Glossary of Terms Related to NMO
- A substance produced by the body’s immune system when it detects what it recognizes as a threat. IgG is an example of an antibody.
- A substance, recognized by the body as a threat, that causes the body’s immune system to produce antibodies against it. An antigen may be a foreign substance that is an actual threat or the body’s own cells which are mistakenly seen as a threat. In NMO, the body mistakenly sees Aquaporin 4 as a threat.
- A substance produced by the body’s immune system against its own cells, which it mistakenly recognizes as a threat. NMO-IgG is an example of an autoantibody.
- Water channels through which water moves in cells; also known as the ‘plumbing system’ of the cells.
- An aquaporin found in the nervous system that is the primary target of NMO.
- Another name for NMO
- Another name for NMO
Evoked potential (EP) tests
- Recordings of the nervous system's electrical response to the stimulation of specific sensory pathways (e.g., visual, auditory, general sensory). Because damage to myelin (demyelination) results in a slowing of response time, EPs can sometimes provide evidence of scarring along nerve pathways that does not show up during the neurologic exam.
Longitudinally Extensive Transverse Myelitis (LETM)
- A spinal cord lesion extending over 3 or more vertebral segments, often with swelling of the cord and enhancement with contrast on MRI imaging.
- A soft, white coating of nerve fibers in the central nervous system, composed of lipids (fats) and protein. Myelin serves as insulation and as an aid to efficient nerve fiber conduction. When myelin is damaged in MS, nerve fiber conduction is faulty or absent. Impaired bodily functions or altered sensations associated with those demyelinated nerve fibers are identified as symptoms of MS in various parts of the body.
- An autoantibody produced by the immune system against aquaporin 4, which it mistakenly recognizes as a threat. NMO-IgG is present in 70% of those diagnosed with NMO and is absent in most people with MS, including those with optic neuritis and myelitis.
- Inflammation or demyelination of the optic (visual) nerve with transient or permanent impairment of vision and occasionally pain.
Optical Coherence Tomography (OCT)
- A scan that measures the thickness of the retina – the lining at the back of the eye.
- Inability to move a part of the body.
- Weakness or partial paralysis of the lower limbs
- Weakness or partial paralysis of both arms and legs.
- An acute attack of inflammatory demyelination that involves both sides of the spinal cord at the same level. The spinal cord loses its ability to transmit nerve impulses up and down. Paralysis and numbness are experienced in the legs and trunk below the level of the inflammation.