usually occur simultaneously with attacks of optic neuritis and myelitis.

4. Paraparesis or quadriparesis

Paraparesis involves the reduction of the motor strength of two of the limbs (usually the lower limbs); it can also (usually the lower limbs); it can also cause paralysis of the lower limbs. Quadriparesis is the same but with involvement of all four limbs.

5. Sensory impairment

The senses of the patient with Devic's disease may deteriorate as the disease progresses, due to the different attacks produced. This will imply difficulties or alterations in his visual and auditory system, mainly.

6. Deterioration of the sphincters

The sphincters, as they depend on the spinal cord and, therefore, on the CNS, will also be affected in this disease. This may result, for example, in urine leakage due to weakening and loss of sphincter control..

7. Other symptoms

Devic's disease may also involve other symptoms, although these are rarer. These may include vomiting, Nausea (caused by inflammation of the medulla), sleep or endocrine disorders (caused by a disturbance in the hypothalamus) and attacks of cerebral edema. The latter can cause some confusion in the patient, even inducing a state of coma.

8. Associated disorders

It is common for people suffering from Devic's disease to also manifest other types of disorders, these being systemic and autoimmune. Examples are Sjögren's syndrome and systemic lupus erythematosus (SLE)..

Causes

The cause of Devic's disease is unknown. However, its etiology has been linked to autoantibodies against aquaporin-4 (a type of antibody). In other words, it is known to have an autoimmune origin, just like multiple sclerosis, is known to have an autoimmune origin, just like multiple sclerosis..

As there is still no well-defined and easy to determine cause of this disease, its diagnosis is basically clinical, based on the observation of the symptoms manifested by the patient, its diagnosis is basically clinical, based on the observation of the symptoms manifested by the patient.. On the other hand, although the diagnosis is mostly clinical, MRI (Magnetic Resonance Imaging) tests are usually performed to detect possible spinal lesions.

In acute attacks of myelitis, spinal lesions usually involve 3 or more vertebral segments. This technique (MRI) can be used to differentiate Devic's disease from other autoimmune disorders, such as Multiple Sclerosis (MS). A difference between these pathologies, and which also helps to establish a diagnosis, is that a normal brain MRI scan in the early stages of Devic's disease.

Sometimes it happens, however, that the patient has had atypical brain lesions, or has only had a first episode of myelitis; in these cases, finding autoantibodies against aquaporin-4 helps to diagnose Devic's disease with a little more certainty.

Treatment

The pharmacological treatment used for Devic's disease includes intravenous corticosteroidsThese drugs usually decrease the duration of the symptoms that cause the attacks of blindness and optic neuritis. In addition, they have the advantage of accelerating the patient's visual recovery.

However, the use of corticosteroids has no influence on the patient's functional recovery or prognosis. Nor does it reduce the risk of developing multiple sclerosis in the future (as these two diseases are closely related).

Prevention of Devic's disease is very important, and any minimal symptom should be taken into account. A good preventive strategy is to perform a brain magnetic resonance imaging (MRI) scan at any suspicion of having the disease. On the other hand, once the disease is diagnosed, it will be of great importance to to see specialized ophthalmologists and neurologists who can recommend a who can recommend an appropriate treatment for each case.

Prognosis

Devic's disease has a good prognosis, although sometimes certain visual disturbances may remain. In more severe cases, the patient may become blind..

Bibliographic references:

• Alvarez, J.C. et al. (2014). Monographs in Multiple Sclerosis. Demyelinating diseases with optic and spinal cord involvement in MS: 9-96.
• Arias-González, N.P., Valencia-Paredes, D. (2014). Neuromyelitis optica, anti-acuaporin 4 antibodies. MD Medical Journal, 6(1): 58-61.
• Wingerchuk, D., Lennon, V., Lucchinetti, C., Pittock, S. & Weinshenker, B. (2007). The spectrum of neuromyelitis optica. The Lancet Neurology, 6: 805-815.