Transverse myelitis

Signs and symptoms

There are disturbances in sensory nerves and motor nerves and dysfunction of the autonomic nervous system at the level of the lesion or below. Therefore, the signs and symptoms depend on the area of spine involved:

Symptoms include weakness and numbness of the limbs, deficits in sensation and motor skills, dysfunctional sphincter activities, and dysfunction of the autonomic nervous system. Symptoms typically develop over the course of hours or days and may progress after weeks. Sensory symptoms of transverse myelitis may include a sensation of pins and needles traveling up from the feet. Back pain can occur at the level of the inflamed segment of the spinal cord. The degree and type of sensory loss will depend upon the extent of the involvement of the various sensory tracts, but there is often a "sensory level" (at the sensory segmental level of the spinal cord below which sensation to pain or light touch is impaired). Motor weakness occurs due to involvement of the pyramidal tracts and mainly affects the muscles that flex the legs and extend the arms. Involvement of the autonomic nervous system is common and frequently leads to impaired function of the bladder and bowel and can also lead to episodes of high blood pressure.

Causes

Transverse myelitis is a heterogeneous condition, that is, there are several identified causes. Sometimes the term Transverse myelitis spectrum disorders is used. It is rare for the condition to have no identifiable cause (called "idiopathic").

When it appears along neuromyelitis optica, it is considered to be caused by NMO-IgG autoimmunity, and when it appears in multiple sclerosis cases, it is considered to be produced by the same underlying condition that produces the lesions. In some cases, the disease is presumed to be caused by viral infections such as cytomegalovirus (CMV) and has also been associated with spinal cord injuries, immune reactions, schistosomiasis and insufficient blood flow through spinal cord vessels. Acute myelitis accounts for 4 to 5 percent of all cases of neuroborreliosis.

Transverse myelitis is associated with:

Pathophysiology

This demyelination arises idiopathically following infections or due to multiple sclerosis. One major theory posits that immune-mediated inflammation is present as the result of exposure to a viral antigen. The diarrhea-causing bacteria Campylobacter jejuni is also a reported cause of transverse myelitis. The lesions are inflammatory, and involve the spinal cord typically on both sides. With acute transverse myelitis, the onset is sudden and progresses rapidly in hours and days. The lesions can be present anywhere in the spinal cord, though they are usually restricted to only a small portion.

Longitudinally extensive transverse myelitis

A proposed special clinical presentation is the "longitudinally extensive transverse myelitis" (LETM) which is defined as a TM with a spinal cord lesion that extends over 3 or more vertebral segments. The causes of LETM are also heterogeneous and the presence of MOG auto-antibodies has been proposed as a biomarker for discrimination.

Diagnostic criteria

In 2002 the Transverse Myelitis Consortium Working Group proposed the following diagnostic criteria for idiopathic acute transverse myelitis:

Investigations

Individuals who develop transverse myelitis are typically transferred to a neurologist or neurosurgeon who can urgently investigate the patient in hospital. Before arranging this transfer, the physician should be certain that breathing is not affected, particularly in high spinal cord lesions. If there is any evidence of this, methods of respiratory assistance must be on hand before and during the transfer procedure. The patient should also be catheterized to test for and, if necessary, drain an over-distended bladder. A lumbar puncture can be performed after the MRI or at the time of CT myelography. Steroids are often given in high doses when symptoms begin with the hope that the degree of inflammation and swelling of the spinal cord will be lessened, but whether this is truly effective is still debated. Lyme disease serology is indicated in patients with transverse myelitis keeping in mind that dissociation in Lyme antibody titers between the blood and the CSF is possible.

Differential diagnosis

The symptoms considered in the differential diagnosis of ATM are demyelination, infections, and possibly other types of inflammatory disorders.

Treatment

Recovery from transverse myelitis is variable between individuals and also depends on the underlying cause. Some patients begin to recover between weeks 2 and 12 following onset and may continue to improve for up to 2 years. Other patients may never show signs of recovery. However, if treated early, some patients experience complete or near complete recovery. Treatment options also vary according to the underlying cause and one treatment option in some cases is plasmapheresis.

The prognosis for transverse myelitis depends if there is improvement in 3 to 6 months; complete recovery is not likely if no improvement occurs between this time. Incomplete recovery can still occur; however, aggressive physical therapy and rehabilitation will be very important. One-third of people with transverse myelitis experience full recovery, one-third experience fair recovery but have significant deficits such as spastic gait. The final 33% experience no recovery at all

Epidemiology

According to at least one source the incidence of transverse myelitis is 4.6 in 1 million, affecting men and women equally. Transverse myelitis can occur at any age (particularly around age 10, age 20, and after age 40).

History

The earliest reports describing the signs and symptoms of transverse myelitis were published in 1885 and 1910 by Bastian. Suchett-Kaye first coined the term transverse myelitis in 1948.

Etymology

The word is from Latin: myelitis transversa and the disorder's name is derived from Greek myelós referring to the "spinal cord", and the suffix -itis, which denotes inflammation.