Neuromyelitis optica also known as Devic disease, is a very rare autoimmune disorder that affects the nerves of your eyes and the central nervous system, which includes the brain and spinal cord. Autoimmune disorders occur when the immune system malfunctions and attacks your body’s own tissues and organs. In neuromyelitis optica, the autoimmune attack causes inflammation of the optic nerve (optic neuritis) and inflammation of the spinal cord (myelitis) and the resulting damage leads to wide range of symptoms, such as weakness, blindness, nerve pain and muscle spasms. These will vary from person to person – some may only have one attack of symptoms and recover well, whereas others may be more severely affected and have a number of attacks that lead to disability. In its early stages, neuromyelitis optica may be confused with multiple sclerosis (MS).

Neuromyelitis optica is characterized by optic neuritis, which is inflammation of the nerve that carries information from the eye to the brain (optic nerve). Optic neuritis causes eye pain and vision loss, which can occur in one or both eyes.

Neuromyelitis optica is also characterized by transverse myelitis, which is inflammation of the spinal cord. The inflammation associated with transverse myelitis damages the spinal cord, causing a lesion that often extends the length of three or more bones of the spine (vertebrae). In addition, myelin, which is the covering that protects nerves and promotes the efficient transmission of nerve impulses, can be damaged. Transverse myelitis causes weakness, numbness, and paralysis of the arms and legs. Other effects of spinal cord damage can include disturbances in sensations, loss of bladder and bowel control, uncontrollable hiccupping, and nausea. In addition, muscle weakness may make breathing difficult and can cause life-threatening respiratory failure in people with neuromyelitis optica.

Some people may only experience transverse myelitis or optic neuritis but, if they have a specific antibody associated with neuromyelitis optica (aquaporin-4 autoantibody - AQP4) in their blood, they will be said to have neuromyelitis optica spectrum disorder. Aquaporin-4 (AQP4) is a membrane water channel expressed in astrocytes 1). Studies suggest that this antibody is pathogenic. Binding of AQP4 immunoglobulin G (IgG) to AQP4 activates complement-dependent cytotoxicity, which leads to a cascade of inflammatory events including leukocyte infiltration and cytokine release along with breakdown of the blood-brain barrier. Inflammatory damage results in demyelination and axonal/neuronal damage responsible for the observed neurologic deficits).

Neuromyelitis optica spectrum disorder is not hereditary (it is very rarely found in more than one family member). People who inherit a tendency to develop an autoimmune disease are at increased risk of developing another autoimmune disease, such as diabetes or thyroid disease. You cannot pass on an increased risk of getting neuromyelitis optica to your family. It is not possible to catch neuromyelitis optica from another person.