Inflammatory demyelinating diseases of the central nervous system

Inflammatory demyelinating diseases (IDDs), sometimes called Idiopathic (IIDDs) due to the unknown etiology of some of them, are a heterogenous group of demyelinating diseases - conditions that cause damage to myelin, the protective sheath of nerve fibers - that occur against the background of an acute or chronic inflammatory process. IDDs share characteristics with and are often grouped together under Multiple Sclerosis. They are sometimes considered different diseases from Multiple Sclerosis, but considered by others to form a spectrum differing only in terms of chronicity, severity, and clinical course.

Multiple sclerosis for some people is a syndrome more than a single disease. As of 2019, three auto-antibodies have been found in atypical MS giving birth to separate diseases: Anti-AQP4 diseases, Anti-MOG and Anti-NF spectrums. A LHON-associated MS has also been reported, and in addition there have been inconclusive reports of TNF-α blockers inducing demyelinating disorders.

The subject is under intense research and the list of MS autoantibodies is expected to grow in the near future.