Transverse myelitis refers to a clinical syndrome in which there is evidence of complete or partial loss of neurologic functions below a lesion which pathologically usually has a limited longitudinal dimension in the spinal Thoracic and cervical segments are most frequently involved. Although inflammation is implied, it should be appreciated that evidence for this is frequently lacking, and thus the term transverse myelopathy is preferred by many neurologists.
Etiology of Transverse Myelitis
As a syndrome rather than a disease, the spectrum of specific causes is broad (see accompanying table). However, the cause remains unknown in the majority of patients presenting with the typical clinical findings. prevalence. No precise epidemiologic data are avail- able. Although rare in general medical practice, the syndrome is not uncommonly encountered in a neurologic setting.
Sixty-seven cases (44 adults and 23 children) were encountered over a 25-year period at the Columbia Presbyterian Medical Center in New York. Males and females are affected about equally. Althhoug,who reported on this experience, excluded compressive lesions, serious trauma, radiation myelopathy, those with evidence of concomitant cerebral involvement, and those thought to probably have multiple sclerosis.
Transverse Myelitis Pathology
The pathology of myelitis or myelopathy includes varying degrees of destruction affecting either white or gray matter or often both, usually in an asymmetrical fashion with this irregular pattern of involvement persisting over the longitudinal extent of the lesion. Patchy destruction frequently involves several segments of the spinal cord but may be ewen more extensive. Demyelination, neuronal injury, and incomplete or complete necrosis of neural tissue have been described and may at times be associated with inflammatory cells, macrophages, or ptoliferation of astroglia. The form of the reaction is probably related to the duration of the disease and its cause. Thickening of small arteries and veins within or adjacent to the parenchyma of spinal cord has been prominent in only a rew of the recorded cases. Because death rarely occurs in the acute stage of the illness today, recent reports characteristically lack postmortem studies employing modern histochemical and cytologic techniques.
Diagnosis of Transverse Myelitis
Although the diagnosis of transverse myelitisor myelopathy can be suspected on clinical grounds, it is incumbent upon the physician to consider first those diseases which demand specific and prompt treatment. Spinal epidural abscess can mimic closely transverse myelitis, although the course of the latter condition is usually more rapid. Contrast myelography should be performed if there is any question about the diagnosis. The risk of this procedure is minimal, and the danger of missing a compressive suppurative lesion which should be treated by surgery is of overriding concern. Intra spinal neoplasms and other compressive tumors will also be excluded by myelography except in those rare instances in which an acutely inflamed, swollen cord may mimic an intraaxial mass. Syphilis, especially the men. ingovascular form, may mimic nonspecific myelitis and deserves immediate treatment.
The treatable nutritional myelopathies evolve more slowly and have a pat- tern of spinal cord involvement which is more diffuse. Other evidence of vitamin Bu deficiency or of pellagra should make exclusion of these disorders relatively easy. A vascular nevus at the segmental level of the spinal cord lesion should signal the IYjssibility of an intraspinal vascular malformation which can be defined by selective spinal cord angiography. Every effort should be made to to establish the diagnosis of specific viral infections by appropriate cultural and serologic means. A diagnosis of multiple sclerosis may become obvious only when lesions of the central nervous system disseminated in time and space appear.
Transverse Myelitis Treatment.
There is no specific treatment for trans- verse myelitis or myelopathy of unknown cause. The efficacy of pharmacologic doses of the glucocorticoids is unproved but might be considered, particularly if there is evidence of swelling of the spinal cord. Prevention or appropriate treatment for the complications of paraplegia is criterial. Prognosis. Proper supportive care, including therapy for complicating infection, prevention of pressure sores, and attention to urinary tract function, renders the prognosis for survival excellent. According to Altrocchi, one third of patients make a good or complete recovery, one third do moderately well, and a poor recovery character- izes the course in the other third. Lipton and Teasdall found similar results. Recurrent neurologic problems are rare among the survivors.