Neuromyelitis Optica

Neuromyelitis optica (NMO), also called neuromyelitis optica spectrum disorder (NMOSD) or Devic disease, is a condition that affects the nerves in the brain and spinal cord. Essentially, the body's immune system mistakenly attacks its own healthy tissues. This attack mainly happens in the optic nerves, which carry signals from the eyes to the brain, and the spinal cord. Sometimes, it can also affect the brain itself.

This attack can be triggered by an infection or might be connected to other autoimmune conditions. When this happens, certain proteins in the central nervous system are targeted by the immune system, leading to inflammation and damage.

NMO is often confused with multiple sclerosis (MS), but they are different diseases. While both affect the nervous system, NMO has unique characteristics and targets specific areas of the nervous system differently.

NMO can cause a range of symptoms, including vision problems, such as blindness, weakness or numbness in the arms and legs, painful muscle spasms, loss of feeling in certain areas of the body, vomiting, hiccups, and bladder or bowel issues. These symptoms can come and go, getting worse and then improving, in what's known as a relapse. Preventing these relapses is important to help people maintain their ability to function. Unfortunately, NMO can lead to permanent vision loss and difficulty walking.

Neuromyelitis optica (NMO) is a condition where the nerves in the eyes and spinal cord become inflamed. This inflammation causes various symptoms.

Eye Problems (Optic Neuritis): NMO can affect vision. People with this condition might experience:

• Blurry or lost vision: This can happen in one or both eyes.
• Color blindness: Difficulty seeing colors.
• Eye pain: Pain in the eye can be a symptom.

Spinal Cord Problems (Transverse Myelitis): The spinal cord inflammation can cause problems with movement and feeling:

• Weakness, numbness, or stiffness: These symptoms can affect the legs, and sometimes the arms.
• Loss of sensation: People might lose the ability to feel touch in their arms or legs.
• Bladder and bowel problems: NMO can make it difficult to control urination or bowel movements.
• Tingling or shooting pain: This pain can be felt in the neck, back, or abdomen.

Other Possible Symptoms:

• Hiccups: These are sometimes a sign of NMO.
• Nausea and vomiting: These digestive issues can occur.

Symptoms in Children: While children can have NMO, confusion, seizures, or comas are more common in a similar condition called myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

Relapses and Long-Term Effects: Symptoms of NMO can come and go. A "relapse" is when symptoms worsen. These relapses can happen at different times, like weeks, months, or years apart. Over a long period of time, repeated relapses can lead to serious complications, like complete blindness or permanent loss of feeling (paralysis) in parts of the body.

Neuromyelitis optica (NMO) is a condition where the body's immune system mistakenly attacks healthy parts of the central nervous system. This system is made up of the spinal cord, brain, and the optic nerves, which carry signals between your eyes and brain.

Scientists aren't completely sure why this happens, but in people with NMO, the immune system produces abnormal antibodies. These antibodies latch onto specific proteins within the central nervous system. This attachment triggers an inflammatory response, like swelling, which damages nerve cells. This damage disrupts the normal communication pathways in the body, leading to the symptoms of NMO.

Neuromyelitis optica (NMO) is a rare condition. Several factors might increase your chances of developing NMO.

• Biological sex: Women are more likely to get NMO than men.

• Age: NMO mostly affects adults. The average person is diagnosed around age 40. However, children and older adults can also be affected.

• Race and ethnicity: People of Hispanic, Asian, African, or Afro-Caribbean descent seem to have a higher risk of NMO compared to white people.

• Vitamin D levels: Some studies suggest that having low levels of vitamin D in your body might increase your risk.

• Smoking: Smoking may also play a role in raising the risk of NMO.

• Early childhood infections: Research indicates that a lack of certain infections during childhood might be a contributing factor. This means that having fewer childhood infections than others might increase the likelihood of getting NMO. It's important to understand that this is still being researched, and more study is needed.

It's crucial to remember that these are potential risk factors, and not everyone who has these factors will develop NMO. If you are concerned about your risk, it's essential to talk to your doctor.

Diagnosing Neuromyelitis Optica (NMO)

Doctors use a combination of physical exams and tests to diagnose neuromyelitis optica (NMO). A key part of the process is ruling out other conditions with similar symptoms. Doctors also look for specific signs and results that point to NMO. In 2015, an international group of experts created guidelines to help diagnose NMO spectrum disorder (NMOSD), which is an umbrella term that includes NMO.

The diagnosis process typically starts with:

1. A thorough review of your medical history and symptoms. The doctor will ask about your past health, any symptoms you're experiencing, and when they started.

2. A physical exam. This includes a neurological exam, which checks your movement, strength, coordination, senses, memory, thinking, vision, and speech. An eye doctor might also be involved to examine your eyes.

3. Imaging tests: A magnetic resonance imaging (MRI) scan is often used. An MRI uses powerful magnets and radio waves to create detailed images of your brain, optic nerves, and spinal cord. These images can show areas of damage or inflammation (called lesions).

4. Blood tests: Doctors might check your blood for a specific antibody called aquaporin-4-immunoglobulin G (AQP4-IgG). This antibody is often found in people with NMO. Finding AQP4-IgG can help doctors distinguish NMO from a similar condition called multiple sclerosis (MS) and potentially make an earlier diagnosis. Other blood tests, such as those for glial fibrillary acidic protein (GFAP) and neurofilament light chain, can help monitor disease activity and relapses. A test for an antibody called MOG-IgG might also be done to check for another inflammatory condition that can mimic NMO.

5. Lumbar Puncture (Spinal Tap): In this procedure, a small amount of spinal fluid is collected from your lower back. This fluid is examined to see levels of immune cells, proteins, and antibodies. High levels of white blood cells in the spinal fluid are often seen during NMO attacks and are often higher than what's typically found in MS. However, this isn't always the case.

6. Stimulus Response Tests: These tests, like evoked potential tests, measure how your brain responds to different types of stimulation (like sounds, lights, or touch). Electrodes are placed on your scalp and other parts of your body to record the brain's electrical activity in response to the stimuli. These tests help pinpoint areas of damage in the nerves, brain, or spinal cord.

7. Optical Coherence Tomography (OCT): This test specifically examines the retina in your eye. People with NMO often have more significant vision loss and thinner retinal nerve fibers compared to those with MS.

These tests work together to provide a comprehensive picture of your condition and help doctors make an accurate diagnosis. Remember, it's essential to discuss any concerns or questions you have with your healthcare provider.