Transverse myelitis is a neurologic disorder caused by a loss of the myelin encasing the spinal cord, also known as demyelination. It may occur alone or together with Multiple Sclerosis. In some cases, the disease is presumedly caused by viral infections or vaccinations and has also been associated with spinal cord injuries, immune reactions, and insufficient blood flow through spinal cord vessels. Symptoms include weakness and numbness of the limbs as well as motor, sensory, and sphincter deficits. Severe backpain may occur in some patients at the onset of the disease. The treatment is usually symptomatic and corticosteroids may be used with limited success.

Prognosis for complete recovery is generally poor. Recovery from transverse myelitis usually takes place between weeks 2 and 12 following onset and may continue for up to 2 years in some patients, many of whom are left with considerable disabilities. A subset of patients so afflicted show no signs of recovery whatsoever.