Transverse Myelitis - Differential Diagnosis

Differential Diagnosis

The three main conditions to be considered in the differential diagnosis are: acute spinal cord trauma, acute compressive lesions of the spinal cord such as epidural metastatic tumour, and infarction of the spinal cord, usually due to insufficiency of the anterior spinal artery. 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.

From the symptoms and signs, it may be very difficult to distinguish acute transverse myelitis from these conditions and it is almost invariably necessary to perform an emergency magnetic resonance imaging (MRI) scan or computerised tomographic (CT) myelogram. Before doing this, routine x-rays are taken of the entire spine, mainly to detect signs of metastatic disease of the vertebrae, that would imply direct extension into the epidural space and compression of the spinal cord. Often, such bony lesions are absent and it is only the MRI or CT that discloses the presence or absence of a compressive lesion.

A family physician seeing such a patient for the first time should immediately arrange transfer to the care of a neurologist or neurosurgeon who can urgently investigate the patient in hospital. Before arranging this transfer, the physician should be certain that respiration 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 dose at the onset, in hope that the degree of inflammation and swelling of the cord will be lessened, but whether this is truly effective is still debated.

The prognosis for significant recovery from acute transverse myelitis is poor in approximately 66% of the cases; that is, significant long-term disabilities will remain. Approximately 2% of these patients will, in later months or years, show lesions in other parts of the central nervous system, indicating, in retrospect, that this was a first attack of multiple sclerosis.