What is Transverse Myelitis?
Transverse myelitis (TM) is a term used to describe inflammation in the spinal cord. This occurs because portions of the immune system leave the blood stream and enter the spinal cord, causing damage. TM may occur in children or adults.
What are the signs and symptoms of Transverse Myelitis?
The signs and symptoms of TM are related to damage to the spinal cord. Typical symptoms of TM include numbness, weakness, trouble with balance, difficulty with walking and changes in bowel/bladder function. Some people may experience pain that typically feels like a burning or prickling sensation. Depending on the extent of the inflammation, some patients may have mild symptoms, whereas others may have severe weakness and sensory loss.
After the initial phase, other symptoms may occur. A tightness in the muscles, called spasticity, may develop, and can require treatment if it is limiting activities or causing discomfort. Patients may experience spasms, which can be painful and require treatment.
The recovery from transverse myelitis is related to the extent of damage to the spinal cord and to the therapies pursued. After treatment is administered, intensive physical and occupational therapy is often necessary to improve strength and balance. In certain situations, transportation aids such as forearm crutches or a wheelchair may be needed. Difficulties with urination may persist and may require special management by a doctor specializing in bladder disorders called a urologist.
How is Transverse Myelitis diagnosed?
Children presenting with neurologic symptoms suggesting a problem with the spinal cord will undergo a detailed neurologic examination. Testing, including an MRI scan of the brain and spinal cord, is often ordered to identify affected portions of the nervous system. A lumbar puncture is often performed to obtain a cerebrospinal fluid sample. Extensive testing on blood and spinal fluid is often performed to identify a cause for the inflammation within the spinal cord. Blood work typically includes testing for antibodies targeting aquaporin-4 or MOG, both of which are associated with TM.
What are the causes of Transverse Myelitis?
TM may occur as part of a relapsing autoimmune disorder, such as multiple sclerosis or neuromyelitis optica. Patients in this category have a high risk of having further relapses in the future, including recurrent episodes of spinal cord inflammation.
Inflammation of the spinal cord may occur without an identifiable cause despite very thorough work-ups by doctors. When this occurs, it is referred to as idiopathic transverse myelitis. Patients in this category typically only have a single episode of spinal cord inflammation. Most idiopathic TM is thought to be post infectious. This means that a patient experiences an infection somewhere in their body (such as a respiratory or gastrointestinal illness) and then recovers. Scientists theorize that the infection triggers an immune response to clear the body of the pathogen which then goes on to cause damage in the brain by mistake. This process is referred to as molecular mimicry. Under the theory of molecular mimicry, there is some protein in the infection that resembles a protein in the spinal cord. After clearing the infection, the immune system goes on to survey the whole body and attacks the spinal cord in error.
How is Transverse Myelitis treated?
The initial evaluation of a child with transverse myelitis involves evaluating for life-threatening complications from spinal cord damage. The spinal cord controls more than movement in our limbs and sensation. Certain portions of the spinal cord control muscles that support breathing, so patients will need to be monitored for signs of breathing difficulties. The spinal cord also has some control of functions such as heart rate and blood pressure, and occasionally measures are needed to maintain a healthy blood pressure.
The inflammation in transverse myelitis is addressed with treatments that acutely reduce inflammation. Common treatment options include steroids, plasmapheresis or intravenous immunoglobulins (also known as IVIG). IV steroids are the most commonly used treatment due to their easy availability and the experience of neurologists. Steroids work by rapidly reducing inflammatory cells. While most children tolerate steroids well, some may experience irritability, increased appetite or sleeping difficulty on high doses of steroids.
Plasmapheresis (PLEX) is a therapy that requires special IV access and a portable machine that cleans the blood of inflammatory proteins. A patient’s blood is circulated through the machine and proteins such as antibodies are removed. A therapy session takes about 90 minutes and is usually well tolerated. A patient usually receives five to seven treatments to complete a PLEX course.
Intravenous immunoglobulin (IVIG) in an infusible therapy that has been used extensively in pediatrics. IVIG is a collection of antibodies collected from blood donors and pooled together. When infused into patients, the antibodies are thought to cause a reduction or blocking of the patient’s abnormal immune response.
In cases where a patient is not responding to steroids, PLEX or IVIG, medications such as cyclophosphamide or methotrexate may be used. These medications can profoundly suppress the immune system and should be used by centers that have experience in prescribing these medications.
If a child has transverse myelitis due to a condition such as multiple sclerosis or neuromyelitis optica, they will be at high risk to have further inflammation within the brain, optic nerves or spinal cord. To prevent this, they may need a medication called a disease modifying therapy, with the goal of preventing future inflammation in the nervous system. In children that are felt to have idiopathic transverse myelitis after extensive evaluation, such a treatment is only needed if episodes of recurrent inflammation occur in the future.
Once the inflammation has been addressed, a child with transverse myelitis may still experience significant troubles with walking, loss of sensation, pain and/or bowel/bladder difficulties. Intensive physical and occupational therapies are often needed. The child may be discharged from the hospital and spend a period of time in a rehabilitation facility to receive intensive therapies, identify needed modifications to the home, and identify appropriate adaptive equipment and longer-term therapies. In addition to evaluation by a neuropsychologist for cognitive, emotional and/or behavioral problems, patients may also require psychosocial support or therapy to manage the impacts of TM.