Devic’s Disease – Uncommon Neurological Ailment

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Devic’s disease or Neuromyelitis optica, NMO, is an uncommon neurological ailment, a heterogeneous condition consisting of recurrent and simultaneous inflammation and demyelination of the optic nerve or optic neuritis as well as the spinal cord or myelitis. 

It is caused by damage to the spinal cord, nerves or the brain. The optic nerves and the spinal cord which commonly gets affected, leads to inflammation of the nerve that leads from the eye to the brain or the optic neuritis, may cause loss of vision which could affect both the eyes simultaneously.

Other symptoms may include eye pain which tends to get worse on movement, reduced colour vision which may appear to be less vivid than usual or washed out. It could also lead to transverse myelitis or inflammation of the spinal cord resulting in weakness in the legs and arms which may range from a mild feeling in one limb to a complete paralysis in all the limbs.

Moreover it may even cause sensitivity to touch, cold, heat with numbness, tingling or burning sensation below the affected region of the spinal cord. Besides this, the individual may also experience tight and painful muscle contraction which is known as tonic muscle spasms.

Antibody – Aquaporin-4 (AQP4) 

NMO has an antibody known as aquaporin-4, AQP4, which is present in the blood and is a protein produced by the body to destroy disease carrying organism and toxins.

The person’s immune system which is the body’s natural defence against infection gets affected reacting abnormally and attacks tissues and organs in the body.

Presently two different causes are assumed based on the presence of auto antibodies against AQP4 along with NMO which is considered as an autoimmune disease or autoimmune astrocytopathy or autoimmune astrocytic channelopathy wherein a person’s immune system tends to attack the astrocytes of the optic nerves and the spinal cord though the cause of AQP4 variants in not known..

 This disease is a rare disorder resembling multiple sclerosis (MS) in many ways but needs various courses of treatment for optimal results and is also suggested to be a form of acute disseminated encephalomyelitis. Though inflammation affects the brain, the lesions tend to be different from those observed in the related condition of multiple sclerosis.

Devic’s connected to many Systemic Diseases

In some rare cases, parts of the brain may get affects and if the brain stem which is the lower part of the brain that is connected to the spinal cord, gets affected, it may cause symptoms like hiccups, vomiting and difficulties in speech and swallowing. In case a person experience only optic neuritis or myelitis, this condition is known as NMO spectrum disorder.

Devic’s disease has been connected with many systemic diseases which are based on anecdotal evidence of some Devic’s disease and patients having comorbid condition may include collagen vascular diseases, infection with varicella zoster virus, auto antibody syndrome, Epstein Barr virus and HIV together with exposure to clioquinol and anti-tuberculosis drugs.

The discovery of NMO-IgG has given rise to new way in research for the causes though it is yet unknown on the appearance of the antibodies against AQP4.