By Dr. James W. Stark

Neuromyelitis optics (NMO), also known as Devic’s Disease, is an autoimmune, demyelinating disorder just like Multiple Sclerosis (MS). However, there are some key differences between the two:

Location

Demyelination in MS is found throughout the brain and spinal cord. 

Demyelination in NMO is almost exclusively restricted to the optic nerves and the spinal cord. 

Mechanism of Inflammation

NMO was long thought to be a subset of MS until. But in 2004, Dr. Vanda Lennon and her colleagues discovered that the cause of the inflammation in NMO is the immune system attacking a specific water-transport channel that is only found in the optic nerves and the spinal cord. 

While we still do not know why this occurs, we do know how: the immune attack is carried out by anti-aquaporin4 antibodies. A test for that antibody is readily available at commercial labs! This simple blood test helps diagnose NMO.

In multiple sclerosis we know that the immune system also causes damage to myelin, but we still do not fully understand the mechanism of how the inflammation occurs. This is one of the reasons why there is no singular test for the diagnosis of MS. 

Treatment

In the past, neurologists have treated NMO with various chemotherapies, as well as some of the MS medications. However, in the last few years, three new medications have been FDA-approved specifically to treat NMO. These include Soliris (eclizumab), Uplizna (inebilizumab), and Enspryng (satralizumab-mwge). Although NMO remains a serious, life-long condition, these medications have greatly improved patient outcomes in this disease.