Evran Burakgazi, M.D.
Neurology Resident, The George Washington University, Washington, DC.

Transverse myelitis is a syndrome of spinal cord dysfunction in which most of the functions, namely motor, sensory and sphincterial are compromised to some degree below a definable sensory level. In more than 80 % of cases, the peak of dysfunction is seen within l0 days. Before the onset of neurological symptoms, non-specific symptoms, such as fever, nausea and muscle pain occur. Initial neurological signs are paresthesias, backache and paresis of legs. Sphincter dysfunction often occurs when weakness and sensory disturbances are present. Thoracic level occurs in 80 %, while cervical and lumbar levels occur in 10% each. In the clinical setting, it is often difficult to distinguish among the various possible causes of TM. MS is often considered a strong possibility, which might not always be the case. Retrospective analyses have provided useful information regarding the acuity of presentation and its relationship with prognosis, but have not often sorted the various etiologies.

Ropper and Poskanzer studied 52 patients and suggested that patients with acute onset of symptoms tended to have poor prognosis. They reported 4 types of presentation according to symptoms, including paresthesias, pain, weakness and urinary retention. 37 % of patients gave history of previous infection, and 13 % were later diagnosed with MS, but presentation, severity of disease and prognosis were not compared.

Berman studied 62 patients in Israel, reported incidence of 1.34/mill/year and no seasonal preponderance. 37% had a history of previous infections and only one patient developed MS. No attempt was made to characterize clinical differences among groups. Prior to our study, a clinical and laboratory comparison of TM based on presumed cause had not been performed.

We attempted to determine whether clinical differences related to various etiological subgroups. We also presented an estimate of the incidence of TM in a US population.

In our study we found that various types of TM may be distinguishable on the basis of clinical presentation, imaging and CSF studies. In contrast with previous studies, which isolated homogeneous patient populations by studying only the most severe cases, we attempted to classify cases according to cause by means of objective criteria.

Patients with parainfectious-TM (PI-TM) were weaker on initial exam and suffered spinal shock more frequently. They were likely to have more severe and persistent back pain. They have ascending cord dysfunction more frequently and over a great number of segments.

Patients with MS-TM more often had numbness and paresthesias and tended to show spastic paraparesis on initial exam.

PI-TM had a tendency to show spinal cord swelling, while patients with MS-TM tended to show small plaque-like lesions with gadolinium enhancement. The PI-TM CSF did not contain Oligoclonal bands, while the MS-TM CSF did. The incidence of TM was 4.6/million/year. In the PI-TM 73% of infections were from the upper respiratory tract.

Recurrences were seen also in the PI TM. The second episode followed periods of neurologic stability up to years and were not preceded by URI.

Prognosis for recovery of ambulation and bladder control was variable. Patients with PI-TM were less likely to recover bladder function or independent ambulation at discharge. However, in the long term, patients with MS more likely required catheterizations. Recovery varied. If ambulation was not recovered within 2 months, patients with PI-TM tended to remain wheelchair bound.

While the number of cases in each category was small and the retrospective nature of the study limits the strength of the conclusions, there do appear to be differences between PI-TM and MS-TM. A larger prospective study should provide more conclusive information.