Neuromyelitis Optica (Devic’s Disease): All you need to know about

By Dr. Sameena

Neuromyelitis Optica is a rare disease. It is a severe demyelinating disease with an autoimmune inflammatory process affecting the central nervous system. It specifically affects the myelin, which is the insulation around nerves and also It mainly affects the spinal cord and optic nerve (which carries signals from the eyes to the brain). This is common among young women.

Types of Neuromyelitis Optica

1. Relapsing Neuromyelitis Optica (RNMO) is an uncommon but devastating inflammatory disorder of the central nervous system among women. It has Periodic flare-ups and a long-term history during a wide series of RNMO is required for better knowledge of the course of the disease and identification of patients at high risk of death.
2. Monophasic Neuromyelitis Optica (MNO) is a single episode of neuromyelitis optica that can last several months. People with this type of condition also can have lasting muscle weakness or paralysis and vision loss. This form affects men and ladies equally.

Causes
• Neuromyelitis Optica is an autoimmune condition. This means the body’s immune system reacts abnormally and attacks healthy tissues in your body called myelin (which is the insulation around the nerves of the spinal cord and optic nerves). This is usually not inherited, but some people associated with Neuromyelitis Optica may have a history of autoimmune disorders in the family and may have another autoimmune condition themselves.
• The aquaporin-4 protein (AQP4), a normal protein within the body, plays a task in neuromyelitis optica. This is found in several body systems but is most abundant in tissues of the central nervous system. Approximately 70 percent of individuals with this disorder produce an immune protein called an antibody that attaches (binds) to the aquaporin-4 protein. Antibodies normally bind to specific foreign particles and germs, marking them for destruction, but the antibody in people with neuromyelitis optica attacks a normal human protein; this kind of antibody is named has autoantibody. The autoantibody during this condition is named NMO-IgG or anti-AQP.
• The binding of the NMO-IgG autoantibody to the aquaporin-4 protein activates the complement system, which may be a group of system proteins that work together to destroy pathogens, trigger inflammation, and take away debris from cells and tissues. Complement activation results in the inflammation of the optic nerve and spinal cord that’s characteristic of neuromyelitis optica, leading to the signs and symptoms of the condition.
• The levels of the NMO-IgG autoantibody are high during episodes of neuromyelitis optica, and therefore the levels decrease between episodes with the treatment of the disorder. However, it is unclear what triggers episodes to start or end.

Symptoms Neuromyelitis Optica

1. Pain in the eye
2. Loss of vision
3. Weakness or numbness in arms
4. Paralysis of arms and legs
5. Difficulty controlling the bladder or bowels
6. Uncontrollable vomiting

In many conditions associated with NMO, the spinal cord becomes swollen and irritated (inflamed). this is often called transverse myelitis. The optica nerve from the eye to the brain also can become inflamed – a condition called optica neuritis.

Diagnosis

1. Neurological examination: – A neurologist will examine your movement, muscle strength, coordination, sensation, memory and thinking (cognitive) functions, and vision and speech. An eye doctor (ophthalmologist) also might be involved in your examination.
2. MRI: – This imaging test uses powerful magnetic and radio waves to create a detailed view of your brain, optic nerves and spinal cord. Your doctor might be able to detect lesions or damaged areas in your brain, optic nerves or spinal cord.
3. Blood test: – Samples of your blood and spinal fluid to check for the early signs of the disease.
4. Stimuli response test: – To learn how well your brain responds to stimuli such as sounds, lights or touch, you’ll undergo a test called evoked potentials or evoked response tests.

Treatment
Neuromyelitis Optica can’t be cured, though long-term remission is sometimes possible with the right management. NMO treatment involves therapies such as

1. Corticosteroids (CS)- Corticosteroids have been the mainstay treatment for NMO in both the acute and maintenance phase. Corticosteroids have been established in a meta-analysis evaluating the treatment of neuroimmunology diseases.
2. Immunosuppressant drugs
3. Plasmapheresis (PE) – Plasmapheresis (PE) has been used as an alternative therapy for autoimmune diseases (Process which removes proteins from the blood).
   Neuromyelitis Optica is a rare disease, however, on a rise across the world, in women more than men. The upswing in cases could be due to changes in susceptibility, the environment or both.

(The author is a Consultant- Obstetrics & Gynecologist, KMC, Hospital Mangalore. Views expressed are personal and do not reflect the official position or policy of FinancialExpress.com.)