One of the most frustrating things for patients who suffer from neuromyelitis optica is that many of its symptoms so closely resemble those of multiple sclerosis. The potential for misdiagnosis at the onset can be extremely high for some individuals.
Overview
Neuromyelitis optica (NMO) is a disorder of the central nervous system. It involves an inflammation of the nerves of the eye and those of the spinal cord. Medical experts believe patients develop this condition due to an autoimmune reaction or after certain illnesses like cancer or an infection.
While NMO is a fairly uncommon disease, the Mayo Clinic reports that the staff annually treats in excess of 2,500 patients, both adults and children, who suffer from it and other disorders of the central nervous system such as multiple sclerosis (MS) and transverse myelitis.
NMO was at one point assumed to be a severe variety of multiple sclerosis. It was eventually named a separate disease due to differences in the severity of attacks and the likelihood of affecting optic and spinal cord nerves very early in the disease process. The condition is also known as Devic’s disease.
Signs and Symptoms
According to the National Institute of Neurological Disorders and Stroke (NINDS), the most common signs of NMO are pain in the eye, vision loss and weakness or numbness of the patient’s arms and legs that sometimes results in paralysis. Many individuals also experience sensory problems and lose control of the bladder and/or bowels.
Experts don’t fully understand what causes a patient’s immune system to produce the antibodies that kick off the disease process. The end result of the process is a loss of myelin–the substance that wraps around nerve fibers and assists in sending message from one cell to another–in the spinal cord and optic nerves.
The course of this illness is highly unpredictable. Some patients initially experience the rapid development of symptoms in their eyes and even blindness, followed by at least some paralysis in their limbs. More common, however, is an interval of up to several years between eye problems and paralysis.
Also typical is a pattern of groups of attacks that precede a period of remission. For every male patient who has the relapsing form of neuromyelitis optica, there are four females who experience it.
A second type of NMO usually results in just one attack that can last up to around eight weeks. It appears to strike males and females equally. Symptoms appear to peak at two stages of life. The first is in childhood. The second occurs in patients in their 40s.
Diagnosis and Treatment
In many patients, it’s very difficult to distinguish between NMO and MS. In Japan, for example, almost one a third of patients with neuromyelitis optica were diagnosed with multiple sclerosis, MS Neighborhood indicates. While the two conditions have similar characteristics, they require distinct treatment protocols.
In order to distinguish between the two disorders, healthcare providers use a combination of clinical, imaging and spinal fluid tests. Diagnosis became much easier with the discovery of the NMO-IgG antibody that appears in around 70 percent of NMO patients but not in those who suffer from MS or similar disorders.
NMO cannot be cured. The goal is to treat an attack in progress, diminish symptoms and prevent recurrences. The most frequent treatment is a combination of corticosteroids to halt a flare and an immunosuppressant to ward off subsequent attacks.
Plasmapheresis, which separates antibodies from the bloodstream, is sometimes used for patients who don’t respond to corticosteroids. Doctors utilize symptom-specific therapies to treat neuromyelitis optica issues such as muscle spasms, pain, stiffness and loss of bowel and bladder control. In the severest cases, patients can permanently lose vision in both eyes and the use of their arms and legs. The most frequent cause of death of an NMO patient is respiratory complications.
Sources:
http://www.mayoclinic.org/neuromyelitis-optica/
http://www.ninds.nih.gov/disorders/neuromyelitis_optica/neuromyelitis_optica.htm
http://www.msneighborhood.com/content/in_the_news/archive_2219.aspx