Nosology of idiopathic transverse myelitis syndromes

Several terms are now commonly used to describe various presentations of idiopathic myelitis, including acute transverse myelitis, acute partial transverse myelitis, and secondary myelitis. Ideally, a classification system would be able to encompass various presentations in a manner that not only assists in prognosis, but also in treatment decisions. Unfortunately, we are limited in our ability to accurately identify those patients who will progress to develop multiple sclerosis, Devic's syndrome, relapsing myelitis, or will remain monophasic. However, general principles are emerging that assist in prognosis based on the particular presenting features of any patient. We review the most recent criteria proposed for various forms of transverse myelitis and highlight the limitations of these classification schemes.