Neuromyelitis optica spectrum disorder (nmosd)

[Marquetta]

Neuromyelitis optica spectrum disorder is a demyelinating disorder that predominantly affects the eyes and spinal cord but can affect other structures in the central nervous system (CNS) that contain aquaporin 4.
(See also Overview of Demyelinating Disorders.)
Neuromyelitis optica spectrum disorder causes acute optic neuritis, sometimes bilateral, plus demyelination of the cervical or thoracic spinal cord. It was previously considered to be a variant of multiple sclerosis (MS) but is now recognized as a different disorder.
In neuromyelitis optica spectrum disorder, the immune system targets aquaporin 4, a protein that is present on astrocytes in the brain and particularly the spinal cord and optic nerves, and possibly other targets. Astrocytes are damaged by autoimmune-mediated inflammation as well as demyelination.