Figure. dr. Douglas Kerr responds:
Q I have had transverse myelitis for nine years but was only diagnosed about two years ago. What causes this condition, and how does it differ from multiple sclerosis?
A Transverse myelitis is caused by inflammation across both sides of spinal-cord segments. Inflammation can destroy myelin, the insulating substance that covers nerve-cell fibers (see illustration, showing neurons and cell fibers in blue and myelin in purple), and damage to myelin causes scars (lesions) in the nervous system that interrupt communication between spinal-cord nerves and the rest of the body. In transverse myelitis there is usually a single lesion in the spinal cord and none in the brain, whereas in multiple sclerosis (MS) there are multiple attacks of inflammation and lesions throughout the brain and spinal cord.
Symptoms of transverse myelitis include the loss of spinal-cord function over several hours to several weeks, lower-back pain, and muscle weakness. MS symptoms include vision loss, unsteadiness, and facial numbness. Some cases of transverse myelitis are idiopathic—that is, without a known trigger—but some are associated with other neurological diseases.
Neurologists first treat the inflammation in the acute phase. Then, they assess whether the inflammation is recurring or is likely to recur by performing an MRI of the brain and spinal cord and a lumbar puncture (spinal tap). Patients are often treated with corticosteroid therapy to reduce inflammation, and those with a high likelihood of recurrence may need chronic immunomodulatory therapy to alter their immune response.
In most cases, transverse myelitis is a one-time event and the inflammation resolves by itself. However, the goal of acute treatment is to hasten the resolution of the inflammation in order to minimize the damage it causes, which often leaves patients with numbness, weakness, and bowel problems. These symptoms can often be managed by medications.