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The Difference Between MS and NMO

June 23, 2016

Neuromyelitis optica (NMO) and multiple sclerosis are often mistaken to be the same condition since they share so many similarities. They are both autoimmune diseases, but the major difference is that in MS the immune system attacks the myelin and in NMO the immune system attacks the optic nerve. Although, there is a possibility that NMO is an early warning sign of MS since an early symptom of multiple sclerosis is vision loss and other vision related problems.

It has been reported that NMO attacks to certain parts of the body are far more detrimental in comparison to those of MS and that NMO does not respond to MS treatment. This puts an emphasis on the importance of a proper diagnosis, MS treatment doesn’t work for NMO and NMO treatment doesn’t work for MS. This reveals that the diseases do not have the same roots, even though it is believed that neuromyelitis is a form of MS.

Another difference between the two is that in NMO symptoms tend to appear suddenly, while a more gradual appearance of symptoms is what occurs in MS. Although, the symptoms do tend to be quite similar; including vision changes, muscle weakness, tremors, fatigue, numbness and spinal cord inflammation.

The causes of disease differ as well, even if the exact causes still remain unknown. Some causes of MS include environmental, genetic, immunologic and infectious factors. Neuromyelitis optica on the other hand is linked to tuberculosis, those with Asian or African decent and does not run in families.

Risk Factors
In MS, risk factors for the disease include being female, having a family history of MS, having certain types of infections, smoking and already having an autoimmune disease. Other factors include being white and of European descent, living furthest away from the equator as well as living in temperate climate regions. With NMO, risk factors also include being female, but also being of Asian or African descent, no smoking history and having Ebstein Barr virus seropositivity.

A series of tests are used to diagnose MS, starting with a physical exam and then an evaluation of symptoms to rule out other possible conditions. This includes blood tests, a spinal tap, an MRI and an evoked potential test.

In order to diagnose NMO, optic neuritis and acute myelitis must be present. There must also be at least two of the following; contiguous spinal cord lesion that compromise at least three spinal cord segments, brain magnetic resonance that does not meet MS criteria or positive titers for anti-NMO-immunoglobulin.