Encephalomyelitis is a general term for inflammation of the brain and spinal cord, describing a number of disorders:

• acute disseminated encephalomyelitis or postinfectious encephalomyelitis, a demyelinating disease of the brain and spinal cord, possibly triggered by vaccination or viral infection;
• encephalomyelitis disseminata, a synonym for multiple sclerosis;
• equine encephalomyelitis, a potentially fatal mosquito-borne viral disease that infects horses and humans;
• myalgic encephalomyelitis, a syndrome involving inflammation of the central nervous system with symptoms of muscle pain and fatigue; the term has sometimes been used interchangeably with chronic fatigue syndrome, though there is still controversy over the distinction.
• experimental autoimmune encephalomyelitis (EAE), an animal model of brain inflammation.