Neuromyelitis optica

Diagnosis

The healthcare provider conducts a thorough examination in order to exclude other nervous system disorders with signs and symptoms that resemble neuromyelitis optica. In 2015, the International Panel for the Diagnosis of NMO introduced criteria for diagnosing this condition.

• Physical and neurological examination: A healthcare provider often does a physical exam, evaluates the patient’s medical history, and looks for symptoms to identify the condition. The movements, muscle power, coordination, sensation, memory, thinking, vision, and speech are all examined by a neurologist. The eye examination might involve an ophthalmologist.
• Imaging test: A thorough image of the brain, optic nerves, and spinal cord is produced by this imaging test using a magnetic field and radio waves. Lesions or damaged regions of the brain, optic nerves, or spinal cord may be noticable to the healthcare provider.
• Blood tests: The aquaporin–4–immunoglobulin G, often known as AQP4–IgG antibody, may be tested for in the blood by a healthcare provider. This examination distinguishes between NMO and MS. This test helps in the early detection of NMO.

Relapses can be identified using additional biomarkers such serum glial fibrillary acidic protein (GFAP) and serum neurofilament light chain. Another inflammatory condition that resembles NMO may be found with a myelin oligodendrocyte glycoprotein immunoglobulin G (MOG–IgG) antibody test.

• Lumbar puncture (spinal tap): In order to remove a small amount of spinal fluid during this test, the neurologist must inject a needle into the lower back. Immune cells, proteins, and antibodies are measured in the fluid using this test to determine their amounts. By using this test, NMO and MS may be identified.

During NMO episodes, the spinal fluid may exhibit extremely high white blood cell counts. Although it doesn’t always happen, this is more amount than what is often seen with MS.

• Stimuli response test: A test known as the evoked potentials test or evoked response test is performed to find out how well the brain reacts to stimuli like sounds, sights, or touch. Electrodes are affixed to the scalp and, in certain instances, to the earlobes, neck, arm, leg, and back. The electrodes’ equipment is used to record the brain’s reactions to stimuli. These examinations help in the discovery of lesions or damaged regions in the brain, spinal cord, optic nerve, or brainstem.
• Optical coherence tomography: This examination evaluates retinal nerve and measures its thickness. Compared to persons with MS, patients with an inflamed optic nerve from NMO experience more severe vision loss and retinal nerve thinning. 

Treatment

Although there is currently no established cure for NMO, successful management strategies can occasionally lead to sustained periods of remission. Treatment for NMO primarily focuses on therapies aimed at reversing existing symptoms and preventing future attacks.

• Reverse recent symptoms: A corticosteroid medication like methylprednisolone may be administered by a healthcare provider in the early stages of an NMO episode. It is administered by an arm vein. The medication is typically given for around five days before being gradually reduced off over several days.

In place of or in addition to steroid medication, plasma exchange is frequently suggested as the first or second line of treatment. During this operation, a little amount of blood is drawn from the patient, and plasma and blood cells are mechanically separated. The blood is then reintroduced to the body after the blood cells have been combined with a replacement solution. This procedure can clean the blood and remove dangerous substances.

• Prevent the future attacks: In order to stop further NMO episodes and relapses, the healthcare provider may advise the patient to take a low dose of corticosteroids.
• Reduce the relapses: Clinical trials have demonstrated the efficacy of monoclonal antibodies in lowering the risk of NMO relapses. Adult relapses can be treated with eculizumab, satralizumab, and inebilizumab.

Clinical trials have also demonstrated the effectiveness of rituximab in minimizing NMO relapses. Although it is not officially FDA authorized, it is frequently used for NMO.

A medication that inhibits the immune system may also be advised by the healthcare provider. Azithromycin, mycophenolate, methotrexate, cyclophosphamide, or tocilizumab may be among them. 

Intravenous immunoglobulins, also known as antibodies, have the potential to reduce the rate of NMO relapses.