Neuromyelitis Optica (NMO) is a central nervous system disorder also called device disease which occurs when the body's immune system reacts against its cells. The ailment causes swelling in the nerves of the eye and the spinal cord, and it happens mainly in the optic nerves that connect the retina of the eye with the brain and the spinal cord. In some rare cases, it can occur in the brain as well and in such scenarios, it can be potentially life-threatening. The disorder may appear on its own or after an infection. Most of the time, NMO is often misdiagnosed as multiple sclerosis, but it is a different health problem.
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Symptoms Of NMO
The most common symptoms of Neuromyelitis Optica are:
- Loss of vision in one or both eyes
- Paralysis in the legs or arms
- Painful spasms
- Loss of sensation
- Uncontrollable vomiting
- Constant hiccups
- Bladder or bowel problems
- Spinal cord damage
- Confusion and seizures in children
Diagnosis
To diagnose this health problem, the healthcare provider reviews the medical history and symptoms and performs a physical check-up to rule out other nervous system conditions that have signs and symptoms like Neuromyelitis Optica. A few other tests apart from blood tests to rule out the exact findings include:
Neurological Testing: A neurologist examines the movements, muscle strength, coordination, sensation, memory, and cognitive abilities through this exam.
MRI: This imaging test uses radio waves to create a detailed view of the brain, optic nerves, and spinal cord. The doctors try to detect lesions or damaged areas in the brain, optic nerves, or the areas surrounding the spinal cord.
Lumbar Puncture: During a lumbar puncture or spinal tap, the neurologist inserts a needle into the lower back and extracts an amount of spinal fluid. This test determines the levels of proteins, immune cells, and antibodies in the fluid. This test is also very helpful to distinguish NMO from MS.
Stimuli Response Test. To learn how well the brain is responding to sounds, sights, or touch, a test called evoked potentials test or evoked response test is performed. In this process, wires or electrodes are attached to the scalp or the earlobes, neck, arm, leg, and back. They help to record the brain's responses to stimuli besides finding lesions or damaged areas in the nerves, spinal cord, optic nerve, and brain.
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Optical Coherence Tomography. Optical Coherence Tomography also called OCT evaluates the retinal nerve and its thickness. Patients with an inflamed optic nerve from NMO may have extensive vision loss and retinal nerve thinning as compared to people suffering from multiple sclerosis- which this test helps to determine.
NMO Treatment
Unfortunately, NMO cannot be treated completely but only managed and a long-term remission is also possible with the right management. Healthcare providers help to manage other possible symptoms, such as pain or muscle problems. To reverse acute symptoms and prevent future attacks, several therapies are involved to manage NMO. In the early stage of an NMO attack, a healthcare provider might administer steroids to ease the symptoms. This may be done for about five to ten days and then tapered off slowly. In addition to steroid therapies for some cases, plasma exchange is often recommended as a second line of treatment wherein the blood is removed from the body, and blood cells are separated from the plasma to remove harmful substances and cleanse the blood. These blood cells are then mixed with a replacement solution and the blood is returned to the body.
Preventing NMO Relapses
Relapses are commonly seen in NMO. Though Neuromyelitis Optica flare-ups might be reversible, they can cause permanent visual loss and problems in the lower limbs. Preventing recurrent attacks is essential to avoid further losses therefore the doctors may recommend a lower dose of steroids to prevent future NMO attacks. Sometimes, doctors may also recommend taking mild doses of immune suppressants that can suppress the immune system. More often, intravenous immunoglobulins (also known as antibodies) are also advised to decrease the relapse rate of NMO.