brain, spinal cord, and nerve disorders
Neuromyelitis Optica Spectrum Disorder (NMOSD)
Introduction
Neuromyelitis optica spectrum disorder affects mainly the nerves in the eyes and spinal cord, causing patches of myelin (the substance that covers most nerve fibers) and the nerve fibers under them to be damaged or destroyed. Neuromyelitis optica spectrum disorder is a Overview of Demyelinating Disorders . It causes symptoms similar to those of The risk of becoming disabled is greater with neuromyelitis optica spectrum disorder than with multiple sclerosis. Thus, people with symptoms suggesting neuromyelitis optica spectrum disorder should see a doctor promptly. Most nerve fibers inside and outside the brain are wrapped with many layers of tissue composed of a fat (lipoprotein) called myelin. These layers form the myelin sheath. Much like the insulation around an electrical wire, the myelin sheath enables nerve signals (electrical impulses) to be conducted along the nerve fiber with speed and accuracy. When the myelin sheath is damaged (called demyelination), nerves do not conduct electrical impulses normally. Neuromyelitis optica spectrum disorder is also an Autoimmune Disorders . Autoimmune disorders occur when the immune system malfunctions and attacks the body’s own tissues. In neuromyelitis optica spectrum disorder, the target of the autoimmune attack is one of the following proteins: A protein called aquaporin 4: This protein is present on the surface of support cells in the brain, spinal cord, and optic nerves. These support cells are called Overview of the Nervous System . Myelin oligodendrocyte glycoprotein: This protein is present in the cells that form a coating around nerve cell axons in the brain, spinal cord, and optic nerves. These cells are called Overview of the Nervous System . ( Damage to astrocytes or oligodendrocytes is thought to lead to demyelination. In some people with neuromyelitis optica spectrum disorder, the immune system targets another protein called myelin oligodendrocyte glycoprotein (MOG), which is present on the outer layer of myelin. 