Neuromyelitis Optica (NMO) Disease: Symptoms, Causes, and Treatment

Overview

Neuromyelitis Optica is an autoimmune disease and a rare condition that damages the nerves in the spinal cord and the optic nerves. Sometimes, the brain also gets affected. Loss of vision in one or both eyes, painful spasms, and the onset of paralysis in the legs and arms are some of the symptoms of Neuromyelitis Optica Disease. 

The blog explains neuromyelitis Optica Disease, its symptoms, causes, and treatment options in detail.

What is Neuromyelitis Optica Disease?

Neuromyelitis Optica Disease is also known as Devic’s disease. It is a rare autoimmune condition that harms the spinal cord and the optic nerves. It occurs when the body’s own immune system sends antibodies to destroy the body’s cells. The disease affects the optic nerve connecting the retina with the brain and also affects the spinal cord. It  affects the protective covering of the nerves, known as myelin. However, in some instances, it can develop in the brain too. 

Neuromyelitis Optica  may develop after an infection or is linked to another autoimmune disease. Whatever the cause, the irregular antibodies attach to the central nervous system to damage the nerves. As a result, it causes vision loss , weakness or paralysis in the legs and arms, painful spasms, loss of sensation, uncontrollable vomiting and hiccups, and bladder and bowel issues from spinal cord damage. In children, the symptoms are confusion, seizures, and coma. Recurrence is common. The flare-up is reversible, but it can cause permanent, irreversible damage. 

The disease often occurs during childhood. It can affect adults as well who are in their 40s. But young women are at a higher risk of developing the disease than men. It is often misdiagnosed as multiple sclerosis. 

What are the types of Neuromyelitis Optica Disease?

There are two types of Neuromyelitis Optica , and they are as follows:

1. Relapsing form: It occurs periodically. It is the most common Neuromyelitis Optica Disease, and women are more susceptible to this form than men. 
2. Monophasic form: A single attack lasts for a month or more. Both men and women are equally prone to develop this type of disease. 

What are the symptoms of Neuromyelitis Optica Disease?

Neuromyelitis Optica disease causes episodic attacks, which means they come and go. These attacks can be severe and last anywhere between a few days and months. 

Sometimes, these attacks may cause permanent nerve damage. Each patient experiences symptoms differently, from mild to severe. 

The symptoms are classified into optic neuritis, myelitis, and brain function disruption. 

Optic neuritis

Typically, the eye picks up the light and sends signals through the optic nerve to the brain. The brain processes the messages and senses light. However, optic neuritis causes inflammation of the optic nerve and the nerve swells. Therefore, the swelling puts increased pressure on the optic nerve, affecting one or both eyes. The following are the symptoms: 

• Pain in the eye: The pain occurs or worsens when the patient moves their affected eye or eyes
• Blurred vision
• Partial loss of vision or blindness: The patient may experience partial loss of vision or blindness. They may also suffer from diminishing vision or trouble seeing colours.
• Vision problems in low light: Patients find it challenging to perform certain activities at night, including driving at night

Myelitis

The inflammation of the spinal cord is called myelitis. The inflammation results in swelling and increased pressure on the spinal cord or the nerves close to the spinal cord. Therefore, it may partially or entirely block the nerve signals that transmit through the affected nerve. The symptoms depend on the location of the inflammation in the spinal cord. The following are the symptoms of myelitis:

• Weakness in the muscle or paralysis affects the body parts below the affected spinal cord or further below the affected spinal nerve causing problems in using the arms and hands and trouble walking and standing. If myelitis is present in the cervical spinal cord, it can result in paralysis or muscle weakness that controls breathing. It can be life-threatening. 
• Spasticity: the lack of control from the spinal cord  to the muscle results in muscles acting independently. Thus, it causes the muscles to flex and tighten uncontrollably. 
• Pain: The increased pressure on the spinal cord causes intense pain. The pain may develop due to the swelling of the nerve, or the swelling mistakenly sends false signals to different body parts. 
• Loss of bladder and bowel control: It disrupts the nerve signals responsible for controlling a person’s urination and defecation. Therefore, the patient loses their bladder and bowel control. 
• Sexual dysfunction: It interrupts nerve signals from the sexual organs and results in decreased sexual function. 

Brain function disruption

It is a rare symptom of Neuromyelitis Optica Disease. However, it interrupts how the brain performs certain bodily functions when it occurs. If there is a disruption in the hypothalamus or brainstem, it can be fatal. 

When to seek medical help?

If a person experiences any symptoms of Neuromyelitis Optica Disease, they should immediately contact their healthcare provider. 

Request an appointment at Apollo Hospitals         

What are the causes of Neuromyelitis Optica Disease?

More than 95 per cent of patients suffering from NMOSD do not report any relatives with this disease, while about 3 per cent of patients do report having other relatives with this condition. There is a strong link with personal or family history of autoimmunity that are present in 50 per cent of cases. While NMOSD is considered to be a autoimmune disease, the exact cause of the autoimmunity is not known.

Autoimmune disorders happen when the natural defenses of the body against disease or invading organisms (like bacteria), for reasons not known, suddenly start attacking healthy tissue. And, for reasons not understood, these defenses attack proteins in the central nervous system, particularly the aquaporin-4. In some people with NMOSD, especially those with a non-relapsing variant, antibodies to MOG-IgG (myelin oligodendrocyte glycoprotein) were discovered. 

Those who are seropositive for MOG differ in certain respects from patients with AQP4-IgG antibodies: these patients don’t as striking a predilection for women, attacks are less serious and recover better, optic neuritis tends to be linked with more swelling of optic nerve head and happens in the anterior optic nerve, while myelitis has a somewhat greater predilection for the caudal spinal cord.

How is Neuromyelitis Optica Disease diagnosed? 

A healthcare provider conducts a thorough physical examination to eliminate other neurological conditions with similar Neuromyelitis Optica Disease symptoms. The doctor also reviews the patient’s medical history and symptoms. The following are some of the tests prescribed by the doctor to confirm their diagnosis:

• Neurological exam: The neurologist examines the movements, muscle strength, coordination, sensation, vision, cognitive ability, and speech of the patient. An eye doctor would assess the vision as well. 
• MRI is a test that uses the help of a magnetic field and radio waves to create a clear and detailed picture of the brain, optic nerve, and spinal cord. The images help doctors to get a clear view of the lesions or areas of the brain, optic nerves, and spinal cord that are damaged.
• Blood tests: An AQP4-IgG blood test, is highly specific and reasonably sensitive for NMOSD. The test has been shown to detect antibodies that are specific for aquaporin-4, an astrocyte protein. This test is very helpful at the first significant doubt of NMOSD, as it is frequently positive at the time of the first symptom even before a clinical diagnosis is possible. MOG-IgG, a recently discovered antibody, is present in close to half of patients who don’t have AQP4-IgG. While it seems specific for a form of NMOSD and is seen rarely in typical MS, it also occurs in a few patients with recurrent optic neuritis and in some with acute disseminated encephalomyelitis –  in the latter patients, it is often transient. Successful diagnosis of NMOSD depends on distinguishing it from MS.It is used to make an early diagnosis of the disease. 
• Spinal tap: The doctor inserts a needle into the lower back to drain spinal fluid and tests for levels of immune cells, proteins, and antibodies present in the fluid. The test may help to make a clear difference between Neuromyelitis Optica Disease and multiple sclerosis. However, the test results may show a high white blood count indicating an infection. This white blood count is higher than usual in patients with Neuromyelitis Optica Disease.
• Stimuli response test: in this procedure, the neurologist tests the brain’s response to stimuli, such as sound, sight, or touch. The test is known as an evoked potential test or evoked response test. 
• Optical coherence tomography: It assesses the retinal nerve and its thickness. Neuromyelitis Optica patients have inflammation of the optic nerve. 

What are the various treatment options for Neuromyelitis Optica Disease?

Neuromyelitis Optica Disease is an incurable disease. However, various treatment options help minimize the pain and prevent the symptoms from worsening. Acute and long-term treatment are two forms of treatment options.

• Acute treatment: In this, the doctors focus on treating the immediate effects of the disease attack, such as inflammation. Corticosteroids and other prescribed anti-inflammatory medicines are the most commonly used medications. 
• Long-term treatment: Neuromuelitis Optical Disease develops as the immune system mistakenly attacks the nervous system. Therefore, doctors suppress or manage the immune system to reduce its ability to damage nerve damage. This, in turn, reduces the disease’s severity and duration. 

The medications prescribed by doctors are as follows:

• Anti-inflammatory medicines: These medicines reduce the inflammation of the nervous system. Corticosteroids are the most common medications prescribed by healthcare providers. When the patient is admitted to the hospital, these medications are intravenously administered to the patient. After discharge, patients are instructed to take these anti-inflammatory medications as a pill orally. 
• Plasmapheresis: When steroids fail to provide relief, the doctors recommend a procedure known as plasma exchange. The patient’s blood plasma is removed from the body and replaced with donor blood plasma. The switch between the plasmas eliminates the immune cells and the circulating chemical markers in the plasma reducing inflammation.
• Intravenous immunoglobulin (IVIG): The doctors infuse the patient with donor plasma containing immunoglobulin. The plasma contains donor antibodies that do not attack the immune system. 
• Immunosuppressants: These medications that the doctor prescribes need to be taken regularly or indefinitely. 
• Medications that prevent the attack: Recently, the FDA approved medicines, namely Eculizumab,  Inebilizumab-cdon , and Satralizumab-mwge. These medication target the defective antibodies that attack the immune system. 

What are the complications of Neuromyelitis Optica Disease?

The following are several complications of the disease:

• Impairment of vision or blindness
• Paralysis or limb weakness
• Muscle spasms and stiffness
• Problems with bowel and bladder control
• Depression
• Fatigue

Conclusion

Neuromyelitis Optica Disease is a rare autoimmune disease that can cause permanent damage. However, treatment options help relieve symptoms and prevent lasting impediments. Timely medical treatment is the key to avoiding the complications of the disease. 

Frequently Asked Questions (FAQs)

How soon will the patient feel better once the treatment begins?

The recovery time for each patient varies. 

Is it a contagious disease?

Neuromyelitis is not a contagious disease.